4fa26a6079
* flags.h (flag_wrapv): New flag controlling overflow semantics. * toplev.c (flag_wrapv): Declare the variable with default false. (lang_independent_options): New option "-fwrapv" to set the above. * fold-const.c (extract_muldiv_1): Disable optimization of (2*x)/2 as x, when signed arithmetic overflow wraps around. (fold): Optimize "-A - B" as "-B - A" if overflow wraps around. * loop.c (basic_induction_var): Ignore BIVs that rely on undefined overflow when flag_wrapv is true. * java/lang.c (java_init_options): Prescribe wrap-around two's complement arithmetic overflow by setting flag_wrapv. * doc/invoke.texi: Document new -fwrapv command line option. * doc/c-tree.texi: Mention that the overflow semantics of NEGATE_EXPR, PLUS_EXPR, MINUS_EXPR and MULT_EXPR is dependent upon both flag_wrapv and flag_trapv. * gcc.dg/fwrapv-1.c: New test case. * gcc.dg/fwrapv-2.c: New test case. * libjava.lang/Overflow.java: New test. * libjava.lang/Overflow.out: New file. From-SVN: r67270
7986 lines
254 KiB
C
7986 lines
254 KiB
C
/* Fold a constant sub-tree into a single node for C-compiler
|
||
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
|
||
2000, 2001, 2002, 2003 Free Software Foundation, Inc.
|
||
|
||
This file is part of GCC.
|
||
|
||
GCC is free software; you can redistribute it and/or modify it under
|
||
the terms of the GNU General Public License as published by the Free
|
||
Software Foundation; either version 2, or (at your option) any later
|
||
version.
|
||
|
||
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
|
||
WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||
for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with GCC; see the file COPYING. If not, write to the Free
|
||
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||
02111-1307, USA. */
|
||
|
||
/*@@ This file should be rewritten to use an arbitrary precision
|
||
@@ representation for "struct tree_int_cst" and "struct tree_real_cst".
|
||
@@ Perhaps the routines could also be used for bc/dc, and made a lib.
|
||
@@ The routines that translate from the ap rep should
|
||
@@ warn if precision et. al. is lost.
|
||
@@ This would also make life easier when this technology is used
|
||
@@ for cross-compilers. */
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||
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||
/* The entry points in this file are fold, size_int_wide, size_binop
|
||
and force_fit_type.
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||
|
||
fold takes a tree as argument and returns a simplified tree.
|
||
|
||
size_binop takes a tree code for an arithmetic operation
|
||
and two operands that are trees, and produces a tree for the
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||
result, assuming the type comes from `sizetype'.
|
||
|
||
size_int takes an integer value, and creates a tree constant
|
||
with type from `sizetype'.
|
||
|
||
force_fit_type takes a constant and prior overflow indicator, and
|
||
forces the value to fit the type. It returns an overflow indicator. */
|
||
|
||
#include "config.h"
|
||
#include "system.h"
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||
#include "coretypes.h"
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||
#include "tm.h"
|
||
#include "flags.h"
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||
#include "tree.h"
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||
#include "real.h"
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||
#include "rtl.h"
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||
#include "expr.h"
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||
#include "tm_p.h"
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||
#include "toplev.h"
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||
#include "ggc.h"
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||
#include "hashtab.h"
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||
#include "langhooks.h"
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||
|
||
static void encode PARAMS ((HOST_WIDE_INT *,
|
||
unsigned HOST_WIDE_INT,
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||
HOST_WIDE_INT));
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||
static void decode PARAMS ((HOST_WIDE_INT *,
|
||
unsigned HOST_WIDE_INT *,
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||
HOST_WIDE_INT *));
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||
static bool negate_expr_p PARAMS ((tree));
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||
static tree negate_expr PARAMS ((tree));
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||
static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
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||
tree *, int));
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||
static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
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||
static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int));
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||
static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
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||
static hashval_t size_htab_hash PARAMS ((const void *));
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static int size_htab_eq PARAMS ((const void *, const void *));
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||
static tree fold_convert PARAMS ((tree, tree));
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||
static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
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||
static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
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static int comparison_to_compcode PARAMS ((enum tree_code));
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static enum tree_code compcode_to_comparison PARAMS ((int));
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||
static int truth_value_p PARAMS ((enum tree_code));
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static int operand_equal_for_comparison_p PARAMS ((tree, tree, tree));
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||
static int twoval_comparison_p PARAMS ((tree, tree *, tree *, int *));
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static tree eval_subst PARAMS ((tree, tree, tree, tree, tree));
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||
static tree pedantic_omit_one_operand PARAMS ((tree, tree, tree));
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static tree distribute_bit_expr PARAMS ((enum tree_code, tree, tree, tree));
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||
static tree make_bit_field_ref PARAMS ((tree, tree, int, int, int));
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||
static tree optimize_bit_field_compare PARAMS ((enum tree_code, tree,
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tree, tree));
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||
static tree decode_field_reference PARAMS ((tree, HOST_WIDE_INT *,
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||
HOST_WIDE_INT *,
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enum machine_mode *, int *,
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int *, tree *, tree *));
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||
static int all_ones_mask_p PARAMS ((tree, int));
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||
static tree sign_bit_p PARAMS ((tree, tree));
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||
static int simple_operand_p PARAMS ((tree));
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static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
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tree, int));
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||
static tree make_range PARAMS ((tree, int *, tree *, tree *));
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||
static tree build_range_check PARAMS ((tree, tree, int, tree, tree));
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||
static int merge_ranges PARAMS ((int *, tree *, tree *, int, tree, tree,
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int, tree, tree));
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||
static tree fold_range_test PARAMS ((tree));
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||
static tree unextend PARAMS ((tree, int, int, tree));
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||
static tree fold_truthop PARAMS ((enum tree_code, tree, tree, tree));
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||
static tree optimize_minmax_comparison PARAMS ((tree));
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||
static tree extract_muldiv PARAMS ((tree, tree, enum tree_code, tree));
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||
static tree extract_muldiv_1 PARAMS ((tree, tree, enum tree_code, tree));
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||
static tree strip_compound_expr PARAMS ((tree, tree));
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||
static int multiple_of_p PARAMS ((tree, tree, tree));
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||
static tree constant_boolean_node PARAMS ((int, tree));
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||
static int count_cond PARAMS ((tree, int));
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||
static tree fold_binary_op_with_conditional_arg
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PARAMS ((enum tree_code, tree, tree, tree, int));
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||
static bool fold_real_zero_addition_p PARAMS ((tree, tree, int));
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||
static tree fold_mathfn_compare PARAMS ((enum built_in_function,
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||
enum tree_code, tree, tree, tree));
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||
static tree fold_inf_compare PARAMS ((enum tree_code, tree, tree, tree));
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||
|
||
/* The following constants represent a bit based encoding of GCC's
|
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comparison operators. This encoding simplifies transformations
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||
on relational comparison operators, such as AND and OR. */
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||
#define COMPCODE_FALSE 0
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||
#define COMPCODE_LT 1
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||
#define COMPCODE_EQ 2
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#define COMPCODE_LE 3
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||
#define COMPCODE_GT 4
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||
#define COMPCODE_NE 5
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||
#define COMPCODE_GE 6
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||
#define COMPCODE_TRUE 7
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||
|
||
/* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
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overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
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and SUM1. Then this yields nonzero if overflow occurred during the
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||
addition.
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Overflow occurs if A and B have the same sign, but A and SUM differ in
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sign. Use `^' to test whether signs differ, and `< 0' to isolate the
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sign. */
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#define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
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||
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||
/* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
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||
We do that by representing the two-word integer in 4 words, with only
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HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
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number. The value of the word is LOWPART + HIGHPART * BASE. */
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#define LOWPART(x) \
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((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
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#define HIGHPART(x) \
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((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
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#define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
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||
|
||
/* Unpack a two-word integer into 4 words.
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LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
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WORDS points to the array of HOST_WIDE_INTs. */
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||
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static void
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encode (words, low, hi)
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HOST_WIDE_INT *words;
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unsigned HOST_WIDE_INT low;
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HOST_WIDE_INT hi;
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{
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words[0] = LOWPART (low);
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words[1] = HIGHPART (low);
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words[2] = LOWPART (hi);
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words[3] = HIGHPART (hi);
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||
}
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||
|
||
/* Pack an array of 4 words into a two-word integer.
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WORDS points to the array of words.
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The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
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||
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static void
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decode (words, low, hi)
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HOST_WIDE_INT *words;
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unsigned HOST_WIDE_INT *low;
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HOST_WIDE_INT *hi;
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||
{
|
||
*low = words[0] + words[1] * BASE;
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||
*hi = words[2] + words[3] * BASE;
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||
}
|
||
|
||
/* Make the integer constant T valid for its type by setting to 0 or 1 all
|
||
the bits in the constant that don't belong in the type.
|
||
|
||
Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
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||
nonzero, a signed overflow has already occurred in calculating T, so
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||
propagate it. */
|
||
|
||
int
|
||
force_fit_type (t, overflow)
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tree t;
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int overflow;
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||
{
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||
unsigned HOST_WIDE_INT low;
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||
HOST_WIDE_INT high;
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unsigned int prec;
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||
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||
if (TREE_CODE (t) == REAL_CST)
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{
|
||
/* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
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||
Consider doing it via real_convert now. */
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||
return overflow;
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||
}
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||
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||
else if (TREE_CODE (t) != INTEGER_CST)
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return overflow;
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||
|
||
low = TREE_INT_CST_LOW (t);
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||
high = TREE_INT_CST_HIGH (t);
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||
|
||
if (POINTER_TYPE_P (TREE_TYPE (t)))
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||
prec = POINTER_SIZE;
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else
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||
prec = TYPE_PRECISION (TREE_TYPE (t));
|
||
|
||
/* First clear all bits that are beyond the type's precision. */
|
||
|
||
if (prec == 2 * HOST_BITS_PER_WIDE_INT)
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;
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||
else if (prec > HOST_BITS_PER_WIDE_INT)
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TREE_INT_CST_HIGH (t)
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&= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
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else
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||
{
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||
TREE_INT_CST_HIGH (t) = 0;
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if (prec < HOST_BITS_PER_WIDE_INT)
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TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
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||
}
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||
|
||
/* Unsigned types do not suffer sign extension or overflow unless they
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are a sizetype. */
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if (TREE_UNSIGNED (TREE_TYPE (t))
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&& ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
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&& TYPE_IS_SIZETYPE (TREE_TYPE (t))))
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||
return overflow;
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||
|
||
/* If the value's sign bit is set, extend the sign. */
|
||
if (prec != 2 * HOST_BITS_PER_WIDE_INT
|
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&& (prec > HOST_BITS_PER_WIDE_INT
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? 0 != (TREE_INT_CST_HIGH (t)
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& ((HOST_WIDE_INT) 1
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<< (prec - HOST_BITS_PER_WIDE_INT - 1)))
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: 0 != (TREE_INT_CST_LOW (t)
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||
& ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
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||
{
|
||
/* Value is negative:
|
||
set to 1 all the bits that are outside this type's precision. */
|
||
if (prec > HOST_BITS_PER_WIDE_INT)
|
||
TREE_INT_CST_HIGH (t)
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|= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
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else
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||
{
|
||
TREE_INT_CST_HIGH (t) = -1;
|
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if (prec < HOST_BITS_PER_WIDE_INT)
|
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TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
|
||
}
|
||
}
|
||
|
||
/* Return nonzero if signed overflow occurred. */
|
||
return
|
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((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
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||
!= 0);
|
||
}
|
||
|
||
/* Add two doubleword integers with doubleword result.
|
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Each argument is given as two `HOST_WIDE_INT' pieces.
|
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One argument is L1 and H1; the other, L2 and H2.
|
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The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
int
|
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add_double (l1, h1, l2, h2, lv, hv)
|
||
unsigned HOST_WIDE_INT l1, l2;
|
||
HOST_WIDE_INT h1, h2;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
{
|
||
unsigned HOST_WIDE_INT l;
|
||
HOST_WIDE_INT h;
|
||
|
||
l = l1 + l2;
|
||
h = h1 + h2 + (l < l1);
|
||
|
||
*lv = l;
|
||
*hv = h;
|
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return OVERFLOW_SUM_SIGN (h1, h2, h);
|
||
}
|
||
|
||
/* Negate a doubleword integer with doubleword result.
|
||
Return nonzero if the operation overflows, assuming it's signed.
|
||
The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
|
||
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
int
|
||
neg_double (l1, h1, lv, hv)
|
||
unsigned HOST_WIDE_INT l1;
|
||
HOST_WIDE_INT h1;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
{
|
||
if (l1 == 0)
|
||
{
|
||
*lv = 0;
|
||
*hv = - h1;
|
||
return (*hv & h1) < 0;
|
||
}
|
||
else
|
||
{
|
||
*lv = -l1;
|
||
*hv = ~h1;
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* Multiply two doubleword integers with doubleword result.
|
||
Return nonzero if the operation overflows, assuming it's signed.
|
||
Each argument is given as two `HOST_WIDE_INT' pieces.
|
||
One argument is L1 and H1; the other, L2 and H2.
|
||
The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
int
|
||
mul_double (l1, h1, l2, h2, lv, hv)
|
||
unsigned HOST_WIDE_INT l1, l2;
|
||
HOST_WIDE_INT h1, h2;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
{
|
||
HOST_WIDE_INT arg1[4];
|
||
HOST_WIDE_INT arg2[4];
|
||
HOST_WIDE_INT prod[4 * 2];
|
||
unsigned HOST_WIDE_INT carry;
|
||
int i, j, k;
|
||
unsigned HOST_WIDE_INT toplow, neglow;
|
||
HOST_WIDE_INT tophigh, neghigh;
|
||
|
||
encode (arg1, l1, h1);
|
||
encode (arg2, l2, h2);
|
||
|
||
memset ((char *) prod, 0, sizeof prod);
|
||
|
||
for (i = 0; i < 4; i++)
|
||
{
|
||
carry = 0;
|
||
for (j = 0; j < 4; j++)
|
||
{
|
||
k = i + j;
|
||
/* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
|
||
carry += arg1[i] * arg2[j];
|
||
/* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
|
||
carry += prod[k];
|
||
prod[k] = LOWPART (carry);
|
||
carry = HIGHPART (carry);
|
||
}
|
||
prod[i + 4] = carry;
|
||
}
|
||
|
||
decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
|
||
|
||
/* Check for overflow by calculating the top half of the answer in full;
|
||
it should agree with the low half's sign bit. */
|
||
decode (prod + 4, &toplow, &tophigh);
|
||
if (h1 < 0)
|
||
{
|
||
neg_double (l2, h2, &neglow, &neghigh);
|
||
add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
|
||
}
|
||
if (h2 < 0)
|
||
{
|
||
neg_double (l1, h1, &neglow, &neghigh);
|
||
add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
|
||
}
|
||
return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
|
||
}
|
||
|
||
/* Shift the doubleword integer in L1, H1 left by COUNT places
|
||
keeping only PREC bits of result.
|
||
Shift right if COUNT is negative.
|
||
ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
|
||
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
void
|
||
lshift_double (l1, h1, count, prec, lv, hv, arith)
|
||
unsigned HOST_WIDE_INT l1;
|
||
HOST_WIDE_INT h1, count;
|
||
unsigned int prec;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
int arith;
|
||
{
|
||
unsigned HOST_WIDE_INT signmask;
|
||
|
||
if (count < 0)
|
||
{
|
||
rshift_double (l1, h1, -count, prec, lv, hv, arith);
|
||
return;
|
||
}
|
||
|
||
#ifdef SHIFT_COUNT_TRUNCATED
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
count %= prec;
|
||
#endif
|
||
|
||
if (count >= 2 * HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
/* Shifting by the host word size is undefined according to the
|
||
ANSI standard, so we must handle this as a special case. */
|
||
*hv = 0;
|
||
*lv = 0;
|
||
}
|
||
else if (count >= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
*hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
|
||
*lv = 0;
|
||
}
|
||
else
|
||
{
|
||
*hv = (((unsigned HOST_WIDE_INT) h1 << count)
|
||
| (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
|
||
*lv = l1 << count;
|
||
}
|
||
|
||
/* Sign extend all bits that are beyond the precision. */
|
||
|
||
signmask = -((prec > HOST_BITS_PER_WIDE_INT
|
||
? ((unsigned HOST_WIDE_INT) *hv
|
||
>> (prec - HOST_BITS_PER_WIDE_INT - 1))
|
||
: (*lv >> (prec - 1))) & 1);
|
||
|
||
if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
|
||
;
|
||
else if (prec >= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
*hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
|
||
*hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
|
||
}
|
||
else
|
||
{
|
||
*hv = signmask;
|
||
*lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
|
||
*lv |= signmask << prec;
|
||
}
|
||
}
|
||
|
||
/* Shift the doubleword integer in L1, H1 right by COUNT places
|
||
keeping only PREC bits of result. COUNT must be positive.
|
||
ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
|
||
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
void
|
||
rshift_double (l1, h1, count, prec, lv, hv, arith)
|
||
unsigned HOST_WIDE_INT l1;
|
||
HOST_WIDE_INT h1, count;
|
||
unsigned int prec;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
int arith;
|
||
{
|
||
unsigned HOST_WIDE_INT signmask;
|
||
|
||
signmask = (arith
|
||
? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
|
||
: 0);
|
||
|
||
#ifdef SHIFT_COUNT_TRUNCATED
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
count %= prec;
|
||
#endif
|
||
|
||
if (count >= 2 * HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
/* Shifting by the host word size is undefined according to the
|
||
ANSI standard, so we must handle this as a special case. */
|
||
*hv = 0;
|
||
*lv = 0;
|
||
}
|
||
else if (count >= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
*hv = 0;
|
||
*lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
|
||
}
|
||
else
|
||
{
|
||
*hv = (unsigned HOST_WIDE_INT) h1 >> count;
|
||
*lv = ((l1 >> count)
|
||
| ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
|
||
}
|
||
|
||
/* Zero / sign extend all bits that are beyond the precision. */
|
||
|
||
if (count >= (HOST_WIDE_INT)prec)
|
||
{
|
||
*hv = signmask;
|
||
*lv = signmask;
|
||
}
|
||
else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
|
||
;
|
||
else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
*hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
|
||
*hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
|
||
}
|
||
else
|
||
{
|
||
*hv = signmask;
|
||
*lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
|
||
*lv |= signmask << (prec - count);
|
||
}
|
||
}
|
||
|
||
/* Rotate the doubleword integer in L1, H1 left by COUNT places
|
||
keeping only PREC bits of result.
|
||
Rotate right if COUNT is negative.
|
||
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
void
|
||
lrotate_double (l1, h1, count, prec, lv, hv)
|
||
unsigned HOST_WIDE_INT l1;
|
||
HOST_WIDE_INT h1, count;
|
||
unsigned int prec;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
{
|
||
unsigned HOST_WIDE_INT s1l, s2l;
|
||
HOST_WIDE_INT s1h, s2h;
|
||
|
||
count %= prec;
|
||
if (count < 0)
|
||
count += prec;
|
||
|
||
lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
|
||
rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
|
||
*lv = s1l | s2l;
|
||
*hv = s1h | s2h;
|
||
}
|
||
|
||
/* Rotate the doubleword integer in L1, H1 left by COUNT places
|
||
keeping only PREC bits of result. COUNT must be positive.
|
||
Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
|
||
|
||
void
|
||
rrotate_double (l1, h1, count, prec, lv, hv)
|
||
unsigned HOST_WIDE_INT l1;
|
||
HOST_WIDE_INT h1, count;
|
||
unsigned int prec;
|
||
unsigned HOST_WIDE_INT *lv;
|
||
HOST_WIDE_INT *hv;
|
||
{
|
||
unsigned HOST_WIDE_INT s1l, s2l;
|
||
HOST_WIDE_INT s1h, s2h;
|
||
|
||
count %= prec;
|
||
if (count < 0)
|
||
count += prec;
|
||
|
||
rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
|
||
lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
|
||
*lv = s1l | s2l;
|
||
*hv = s1h | s2h;
|
||
}
|
||
|
||
/* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
|
||
for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
|
||
CODE is a tree code for a kind of division, one of
|
||
TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
|
||
or EXACT_DIV_EXPR
|
||
It controls how the quotient is rounded to an integer.
|
||
Return nonzero if the operation overflows.
|
||
UNS nonzero says do unsigned division. */
|
||
|
||
int
|
||
div_and_round_double (code, uns,
|
||
lnum_orig, hnum_orig, lden_orig, hden_orig,
|
||
lquo, hquo, lrem, hrem)
|
||
enum tree_code code;
|
||
int uns;
|
||
unsigned HOST_WIDE_INT lnum_orig; /* num == numerator == dividend */
|
||
HOST_WIDE_INT hnum_orig;
|
||
unsigned HOST_WIDE_INT lden_orig; /* den == denominator == divisor */
|
||
HOST_WIDE_INT hden_orig;
|
||
unsigned HOST_WIDE_INT *lquo, *lrem;
|
||
HOST_WIDE_INT *hquo, *hrem;
|
||
{
|
||
int quo_neg = 0;
|
||
HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
|
||
HOST_WIDE_INT den[4], quo[4];
|
||
int i, j;
|
||
unsigned HOST_WIDE_INT work;
|
||
unsigned HOST_WIDE_INT carry = 0;
|
||
unsigned HOST_WIDE_INT lnum = lnum_orig;
|
||
HOST_WIDE_INT hnum = hnum_orig;
|
||
unsigned HOST_WIDE_INT lden = lden_orig;
|
||
HOST_WIDE_INT hden = hden_orig;
|
||
int overflow = 0;
|
||
|
||
if (hden == 0 && lden == 0)
|
||
overflow = 1, lden = 1;
|
||
|
||
/* calculate quotient sign and convert operands to unsigned. */
|
||
if (!uns)
|
||
{
|
||
if (hnum < 0)
|
||
{
|
||
quo_neg = ~ quo_neg;
|
||
/* (minimum integer) / (-1) is the only overflow case. */
|
||
if (neg_double (lnum, hnum, &lnum, &hnum)
|
||
&& ((HOST_WIDE_INT) lden & hden) == -1)
|
||
overflow = 1;
|
||
}
|
||
if (hden < 0)
|
||
{
|
||
quo_neg = ~ quo_neg;
|
||
neg_double (lden, hden, &lden, &hden);
|
||
}
|
||
}
|
||
|
||
if (hnum == 0 && hden == 0)
|
||
{ /* single precision */
|
||
*hquo = *hrem = 0;
|
||
/* This unsigned division rounds toward zero. */
|
||
*lquo = lnum / lden;
|
||
goto finish_up;
|
||
}
|
||
|
||
if (hnum == 0)
|
||
{ /* trivial case: dividend < divisor */
|
||
/* hden != 0 already checked. */
|
||
*hquo = *lquo = 0;
|
||
*hrem = hnum;
|
||
*lrem = lnum;
|
||
goto finish_up;
|
||
}
|
||
|
||
memset ((char *) quo, 0, sizeof quo);
|
||
|
||
memset ((char *) num, 0, sizeof num); /* to zero 9th element */
|
||
memset ((char *) den, 0, sizeof den);
|
||
|
||
encode (num, lnum, hnum);
|
||
encode (den, lden, hden);
|
||
|
||
/* Special code for when the divisor < BASE. */
|
||
if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
|
||
{
|
||
/* hnum != 0 already checked. */
|
||
for (i = 4 - 1; i >= 0; i--)
|
||
{
|
||
work = num[i] + carry * BASE;
|
||
quo[i] = work / lden;
|
||
carry = work % lden;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Full double precision division,
|
||
with thanks to Don Knuth's "Seminumerical Algorithms". */
|
||
int num_hi_sig, den_hi_sig;
|
||
unsigned HOST_WIDE_INT quo_est, scale;
|
||
|
||
/* Find the highest nonzero divisor digit. */
|
||
for (i = 4 - 1;; i--)
|
||
if (den[i] != 0)
|
||
{
|
||
den_hi_sig = i;
|
||
break;
|
||
}
|
||
|
||
/* Insure that the first digit of the divisor is at least BASE/2.
|
||
This is required by the quotient digit estimation algorithm. */
|
||
|
||
scale = BASE / (den[den_hi_sig] + 1);
|
||
if (scale > 1)
|
||
{ /* scale divisor and dividend */
|
||
carry = 0;
|
||
for (i = 0; i <= 4 - 1; i++)
|
||
{
|
||
work = (num[i] * scale) + carry;
|
||
num[i] = LOWPART (work);
|
||
carry = HIGHPART (work);
|
||
}
|
||
|
||
num[4] = carry;
|
||
carry = 0;
|
||
for (i = 0; i <= 4 - 1; i++)
|
||
{
|
||
work = (den[i] * scale) + carry;
|
||
den[i] = LOWPART (work);
|
||
carry = HIGHPART (work);
|
||
if (den[i] != 0) den_hi_sig = i;
|
||
}
|
||
}
|
||
|
||
num_hi_sig = 4;
|
||
|
||
/* Main loop */
|
||
for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
|
||
{
|
||
/* Guess the next quotient digit, quo_est, by dividing the first
|
||
two remaining dividend digits by the high order quotient digit.
|
||
quo_est is never low and is at most 2 high. */
|
||
unsigned HOST_WIDE_INT tmp;
|
||
|
||
num_hi_sig = i + den_hi_sig + 1;
|
||
work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
|
||
if (num[num_hi_sig] != den[den_hi_sig])
|
||
quo_est = work / den[den_hi_sig];
|
||
else
|
||
quo_est = BASE - 1;
|
||
|
||
/* Refine quo_est so it's usually correct, and at most one high. */
|
||
tmp = work - quo_est * den[den_hi_sig];
|
||
if (tmp < BASE
|
||
&& (den[den_hi_sig - 1] * quo_est
|
||
> (tmp * BASE + num[num_hi_sig - 2])))
|
||
quo_est--;
|
||
|
||
/* Try QUO_EST as the quotient digit, by multiplying the
|
||
divisor by QUO_EST and subtracting from the remaining dividend.
|
||
Keep in mind that QUO_EST is the I - 1st digit. */
|
||
|
||
carry = 0;
|
||
for (j = 0; j <= den_hi_sig; j++)
|
||
{
|
||
work = quo_est * den[j] + carry;
|
||
carry = HIGHPART (work);
|
||
work = num[i + j] - LOWPART (work);
|
||
num[i + j] = LOWPART (work);
|
||
carry += HIGHPART (work) != 0;
|
||
}
|
||
|
||
/* If quo_est was high by one, then num[i] went negative and
|
||
we need to correct things. */
|
||
if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
|
||
{
|
||
quo_est--;
|
||
carry = 0; /* add divisor back in */
|
||
for (j = 0; j <= den_hi_sig; j++)
|
||
{
|
||
work = num[i + j] + den[j] + carry;
|
||
carry = HIGHPART (work);
|
||
num[i + j] = LOWPART (work);
|
||
}
|
||
|
||
num [num_hi_sig] += carry;
|
||
}
|
||
|
||
/* Store the quotient digit. */
|
||
quo[i] = quo_est;
|
||
}
|
||
}
|
||
|
||
decode (quo, lquo, hquo);
|
||
|
||
finish_up:
|
||
/* if result is negative, make it so. */
|
||
if (quo_neg)
|
||
neg_double (*lquo, *hquo, lquo, hquo);
|
||
|
||
/* compute trial remainder: rem = num - (quo * den) */
|
||
mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
|
||
neg_double (*lrem, *hrem, lrem, hrem);
|
||
add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
|
||
|
||
switch (code)
|
||
{
|
||
case TRUNC_DIV_EXPR:
|
||
case TRUNC_MOD_EXPR: /* round toward zero */
|
||
case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
|
||
return overflow;
|
||
|
||
case FLOOR_DIV_EXPR:
|
||
case FLOOR_MOD_EXPR: /* round toward negative infinity */
|
||
if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
|
||
{
|
||
/* quo = quo - 1; */
|
||
add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
|
||
lquo, hquo);
|
||
}
|
||
else
|
||
return overflow;
|
||
break;
|
||
|
||
case CEIL_DIV_EXPR:
|
||
case CEIL_MOD_EXPR: /* round toward positive infinity */
|
||
if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
|
||
{
|
||
add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
|
||
lquo, hquo);
|
||
}
|
||
else
|
||
return overflow;
|
||
break;
|
||
|
||
case ROUND_DIV_EXPR:
|
||
case ROUND_MOD_EXPR: /* round to closest integer */
|
||
{
|
||
unsigned HOST_WIDE_INT labs_rem = *lrem;
|
||
HOST_WIDE_INT habs_rem = *hrem;
|
||
unsigned HOST_WIDE_INT labs_den = lden, ltwice;
|
||
HOST_WIDE_INT habs_den = hden, htwice;
|
||
|
||
/* Get absolute values */
|
||
if (*hrem < 0)
|
||
neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
|
||
if (hden < 0)
|
||
neg_double (lden, hden, &labs_den, &habs_den);
|
||
|
||
/* If (2 * abs (lrem) >= abs (lden)) */
|
||
mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
|
||
labs_rem, habs_rem, <wice, &htwice);
|
||
|
||
if (((unsigned HOST_WIDE_INT) habs_den
|
||
< (unsigned HOST_WIDE_INT) htwice)
|
||
|| (((unsigned HOST_WIDE_INT) habs_den
|
||
== (unsigned HOST_WIDE_INT) htwice)
|
||
&& (labs_den < ltwice)))
|
||
{
|
||
if (*hquo < 0)
|
||
/* quo = quo - 1; */
|
||
add_double (*lquo, *hquo,
|
||
(HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
|
||
else
|
||
/* quo = quo + 1; */
|
||
add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
|
||
lquo, hquo);
|
||
}
|
||
else
|
||
return overflow;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
/* compute true remainder: rem = num - (quo * den) */
|
||
mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
|
||
neg_double (*lrem, *hrem, lrem, hrem);
|
||
add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
|
||
return overflow;
|
||
}
|
||
|
||
/* Determine whether an expression T can be cheaply negated using
|
||
the function negate_expr. */
|
||
|
||
static bool
|
||
negate_expr_p (t)
|
||
tree t;
|
||
{
|
||
unsigned HOST_WIDE_INT val;
|
||
unsigned int prec;
|
||
tree type;
|
||
|
||
if (t == 0)
|
||
return false;
|
||
|
||
type = TREE_TYPE (t);
|
||
|
||
STRIP_SIGN_NOPS (t);
|
||
switch (TREE_CODE (t))
|
||
{
|
||
case INTEGER_CST:
|
||
if (TREE_UNSIGNED (type))
|
||
return false;
|
||
|
||
/* Check that -CST will not overflow type. */
|
||
prec = TYPE_PRECISION (type);
|
||
if (prec > HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
if (TREE_INT_CST_LOW (t) != 0)
|
||
return true;
|
||
prec -= HOST_BITS_PER_WIDE_INT;
|
||
val = TREE_INT_CST_HIGH (t);
|
||
}
|
||
else
|
||
val = TREE_INT_CST_LOW (t);
|
||
if (prec < HOST_BITS_PER_WIDE_INT)
|
||
val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
|
||
return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
|
||
|
||
case REAL_CST:
|
||
case NEGATE_EXPR:
|
||
case MINUS_EXPR:
|
||
return true;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
return false;
|
||
}
|
||
|
||
/* Given T, an expression, return the negation of T. Allow for T to be
|
||
null, in which case return null. */
|
||
|
||
static tree
|
||
negate_expr (t)
|
||
tree t;
|
||
{
|
||
tree type;
|
||
tree tem;
|
||
|
||
if (t == 0)
|
||
return 0;
|
||
|
||
type = TREE_TYPE (t);
|
||
STRIP_SIGN_NOPS (t);
|
||
|
||
switch (TREE_CODE (t))
|
||
{
|
||
case INTEGER_CST:
|
||
case REAL_CST:
|
||
if (! TREE_UNSIGNED (type)
|
||
&& 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
|
||
&& ! TREE_OVERFLOW (tem))
|
||
return tem;
|
||
break;
|
||
|
||
case NEGATE_EXPR:
|
||
return convert (type, TREE_OPERAND (t, 0));
|
||
|
||
case MINUS_EXPR:
|
||
/* - (A - B) -> B - A */
|
||
if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
|
||
return convert (type,
|
||
fold (build (MINUS_EXPR, TREE_TYPE (t),
|
||
TREE_OPERAND (t, 1),
|
||
TREE_OPERAND (t, 0))));
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
|
||
}
|
||
|
||
/* Split a tree IN into a constant, literal and variable parts that could be
|
||
combined with CODE to make IN. "constant" means an expression with
|
||
TREE_CONSTANT but that isn't an actual constant. CODE must be a
|
||
commutative arithmetic operation. Store the constant part into *CONP,
|
||
the literal in *LITP and return the variable part. If a part isn't
|
||
present, set it to null. If the tree does not decompose in this way,
|
||
return the entire tree as the variable part and the other parts as null.
|
||
|
||
If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
|
||
case, we negate an operand that was subtracted. Except if it is a
|
||
literal for which we use *MINUS_LITP instead.
|
||
|
||
If NEGATE_P is true, we are negating all of IN, again except a literal
|
||
for which we use *MINUS_LITP instead.
|
||
|
||
If IN is itself a literal or constant, return it as appropriate.
|
||
|
||
Note that we do not guarantee that any of the three values will be the
|
||
same type as IN, but they will have the same signedness and mode. */
|
||
|
||
static tree
|
||
split_tree (in, code, conp, litp, minus_litp, negate_p)
|
||
tree in;
|
||
enum tree_code code;
|
||
tree *conp, *litp, *minus_litp;
|
||
int negate_p;
|
||
{
|
||
tree var = 0;
|
||
|
||
*conp = 0;
|
||
*litp = 0;
|
||
*minus_litp = 0;
|
||
|
||
/* Strip any conversions that don't change the machine mode or signedness. */
|
||
STRIP_SIGN_NOPS (in);
|
||
|
||
if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
|
||
*litp = in;
|
||
else if (TREE_CODE (in) == code
|
||
|| (! FLOAT_TYPE_P (TREE_TYPE (in))
|
||
/* We can associate addition and subtraction together (even
|
||
though the C standard doesn't say so) for integers because
|
||
the value is not affected. For reals, the value might be
|
||
affected, so we can't. */
|
||
&& ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
|
||
|| (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
|
||
{
|
||
tree op0 = TREE_OPERAND (in, 0);
|
||
tree op1 = TREE_OPERAND (in, 1);
|
||
int neg1_p = TREE_CODE (in) == MINUS_EXPR;
|
||
int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
|
||
|
||
/* First see if either of the operands is a literal, then a constant. */
|
||
if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
|
||
*litp = op0, op0 = 0;
|
||
else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
|
||
*litp = op1, neg_litp_p = neg1_p, op1 = 0;
|
||
|
||
if (op0 != 0 && TREE_CONSTANT (op0))
|
||
*conp = op0, op0 = 0;
|
||
else if (op1 != 0 && TREE_CONSTANT (op1))
|
||
*conp = op1, neg_conp_p = neg1_p, op1 = 0;
|
||
|
||
/* If we haven't dealt with either operand, this is not a case we can
|
||
decompose. Otherwise, VAR is either of the ones remaining, if any. */
|
||
if (op0 != 0 && op1 != 0)
|
||
var = in;
|
||
else if (op0 != 0)
|
||
var = op0;
|
||
else
|
||
var = op1, neg_var_p = neg1_p;
|
||
|
||
/* Now do any needed negations. */
|
||
if (neg_litp_p)
|
||
*minus_litp = *litp, *litp = 0;
|
||
if (neg_conp_p)
|
||
*conp = negate_expr (*conp);
|
||
if (neg_var_p)
|
||
var = negate_expr (var);
|
||
}
|
||
else if (TREE_CONSTANT (in))
|
||
*conp = in;
|
||
else
|
||
var = in;
|
||
|
||
if (negate_p)
|
||
{
|
||
if (*litp)
|
||
*minus_litp = *litp, *litp = 0;
|
||
else if (*minus_litp)
|
||
*litp = *minus_litp, *minus_litp = 0;
|
||
*conp = negate_expr (*conp);
|
||
var = negate_expr (var);
|
||
}
|
||
|
||
return var;
|
||
}
|
||
|
||
/* Re-associate trees split by the above function. T1 and T2 are either
|
||
expressions to associate or null. Return the new expression, if any. If
|
||
we build an operation, do it in TYPE and with CODE. */
|
||
|
||
static tree
|
||
associate_trees (t1, t2, code, type)
|
||
tree t1, t2;
|
||
enum tree_code code;
|
||
tree type;
|
||
{
|
||
if (t1 == 0)
|
||
return t2;
|
||
else if (t2 == 0)
|
||
return t1;
|
||
|
||
/* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
|
||
try to fold this since we will have infinite recursion. But do
|
||
deal with any NEGATE_EXPRs. */
|
||
if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
|
||
|| TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
|
||
{
|
||
if (code == PLUS_EXPR)
|
||
{
|
||
if (TREE_CODE (t1) == NEGATE_EXPR)
|
||
return build (MINUS_EXPR, type, convert (type, t2),
|
||
convert (type, TREE_OPERAND (t1, 0)));
|
||
else if (TREE_CODE (t2) == NEGATE_EXPR)
|
||
return build (MINUS_EXPR, type, convert (type, t1),
|
||
convert (type, TREE_OPERAND (t2, 0)));
|
||
}
|
||
return build (code, type, convert (type, t1), convert (type, t2));
|
||
}
|
||
|
||
return fold (build (code, type, convert (type, t1), convert (type, t2)));
|
||
}
|
||
|
||
/* Combine two integer constants ARG1 and ARG2 under operation CODE
|
||
to produce a new constant.
|
||
|
||
If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
|
||
|
||
static tree
|
||
int_const_binop (code, arg1, arg2, notrunc)
|
||
enum tree_code code;
|
||
tree arg1, arg2;
|
||
int notrunc;
|
||
{
|
||
unsigned HOST_WIDE_INT int1l, int2l;
|
||
HOST_WIDE_INT int1h, int2h;
|
||
unsigned HOST_WIDE_INT low;
|
||
HOST_WIDE_INT hi;
|
||
unsigned HOST_WIDE_INT garbagel;
|
||
HOST_WIDE_INT garbageh;
|
||
tree t;
|
||
tree type = TREE_TYPE (arg1);
|
||
int uns = TREE_UNSIGNED (type);
|
||
int is_sizetype
|
||
= (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
|
||
int overflow = 0;
|
||
int no_overflow = 0;
|
||
|
||
int1l = TREE_INT_CST_LOW (arg1);
|
||
int1h = TREE_INT_CST_HIGH (arg1);
|
||
int2l = TREE_INT_CST_LOW (arg2);
|
||
int2h = TREE_INT_CST_HIGH (arg2);
|
||
|
||
switch (code)
|
||
{
|
||
case BIT_IOR_EXPR:
|
||
low = int1l | int2l, hi = int1h | int2h;
|
||
break;
|
||
|
||
case BIT_XOR_EXPR:
|
||
low = int1l ^ int2l, hi = int1h ^ int2h;
|
||
break;
|
||
|
||
case BIT_AND_EXPR:
|
||
low = int1l & int2l, hi = int1h & int2h;
|
||
break;
|
||
|
||
case BIT_ANDTC_EXPR:
|
||
low = int1l & ~int2l, hi = int1h & ~int2h;
|
||
break;
|
||
|
||
case RSHIFT_EXPR:
|
||
int2l = -int2l;
|
||
case LSHIFT_EXPR:
|
||
/* It's unclear from the C standard whether shifts can overflow.
|
||
The following code ignores overflow; perhaps a C standard
|
||
interpretation ruling is needed. */
|
||
lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
|
||
&low, &hi, !uns);
|
||
no_overflow = 1;
|
||
break;
|
||
|
||
case RROTATE_EXPR:
|
||
int2l = - int2l;
|
||
case LROTATE_EXPR:
|
||
lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
|
||
&low, &hi);
|
||
break;
|
||
|
||
case PLUS_EXPR:
|
||
overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
|
||
break;
|
||
|
||
case MINUS_EXPR:
|
||
neg_double (int2l, int2h, &low, &hi);
|
||
add_double (int1l, int1h, low, hi, &low, &hi);
|
||
overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
|
||
break;
|
||
|
||
case MULT_EXPR:
|
||
overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
|
||
break;
|
||
|
||
case TRUNC_DIV_EXPR:
|
||
case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
|
||
case EXACT_DIV_EXPR:
|
||
/* This is a shortcut for a common special case. */
|
||
if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg1)
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg2)
|
||
&& int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
|
||
{
|
||
if (code == CEIL_DIV_EXPR)
|
||
int1l += int2l - 1;
|
||
|
||
low = int1l / int2l, hi = 0;
|
||
break;
|
||
}
|
||
|
||
/* ... fall through ... */
|
||
|
||
case ROUND_DIV_EXPR:
|
||
if (int2h == 0 && int2l == 1)
|
||
{
|
||
low = int1l, hi = int1h;
|
||
break;
|
||
}
|
||
if (int1l == int2l && int1h == int2h
|
||
&& ! (int1l == 0 && int1h == 0))
|
||
{
|
||
low = 1, hi = 0;
|
||
break;
|
||
}
|
||
overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
|
||
&low, &hi, &garbagel, &garbageh);
|
||
break;
|
||
|
||
case TRUNC_MOD_EXPR:
|
||
case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
|
||
/* This is a shortcut for a common special case. */
|
||
if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg1)
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg2)
|
||
&& int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
|
||
{
|
||
if (code == CEIL_MOD_EXPR)
|
||
int1l += int2l - 1;
|
||
low = int1l % int2l, hi = 0;
|
||
break;
|
||
}
|
||
|
||
/* ... fall through ... */
|
||
|
||
case ROUND_MOD_EXPR:
|
||
overflow = div_and_round_double (code, uns,
|
||
int1l, int1h, int2l, int2h,
|
||
&garbagel, &garbageh, &low, &hi);
|
||
break;
|
||
|
||
case MIN_EXPR:
|
||
case MAX_EXPR:
|
||
if (uns)
|
||
low = (((unsigned HOST_WIDE_INT) int1h
|
||
< (unsigned HOST_WIDE_INT) int2h)
|
||
|| (((unsigned HOST_WIDE_INT) int1h
|
||
== (unsigned HOST_WIDE_INT) int2h)
|
||
&& int1l < int2l));
|
||
else
|
||
low = (int1h < int2h
|
||
|| (int1h == int2h && int1l < int2l));
|
||
|
||
if (low == (code == MIN_EXPR))
|
||
low = int1l, hi = int1h;
|
||
else
|
||
low = int2l, hi = int2h;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
/* If this is for a sizetype, can be represented as one (signed)
|
||
HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
|
||
constants. */
|
||
if (is_sizetype
|
||
&& ((hi == 0 && (HOST_WIDE_INT) low >= 0)
|
||
|| (hi == -1 && (HOST_WIDE_INT) low < 0))
|
||
&& overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
|
||
return size_int_type_wide (low, type);
|
||
else
|
||
{
|
||
t = build_int_2 (low, hi);
|
||
TREE_TYPE (t) = TREE_TYPE (arg1);
|
||
}
|
||
|
||
TREE_OVERFLOW (t)
|
||
= ((notrunc
|
||
? (!uns || is_sizetype) && overflow
|
||
: (force_fit_type (t, (!uns || is_sizetype) && overflow)
|
||
&& ! no_overflow))
|
||
| TREE_OVERFLOW (arg1)
|
||
| TREE_OVERFLOW (arg2));
|
||
|
||
/* If we're doing a size calculation, unsigned arithmetic does overflow.
|
||
So check if force_fit_type truncated the value. */
|
||
if (is_sizetype
|
||
&& ! TREE_OVERFLOW (t)
|
||
&& (TREE_INT_CST_HIGH (t) != hi
|
||
|| TREE_INT_CST_LOW (t) != low))
|
||
TREE_OVERFLOW (t) = 1;
|
||
|
||
TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
|
||
| TREE_CONSTANT_OVERFLOW (arg1)
|
||
| TREE_CONSTANT_OVERFLOW (arg2));
|
||
return t;
|
||
}
|
||
|
||
/* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
|
||
constant. We assume ARG1 and ARG2 have the same data type, or at least
|
||
are the same kind of constant and the same machine mode.
|
||
|
||
If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
|
||
|
||
static tree
|
||
const_binop (code, arg1, arg2, notrunc)
|
||
enum tree_code code;
|
||
tree arg1, arg2;
|
||
int notrunc;
|
||
{
|
||
STRIP_NOPS (arg1);
|
||
STRIP_NOPS (arg2);
|
||
|
||
if (TREE_CODE (arg1) == INTEGER_CST)
|
||
return int_const_binop (code, arg1, arg2, notrunc);
|
||
|
||
if (TREE_CODE (arg1) == REAL_CST)
|
||
{
|
||
REAL_VALUE_TYPE d1;
|
||
REAL_VALUE_TYPE d2;
|
||
REAL_VALUE_TYPE value;
|
||
tree t;
|
||
|
||
d1 = TREE_REAL_CST (arg1);
|
||
d2 = TREE_REAL_CST (arg2);
|
||
|
||
/* If either operand is a NaN, just return it. Otherwise, set up
|
||
for floating-point trap; we return an overflow. */
|
||
if (REAL_VALUE_ISNAN (d1))
|
||
return arg1;
|
||
else if (REAL_VALUE_ISNAN (d2))
|
||
return arg2;
|
||
|
||
REAL_ARITHMETIC (value, code, d1, d2);
|
||
|
||
t = build_real (TREE_TYPE (arg1),
|
||
real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
|
||
value));
|
||
|
||
TREE_OVERFLOW (t)
|
||
= (force_fit_type (t, 0)
|
||
| TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
|
||
TREE_CONSTANT_OVERFLOW (t)
|
||
= TREE_OVERFLOW (t)
|
||
| TREE_CONSTANT_OVERFLOW (arg1)
|
||
| TREE_CONSTANT_OVERFLOW (arg2);
|
||
return t;
|
||
}
|
||
if (TREE_CODE (arg1) == COMPLEX_CST)
|
||
{
|
||
tree type = TREE_TYPE (arg1);
|
||
tree r1 = TREE_REALPART (arg1);
|
||
tree i1 = TREE_IMAGPART (arg1);
|
||
tree r2 = TREE_REALPART (arg2);
|
||
tree i2 = TREE_IMAGPART (arg2);
|
||
tree t;
|
||
|
||
switch (code)
|
||
{
|
||
case PLUS_EXPR:
|
||
t = build_complex (type,
|
||
const_binop (PLUS_EXPR, r1, r2, notrunc),
|
||
const_binop (PLUS_EXPR, i1, i2, notrunc));
|
||
break;
|
||
|
||
case MINUS_EXPR:
|
||
t = build_complex (type,
|
||
const_binop (MINUS_EXPR, r1, r2, notrunc),
|
||
const_binop (MINUS_EXPR, i1, i2, notrunc));
|
||
break;
|
||
|
||
case MULT_EXPR:
|
||
t = build_complex (type,
|
||
const_binop (MINUS_EXPR,
|
||
const_binop (MULT_EXPR,
|
||
r1, r2, notrunc),
|
||
const_binop (MULT_EXPR,
|
||
i1, i2, notrunc),
|
||
notrunc),
|
||
const_binop (PLUS_EXPR,
|
||
const_binop (MULT_EXPR,
|
||
r1, i2, notrunc),
|
||
const_binop (MULT_EXPR,
|
||
i1, r2, notrunc),
|
||
notrunc));
|
||
break;
|
||
|
||
case RDIV_EXPR:
|
||
{
|
||
tree magsquared
|
||
= const_binop (PLUS_EXPR,
|
||
const_binop (MULT_EXPR, r2, r2, notrunc),
|
||
const_binop (MULT_EXPR, i2, i2, notrunc),
|
||
notrunc);
|
||
|
||
t = build_complex (type,
|
||
const_binop
|
||
(INTEGRAL_TYPE_P (TREE_TYPE (r1))
|
||
? TRUNC_DIV_EXPR : RDIV_EXPR,
|
||
const_binop (PLUS_EXPR,
|
||
const_binop (MULT_EXPR, r1, r2,
|
||
notrunc),
|
||
const_binop (MULT_EXPR, i1, i2,
|
||
notrunc),
|
||
notrunc),
|
||
magsquared, notrunc),
|
||
const_binop
|
||
(INTEGRAL_TYPE_P (TREE_TYPE (r1))
|
||
? TRUNC_DIV_EXPR : RDIV_EXPR,
|
||
const_binop (MINUS_EXPR,
|
||
const_binop (MULT_EXPR, i1, r2,
|
||
notrunc),
|
||
const_binop (MULT_EXPR, r1, i2,
|
||
notrunc),
|
||
notrunc),
|
||
magsquared, notrunc));
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
return t;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* These are the hash table functions for the hash table of INTEGER_CST
|
||
nodes of a sizetype. */
|
||
|
||
/* Return the hash code code X, an INTEGER_CST. */
|
||
|
||
static hashval_t
|
||
size_htab_hash (x)
|
||
const void *x;
|
||
{
|
||
tree t = (tree) x;
|
||
|
||
return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
|
||
^ htab_hash_pointer (TREE_TYPE (t))
|
||
^ (TREE_OVERFLOW (t) << 20));
|
||
}
|
||
|
||
/* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
|
||
is the same as that given by *Y, which is the same. */
|
||
|
||
static int
|
||
size_htab_eq (x, y)
|
||
const void *x;
|
||
const void *y;
|
||
{
|
||
tree xt = (tree) x;
|
||
tree yt = (tree) y;
|
||
|
||
return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
|
||
&& TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
|
||
&& TREE_TYPE (xt) == TREE_TYPE (yt)
|
||
&& TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
|
||
}
|
||
|
||
/* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
|
||
bits are given by NUMBER and of the sizetype represented by KIND. */
|
||
|
||
tree
|
||
size_int_wide (number, kind)
|
||
HOST_WIDE_INT number;
|
||
enum size_type_kind kind;
|
||
{
|
||
return size_int_type_wide (number, sizetype_tab[(int) kind]);
|
||
}
|
||
|
||
/* Likewise, but the desired type is specified explicitly. */
|
||
|
||
static GTY (()) tree new_const;
|
||
static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
|
||
htab_t size_htab;
|
||
|
||
tree
|
||
size_int_type_wide (number, type)
|
||
HOST_WIDE_INT number;
|
||
tree type;
|
||
{
|
||
PTR *slot;
|
||
|
||
if (size_htab == 0)
|
||
{
|
||
size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
|
||
new_const = make_node (INTEGER_CST);
|
||
}
|
||
|
||
/* Adjust NEW_CONST to be the constant we want. If it's already in the
|
||
hash table, we return the value from the hash table. Otherwise, we
|
||
place that in the hash table and make a new node for the next time. */
|
||
TREE_INT_CST_LOW (new_const) = number;
|
||
TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
|
||
TREE_TYPE (new_const) = type;
|
||
TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
|
||
= force_fit_type (new_const, 0);
|
||
|
||
slot = htab_find_slot (size_htab, new_const, INSERT);
|
||
if (*slot == 0)
|
||
{
|
||
tree t = new_const;
|
||
|
||
*slot = (PTR) new_const;
|
||
new_const = make_node (INTEGER_CST);
|
||
return t;
|
||
}
|
||
else
|
||
return (tree) *slot;
|
||
}
|
||
|
||
/* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
|
||
is a tree code. The type of the result is taken from the operands.
|
||
Both must be the same type integer type and it must be a size type.
|
||
If the operands are constant, so is the result. */
|
||
|
||
tree
|
||
size_binop (code, arg0, arg1)
|
||
enum tree_code code;
|
||
tree arg0, arg1;
|
||
{
|
||
tree type = TREE_TYPE (arg0);
|
||
|
||
if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
|
||
|| type != TREE_TYPE (arg1))
|
||
abort ();
|
||
|
||
/* Handle the special case of two integer constants faster. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
|
||
{
|
||
/* And some specific cases even faster than that. */
|
||
if (code == PLUS_EXPR && integer_zerop (arg0))
|
||
return arg1;
|
||
else if ((code == MINUS_EXPR || code == PLUS_EXPR)
|
||
&& integer_zerop (arg1))
|
||
return arg0;
|
||
else if (code == MULT_EXPR && integer_onep (arg0))
|
||
return arg1;
|
||
|
||
/* Handle general case of two integer constants. */
|
||
return int_const_binop (code, arg0, arg1, 0);
|
||
}
|
||
|
||
if (arg0 == error_mark_node || arg1 == error_mark_node)
|
||
return error_mark_node;
|
||
|
||
return fold (build (code, type, arg0, arg1));
|
||
}
|
||
|
||
/* Given two values, either both of sizetype or both of bitsizetype,
|
||
compute the difference between the two values. Return the value
|
||
in signed type corresponding to the type of the operands. */
|
||
|
||
tree
|
||
size_diffop (arg0, arg1)
|
||
tree arg0, arg1;
|
||
{
|
||
tree type = TREE_TYPE (arg0);
|
||
tree ctype;
|
||
|
||
if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
|
||
|| type != TREE_TYPE (arg1))
|
||
abort ();
|
||
|
||
/* If the type is already signed, just do the simple thing. */
|
||
if (! TREE_UNSIGNED (type))
|
||
return size_binop (MINUS_EXPR, arg0, arg1);
|
||
|
||
ctype = (type == bitsizetype || type == ubitsizetype
|
||
? sbitsizetype : ssizetype);
|
||
|
||
/* If either operand is not a constant, do the conversions to the signed
|
||
type and subtract. The hardware will do the right thing with any
|
||
overflow in the subtraction. */
|
||
if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
|
||
return size_binop (MINUS_EXPR, convert (ctype, arg0),
|
||
convert (ctype, arg1));
|
||
|
||
/* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
|
||
Otherwise, subtract the other way, convert to CTYPE (we know that can't
|
||
overflow) and negate (which can't either). Special-case a result
|
||
of zero while we're here. */
|
||
if (tree_int_cst_equal (arg0, arg1))
|
||
return convert (ctype, integer_zero_node);
|
||
else if (tree_int_cst_lt (arg1, arg0))
|
||
return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
|
||
else
|
||
return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
|
||
convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
|
||
}
|
||
|
||
|
||
/* Given T, a tree representing type conversion of ARG1, a constant,
|
||
return a constant tree representing the result of conversion. */
|
||
|
||
static tree
|
||
fold_convert (t, arg1)
|
||
tree t;
|
||
tree arg1;
|
||
{
|
||
tree type = TREE_TYPE (t);
|
||
int overflow = 0;
|
||
|
||
if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
|
||
{
|
||
if (TREE_CODE (arg1) == INTEGER_CST)
|
||
{
|
||
/* If we would build a constant wider than GCC supports,
|
||
leave the conversion unfolded. */
|
||
if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
|
||
return t;
|
||
|
||
/* If we are trying to make a sizetype for a small integer, use
|
||
size_int to pick up cached types to reduce duplicate nodes. */
|
||
if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
|
||
&& !TREE_CONSTANT_OVERFLOW (arg1)
|
||
&& compare_tree_int (arg1, 10000) < 0)
|
||
return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
|
||
|
||
/* Given an integer constant, make new constant with new type,
|
||
appropriately sign-extended or truncated. */
|
||
t = build_int_2 (TREE_INT_CST_LOW (arg1),
|
||
TREE_INT_CST_HIGH (arg1));
|
||
TREE_TYPE (t) = type;
|
||
/* Indicate an overflow if (1) ARG1 already overflowed,
|
||
or (2) force_fit_type indicates an overflow.
|
||
Tell force_fit_type that an overflow has already occurred
|
||
if ARG1 is a too-large unsigned value and T is signed.
|
||
But don't indicate an overflow if converting a pointer. */
|
||
TREE_OVERFLOW (t)
|
||
= ((force_fit_type (t,
|
||
(TREE_INT_CST_HIGH (arg1) < 0
|
||
&& (TREE_UNSIGNED (type)
|
||
< TREE_UNSIGNED (TREE_TYPE (arg1)))))
|
||
&& ! POINTER_TYPE_P (TREE_TYPE (arg1)))
|
||
|| TREE_OVERFLOW (arg1));
|
||
TREE_CONSTANT_OVERFLOW (t)
|
||
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
|
||
}
|
||
else if (TREE_CODE (arg1) == REAL_CST)
|
||
{
|
||
/* Don't initialize these, use assignments.
|
||
Initialized local aggregates don't work on old compilers. */
|
||
REAL_VALUE_TYPE x;
|
||
REAL_VALUE_TYPE l;
|
||
REAL_VALUE_TYPE u;
|
||
tree type1 = TREE_TYPE (arg1);
|
||
int no_upper_bound;
|
||
|
||
x = TREE_REAL_CST (arg1);
|
||
l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
|
||
|
||
no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
|
||
if (!no_upper_bound)
|
||
u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
|
||
|
||
/* See if X will be in range after truncation towards 0.
|
||
To compensate for truncation, move the bounds away from 0,
|
||
but reject if X exactly equals the adjusted bounds. */
|
||
REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
|
||
if (!no_upper_bound)
|
||
REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
|
||
/* If X is a NaN, use zero instead and show we have an overflow.
|
||
Otherwise, range check. */
|
||
if (REAL_VALUE_ISNAN (x))
|
||
overflow = 1, x = dconst0;
|
||
else if (! (REAL_VALUES_LESS (l, x)
|
||
&& !no_upper_bound
|
||
&& REAL_VALUES_LESS (x, u)))
|
||
overflow = 1;
|
||
|
||
{
|
||
HOST_WIDE_INT low, high;
|
||
REAL_VALUE_TO_INT (&low, &high, x);
|
||
t = build_int_2 (low, high);
|
||
}
|
||
TREE_TYPE (t) = type;
|
||
TREE_OVERFLOW (t)
|
||
= TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
|
||
TREE_CONSTANT_OVERFLOW (t)
|
||
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
|
||
}
|
||
TREE_TYPE (t) = type;
|
||
}
|
||
else if (TREE_CODE (type) == REAL_TYPE)
|
||
{
|
||
if (TREE_CODE (arg1) == INTEGER_CST)
|
||
return build_real_from_int_cst (type, arg1);
|
||
if (TREE_CODE (arg1) == REAL_CST)
|
||
{
|
||
if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
|
||
{
|
||
/* We make a copy of ARG1 so that we don't modify an
|
||
existing constant tree. */
|
||
t = copy_node (arg1);
|
||
TREE_TYPE (t) = type;
|
||
return t;
|
||
}
|
||
|
||
t = build_real (type,
|
||
real_value_truncate (TYPE_MODE (type),
|
||
TREE_REAL_CST (arg1)));
|
||
|
||
TREE_OVERFLOW (t)
|
||
= TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
|
||
TREE_CONSTANT_OVERFLOW (t)
|
||
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
|
||
return t;
|
||
}
|
||
}
|
||
TREE_CONSTANT (t) = 1;
|
||
return t;
|
||
}
|
||
|
||
/* Return an expr equal to X but certainly not valid as an lvalue. */
|
||
|
||
tree
|
||
non_lvalue (x)
|
||
tree x;
|
||
{
|
||
tree result;
|
||
|
||
/* These things are certainly not lvalues. */
|
||
if (TREE_CODE (x) == NON_LVALUE_EXPR
|
||
|| TREE_CODE (x) == INTEGER_CST
|
||
|| TREE_CODE (x) == REAL_CST
|
||
|| TREE_CODE (x) == STRING_CST
|
||
|| TREE_CODE (x) == ADDR_EXPR)
|
||
return x;
|
||
|
||
result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
|
||
TREE_CONSTANT (result) = TREE_CONSTANT (x);
|
||
return result;
|
||
}
|
||
|
||
/* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
|
||
Zero means allow extended lvalues. */
|
||
|
||
int pedantic_lvalues;
|
||
|
||
/* When pedantic, return an expr equal to X but certainly not valid as a
|
||
pedantic lvalue. Otherwise, return X. */
|
||
|
||
tree
|
||
pedantic_non_lvalue (x)
|
||
tree x;
|
||
{
|
||
if (pedantic_lvalues)
|
||
return non_lvalue (x);
|
||
else
|
||
return x;
|
||
}
|
||
|
||
/* Given a tree comparison code, return the code that is the logical inverse
|
||
of the given code. It is not safe to do this for floating-point
|
||
comparisons, except for NE_EXPR and EQ_EXPR. */
|
||
|
||
static enum tree_code
|
||
invert_tree_comparison (code)
|
||
enum tree_code code;
|
||
{
|
||
switch (code)
|
||
{
|
||
case EQ_EXPR:
|
||
return NE_EXPR;
|
||
case NE_EXPR:
|
||
return EQ_EXPR;
|
||
case GT_EXPR:
|
||
return LE_EXPR;
|
||
case GE_EXPR:
|
||
return LT_EXPR;
|
||
case LT_EXPR:
|
||
return GE_EXPR;
|
||
case LE_EXPR:
|
||
return GT_EXPR;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Similar, but return the comparison that results if the operands are
|
||
swapped. This is safe for floating-point. */
|
||
|
||
static enum tree_code
|
||
swap_tree_comparison (code)
|
||
enum tree_code code;
|
||
{
|
||
switch (code)
|
||
{
|
||
case EQ_EXPR:
|
||
case NE_EXPR:
|
||
return code;
|
||
case GT_EXPR:
|
||
return LT_EXPR;
|
||
case GE_EXPR:
|
||
return LE_EXPR;
|
||
case LT_EXPR:
|
||
return GT_EXPR;
|
||
case LE_EXPR:
|
||
return GE_EXPR;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
|
||
/* Convert a comparison tree code from an enum tree_code representation
|
||
into a compcode bit-based encoding. This function is the inverse of
|
||
compcode_to_comparison. */
|
||
|
||
static int
|
||
comparison_to_compcode (code)
|
||
enum tree_code code;
|
||
{
|
||
switch (code)
|
||
{
|
||
case LT_EXPR:
|
||
return COMPCODE_LT;
|
||
case EQ_EXPR:
|
||
return COMPCODE_EQ;
|
||
case LE_EXPR:
|
||
return COMPCODE_LE;
|
||
case GT_EXPR:
|
||
return COMPCODE_GT;
|
||
case NE_EXPR:
|
||
return COMPCODE_NE;
|
||
case GE_EXPR:
|
||
return COMPCODE_GE;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Convert a compcode bit-based encoding of a comparison operator back
|
||
to GCC's enum tree_code representation. This function is the
|
||
inverse of comparison_to_compcode. */
|
||
|
||
static enum tree_code
|
||
compcode_to_comparison (code)
|
||
int code;
|
||
{
|
||
switch (code)
|
||
{
|
||
case COMPCODE_LT:
|
||
return LT_EXPR;
|
||
case COMPCODE_EQ:
|
||
return EQ_EXPR;
|
||
case COMPCODE_LE:
|
||
return LE_EXPR;
|
||
case COMPCODE_GT:
|
||
return GT_EXPR;
|
||
case COMPCODE_NE:
|
||
return NE_EXPR;
|
||
case COMPCODE_GE:
|
||
return GE_EXPR;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Return nonzero if CODE is a tree code that represents a truth value. */
|
||
|
||
static int
|
||
truth_value_p (code)
|
||
enum tree_code code;
|
||
{
|
||
return (TREE_CODE_CLASS (code) == '<'
|
||
|| code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
|
||
|| code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
|
||
|| code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
|
||
}
|
||
|
||
/* Return nonzero if two operands are necessarily equal.
|
||
If ONLY_CONST is nonzero, only return nonzero for constants.
|
||
This function tests whether the operands are indistinguishable;
|
||
it does not test whether they are equal using C's == operation.
|
||
The distinction is important for IEEE floating point, because
|
||
(1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
|
||
(2) two NaNs may be indistinguishable, but NaN!=NaN. */
|
||
|
||
int
|
||
operand_equal_p (arg0, arg1, only_const)
|
||
tree arg0, arg1;
|
||
int only_const;
|
||
{
|
||
/* If both types don't have the same signedness, then we can't consider
|
||
them equal. We must check this before the STRIP_NOPS calls
|
||
because they may change the signedness of the arguments. */
|
||
if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
|
||
return 0;
|
||
|
||
STRIP_NOPS (arg0);
|
||
STRIP_NOPS (arg1);
|
||
|
||
if (TREE_CODE (arg0) != TREE_CODE (arg1)
|
||
/* This is needed for conversions and for COMPONENT_REF.
|
||
Might as well play it safe and always test this. */
|
||
|| TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
|
||
|| TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
|
||
|| TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
|
||
return 0;
|
||
|
||
/* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
|
||
We don't care about side effects in that case because the SAVE_EXPR
|
||
takes care of that for us. In all other cases, two expressions are
|
||
equal if they have no side effects. If we have two identical
|
||
expressions with side effects that should be treated the same due
|
||
to the only side effects being identical SAVE_EXPR's, that will
|
||
be detected in the recursive calls below. */
|
||
if (arg0 == arg1 && ! only_const
|
||
&& (TREE_CODE (arg0) == SAVE_EXPR
|
||
|| (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
|
||
return 1;
|
||
|
||
/* Next handle constant cases, those for which we can return 1 even
|
||
if ONLY_CONST is set. */
|
||
if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
|
||
switch (TREE_CODE (arg0))
|
||
{
|
||
case INTEGER_CST:
|
||
return (! TREE_CONSTANT_OVERFLOW (arg0)
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg1)
|
||
&& tree_int_cst_equal (arg0, arg1));
|
||
|
||
case REAL_CST:
|
||
return (! TREE_CONSTANT_OVERFLOW (arg0)
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg1)
|
||
&& REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
|
||
TREE_REAL_CST (arg1)));
|
||
|
||
case VECTOR_CST:
|
||
{
|
||
tree v1, v2;
|
||
|
||
if (TREE_CONSTANT_OVERFLOW (arg0)
|
||
|| TREE_CONSTANT_OVERFLOW (arg1))
|
||
return 0;
|
||
|
||
v1 = TREE_VECTOR_CST_ELTS (arg0);
|
||
v2 = TREE_VECTOR_CST_ELTS (arg1);
|
||
while (v1 && v2)
|
||
{
|
||
if (!operand_equal_p (v1, v2, only_const))
|
||
return 0;
|
||
v1 = TREE_CHAIN (v1);
|
||
v2 = TREE_CHAIN (v2);
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
case COMPLEX_CST:
|
||
return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
|
||
only_const)
|
||
&& operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
|
||
only_const));
|
||
|
||
case STRING_CST:
|
||
return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
|
||
&& ! memcmp (TREE_STRING_POINTER (arg0),
|
||
TREE_STRING_POINTER (arg1),
|
||
TREE_STRING_LENGTH (arg0)));
|
||
|
||
case ADDR_EXPR:
|
||
return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
|
||
0);
|
||
default:
|
||
break;
|
||
}
|
||
|
||
if (only_const)
|
||
return 0;
|
||
|
||
switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
|
||
{
|
||
case '1':
|
||
/* Two conversions are equal only if signedness and modes match. */
|
||
if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
|
||
&& (TREE_UNSIGNED (TREE_TYPE (arg0))
|
||
!= TREE_UNSIGNED (TREE_TYPE (arg1))))
|
||
return 0;
|
||
|
||
return operand_equal_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0), 0);
|
||
|
||
case '<':
|
||
case '2':
|
||
if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
|
||
0))
|
||
return 1;
|
||
|
||
/* For commutative ops, allow the other order. */
|
||
return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
|
||
|| TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
|
||
|| TREE_CODE (arg0) == BIT_IOR_EXPR
|
||
|| TREE_CODE (arg0) == BIT_XOR_EXPR
|
||
|| TREE_CODE (arg0) == BIT_AND_EXPR
|
||
|| TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 1), 0)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg1, 0), 0));
|
||
|
||
case 'r':
|
||
/* If either of the pointer (or reference) expressions we are dereferencing
|
||
contain a side effect, these cannot be equal. */
|
||
if (TREE_SIDE_EFFECTS (arg0)
|
||
|| TREE_SIDE_EFFECTS (arg1))
|
||
return 0;
|
||
|
||
switch (TREE_CODE (arg0))
|
||
{
|
||
case INDIRECT_REF:
|
||
return operand_equal_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0), 0);
|
||
|
||
case COMPONENT_REF:
|
||
case ARRAY_REF:
|
||
case ARRAY_RANGE_REF:
|
||
return (operand_equal_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0), 0)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg1, 1), 0));
|
||
|
||
case BIT_FIELD_REF:
|
||
return (operand_equal_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0), 0)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg1, 1), 0)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 2),
|
||
TREE_OPERAND (arg1, 2), 0));
|
||
default:
|
||
return 0;
|
||
}
|
||
|
||
case 'e':
|
||
if (TREE_CODE (arg0) == RTL_EXPR)
|
||
return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
|
||
return 0;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* Similar to operand_equal_p, but see if ARG0 might have been made by
|
||
shorten_compare from ARG1 when ARG1 was being compared with OTHER.
|
||
|
||
When in doubt, return 0. */
|
||
|
||
static int
|
||
operand_equal_for_comparison_p (arg0, arg1, other)
|
||
tree arg0, arg1;
|
||
tree other;
|
||
{
|
||
int unsignedp1, unsignedpo;
|
||
tree primarg0, primarg1, primother;
|
||
unsigned int correct_width;
|
||
|
||
if (operand_equal_p (arg0, arg1, 0))
|
||
return 1;
|
||
|
||
if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
|
||
|| ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
|
||
return 0;
|
||
|
||
/* Discard any conversions that don't change the modes of ARG0 and ARG1
|
||
and see if the inner values are the same. This removes any
|
||
signedness comparison, which doesn't matter here. */
|
||
primarg0 = arg0, primarg1 = arg1;
|
||
STRIP_NOPS (primarg0);
|
||
STRIP_NOPS (primarg1);
|
||
if (operand_equal_p (primarg0, primarg1, 0))
|
||
return 1;
|
||
|
||
/* Duplicate what shorten_compare does to ARG1 and see if that gives the
|
||
actual comparison operand, ARG0.
|
||
|
||
First throw away any conversions to wider types
|
||
already present in the operands. */
|
||
|
||
primarg1 = get_narrower (arg1, &unsignedp1);
|
||
primother = get_narrower (other, &unsignedpo);
|
||
|
||
correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
|
||
if (unsignedp1 == unsignedpo
|
||
&& TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
|
||
&& TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
|
||
{
|
||
tree type = TREE_TYPE (arg0);
|
||
|
||
/* Make sure shorter operand is extended the right way
|
||
to match the longer operand. */
|
||
primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
|
||
(unsignedp1, TREE_TYPE (primarg1)), primarg1);
|
||
|
||
if (operand_equal_p (arg0, convert (type, primarg1), 0))
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* See if ARG is an expression that is either a comparison or is performing
|
||
arithmetic on comparisons. The comparisons must only be comparing
|
||
two different values, which will be stored in *CVAL1 and *CVAL2; if
|
||
they are nonzero it means that some operands have already been found.
|
||
No variables may be used anywhere else in the expression except in the
|
||
comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
|
||
the expression and save_expr needs to be called with CVAL1 and CVAL2.
|
||
|
||
If this is true, return 1. Otherwise, return zero. */
|
||
|
||
static int
|
||
twoval_comparison_p (arg, cval1, cval2, save_p)
|
||
tree arg;
|
||
tree *cval1, *cval2;
|
||
int *save_p;
|
||
{
|
||
enum tree_code code = TREE_CODE (arg);
|
||
char class = TREE_CODE_CLASS (code);
|
||
|
||
/* We can handle some of the 'e' cases here. */
|
||
if (class == 'e' && code == TRUTH_NOT_EXPR)
|
||
class = '1';
|
||
else if (class == 'e'
|
||
&& (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
|
||
|| code == COMPOUND_EXPR))
|
||
class = '2';
|
||
|
||
else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
|
||
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
|
||
{
|
||
/* If we've already found a CVAL1 or CVAL2, this expression is
|
||
two complex to handle. */
|
||
if (*cval1 || *cval2)
|
||
return 0;
|
||
|
||
class = '1';
|
||
*save_p = 1;
|
||
}
|
||
|
||
switch (class)
|
||
{
|
||
case '1':
|
||
return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
|
||
|
||
case '2':
|
||
return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
|
||
&& twoval_comparison_p (TREE_OPERAND (arg, 1),
|
||
cval1, cval2, save_p));
|
||
|
||
case 'c':
|
||
return 1;
|
||
|
||
case 'e':
|
||
if (code == COND_EXPR)
|
||
return (twoval_comparison_p (TREE_OPERAND (arg, 0),
|
||
cval1, cval2, save_p)
|
||
&& twoval_comparison_p (TREE_OPERAND (arg, 1),
|
||
cval1, cval2, save_p)
|
||
&& twoval_comparison_p (TREE_OPERAND (arg, 2),
|
||
cval1, cval2, save_p));
|
||
return 0;
|
||
|
||
case '<':
|
||
/* First see if we can handle the first operand, then the second. For
|
||
the second operand, we know *CVAL1 can't be zero. It must be that
|
||
one side of the comparison is each of the values; test for the
|
||
case where this isn't true by failing if the two operands
|
||
are the same. */
|
||
|
||
if (operand_equal_p (TREE_OPERAND (arg, 0),
|
||
TREE_OPERAND (arg, 1), 0))
|
||
return 0;
|
||
|
||
if (*cval1 == 0)
|
||
*cval1 = TREE_OPERAND (arg, 0);
|
||
else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
|
||
;
|
||
else if (*cval2 == 0)
|
||
*cval2 = TREE_OPERAND (arg, 0);
|
||
else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
|
||
;
|
||
else
|
||
return 0;
|
||
|
||
if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
|
||
;
|
||
else if (*cval2 == 0)
|
||
*cval2 = TREE_OPERAND (arg, 1);
|
||
else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
|
||
;
|
||
else
|
||
return 0;
|
||
|
||
return 1;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* ARG is a tree that is known to contain just arithmetic operations and
|
||
comparisons. Evaluate the operations in the tree substituting NEW0 for
|
||
any occurrence of OLD0 as an operand of a comparison and likewise for
|
||
NEW1 and OLD1. */
|
||
|
||
static tree
|
||
eval_subst (arg, old0, new0, old1, new1)
|
||
tree arg;
|
||
tree old0, new0, old1, new1;
|
||
{
|
||
tree type = TREE_TYPE (arg);
|
||
enum tree_code code = TREE_CODE (arg);
|
||
char class = TREE_CODE_CLASS (code);
|
||
|
||
/* We can handle some of the 'e' cases here. */
|
||
if (class == 'e' && code == TRUTH_NOT_EXPR)
|
||
class = '1';
|
||
else if (class == 'e'
|
||
&& (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
|
||
class = '2';
|
||
|
||
switch (class)
|
||
{
|
||
case '1':
|
||
return fold (build1 (code, type,
|
||
eval_subst (TREE_OPERAND (arg, 0),
|
||
old0, new0, old1, new1)));
|
||
|
||
case '2':
|
||
return fold (build (code, type,
|
||
eval_subst (TREE_OPERAND (arg, 0),
|
||
old0, new0, old1, new1),
|
||
eval_subst (TREE_OPERAND (arg, 1),
|
||
old0, new0, old1, new1)));
|
||
|
||
case 'e':
|
||
switch (code)
|
||
{
|
||
case SAVE_EXPR:
|
||
return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
|
||
|
||
case COMPOUND_EXPR:
|
||
return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
|
||
|
||
case COND_EXPR:
|
||
return fold (build (code, type,
|
||
eval_subst (TREE_OPERAND (arg, 0),
|
||
old0, new0, old1, new1),
|
||
eval_subst (TREE_OPERAND (arg, 1),
|
||
old0, new0, old1, new1),
|
||
eval_subst (TREE_OPERAND (arg, 2),
|
||
old0, new0, old1, new1)));
|
||
default:
|
||
break;
|
||
}
|
||
/* fall through - ??? */
|
||
|
||
case '<':
|
||
{
|
||
tree arg0 = TREE_OPERAND (arg, 0);
|
||
tree arg1 = TREE_OPERAND (arg, 1);
|
||
|
||
/* We need to check both for exact equality and tree equality. The
|
||
former will be true if the operand has a side-effect. In that
|
||
case, we know the operand occurred exactly once. */
|
||
|
||
if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
|
||
arg0 = new0;
|
||
else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
|
||
arg0 = new1;
|
||
|
||
if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
|
||
arg1 = new0;
|
||
else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
|
||
arg1 = new1;
|
||
|
||
return fold (build (code, type, arg0, arg1));
|
||
}
|
||
|
||
default:
|
||
return arg;
|
||
}
|
||
}
|
||
|
||
/* Return a tree for the case when the result of an expression is RESULT
|
||
converted to TYPE and OMITTED was previously an operand of the expression
|
||
but is now not needed (e.g., we folded OMITTED * 0).
|
||
|
||
If OMITTED has side effects, we must evaluate it. Otherwise, just do
|
||
the conversion of RESULT to TYPE. */
|
||
|
||
tree
|
||
omit_one_operand (type, result, omitted)
|
||
tree type, result, omitted;
|
||
{
|
||
tree t = convert (type, result);
|
||
|
||
if (TREE_SIDE_EFFECTS (omitted))
|
||
return build (COMPOUND_EXPR, type, omitted, t);
|
||
|
||
return non_lvalue (t);
|
||
}
|
||
|
||
/* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
|
||
|
||
static tree
|
||
pedantic_omit_one_operand (type, result, omitted)
|
||
tree type, result, omitted;
|
||
{
|
||
tree t = convert (type, result);
|
||
|
||
if (TREE_SIDE_EFFECTS (omitted))
|
||
return build (COMPOUND_EXPR, type, omitted, t);
|
||
|
||
return pedantic_non_lvalue (t);
|
||
}
|
||
|
||
/* Return a simplified tree node for the truth-negation of ARG. This
|
||
never alters ARG itself. We assume that ARG is an operation that
|
||
returns a truth value (0 or 1). */
|
||
|
||
tree
|
||
invert_truthvalue (arg)
|
||
tree arg;
|
||
{
|
||
tree type = TREE_TYPE (arg);
|
||
enum tree_code code = TREE_CODE (arg);
|
||
|
||
if (code == ERROR_MARK)
|
||
return arg;
|
||
|
||
/* If this is a comparison, we can simply invert it, except for
|
||
floating-point non-equality comparisons, in which case we just
|
||
enclose a TRUTH_NOT_EXPR around what we have. */
|
||
|
||
if (TREE_CODE_CLASS (code) == '<')
|
||
{
|
||
if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
|
||
&& !flag_unsafe_math_optimizations
|
||
&& code != NE_EXPR
|
||
&& code != EQ_EXPR)
|
||
return build1 (TRUTH_NOT_EXPR, type, arg);
|
||
else
|
||
return build (invert_tree_comparison (code), type,
|
||
TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
|
||
}
|
||
|
||
switch (code)
|
||
{
|
||
case INTEGER_CST:
|
||
return convert (type, build_int_2 (integer_zerop (arg), 0));
|
||
|
||
case TRUTH_AND_EXPR:
|
||
return build (TRUTH_OR_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)),
|
||
invert_truthvalue (TREE_OPERAND (arg, 1)));
|
||
|
||
case TRUTH_OR_EXPR:
|
||
return build (TRUTH_AND_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)),
|
||
invert_truthvalue (TREE_OPERAND (arg, 1)));
|
||
|
||
case TRUTH_XOR_EXPR:
|
||
/* Here we can invert either operand. We invert the first operand
|
||
unless the second operand is a TRUTH_NOT_EXPR in which case our
|
||
result is the XOR of the first operand with the inside of the
|
||
negation of the second operand. */
|
||
|
||
if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
|
||
return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
|
||
TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
|
||
else
|
||
return build (TRUTH_XOR_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)),
|
||
TREE_OPERAND (arg, 1));
|
||
|
||
case TRUTH_ANDIF_EXPR:
|
||
return build (TRUTH_ORIF_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)),
|
||
invert_truthvalue (TREE_OPERAND (arg, 1)));
|
||
|
||
case TRUTH_ORIF_EXPR:
|
||
return build (TRUTH_ANDIF_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)),
|
||
invert_truthvalue (TREE_OPERAND (arg, 1)));
|
||
|
||
case TRUTH_NOT_EXPR:
|
||
return TREE_OPERAND (arg, 0);
|
||
|
||
case COND_EXPR:
|
||
return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
|
||
invert_truthvalue (TREE_OPERAND (arg, 1)),
|
||
invert_truthvalue (TREE_OPERAND (arg, 2)));
|
||
|
||
case COMPOUND_EXPR:
|
||
return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
|
||
invert_truthvalue (TREE_OPERAND (arg, 1)));
|
||
|
||
case WITH_RECORD_EXPR:
|
||
return build (WITH_RECORD_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)),
|
||
TREE_OPERAND (arg, 1));
|
||
|
||
case NON_LVALUE_EXPR:
|
||
return invert_truthvalue (TREE_OPERAND (arg, 0));
|
||
|
||
case NOP_EXPR:
|
||
case CONVERT_EXPR:
|
||
case FLOAT_EXPR:
|
||
return build1 (TREE_CODE (arg), type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)));
|
||
|
||
case BIT_AND_EXPR:
|
||
if (!integer_onep (TREE_OPERAND (arg, 1)))
|
||
break;
|
||
return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
|
||
|
||
case SAVE_EXPR:
|
||
return build1 (TRUTH_NOT_EXPR, type, arg);
|
||
|
||
case CLEANUP_POINT_EXPR:
|
||
return build1 (CLEANUP_POINT_EXPR, type,
|
||
invert_truthvalue (TREE_OPERAND (arg, 0)));
|
||
|
||
default:
|
||
break;
|
||
}
|
||
if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
|
||
abort ();
|
||
return build1 (TRUTH_NOT_EXPR, type, arg);
|
||
}
|
||
|
||
/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
|
||
operands are another bit-wise operation with a common input. If so,
|
||
distribute the bit operations to save an operation and possibly two if
|
||
constants are involved. For example, convert
|
||
(A | B) & (A | C) into A | (B & C)
|
||
Further simplification will occur if B and C are constants.
|
||
|
||
If this optimization cannot be done, 0 will be returned. */
|
||
|
||
static tree
|
||
distribute_bit_expr (code, type, arg0, arg1)
|
||
enum tree_code code;
|
||
tree type;
|
||
tree arg0, arg1;
|
||
{
|
||
tree common;
|
||
tree left, right;
|
||
|
||
if (TREE_CODE (arg0) != TREE_CODE (arg1)
|
||
|| TREE_CODE (arg0) == code
|
||
|| (TREE_CODE (arg0) != BIT_AND_EXPR
|
||
&& TREE_CODE (arg0) != BIT_IOR_EXPR))
|
||
return 0;
|
||
|
||
if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
|
||
{
|
||
common = TREE_OPERAND (arg0, 0);
|
||
left = TREE_OPERAND (arg0, 1);
|
||
right = TREE_OPERAND (arg1, 1);
|
||
}
|
||
else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
|
||
{
|
||
common = TREE_OPERAND (arg0, 0);
|
||
left = TREE_OPERAND (arg0, 1);
|
||
right = TREE_OPERAND (arg1, 0);
|
||
}
|
||
else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
|
||
{
|
||
common = TREE_OPERAND (arg0, 1);
|
||
left = TREE_OPERAND (arg0, 0);
|
||
right = TREE_OPERAND (arg1, 1);
|
||
}
|
||
else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
|
||
{
|
||
common = TREE_OPERAND (arg0, 1);
|
||
left = TREE_OPERAND (arg0, 0);
|
||
right = TREE_OPERAND (arg1, 0);
|
||
}
|
||
else
|
||
return 0;
|
||
|
||
return fold (build (TREE_CODE (arg0), type, common,
|
||
fold (build (code, type, left, right))));
|
||
}
|
||
|
||
/* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
|
||
starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
|
||
|
||
static tree
|
||
make_bit_field_ref (inner, type, bitsize, bitpos, unsignedp)
|
||
tree inner;
|
||
tree type;
|
||
int bitsize, bitpos;
|
||
int unsignedp;
|
||
{
|
||
tree result = build (BIT_FIELD_REF, type, inner,
|
||
size_int (bitsize), bitsize_int (bitpos));
|
||
|
||
TREE_UNSIGNED (result) = unsignedp;
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Optimize a bit-field compare.
|
||
|
||
There are two cases: First is a compare against a constant and the
|
||
second is a comparison of two items where the fields are at the same
|
||
bit position relative to the start of a chunk (byte, halfword, word)
|
||
large enough to contain it. In these cases we can avoid the shift
|
||
implicit in bitfield extractions.
|
||
|
||
For constants, we emit a compare of the shifted constant with the
|
||
BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
|
||
compared. For two fields at the same position, we do the ANDs with the
|
||
similar mask and compare the result of the ANDs.
|
||
|
||
CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
|
||
COMPARE_TYPE is the type of the comparison, and LHS and RHS
|
||
are the left and right operands of the comparison, respectively.
|
||
|
||
If the optimization described above can be done, we return the resulting
|
||
tree. Otherwise we return zero. */
|
||
|
||
static tree
|
||
optimize_bit_field_compare (code, compare_type, lhs, rhs)
|
||
enum tree_code code;
|
||
tree compare_type;
|
||
tree lhs, rhs;
|
||
{
|
||
HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
|
||
tree type = TREE_TYPE (lhs);
|
||
tree signed_type, unsigned_type;
|
||
int const_p = TREE_CODE (rhs) == INTEGER_CST;
|
||
enum machine_mode lmode, rmode, nmode;
|
||
int lunsignedp, runsignedp;
|
||
int lvolatilep = 0, rvolatilep = 0;
|
||
tree linner, rinner = NULL_TREE;
|
||
tree mask;
|
||
tree offset;
|
||
|
||
/* Get all the information about the extractions being done. If the bit size
|
||
if the same as the size of the underlying object, we aren't doing an
|
||
extraction at all and so can do nothing. We also don't want to
|
||
do anything if the inner expression is a PLACEHOLDER_EXPR since we
|
||
then will no longer be able to replace it. */
|
||
linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
|
||
&lunsignedp, &lvolatilep);
|
||
if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
|
||
|| offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
|
||
return 0;
|
||
|
||
if (!const_p)
|
||
{
|
||
/* If this is not a constant, we can only do something if bit positions,
|
||
sizes, and signedness are the same. */
|
||
rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
|
||
&runsignedp, &rvolatilep);
|
||
|
||
if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
|
||
|| lunsignedp != runsignedp || offset != 0
|
||
|| TREE_CODE (rinner) == PLACEHOLDER_EXPR)
|
||
return 0;
|
||
}
|
||
|
||
/* See if we can find a mode to refer to this field. We should be able to,
|
||
but fail if we can't. */
|
||
nmode = get_best_mode (lbitsize, lbitpos,
|
||
const_p ? TYPE_ALIGN (TREE_TYPE (linner))
|
||
: MIN (TYPE_ALIGN (TREE_TYPE (linner)),
|
||
TYPE_ALIGN (TREE_TYPE (rinner))),
|
||
word_mode, lvolatilep || rvolatilep);
|
||
if (nmode == VOIDmode)
|
||
return 0;
|
||
|
||
/* Set signed and unsigned types of the precision of this mode for the
|
||
shifts below. */
|
||
signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
|
||
unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
|
||
|
||
/* Compute the bit position and size for the new reference and our offset
|
||
within it. If the new reference is the same size as the original, we
|
||
won't optimize anything, so return zero. */
|
||
nbitsize = GET_MODE_BITSIZE (nmode);
|
||
nbitpos = lbitpos & ~ (nbitsize - 1);
|
||
lbitpos -= nbitpos;
|
||
if (nbitsize == lbitsize)
|
||
return 0;
|
||
|
||
if (BYTES_BIG_ENDIAN)
|
||
lbitpos = nbitsize - lbitsize - lbitpos;
|
||
|
||
/* Make the mask to be used against the extracted field. */
|
||
mask = build_int_2 (~0, ~0);
|
||
TREE_TYPE (mask) = unsigned_type;
|
||
force_fit_type (mask, 0);
|
||
mask = convert (unsigned_type, mask);
|
||
mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
|
||
mask = const_binop (RSHIFT_EXPR, mask,
|
||
size_int (nbitsize - lbitsize - lbitpos), 0);
|
||
|
||
if (! const_p)
|
||
/* If not comparing with constant, just rework the comparison
|
||
and return. */
|
||
return build (code, compare_type,
|
||
build (BIT_AND_EXPR, unsigned_type,
|
||
make_bit_field_ref (linner, unsigned_type,
|
||
nbitsize, nbitpos, 1),
|
||
mask),
|
||
build (BIT_AND_EXPR, unsigned_type,
|
||
make_bit_field_ref (rinner, unsigned_type,
|
||
nbitsize, nbitpos, 1),
|
||
mask));
|
||
|
||
/* Otherwise, we are handling the constant case. See if the constant is too
|
||
big for the field. Warn and return a tree of for 0 (false) if so. We do
|
||
this not only for its own sake, but to avoid having to test for this
|
||
error case below. If we didn't, we might generate wrong code.
|
||
|
||
For unsigned fields, the constant shifted right by the field length should
|
||
be all zero. For signed fields, the high-order bits should agree with
|
||
the sign bit. */
|
||
|
||
if (lunsignedp)
|
||
{
|
||
if (! integer_zerop (const_binop (RSHIFT_EXPR,
|
||
convert (unsigned_type, rhs),
|
||
size_int (lbitsize), 0)))
|
||
{
|
||
warning ("comparison is always %d due to width of bit-field",
|
||
code == NE_EXPR);
|
||
return convert (compare_type,
|
||
(code == NE_EXPR
|
||
? integer_one_node : integer_zero_node));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
|
||
size_int (lbitsize - 1), 0);
|
||
if (! integer_zerop (tem) && ! integer_all_onesp (tem))
|
||
{
|
||
warning ("comparison is always %d due to width of bit-field",
|
||
code == NE_EXPR);
|
||
return convert (compare_type,
|
||
(code == NE_EXPR
|
||
? integer_one_node : integer_zero_node));
|
||
}
|
||
}
|
||
|
||
/* Single-bit compares should always be against zero. */
|
||
if (lbitsize == 1 && ! integer_zerop (rhs))
|
||
{
|
||
code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
|
||
rhs = convert (type, integer_zero_node);
|
||
}
|
||
|
||
/* Make a new bitfield reference, shift the constant over the
|
||
appropriate number of bits and mask it with the computed mask
|
||
(in case this was a signed field). If we changed it, make a new one. */
|
||
lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
|
||
if (lvolatilep)
|
||
{
|
||
TREE_SIDE_EFFECTS (lhs) = 1;
|
||
TREE_THIS_VOLATILE (lhs) = 1;
|
||
}
|
||
|
||
rhs = fold (const_binop (BIT_AND_EXPR,
|
||
const_binop (LSHIFT_EXPR,
|
||
convert (unsigned_type, rhs),
|
||
size_int (lbitpos), 0),
|
||
mask, 0));
|
||
|
||
return build (code, compare_type,
|
||
build (BIT_AND_EXPR, unsigned_type, lhs, mask),
|
||
rhs);
|
||
}
|
||
|
||
/* Subroutine for fold_truthop: decode a field reference.
|
||
|
||
If EXP is a comparison reference, we return the innermost reference.
|
||
|
||
*PBITSIZE is set to the number of bits in the reference, *PBITPOS is
|
||
set to the starting bit number.
|
||
|
||
If the innermost field can be completely contained in a mode-sized
|
||
unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
|
||
|
||
*PVOLATILEP is set to 1 if the any expression encountered is volatile;
|
||
otherwise it is not changed.
|
||
|
||
*PUNSIGNEDP is set to the signedness of the field.
|
||
|
||
*PMASK is set to the mask used. This is either contained in a
|
||
BIT_AND_EXPR or derived from the width of the field.
|
||
|
||
*PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
|
||
|
||
Return 0 if this is not a component reference or is one that we can't
|
||
do anything with. */
|
||
|
||
static tree
|
||
decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp,
|
||
pvolatilep, pmask, pand_mask)
|
||
tree exp;
|
||
HOST_WIDE_INT *pbitsize, *pbitpos;
|
||
enum machine_mode *pmode;
|
||
int *punsignedp, *pvolatilep;
|
||
tree *pmask;
|
||
tree *pand_mask;
|
||
{
|
||
tree and_mask = 0;
|
||
tree mask, inner, offset;
|
||
tree unsigned_type;
|
||
unsigned int precision;
|
||
|
||
/* All the optimizations using this function assume integer fields.
|
||
There are problems with FP fields since the type_for_size call
|
||
below can fail for, e.g., XFmode. */
|
||
if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
|
||
return 0;
|
||
|
||
STRIP_NOPS (exp);
|
||
|
||
if (TREE_CODE (exp) == BIT_AND_EXPR)
|
||
{
|
||
and_mask = TREE_OPERAND (exp, 1);
|
||
exp = TREE_OPERAND (exp, 0);
|
||
STRIP_NOPS (exp); STRIP_NOPS (and_mask);
|
||
if (TREE_CODE (and_mask) != INTEGER_CST)
|
||
return 0;
|
||
}
|
||
|
||
inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
|
||
punsignedp, pvolatilep);
|
||
if ((inner == exp && and_mask == 0)
|
||
|| *pbitsize < 0 || offset != 0
|
||
|| TREE_CODE (inner) == PLACEHOLDER_EXPR)
|
||
return 0;
|
||
|
||
/* Compute the mask to access the bitfield. */
|
||
unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
|
||
precision = TYPE_PRECISION (unsigned_type);
|
||
|
||
mask = build_int_2 (~0, ~0);
|
||
TREE_TYPE (mask) = unsigned_type;
|
||
force_fit_type (mask, 0);
|
||
mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
|
||
mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
|
||
|
||
/* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
|
||
if (and_mask != 0)
|
||
mask = fold (build (BIT_AND_EXPR, unsigned_type,
|
||
convert (unsigned_type, and_mask), mask));
|
||
|
||
*pmask = mask;
|
||
*pand_mask = and_mask;
|
||
return inner;
|
||
}
|
||
|
||
/* Return nonzero if MASK represents a mask of SIZE ones in the low-order
|
||
bit positions. */
|
||
|
||
static int
|
||
all_ones_mask_p (mask, size)
|
||
tree mask;
|
||
int size;
|
||
{
|
||
tree type = TREE_TYPE (mask);
|
||
unsigned int precision = TYPE_PRECISION (type);
|
||
tree tmask;
|
||
|
||
tmask = build_int_2 (~0, ~0);
|
||
TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
|
||
force_fit_type (tmask, 0);
|
||
return
|
||
tree_int_cst_equal (mask,
|
||
const_binop (RSHIFT_EXPR,
|
||
const_binop (LSHIFT_EXPR, tmask,
|
||
size_int (precision - size),
|
||
0),
|
||
size_int (precision - size), 0));
|
||
}
|
||
|
||
/* Subroutine for fold: determine if VAL is the INTEGER_CONST that
|
||
represents the sign bit of EXP's type. If EXP represents a sign
|
||
or zero extension, also test VAL against the unextended type.
|
||
The return value is the (sub)expression whose sign bit is VAL,
|
||
or NULL_TREE otherwise. */
|
||
|
||
static tree
|
||
sign_bit_p (exp, val)
|
||
tree exp;
|
||
tree val;
|
||
{
|
||
unsigned HOST_WIDE_INT lo;
|
||
HOST_WIDE_INT hi;
|
||
int width;
|
||
tree t;
|
||
|
||
/* Tree EXP must have an integral type. */
|
||
t = TREE_TYPE (exp);
|
||
if (! INTEGRAL_TYPE_P (t))
|
||
return NULL_TREE;
|
||
|
||
/* Tree VAL must be an integer constant. */
|
||
if (TREE_CODE (val) != INTEGER_CST
|
||
|| TREE_CONSTANT_OVERFLOW (val))
|
||
return NULL_TREE;
|
||
|
||
width = TYPE_PRECISION (t);
|
||
if (width > HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
|
||
lo = 0;
|
||
}
|
||
else
|
||
{
|
||
hi = 0;
|
||
lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
|
||
}
|
||
|
||
if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
|
||
return exp;
|
||
|
||
/* Handle extension from a narrower type. */
|
||
if (TREE_CODE (exp) == NOP_EXPR
|
||
&& TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
|
||
return sign_bit_p (TREE_OPERAND (exp, 0), val);
|
||
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Subroutine for fold_truthop: determine if an operand is simple enough
|
||
to be evaluated unconditionally. */
|
||
|
||
static int
|
||
simple_operand_p (exp)
|
||
tree exp;
|
||
{
|
||
/* Strip any conversions that don't change the machine mode. */
|
||
while ((TREE_CODE (exp) == NOP_EXPR
|
||
|| TREE_CODE (exp) == CONVERT_EXPR)
|
||
&& (TYPE_MODE (TREE_TYPE (exp))
|
||
== TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
|
||
exp = TREE_OPERAND (exp, 0);
|
||
|
||
return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
|
||
|| (DECL_P (exp)
|
||
&& ! TREE_ADDRESSABLE (exp)
|
||
&& ! TREE_THIS_VOLATILE (exp)
|
||
&& ! DECL_NONLOCAL (exp)
|
||
/* Don't regard global variables as simple. They may be
|
||
allocated in ways unknown to the compiler (shared memory,
|
||
#pragma weak, etc). */
|
||
&& ! TREE_PUBLIC (exp)
|
||
&& ! DECL_EXTERNAL (exp)
|
||
/* Loading a static variable is unduly expensive, but global
|
||
registers aren't expensive. */
|
||
&& (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
|
||
}
|
||
|
||
/* The following functions are subroutines to fold_range_test and allow it to
|
||
try to change a logical combination of comparisons into a range test.
|
||
|
||
For example, both
|
||
X == 2 || X == 3 || X == 4 || X == 5
|
||
and
|
||
X >= 2 && X <= 5
|
||
are converted to
|
||
(unsigned) (X - 2) <= 3
|
||
|
||
We describe each set of comparisons as being either inside or outside
|
||
a range, using a variable named like IN_P, and then describe the
|
||
range with a lower and upper bound. If one of the bounds is omitted,
|
||
it represents either the highest or lowest value of the type.
|
||
|
||
In the comments below, we represent a range by two numbers in brackets
|
||
preceded by a "+" to designate being inside that range, or a "-" to
|
||
designate being outside that range, so the condition can be inverted by
|
||
flipping the prefix. An omitted bound is represented by a "-". For
|
||
example, "- [-, 10]" means being outside the range starting at the lowest
|
||
possible value and ending at 10, in other words, being greater than 10.
|
||
The range "+ [-, -]" is always true and hence the range "- [-, -]" is
|
||
always false.
|
||
|
||
We set up things so that the missing bounds are handled in a consistent
|
||
manner so neither a missing bound nor "true" and "false" need to be
|
||
handled using a special case. */
|
||
|
||
/* Return the result of applying CODE to ARG0 and ARG1, but handle the case
|
||
of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
|
||
and UPPER1_P are nonzero if the respective argument is an upper bound
|
||
and zero for a lower. TYPE, if nonzero, is the type of the result; it
|
||
must be specified for a comparison. ARG1 will be converted to ARG0's
|
||
type if both are specified. */
|
||
|
||
static tree
|
||
range_binop (code, type, arg0, upper0_p, arg1, upper1_p)
|
||
enum tree_code code;
|
||
tree type;
|
||
tree arg0, arg1;
|
||
int upper0_p, upper1_p;
|
||
{
|
||
tree tem;
|
||
int result;
|
||
int sgn0, sgn1;
|
||
|
||
/* If neither arg represents infinity, do the normal operation.
|
||
Else, if not a comparison, return infinity. Else handle the special
|
||
comparison rules. Note that most of the cases below won't occur, but
|
||
are handled for consistency. */
|
||
|
||
if (arg0 != 0 && arg1 != 0)
|
||
{
|
||
tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
|
||
arg0, convert (TREE_TYPE (arg0), arg1)));
|
||
STRIP_NOPS (tem);
|
||
return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
|
||
}
|
||
|
||
if (TREE_CODE_CLASS (code) != '<')
|
||
return 0;
|
||
|
||
/* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
|
||
for neither. In real maths, we cannot assume open ended ranges are
|
||
the same. But, this is computer arithmetic, where numbers are finite.
|
||
We can therefore make the transformation of any unbounded range with
|
||
the value Z, Z being greater than any representable number. This permits
|
||
us to treat unbounded ranges as equal. */
|
||
sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
|
||
sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
|
||
switch (code)
|
||
{
|
||
case EQ_EXPR:
|
||
result = sgn0 == sgn1;
|
||
break;
|
||
case NE_EXPR:
|
||
result = sgn0 != sgn1;
|
||
break;
|
||
case LT_EXPR:
|
||
result = sgn0 < sgn1;
|
||
break;
|
||
case LE_EXPR:
|
||
result = sgn0 <= sgn1;
|
||
break;
|
||
case GT_EXPR:
|
||
result = sgn0 > sgn1;
|
||
break;
|
||
case GE_EXPR:
|
||
result = sgn0 >= sgn1;
|
||
break;
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
return convert (type, result ? integer_one_node : integer_zero_node);
|
||
}
|
||
|
||
/* Given EXP, a logical expression, set the range it is testing into
|
||
variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
|
||
actually being tested. *PLOW and *PHIGH will be made of the same type
|
||
as the returned expression. If EXP is not a comparison, we will most
|
||
likely not be returning a useful value and range. */
|
||
|
||
static tree
|
||
make_range (exp, pin_p, plow, phigh)
|
||
tree exp;
|
||
int *pin_p;
|
||
tree *plow, *phigh;
|
||
{
|
||
enum tree_code code;
|
||
tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
|
||
tree orig_type = NULL_TREE;
|
||
int in_p, n_in_p;
|
||
tree low, high, n_low, n_high;
|
||
|
||
/* Start with simply saying "EXP != 0" and then look at the code of EXP
|
||
and see if we can refine the range. Some of the cases below may not
|
||
happen, but it doesn't seem worth worrying about this. We "continue"
|
||
the outer loop when we've changed something; otherwise we "break"
|
||
the switch, which will "break" the while. */
|
||
|
||
in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
|
||
|
||
while (1)
|
||
{
|
||
code = TREE_CODE (exp);
|
||
|
||
if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
|
||
{
|
||
arg0 = TREE_OPERAND (exp, 0);
|
||
if (TREE_CODE_CLASS (code) == '<'
|
||
|| TREE_CODE_CLASS (code) == '1'
|
||
|| TREE_CODE_CLASS (code) == '2')
|
||
type = TREE_TYPE (arg0);
|
||
if (TREE_CODE_CLASS (code) == '2'
|
||
|| TREE_CODE_CLASS (code) == '<'
|
||
|| (TREE_CODE_CLASS (code) == 'e'
|
||
&& TREE_CODE_LENGTH (code) > 1))
|
||
arg1 = TREE_OPERAND (exp, 1);
|
||
}
|
||
|
||
/* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
|
||
lose a cast by accident. */
|
||
if (type != NULL_TREE && orig_type == NULL_TREE)
|
||
orig_type = type;
|
||
|
||
switch (code)
|
||
{
|
||
case TRUTH_NOT_EXPR:
|
||
in_p = ! in_p, exp = arg0;
|
||
continue;
|
||
|
||
case EQ_EXPR: case NE_EXPR:
|
||
case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
|
||
/* We can only do something if the range is testing for zero
|
||
and if the second operand is an integer constant. Note that
|
||
saying something is "in" the range we make is done by
|
||
complementing IN_P since it will set in the initial case of
|
||
being not equal to zero; "out" is leaving it alone. */
|
||
if (low == 0 || high == 0
|
||
|| ! integer_zerop (low) || ! integer_zerop (high)
|
||
|| TREE_CODE (arg1) != INTEGER_CST)
|
||
break;
|
||
|
||
switch (code)
|
||
{
|
||
case NE_EXPR: /* - [c, c] */
|
||
low = high = arg1;
|
||
break;
|
||
case EQ_EXPR: /* + [c, c] */
|
||
in_p = ! in_p, low = high = arg1;
|
||
break;
|
||
case GT_EXPR: /* - [-, c] */
|
||
low = 0, high = arg1;
|
||
break;
|
||
case GE_EXPR: /* + [c, -] */
|
||
in_p = ! in_p, low = arg1, high = 0;
|
||
break;
|
||
case LT_EXPR: /* - [c, -] */
|
||
low = arg1, high = 0;
|
||
break;
|
||
case LE_EXPR: /* + [-, c] */
|
||
in_p = ! in_p, low = 0, high = arg1;
|
||
break;
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
exp = arg0;
|
||
|
||
/* If this is an unsigned comparison, we also know that EXP is
|
||
greater than or equal to zero. We base the range tests we make
|
||
on that fact, so we record it here so we can parse existing
|
||
range tests. */
|
||
if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
|
||
{
|
||
if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
|
||
1, convert (type, integer_zero_node),
|
||
NULL_TREE))
|
||
break;
|
||
|
||
in_p = n_in_p, low = n_low, high = n_high;
|
||
|
||
/* If the high bound is missing, but we
|
||
have a low bound, reverse the range so
|
||
it goes from zero to the low bound minus 1. */
|
||
if (high == 0 && low)
|
||
{
|
||
in_p = ! in_p;
|
||
high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
|
||
integer_one_node, 0);
|
||
low = convert (type, integer_zero_node);
|
||
}
|
||
}
|
||
continue;
|
||
|
||
case NEGATE_EXPR:
|
||
/* (-x) IN [a,b] -> x in [-b, -a] */
|
||
n_low = range_binop (MINUS_EXPR, type,
|
||
convert (type, integer_zero_node), 0, high, 1);
|
||
n_high = range_binop (MINUS_EXPR, type,
|
||
convert (type, integer_zero_node), 0, low, 0);
|
||
low = n_low, high = n_high;
|
||
exp = arg0;
|
||
continue;
|
||
|
||
case BIT_NOT_EXPR:
|
||
/* ~ X -> -X - 1 */
|
||
exp = build (MINUS_EXPR, type, negate_expr (arg0),
|
||
convert (type, integer_one_node));
|
||
continue;
|
||
|
||
case PLUS_EXPR: case MINUS_EXPR:
|
||
if (TREE_CODE (arg1) != INTEGER_CST)
|
||
break;
|
||
|
||
/* If EXP is signed, any overflow in the computation is undefined,
|
||
so we don't worry about it so long as our computations on
|
||
the bounds don't overflow. For unsigned, overflow is defined
|
||
and this is exactly the right thing. */
|
||
n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
|
||
type, low, 0, arg1, 0);
|
||
n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
|
||
type, high, 1, arg1, 0);
|
||
if ((n_low != 0 && TREE_OVERFLOW (n_low))
|
||
|| (n_high != 0 && TREE_OVERFLOW (n_high)))
|
||
break;
|
||
|
||
/* Check for an unsigned range which has wrapped around the maximum
|
||
value thus making n_high < n_low, and normalize it. */
|
||
if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
|
||
{
|
||
low = range_binop (PLUS_EXPR, type, n_high, 0,
|
||
integer_one_node, 0);
|
||
high = range_binop (MINUS_EXPR, type, n_low, 0,
|
||
integer_one_node, 0);
|
||
|
||
/* If the range is of the form +/- [ x+1, x ], we won't
|
||
be able to normalize it. But then, it represents the
|
||
whole range or the empty set, so make it
|
||
+/- [ -, - ]. */
|
||
if (tree_int_cst_equal (n_low, low)
|
||
&& tree_int_cst_equal (n_high, high))
|
||
low = high = 0;
|
||
else
|
||
in_p = ! in_p;
|
||
}
|
||
else
|
||
low = n_low, high = n_high;
|
||
|
||
exp = arg0;
|
||
continue;
|
||
|
||
case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
|
||
if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
|
||
break;
|
||
|
||
if (! INTEGRAL_TYPE_P (type)
|
||
|| (low != 0 && ! int_fits_type_p (low, type))
|
||
|| (high != 0 && ! int_fits_type_p (high, type)))
|
||
break;
|
||
|
||
n_low = low, n_high = high;
|
||
|
||
if (n_low != 0)
|
||
n_low = convert (type, n_low);
|
||
|
||
if (n_high != 0)
|
||
n_high = convert (type, n_high);
|
||
|
||
/* If we're converting from an unsigned to a signed type,
|
||
we will be doing the comparison as unsigned. The tests above
|
||
have already verified that LOW and HIGH are both positive.
|
||
|
||
So we have to make sure that the original unsigned value will
|
||
be interpreted as positive. */
|
||
if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
|
||
{
|
||
tree equiv_type = (*lang_hooks.types.type_for_mode)
|
||
(TYPE_MODE (type), 1);
|
||
tree high_positive;
|
||
|
||
/* A range without an upper bound is, naturally, unbounded.
|
||
Since convert would have cropped a very large value, use
|
||
the max value for the destination type. */
|
||
high_positive
|
||
= TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
|
||
: TYPE_MAX_VALUE (type);
|
||
|
||
if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
|
||
high_positive = fold (build (RSHIFT_EXPR, type,
|
||
convert (type, high_positive),
|
||
convert (type, integer_one_node)));
|
||
|
||
/* If the low bound is specified, "and" the range with the
|
||
range for which the original unsigned value will be
|
||
positive. */
|
||
if (low != 0)
|
||
{
|
||
if (! merge_ranges (&n_in_p, &n_low, &n_high,
|
||
1, n_low, n_high,
|
||
1, convert (type, integer_zero_node),
|
||
high_positive))
|
||
break;
|
||
|
||
in_p = (n_in_p == in_p);
|
||
}
|
||
else
|
||
{
|
||
/* Otherwise, "or" the range with the range of the input
|
||
that will be interpreted as negative. */
|
||
if (! merge_ranges (&n_in_p, &n_low, &n_high,
|
||
0, n_low, n_high,
|
||
1, convert (type, integer_zero_node),
|
||
high_positive))
|
||
break;
|
||
|
||
in_p = (in_p != n_in_p);
|
||
}
|
||
}
|
||
|
||
exp = arg0;
|
||
low = n_low, high = n_high;
|
||
continue;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
break;
|
||
}
|
||
|
||
/* If EXP is a constant, we can evaluate whether this is true or false. */
|
||
if (TREE_CODE (exp) == INTEGER_CST)
|
||
{
|
||
in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
|
||
exp, 0, low, 0))
|
||
&& integer_onep (range_binop (LE_EXPR, integer_type_node,
|
||
exp, 1, high, 1)));
|
||
low = high = 0;
|
||
exp = 0;
|
||
}
|
||
|
||
*pin_p = in_p, *plow = low, *phigh = high;
|
||
return exp;
|
||
}
|
||
|
||
/* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
|
||
type, TYPE, return an expression to test if EXP is in (or out of, depending
|
||
on IN_P) the range. */
|
||
|
||
static tree
|
||
build_range_check (type, exp, in_p, low, high)
|
||
tree type;
|
||
tree exp;
|
||
int in_p;
|
||
tree low, high;
|
||
{
|
||
tree etype = TREE_TYPE (exp);
|
||
tree value;
|
||
|
||
if (! in_p
|
||
&& (0 != (value = build_range_check (type, exp, 1, low, high))))
|
||
return invert_truthvalue (value);
|
||
|
||
if (low == 0 && high == 0)
|
||
return convert (type, integer_one_node);
|
||
|
||
if (low == 0)
|
||
return fold (build (LE_EXPR, type, exp, high));
|
||
|
||
if (high == 0)
|
||
return fold (build (GE_EXPR, type, exp, low));
|
||
|
||
if (operand_equal_p (low, high, 0))
|
||
return fold (build (EQ_EXPR, type, exp, low));
|
||
|
||
if (integer_zerop (low))
|
||
{
|
||
if (! TREE_UNSIGNED (etype))
|
||
{
|
||
etype = (*lang_hooks.types.unsigned_type) (etype);
|
||
high = convert (etype, high);
|
||
exp = convert (etype, exp);
|
||
}
|
||
return build_range_check (type, exp, 1, 0, high);
|
||
}
|
||
|
||
/* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
|
||
if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
|
||
{
|
||
unsigned HOST_WIDE_INT lo;
|
||
HOST_WIDE_INT hi;
|
||
int prec;
|
||
|
||
prec = TYPE_PRECISION (etype);
|
||
if (prec <= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
hi = 0;
|
||
lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
|
||
}
|
||
else
|
||
{
|
||
hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
|
||
lo = (unsigned HOST_WIDE_INT) -1;
|
||
}
|
||
|
||
if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
|
||
{
|
||
if (TREE_UNSIGNED (etype))
|
||
{
|
||
etype = (*lang_hooks.types.signed_type) (etype);
|
||
exp = convert (etype, exp);
|
||
}
|
||
return fold (build (GT_EXPR, type, exp,
|
||
convert (etype, integer_zero_node)));
|
||
}
|
||
}
|
||
|
||
if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
|
||
&& ! TREE_OVERFLOW (value))
|
||
return build_range_check (type,
|
||
fold (build (MINUS_EXPR, etype, exp, low)),
|
||
1, convert (etype, integer_zero_node), value);
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Given two ranges, see if we can merge them into one. Return 1 if we
|
||
can, 0 if we can't. Set the output range into the specified parameters. */
|
||
|
||
static int
|
||
merge_ranges (pin_p, plow, phigh, in0_p, low0, high0, in1_p, low1, high1)
|
||
int *pin_p;
|
||
tree *plow, *phigh;
|
||
int in0_p, in1_p;
|
||
tree low0, high0, low1, high1;
|
||
{
|
||
int no_overlap;
|
||
int subset;
|
||
int temp;
|
||
tree tem;
|
||
int in_p;
|
||
tree low, high;
|
||
int lowequal = ((low0 == 0 && low1 == 0)
|
||
|| integer_onep (range_binop (EQ_EXPR, integer_type_node,
|
||
low0, 0, low1, 0)));
|
||
int highequal = ((high0 == 0 && high1 == 0)
|
||
|| integer_onep (range_binop (EQ_EXPR, integer_type_node,
|
||
high0, 1, high1, 1)));
|
||
|
||
/* Make range 0 be the range that starts first, or ends last if they
|
||
start at the same value. Swap them if it isn't. */
|
||
if (integer_onep (range_binop (GT_EXPR, integer_type_node,
|
||
low0, 0, low1, 0))
|
||
|| (lowequal
|
||
&& integer_onep (range_binop (GT_EXPR, integer_type_node,
|
||
high1, 1, high0, 1))))
|
||
{
|
||
temp = in0_p, in0_p = in1_p, in1_p = temp;
|
||
tem = low0, low0 = low1, low1 = tem;
|
||
tem = high0, high0 = high1, high1 = tem;
|
||
}
|
||
|
||
/* Now flag two cases, whether the ranges are disjoint or whether the
|
||
second range is totally subsumed in the first. Note that the tests
|
||
below are simplified by the ones above. */
|
||
no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
|
||
high0, 1, low1, 0));
|
||
subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
|
||
high1, 1, high0, 1));
|
||
|
||
/* We now have four cases, depending on whether we are including or
|
||
excluding the two ranges. */
|
||
if (in0_p && in1_p)
|
||
{
|
||
/* If they don't overlap, the result is false. If the second range
|
||
is a subset it is the result. Otherwise, the range is from the start
|
||
of the second to the end of the first. */
|
||
if (no_overlap)
|
||
in_p = 0, low = high = 0;
|
||
else if (subset)
|
||
in_p = 1, low = low1, high = high1;
|
||
else
|
||
in_p = 1, low = low1, high = high0;
|
||
}
|
||
|
||
else if (in0_p && ! in1_p)
|
||
{
|
||
/* If they don't overlap, the result is the first range. If they are
|
||
equal, the result is false. If the second range is a subset of the
|
||
first, and the ranges begin at the same place, we go from just after
|
||
the end of the first range to the end of the second. If the second
|
||
range is not a subset of the first, or if it is a subset and both
|
||
ranges end at the same place, the range starts at the start of the
|
||
first range and ends just before the second range.
|
||
Otherwise, we can't describe this as a single range. */
|
||
if (no_overlap)
|
||
in_p = 1, low = low0, high = high0;
|
||
else if (lowequal && highequal)
|
||
in_p = 0, low = high = 0;
|
||
else if (subset && lowequal)
|
||
{
|
||
in_p = 1, high = high0;
|
||
low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
|
||
integer_one_node, 0);
|
||
}
|
||
else if (! subset || highequal)
|
||
{
|
||
in_p = 1, low = low0;
|
||
high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
|
||
integer_one_node, 0);
|
||
}
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
else if (! in0_p && in1_p)
|
||
{
|
||
/* If they don't overlap, the result is the second range. If the second
|
||
is a subset of the first, the result is false. Otherwise,
|
||
the range starts just after the first range and ends at the
|
||
end of the second. */
|
||
if (no_overlap)
|
||
in_p = 1, low = low1, high = high1;
|
||
else if (subset || highequal)
|
||
in_p = 0, low = high = 0;
|
||
else
|
||
{
|
||
in_p = 1, high = high1;
|
||
low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
|
||
integer_one_node, 0);
|
||
}
|
||
}
|
||
|
||
else
|
||
{
|
||
/* The case where we are excluding both ranges. Here the complex case
|
||
is if they don't overlap. In that case, the only time we have a
|
||
range is if they are adjacent. If the second is a subset of the
|
||
first, the result is the first. Otherwise, the range to exclude
|
||
starts at the beginning of the first range and ends at the end of the
|
||
second. */
|
||
if (no_overlap)
|
||
{
|
||
if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
|
||
range_binop (PLUS_EXPR, NULL_TREE,
|
||
high0, 1,
|
||
integer_one_node, 1),
|
||
1, low1, 0)))
|
||
in_p = 0, low = low0, high = high1;
|
||
else
|
||
return 0;
|
||
}
|
||
else if (subset)
|
||
in_p = 0, low = low0, high = high0;
|
||
else
|
||
in_p = 0, low = low0, high = high1;
|
||
}
|
||
|
||
*pin_p = in_p, *plow = low, *phigh = high;
|
||
return 1;
|
||
}
|
||
|
||
#ifndef RANGE_TEST_NON_SHORT_CIRCUIT
|
||
#define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
|
||
#endif
|
||
|
||
/* EXP is some logical combination of boolean tests. See if we can
|
||
merge it into some range test. Return the new tree if so. */
|
||
|
||
static tree
|
||
fold_range_test (exp)
|
||
tree exp;
|
||
{
|
||
int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
|
||
|| TREE_CODE (exp) == TRUTH_OR_EXPR);
|
||
int in0_p, in1_p, in_p;
|
||
tree low0, low1, low, high0, high1, high;
|
||
tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
|
||
tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
|
||
tree tem;
|
||
|
||
/* If this is an OR operation, invert both sides; we will invert
|
||
again at the end. */
|
||
if (or_op)
|
||
in0_p = ! in0_p, in1_p = ! in1_p;
|
||
|
||
/* If both expressions are the same, if we can merge the ranges, and we
|
||
can build the range test, return it or it inverted. If one of the
|
||
ranges is always true or always false, consider it to be the same
|
||
expression as the other. */
|
||
if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
|
||
&& merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
|
||
in1_p, low1, high1)
|
||
&& 0 != (tem = (build_range_check (TREE_TYPE (exp),
|
||
lhs != 0 ? lhs
|
||
: rhs != 0 ? rhs : integer_zero_node,
|
||
in_p, low, high))))
|
||
return or_op ? invert_truthvalue (tem) : tem;
|
||
|
||
/* On machines where the branch cost is expensive, if this is a
|
||
short-circuited branch and the underlying object on both sides
|
||
is the same, make a non-short-circuit operation. */
|
||
else if (RANGE_TEST_NON_SHORT_CIRCUIT
|
||
&& lhs != 0 && rhs != 0
|
||
&& (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
|
||
|| TREE_CODE (exp) == TRUTH_ORIF_EXPR)
|
||
&& operand_equal_p (lhs, rhs, 0))
|
||
{
|
||
/* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
|
||
unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
|
||
which cases we can't do this. */
|
||
if (simple_operand_p (lhs))
|
||
return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
|
||
? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
|
||
TREE_TYPE (exp), TREE_OPERAND (exp, 0),
|
||
TREE_OPERAND (exp, 1));
|
||
|
||
else if ((*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ! CONTAINS_PLACEHOLDER_P (lhs))
|
||
{
|
||
tree common = save_expr (lhs);
|
||
|
||
if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
|
||
or_op ? ! in0_p : in0_p,
|
||
low0, high0))
|
||
&& (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
|
||
or_op ? ! in1_p : in1_p,
|
||
low1, high1))))
|
||
return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
|
||
? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
|
||
TREE_TYPE (exp), lhs, rhs);
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
|
||
bit value. Arrange things so the extra bits will be set to zero if and
|
||
only if C is signed-extended to its full width. If MASK is nonzero,
|
||
it is an INTEGER_CST that should be AND'ed with the extra bits. */
|
||
|
||
static tree
|
||
unextend (c, p, unsignedp, mask)
|
||
tree c;
|
||
int p;
|
||
int unsignedp;
|
||
tree mask;
|
||
{
|
||
tree type = TREE_TYPE (c);
|
||
int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
|
||
tree temp;
|
||
|
||
if (p == modesize || unsignedp)
|
||
return c;
|
||
|
||
/* We work by getting just the sign bit into the low-order bit, then
|
||
into the high-order bit, then sign-extend. We then XOR that value
|
||
with C. */
|
||
temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
|
||
temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
|
||
|
||
/* We must use a signed type in order to get an arithmetic right shift.
|
||
However, we must also avoid introducing accidental overflows, so that
|
||
a subsequent call to integer_zerop will work. Hence we must
|
||
do the type conversion here. At this point, the constant is either
|
||
zero or one, and the conversion to a signed type can never overflow.
|
||
We could get an overflow if this conversion is done anywhere else. */
|
||
if (TREE_UNSIGNED (type))
|
||
temp = convert ((*lang_hooks.types.signed_type) (type), temp);
|
||
|
||
temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
|
||
temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
|
||
if (mask != 0)
|
||
temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
|
||
/* If necessary, convert the type back to match the type of C. */
|
||
if (TREE_UNSIGNED (type))
|
||
temp = convert (type, temp);
|
||
|
||
return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
|
||
}
|
||
|
||
/* Find ways of folding logical expressions of LHS and RHS:
|
||
Try to merge two comparisons to the same innermost item.
|
||
Look for range tests like "ch >= '0' && ch <= '9'".
|
||
Look for combinations of simple terms on machines with expensive branches
|
||
and evaluate the RHS unconditionally.
|
||
|
||
For example, if we have p->a == 2 && p->b == 4 and we can make an
|
||
object large enough to span both A and B, we can do this with a comparison
|
||
against the object ANDed with the a mask.
|
||
|
||
If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
|
||
operations to do this with one comparison.
|
||
|
||
We check for both normal comparisons and the BIT_AND_EXPRs made this by
|
||
function and the one above.
|
||
|
||
CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
|
||
TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
|
||
|
||
TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
|
||
two operands.
|
||
|
||
We return the simplified tree or 0 if no optimization is possible. */
|
||
|
||
static tree
|
||
fold_truthop (code, truth_type, lhs, rhs)
|
||
enum tree_code code;
|
||
tree truth_type, lhs, rhs;
|
||
{
|
||
/* If this is the "or" of two comparisons, we can do something if
|
||
the comparisons are NE_EXPR. If this is the "and", we can do something
|
||
if the comparisons are EQ_EXPR. I.e.,
|
||
(a->b == 2 && a->c == 4) can become (a->new == NEW).
|
||
|
||
WANTED_CODE is this operation code. For single bit fields, we can
|
||
convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
|
||
comparison for one-bit fields. */
|
||
|
||
enum tree_code wanted_code;
|
||
enum tree_code lcode, rcode;
|
||
tree ll_arg, lr_arg, rl_arg, rr_arg;
|
||
tree ll_inner, lr_inner, rl_inner, rr_inner;
|
||
HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
|
||
HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
|
||
HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
|
||
HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
|
||
int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
|
||
enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
|
||
enum machine_mode lnmode, rnmode;
|
||
tree ll_mask, lr_mask, rl_mask, rr_mask;
|
||
tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
|
||
tree l_const, r_const;
|
||
tree lntype, rntype, result;
|
||
int first_bit, end_bit;
|
||
int volatilep;
|
||
|
||
/* Start by getting the comparison codes. Fail if anything is volatile.
|
||
If one operand is a BIT_AND_EXPR with the constant one, treat it as if
|
||
it were surrounded with a NE_EXPR. */
|
||
|
||
if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
|
||
return 0;
|
||
|
||
lcode = TREE_CODE (lhs);
|
||
rcode = TREE_CODE (rhs);
|
||
|
||
if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
|
||
lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
|
||
|
||
if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
|
||
rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
|
||
|
||
if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
|
||
return 0;
|
||
|
||
code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
|
||
? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
|
||
|
||
ll_arg = TREE_OPERAND (lhs, 0);
|
||
lr_arg = TREE_OPERAND (lhs, 1);
|
||
rl_arg = TREE_OPERAND (rhs, 0);
|
||
rr_arg = TREE_OPERAND (rhs, 1);
|
||
|
||
/* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
|
||
if (simple_operand_p (ll_arg)
|
||
&& simple_operand_p (lr_arg)
|
||
&& !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
|
||
{
|
||
int compcode;
|
||
|
||
if (operand_equal_p (ll_arg, rl_arg, 0)
|
||
&& operand_equal_p (lr_arg, rr_arg, 0))
|
||
{
|
||
int lcompcode, rcompcode;
|
||
|
||
lcompcode = comparison_to_compcode (lcode);
|
||
rcompcode = comparison_to_compcode (rcode);
|
||
compcode = (code == TRUTH_AND_EXPR)
|
||
? lcompcode & rcompcode
|
||
: lcompcode | rcompcode;
|
||
}
|
||
else if (operand_equal_p (ll_arg, rr_arg, 0)
|
||
&& operand_equal_p (lr_arg, rl_arg, 0))
|
||
{
|
||
int lcompcode, rcompcode;
|
||
|
||
rcode = swap_tree_comparison (rcode);
|
||
lcompcode = comparison_to_compcode (lcode);
|
||
rcompcode = comparison_to_compcode (rcode);
|
||
compcode = (code == TRUTH_AND_EXPR)
|
||
? lcompcode & rcompcode
|
||
: lcompcode | rcompcode;
|
||
}
|
||
else
|
||
compcode = -1;
|
||
|
||
if (compcode == COMPCODE_TRUE)
|
||
return convert (truth_type, integer_one_node);
|
||
else if (compcode == COMPCODE_FALSE)
|
||
return convert (truth_type, integer_zero_node);
|
||
else if (compcode != -1)
|
||
return build (compcode_to_comparison (compcode),
|
||
truth_type, ll_arg, lr_arg);
|
||
}
|
||
|
||
/* If the RHS can be evaluated unconditionally and its operands are
|
||
simple, it wins to evaluate the RHS unconditionally on machines
|
||
with expensive branches. In this case, this isn't a comparison
|
||
that can be merged. Avoid doing this if the RHS is a floating-point
|
||
comparison since those can trap. */
|
||
|
||
if (BRANCH_COST >= 2
|
||
&& ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
|
||
&& simple_operand_p (rl_arg)
|
||
&& simple_operand_p (rr_arg))
|
||
{
|
||
/* Convert (a != 0) || (b != 0) into (a | b) != 0. */
|
||
if (code == TRUTH_OR_EXPR
|
||
&& lcode == NE_EXPR && integer_zerop (lr_arg)
|
||
&& rcode == NE_EXPR && integer_zerop (rr_arg)
|
||
&& TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
|
||
return build (NE_EXPR, truth_type,
|
||
build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
|
||
ll_arg, rl_arg),
|
||
integer_zero_node);
|
||
|
||
/* Convert (a == 0) && (b == 0) into (a | b) == 0. */
|
||
if (code == TRUTH_AND_EXPR
|
||
&& lcode == EQ_EXPR && integer_zerop (lr_arg)
|
||
&& rcode == EQ_EXPR && integer_zerop (rr_arg)
|
||
&& TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
|
||
return build (EQ_EXPR, truth_type,
|
||
build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
|
||
ll_arg, rl_arg),
|
||
integer_zero_node);
|
||
|
||
return build (code, truth_type, lhs, rhs);
|
||
}
|
||
|
||
/* See if the comparisons can be merged. Then get all the parameters for
|
||
each side. */
|
||
|
||
if ((lcode != EQ_EXPR && lcode != NE_EXPR)
|
||
|| (rcode != EQ_EXPR && rcode != NE_EXPR))
|
||
return 0;
|
||
|
||
volatilep = 0;
|
||
ll_inner = decode_field_reference (ll_arg,
|
||
&ll_bitsize, &ll_bitpos, &ll_mode,
|
||
&ll_unsignedp, &volatilep, &ll_mask,
|
||
&ll_and_mask);
|
||
lr_inner = decode_field_reference (lr_arg,
|
||
&lr_bitsize, &lr_bitpos, &lr_mode,
|
||
&lr_unsignedp, &volatilep, &lr_mask,
|
||
&lr_and_mask);
|
||
rl_inner = decode_field_reference (rl_arg,
|
||
&rl_bitsize, &rl_bitpos, &rl_mode,
|
||
&rl_unsignedp, &volatilep, &rl_mask,
|
||
&rl_and_mask);
|
||
rr_inner = decode_field_reference (rr_arg,
|
||
&rr_bitsize, &rr_bitpos, &rr_mode,
|
||
&rr_unsignedp, &volatilep, &rr_mask,
|
||
&rr_and_mask);
|
||
|
||
/* It must be true that the inner operation on the lhs of each
|
||
comparison must be the same if we are to be able to do anything.
|
||
Then see if we have constants. If not, the same must be true for
|
||
the rhs's. */
|
||
if (volatilep || ll_inner == 0 || rl_inner == 0
|
||
|| ! operand_equal_p (ll_inner, rl_inner, 0))
|
||
return 0;
|
||
|
||
if (TREE_CODE (lr_arg) == INTEGER_CST
|
||
&& TREE_CODE (rr_arg) == INTEGER_CST)
|
||
l_const = lr_arg, r_const = rr_arg;
|
||
else if (lr_inner == 0 || rr_inner == 0
|
||
|| ! operand_equal_p (lr_inner, rr_inner, 0))
|
||
return 0;
|
||
else
|
||
l_const = r_const = 0;
|
||
|
||
/* If either comparison code is not correct for our logical operation,
|
||
fail. However, we can convert a one-bit comparison against zero into
|
||
the opposite comparison against that bit being set in the field. */
|
||
|
||
wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
|
||
if (lcode != wanted_code)
|
||
{
|
||
if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
|
||
{
|
||
/* Make the left operand unsigned, since we are only interested
|
||
in the value of one bit. Otherwise we are doing the wrong
|
||
thing below. */
|
||
ll_unsignedp = 1;
|
||
l_const = ll_mask;
|
||
}
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* This is analogous to the code for l_const above. */
|
||
if (rcode != wanted_code)
|
||
{
|
||
if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
|
||
{
|
||
rl_unsignedp = 1;
|
||
r_const = rl_mask;
|
||
}
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* After this point all optimizations will generate bit-field
|
||
references, which we might not want. */
|
||
if (! (*lang_hooks.can_use_bit_fields_p) ())
|
||
return 0;
|
||
|
||
/* See if we can find a mode that contains both fields being compared on
|
||
the left. If we can't, fail. Otherwise, update all constants and masks
|
||
to be relative to a field of that size. */
|
||
first_bit = MIN (ll_bitpos, rl_bitpos);
|
||
end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
|
||
lnmode = get_best_mode (end_bit - first_bit, first_bit,
|
||
TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
|
||
volatilep);
|
||
if (lnmode == VOIDmode)
|
||
return 0;
|
||
|
||
lnbitsize = GET_MODE_BITSIZE (lnmode);
|
||
lnbitpos = first_bit & ~ (lnbitsize - 1);
|
||
lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
|
||
xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
|
||
|
||
if (BYTES_BIG_ENDIAN)
|
||
{
|
||
xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
|
||
xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
|
||
}
|
||
|
||
ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
|
||
size_int (xll_bitpos), 0);
|
||
rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
|
||
size_int (xrl_bitpos), 0);
|
||
|
||
if (l_const)
|
||
{
|
||
l_const = convert (lntype, l_const);
|
||
l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
|
||
l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
|
||
if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
|
||
fold (build1 (BIT_NOT_EXPR,
|
||
lntype, ll_mask)),
|
||
0)))
|
||
{
|
||
warning ("comparison is always %d", wanted_code == NE_EXPR);
|
||
|
||
return convert (truth_type,
|
||
wanted_code == NE_EXPR
|
||
? integer_one_node : integer_zero_node);
|
||
}
|
||
}
|
||
if (r_const)
|
||
{
|
||
r_const = convert (lntype, r_const);
|
||
r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
|
||
r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
|
||
if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
|
||
fold (build1 (BIT_NOT_EXPR,
|
||
lntype, rl_mask)),
|
||
0)))
|
||
{
|
||
warning ("comparison is always %d", wanted_code == NE_EXPR);
|
||
|
||
return convert (truth_type,
|
||
wanted_code == NE_EXPR
|
||
? integer_one_node : integer_zero_node);
|
||
}
|
||
}
|
||
|
||
/* If the right sides are not constant, do the same for it. Also,
|
||
disallow this optimization if a size or signedness mismatch occurs
|
||
between the left and right sides. */
|
||
if (l_const == 0)
|
||
{
|
||
if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
|
||
|| ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
|
||
/* Make sure the two fields on the right
|
||
correspond to the left without being swapped. */
|
||
|| ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
|
||
return 0;
|
||
|
||
first_bit = MIN (lr_bitpos, rr_bitpos);
|
||
end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
|
||
rnmode = get_best_mode (end_bit - first_bit, first_bit,
|
||
TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
|
||
volatilep);
|
||
if (rnmode == VOIDmode)
|
||
return 0;
|
||
|
||
rnbitsize = GET_MODE_BITSIZE (rnmode);
|
||
rnbitpos = first_bit & ~ (rnbitsize - 1);
|
||
rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
|
||
xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
|
||
|
||
if (BYTES_BIG_ENDIAN)
|
||
{
|
||
xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
|
||
xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
|
||
}
|
||
|
||
lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
|
||
size_int (xlr_bitpos), 0);
|
||
rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
|
||
size_int (xrr_bitpos), 0);
|
||
|
||
/* Make a mask that corresponds to both fields being compared.
|
||
Do this for both items being compared. If the operands are the
|
||
same size and the bits being compared are in the same position
|
||
then we can do this by masking both and comparing the masked
|
||
results. */
|
||
ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
|
||
lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
|
||
if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
|
||
{
|
||
lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
|
||
ll_unsignedp || rl_unsignedp);
|
||
if (! all_ones_mask_p (ll_mask, lnbitsize))
|
||
lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
|
||
|
||
rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
|
||
lr_unsignedp || rr_unsignedp);
|
||
if (! all_ones_mask_p (lr_mask, rnbitsize))
|
||
rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
|
||
|
||
return build (wanted_code, truth_type, lhs, rhs);
|
||
}
|
||
|
||
/* There is still another way we can do something: If both pairs of
|
||
fields being compared are adjacent, we may be able to make a wider
|
||
field containing them both.
|
||
|
||
Note that we still must mask the lhs/rhs expressions. Furthermore,
|
||
the mask must be shifted to account for the shift done by
|
||
make_bit_field_ref. */
|
||
if ((ll_bitsize + ll_bitpos == rl_bitpos
|
||
&& lr_bitsize + lr_bitpos == rr_bitpos)
|
||
|| (ll_bitpos == rl_bitpos + rl_bitsize
|
||
&& lr_bitpos == rr_bitpos + rr_bitsize))
|
||
{
|
||
tree type;
|
||
|
||
lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
|
||
MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
|
||
rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
|
||
MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
|
||
|
||
ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
|
||
size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
|
||
lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
|
||
size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
|
||
|
||
/* Convert to the smaller type before masking out unwanted bits. */
|
||
type = lntype;
|
||
if (lntype != rntype)
|
||
{
|
||
if (lnbitsize > rnbitsize)
|
||
{
|
||
lhs = convert (rntype, lhs);
|
||
ll_mask = convert (rntype, ll_mask);
|
||
type = rntype;
|
||
}
|
||
else if (lnbitsize < rnbitsize)
|
||
{
|
||
rhs = convert (lntype, rhs);
|
||
lr_mask = convert (lntype, lr_mask);
|
||
type = lntype;
|
||
}
|
||
}
|
||
|
||
if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
|
||
lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
|
||
|
||
if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
|
||
rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
|
||
|
||
return build (wanted_code, truth_type, lhs, rhs);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Handle the case of comparisons with constants. If there is something in
|
||
common between the masks, those bits of the constants must be the same.
|
||
If not, the condition is always false. Test for this to avoid generating
|
||
incorrect code below. */
|
||
result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
|
||
if (! integer_zerop (result)
|
||
&& simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
|
||
const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
|
||
{
|
||
if (wanted_code == NE_EXPR)
|
||
{
|
||
warning ("`or' of unmatched not-equal tests is always 1");
|
||
return convert (truth_type, integer_one_node);
|
||
}
|
||
else
|
||
{
|
||
warning ("`and' of mutually exclusive equal-tests is always 0");
|
||
return convert (truth_type, integer_zero_node);
|
||
}
|
||
}
|
||
|
||
/* Construct the expression we will return. First get the component
|
||
reference we will make. Unless the mask is all ones the width of
|
||
that field, perform the mask operation. Then compare with the
|
||
merged constant. */
|
||
result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
|
||
ll_unsignedp || rl_unsignedp);
|
||
|
||
ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
|
||
if (! all_ones_mask_p (ll_mask, lnbitsize))
|
||
result = build (BIT_AND_EXPR, lntype, result, ll_mask);
|
||
|
||
return build (wanted_code, truth_type, result,
|
||
const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
|
||
}
|
||
|
||
/* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
|
||
constant. */
|
||
|
||
static tree
|
||
optimize_minmax_comparison (t)
|
||
tree t;
|
||
{
|
||
tree type = TREE_TYPE (t);
|
||
tree arg0 = TREE_OPERAND (t, 0);
|
||
enum tree_code op_code;
|
||
tree comp_const = TREE_OPERAND (t, 1);
|
||
tree minmax_const;
|
||
int consts_equal, consts_lt;
|
||
tree inner;
|
||
|
||
STRIP_SIGN_NOPS (arg0);
|
||
|
||
op_code = TREE_CODE (arg0);
|
||
minmax_const = TREE_OPERAND (arg0, 1);
|
||
consts_equal = tree_int_cst_equal (minmax_const, comp_const);
|
||
consts_lt = tree_int_cst_lt (minmax_const, comp_const);
|
||
inner = TREE_OPERAND (arg0, 0);
|
||
|
||
/* If something does not permit us to optimize, return the original tree. */
|
||
if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
|
||
|| TREE_CODE (comp_const) != INTEGER_CST
|
||
|| TREE_CONSTANT_OVERFLOW (comp_const)
|
||
|| TREE_CODE (minmax_const) != INTEGER_CST
|
||
|| TREE_CONSTANT_OVERFLOW (minmax_const))
|
||
return t;
|
||
|
||
/* Now handle all the various comparison codes. We only handle EQ_EXPR
|
||
and GT_EXPR, doing the rest with recursive calls using logical
|
||
simplifications. */
|
||
switch (TREE_CODE (t))
|
||
{
|
||
case NE_EXPR: case LT_EXPR: case LE_EXPR:
|
||
return
|
||
invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
|
||
|
||
case GE_EXPR:
|
||
return
|
||
fold (build (TRUTH_ORIF_EXPR, type,
|
||
optimize_minmax_comparison
|
||
(build (EQ_EXPR, type, arg0, comp_const)),
|
||
optimize_minmax_comparison
|
||
(build (GT_EXPR, type, arg0, comp_const))));
|
||
|
||
case EQ_EXPR:
|
||
if (op_code == MAX_EXPR && consts_equal)
|
||
/* MAX (X, 0) == 0 -> X <= 0 */
|
||
return fold (build (LE_EXPR, type, inner, comp_const));
|
||
|
||
else if (op_code == MAX_EXPR && consts_lt)
|
||
/* MAX (X, 0) == 5 -> X == 5 */
|
||
return fold (build (EQ_EXPR, type, inner, comp_const));
|
||
|
||
else if (op_code == MAX_EXPR)
|
||
/* MAX (X, 0) == -1 -> false */
|
||
return omit_one_operand (type, integer_zero_node, inner);
|
||
|
||
else if (consts_equal)
|
||
/* MIN (X, 0) == 0 -> X >= 0 */
|
||
return fold (build (GE_EXPR, type, inner, comp_const));
|
||
|
||
else if (consts_lt)
|
||
/* MIN (X, 0) == 5 -> false */
|
||
return omit_one_operand (type, integer_zero_node, inner);
|
||
|
||
else
|
||
/* MIN (X, 0) == -1 -> X == -1 */
|
||
return fold (build (EQ_EXPR, type, inner, comp_const));
|
||
|
||
case GT_EXPR:
|
||
if (op_code == MAX_EXPR && (consts_equal || consts_lt))
|
||
/* MAX (X, 0) > 0 -> X > 0
|
||
MAX (X, 0) > 5 -> X > 5 */
|
||
return fold (build (GT_EXPR, type, inner, comp_const));
|
||
|
||
else if (op_code == MAX_EXPR)
|
||
/* MAX (X, 0) > -1 -> true */
|
||
return omit_one_operand (type, integer_one_node, inner);
|
||
|
||
else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
|
||
/* MIN (X, 0) > 0 -> false
|
||
MIN (X, 0) > 5 -> false */
|
||
return omit_one_operand (type, integer_zero_node, inner);
|
||
|
||
else
|
||
/* MIN (X, 0) > -1 -> X > -1 */
|
||
return fold (build (GT_EXPR, type, inner, comp_const));
|
||
|
||
default:
|
||
return t;
|
||
}
|
||
}
|
||
|
||
/* T is an integer expression that is being multiplied, divided, or taken a
|
||
modulus (CODE says which and what kind of divide or modulus) by a
|
||
constant C. See if we can eliminate that operation by folding it with
|
||
other operations already in T. WIDE_TYPE, if non-null, is a type that
|
||
should be used for the computation if wider than our type.
|
||
|
||
For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
|
||
(X * 2) + (Y * 4). We must, however, be assured that either the original
|
||
expression would not overflow or that overflow is undefined for the type
|
||
in the language in question.
|
||
|
||
We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
|
||
the machine has a multiply-accumulate insn or that this is part of an
|
||
addressing calculation.
|
||
|
||
If we return a non-null expression, it is an equivalent form of the
|
||
original computation, but need not be in the original type. */
|
||
|
||
static tree
|
||
extract_muldiv (t, c, code, wide_type)
|
||
tree t;
|
||
tree c;
|
||
enum tree_code code;
|
||
tree wide_type;
|
||
{
|
||
/* To avoid exponential search depth, refuse to allow recursion past
|
||
three levels. Beyond that (1) it's highly unlikely that we'll find
|
||
something interesting and (2) we've probably processed it before
|
||
when we built the inner expression. */
|
||
|
||
static int depth;
|
||
tree ret;
|
||
|
||
if (depth > 3)
|
||
return NULL;
|
||
|
||
depth++;
|
||
ret = extract_muldiv_1 (t, c, code, wide_type);
|
||
depth--;
|
||
|
||
return ret;
|
||
}
|
||
|
||
static tree
|
||
extract_muldiv_1 (t, c, code, wide_type)
|
||
tree t;
|
||
tree c;
|
||
enum tree_code code;
|
||
tree wide_type;
|
||
{
|
||
tree type = TREE_TYPE (t);
|
||
enum tree_code tcode = TREE_CODE (t);
|
||
tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
|
||
> GET_MODE_SIZE (TYPE_MODE (type)))
|
||
? wide_type : type);
|
||
tree t1, t2;
|
||
int same_p = tcode == code;
|
||
tree op0 = NULL_TREE, op1 = NULL_TREE;
|
||
|
||
/* Don't deal with constants of zero here; they confuse the code below. */
|
||
if (integer_zerop (c))
|
||
return NULL_TREE;
|
||
|
||
if (TREE_CODE_CLASS (tcode) == '1')
|
||
op0 = TREE_OPERAND (t, 0);
|
||
|
||
if (TREE_CODE_CLASS (tcode) == '2')
|
||
op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
|
||
|
||
/* Note that we need not handle conditional operations here since fold
|
||
already handles those cases. So just do arithmetic here. */
|
||
switch (tcode)
|
||
{
|
||
case INTEGER_CST:
|
||
/* For a constant, we can always simplify if we are a multiply
|
||
or (for divide and modulus) if it is a multiple of our constant. */
|
||
if (code == MULT_EXPR
|
||
|| integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
|
||
return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
|
||
break;
|
||
|
||
case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
|
||
/* If op0 is an expression ... */
|
||
if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
|
||
|| TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
|
||
|| TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
|
||
|| TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
|
||
/* ... and is unsigned, and its type is smaller than ctype,
|
||
then we cannot pass through as widening. */
|
||
&& ((TREE_UNSIGNED (TREE_TYPE (op0))
|
||
&& ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
|
||
&& TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
|
||
&& (GET_MODE_SIZE (TYPE_MODE (ctype))
|
||
> GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
|
||
/* ... or its type is larger than ctype,
|
||
then we cannot pass through this truncation. */
|
||
|| (GET_MODE_SIZE (TYPE_MODE (ctype))
|
||
< GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
|
||
/* ... or signedness changes for division or modulus,
|
||
then we cannot pass through this conversion. */
|
||
|| (code != MULT_EXPR
|
||
&& (TREE_UNSIGNED (ctype)
|
||
!= TREE_UNSIGNED (TREE_TYPE (op0))))))
|
||
break;
|
||
|
||
/* Pass the constant down and see if we can make a simplification. If
|
||
we can, replace this expression with the inner simplification for
|
||
possible later conversion to our or some other type. */
|
||
if ((t2 = convert (TREE_TYPE (op0), c)) != 0
|
||
&& TREE_CODE (t2) == INTEGER_CST
|
||
&& ! TREE_CONSTANT_OVERFLOW (t2)
|
||
&& (0 != (t1 = extract_muldiv (op0, t2, code,
|
||
code == MULT_EXPR
|
||
? ctype : NULL_TREE))))
|
||
return t1;
|
||
break;
|
||
|
||
case NEGATE_EXPR: case ABS_EXPR:
|
||
if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
|
||
return fold (build1 (tcode, ctype, convert (ctype, t1)));
|
||
break;
|
||
|
||
case MIN_EXPR: case MAX_EXPR:
|
||
/* If widening the type changes the signedness, then we can't perform
|
||
this optimization as that changes the result. */
|
||
if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
|
||
break;
|
||
|
||
/* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
|
||
if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
|
||
&& (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
|
||
{
|
||
if (tree_int_cst_sgn (c) < 0)
|
||
tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
|
||
|
||
return fold (build (tcode, ctype, convert (ctype, t1),
|
||
convert (ctype, t2)));
|
||
}
|
||
break;
|
||
|
||
case WITH_RECORD_EXPR:
|
||
if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
|
||
return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
|
||
TREE_OPERAND (t, 1));
|
||
break;
|
||
|
||
case SAVE_EXPR:
|
||
/* If this has not been evaluated and the operand has no side effects,
|
||
we can see if we can do something inside it and make a new one.
|
||
Note that this test is overly conservative since we can do this
|
||
if the only reason it had side effects is that it was another
|
||
similar SAVE_EXPR, but that isn't worth bothering with. */
|
||
if (SAVE_EXPR_RTL (t) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
|
||
&& 0 != (t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code,
|
||
wide_type)))
|
||
{
|
||
t1 = save_expr (t1);
|
||
if (SAVE_EXPR_PERSISTENT_P (t) && TREE_CODE (t1) == SAVE_EXPR)
|
||
SAVE_EXPR_PERSISTENT_P (t1) = 1;
|
||
if (is_pending_size (t))
|
||
put_pending_size (t1);
|
||
return t1;
|
||
}
|
||
break;
|
||
|
||
case LSHIFT_EXPR: case RSHIFT_EXPR:
|
||
/* If the second operand is constant, this is a multiplication
|
||
or floor division, by a power of two, so we can treat it that
|
||
way unless the multiplier or divisor overflows. */
|
||
if (TREE_CODE (op1) == INTEGER_CST
|
||
/* const_binop may not detect overflow correctly,
|
||
so check for it explicitly here. */
|
||
&& TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
|
||
&& TREE_INT_CST_HIGH (op1) == 0
|
||
&& 0 != (t1 = convert (ctype,
|
||
const_binop (LSHIFT_EXPR, size_one_node,
|
||
op1, 0)))
|
||
&& ! TREE_OVERFLOW (t1))
|
||
return extract_muldiv (build (tcode == LSHIFT_EXPR
|
||
? MULT_EXPR : FLOOR_DIV_EXPR,
|
||
ctype, convert (ctype, op0), t1),
|
||
c, code, wide_type);
|
||
break;
|
||
|
||
case PLUS_EXPR: case MINUS_EXPR:
|
||
/* See if we can eliminate the operation on both sides. If we can, we
|
||
can return a new PLUS or MINUS. If we can't, the only remaining
|
||
cases where we can do anything are if the second operand is a
|
||
constant. */
|
||
t1 = extract_muldiv (op0, c, code, wide_type);
|
||
t2 = extract_muldiv (op1, c, code, wide_type);
|
||
if (t1 != 0 && t2 != 0
|
||
&& (code == MULT_EXPR
|
||
/* If not multiplication, we can only do this if both operands
|
||
are divisible by c. */
|
||
|| (multiple_of_p (ctype, op0, c)
|
||
&& multiple_of_p (ctype, op1, c))))
|
||
return fold (build (tcode, ctype, convert (ctype, t1),
|
||
convert (ctype, t2)));
|
||
|
||
/* If this was a subtraction, negate OP1 and set it to be an addition.
|
||
This simplifies the logic below. */
|
||
if (tcode == MINUS_EXPR)
|
||
tcode = PLUS_EXPR, op1 = negate_expr (op1);
|
||
|
||
if (TREE_CODE (op1) != INTEGER_CST)
|
||
break;
|
||
|
||
/* If either OP1 or C are negative, this optimization is not safe for
|
||
some of the division and remainder types while for others we need
|
||
to change the code. */
|
||
if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
|
||
{
|
||
if (code == CEIL_DIV_EXPR)
|
||
code = FLOOR_DIV_EXPR;
|
||
else if (code == FLOOR_DIV_EXPR)
|
||
code = CEIL_DIV_EXPR;
|
||
else if (code != MULT_EXPR
|
||
&& code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
|
||
break;
|
||
}
|
||
|
||
/* If it's a multiply or a division/modulus operation of a multiple
|
||
of our constant, do the operation and verify it doesn't overflow. */
|
||
if (code == MULT_EXPR
|
||
|| integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
|
||
{
|
||
op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
|
||
if (op1 == 0 || TREE_OVERFLOW (op1))
|
||
break;
|
||
}
|
||
else
|
||
break;
|
||
|
||
/* If we have an unsigned type is not a sizetype, we cannot widen
|
||
the operation since it will change the result if the original
|
||
computation overflowed. */
|
||
if (TREE_UNSIGNED (ctype)
|
||
&& ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
|
||
&& ctype != type)
|
||
break;
|
||
|
||
/* If we were able to eliminate our operation from the first side,
|
||
apply our operation to the second side and reform the PLUS. */
|
||
if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
|
||
return fold (build (tcode, ctype, convert (ctype, t1), op1));
|
||
|
||
/* The last case is if we are a multiply. In that case, we can
|
||
apply the distributive law to commute the multiply and addition
|
||
if the multiplication of the constants doesn't overflow. */
|
||
if (code == MULT_EXPR)
|
||
return fold (build (tcode, ctype, fold (build (code, ctype,
|
||
convert (ctype, op0),
|
||
convert (ctype, c))),
|
||
op1));
|
||
|
||
break;
|
||
|
||
case MULT_EXPR:
|
||
/* We have a special case here if we are doing something like
|
||
(C * 8) % 4 since we know that's zero. */
|
||
if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
|
||
|| code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
|
||
&& integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
|
||
return omit_one_operand (type, integer_zero_node, op0);
|
||
|
||
/* ... fall through ... */
|
||
|
||
case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
|
||
case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
|
||
/* If we can extract our operation from the LHS, do so and return a
|
||
new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
|
||
do something only if the second operand is a constant. */
|
||
if (same_p
|
||
&& (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
|
||
return fold (build (tcode, ctype, convert (ctype, t1),
|
||
convert (ctype, op1)));
|
||
else if (tcode == MULT_EXPR && code == MULT_EXPR
|
||
&& (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
|
||
return fold (build (tcode, ctype, convert (ctype, op0),
|
||
convert (ctype, t1)));
|
||
else if (TREE_CODE (op1) != INTEGER_CST)
|
||
return 0;
|
||
|
||
/* If these are the same operation types, we can associate them
|
||
assuming no overflow. */
|
||
if (tcode == code
|
||
&& 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
|
||
convert (ctype, c), 0))
|
||
&& ! TREE_OVERFLOW (t1))
|
||
return fold (build (tcode, ctype, convert (ctype, op0), t1));
|
||
|
||
/* If these operations "cancel" each other, we have the main
|
||
optimizations of this pass, which occur when either constant is a
|
||
multiple of the other, in which case we replace this with either an
|
||
operation or CODE or TCODE.
|
||
|
||
If we have an unsigned type that is not a sizetype, we cannot do
|
||
this since it will change the result if the original computation
|
||
overflowed. */
|
||
if ((! TREE_UNSIGNED (ctype)
|
||
|| (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
|
||
&& ! flag_wrapv
|
||
&& ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
|
||
|| (tcode == MULT_EXPR
|
||
&& code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
|
||
&& code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
|
||
{
|
||
if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
|
||
return fold (build (tcode, ctype, convert (ctype, op0),
|
||
convert (ctype,
|
||
const_binop (TRUNC_DIV_EXPR,
|
||
op1, c, 0))));
|
||
else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
|
||
return fold (build (code, ctype, convert (ctype, op0),
|
||
convert (ctype,
|
||
const_binop (TRUNC_DIV_EXPR,
|
||
c, op1, 0))));
|
||
}
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
|
||
S, a SAVE_EXPR, return the expression actually being evaluated. Note
|
||
that we may sometimes modify the tree. */
|
||
|
||
static tree
|
||
strip_compound_expr (t, s)
|
||
tree t;
|
||
tree s;
|
||
{
|
||
enum tree_code code = TREE_CODE (t);
|
||
|
||
/* See if this is the COMPOUND_EXPR we want to eliminate. */
|
||
if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
|
||
&& TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
|
||
return TREE_OPERAND (t, 1);
|
||
|
||
/* See if this is a COND_EXPR or a simple arithmetic operator. We
|
||
don't bother handling any other types. */
|
||
else if (code == COND_EXPR)
|
||
{
|
||
TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
|
||
TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
|
||
TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
|
||
}
|
||
else if (TREE_CODE_CLASS (code) == '1')
|
||
TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
|
||
else if (TREE_CODE_CLASS (code) == '<'
|
||
|| TREE_CODE_CLASS (code) == '2')
|
||
{
|
||
TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
|
||
TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
|
||
}
|
||
|
||
return t;
|
||
}
|
||
|
||
/* Return a node which has the indicated constant VALUE (either 0 or
|
||
1), and is of the indicated TYPE. */
|
||
|
||
static tree
|
||
constant_boolean_node (value, type)
|
||
int value;
|
||
tree type;
|
||
{
|
||
if (type == integer_type_node)
|
||
return value ? integer_one_node : integer_zero_node;
|
||
else if (TREE_CODE (type) == BOOLEAN_TYPE)
|
||
return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
|
||
integer_zero_node);
|
||
else
|
||
{
|
||
tree t = build_int_2 (value, 0);
|
||
|
||
TREE_TYPE (t) = type;
|
||
return t;
|
||
}
|
||
}
|
||
|
||
/* Utility function for the following routine, to see how complex a nesting of
|
||
COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
|
||
we don't care (to avoid spending too much time on complex expressions.). */
|
||
|
||
static int
|
||
count_cond (expr, lim)
|
||
tree expr;
|
||
int lim;
|
||
{
|
||
int ctrue, cfalse;
|
||
|
||
if (TREE_CODE (expr) != COND_EXPR)
|
||
return 0;
|
||
else if (lim <= 0)
|
||
return 0;
|
||
|
||
ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
|
||
cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
|
||
return MIN (lim, 1 + ctrue + cfalse);
|
||
}
|
||
|
||
/* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
|
||
Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
|
||
CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
|
||
expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
|
||
COND is the first argument to CODE; otherwise (as in the example
|
||
given here), it is the second argument. TYPE is the type of the
|
||
original expression. */
|
||
|
||
static tree
|
||
fold_binary_op_with_conditional_arg (code, type, cond, arg, cond_first_p)
|
||
enum tree_code code;
|
||
tree type;
|
||
tree cond;
|
||
tree arg;
|
||
int cond_first_p;
|
||
{
|
||
tree test, true_value, false_value;
|
||
tree lhs = NULL_TREE;
|
||
tree rhs = NULL_TREE;
|
||
/* In the end, we'll produce a COND_EXPR. Both arms of the
|
||
conditional expression will be binary operations. The left-hand
|
||
side of the expression to be executed if the condition is true
|
||
will be pointed to by TRUE_LHS. Similarly, the right-hand side
|
||
of the expression to be executed if the condition is true will be
|
||
pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
|
||
but apply to the expression to be executed if the conditional is
|
||
false. */
|
||
tree *true_lhs;
|
||
tree *true_rhs;
|
||
tree *false_lhs;
|
||
tree *false_rhs;
|
||
/* These are the codes to use for the left-hand side and right-hand
|
||
side of the COND_EXPR. Normally, they are the same as CODE. */
|
||
enum tree_code lhs_code = code;
|
||
enum tree_code rhs_code = code;
|
||
/* And these are the types of the expressions. */
|
||
tree lhs_type = type;
|
||
tree rhs_type = type;
|
||
int save = 0;
|
||
|
||
if (cond_first_p)
|
||
{
|
||
true_rhs = false_rhs = &arg;
|
||
true_lhs = &true_value;
|
||
false_lhs = &false_value;
|
||
}
|
||
else
|
||
{
|
||
true_lhs = false_lhs = &arg;
|
||
true_rhs = &true_value;
|
||
false_rhs = &false_value;
|
||
}
|
||
|
||
if (TREE_CODE (cond) == COND_EXPR)
|
||
{
|
||
test = TREE_OPERAND (cond, 0);
|
||
true_value = TREE_OPERAND (cond, 1);
|
||
false_value = TREE_OPERAND (cond, 2);
|
||
/* If this operand throws an expression, then it does not make
|
||
sense to try to perform a logical or arithmetic operation
|
||
involving it. Instead of building `a + throw 3' for example,
|
||
we simply build `a, throw 3'. */
|
||
if (VOID_TYPE_P (TREE_TYPE (true_value)))
|
||
{
|
||
if (! cond_first_p)
|
||
{
|
||
lhs_code = COMPOUND_EXPR;
|
||
lhs_type = void_type_node;
|
||
}
|
||
else
|
||
lhs = true_value;
|
||
}
|
||
if (VOID_TYPE_P (TREE_TYPE (false_value)))
|
||
{
|
||
if (! cond_first_p)
|
||
{
|
||
rhs_code = COMPOUND_EXPR;
|
||
rhs_type = void_type_node;
|
||
}
|
||
else
|
||
rhs = false_value;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
tree testtype = TREE_TYPE (cond);
|
||
test = cond;
|
||
true_value = convert (testtype, integer_one_node);
|
||
false_value = convert (testtype, integer_zero_node);
|
||
}
|
||
|
||
/* If ARG is complex we want to make sure we only evaluate it once. Though
|
||
this is only required if it is volatile, it might be more efficient even
|
||
if it is not. However, if we succeed in folding one part to a constant,
|
||
we do not need to make this SAVE_EXPR. Since we do this optimization
|
||
primarily to see if we do end up with constant and this SAVE_EXPR
|
||
interferes with later optimizations, suppressing it when we can is
|
||
important.
|
||
|
||
If we are not in a function, we can't make a SAVE_EXPR, so don't try to
|
||
do so. Don't try to see if the result is a constant if an arm is a
|
||
COND_EXPR since we get exponential behavior in that case. */
|
||
|
||
if (saved_expr_p (arg))
|
||
save = 1;
|
||
else if (lhs == 0 && rhs == 0
|
||
&& !TREE_CONSTANT (arg)
|
||
&& (*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
|
||
|| TREE_SIDE_EFFECTS (arg)))
|
||
{
|
||
if (TREE_CODE (true_value) != COND_EXPR)
|
||
lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
|
||
|
||
if (TREE_CODE (false_value) != COND_EXPR)
|
||
rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
|
||
|
||
if ((lhs == 0 || ! TREE_CONSTANT (lhs))
|
||
&& (rhs == 0 || !TREE_CONSTANT (rhs)))
|
||
{
|
||
arg = save_expr (arg);
|
||
lhs = rhs = 0;
|
||
save = 1;
|
||
}
|
||
}
|
||
|
||
if (lhs == 0)
|
||
lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
|
||
if (rhs == 0)
|
||
rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
|
||
|
||
test = fold (build (COND_EXPR, type, test, lhs, rhs));
|
||
|
||
if (save)
|
||
return build (COMPOUND_EXPR, type,
|
||
convert (void_type_node, arg),
|
||
strip_compound_expr (test, arg));
|
||
else
|
||
return convert (type, test);
|
||
}
|
||
|
||
|
||
/* Subroutine of fold() that checks for the addition of +/- 0.0.
|
||
|
||
If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
|
||
TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
|
||
ADDEND is the same as X.
|
||
|
||
X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
|
||
and finite. The problematic cases are when X is zero, and its mode
|
||
has signed zeros. In the case of rounding towards -infinity,
|
||
X - 0 is not the same as X because 0 - 0 is -0. In other rounding
|
||
modes, X + 0 is not the same as X because -0 + 0 is 0. */
|
||
|
||
static bool
|
||
fold_real_zero_addition_p (type, addend, negate)
|
||
tree type, addend;
|
||
int negate;
|
||
{
|
||
if (!real_zerop (addend))
|
||
return false;
|
||
|
||
/* Don't allow the fold with -fsignaling-nans. */
|
||
if (HONOR_SNANS (TYPE_MODE (type)))
|
||
return false;
|
||
|
||
/* Allow the fold if zeros aren't signed, or their sign isn't important. */
|
||
if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
|
||
return true;
|
||
|
||
/* Treat x + -0 as x - 0 and x - -0 as x + 0. */
|
||
if (TREE_CODE (addend) == REAL_CST
|
||
&& REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
|
||
negate = !negate;
|
||
|
||
/* The mode has signed zeros, and we have to honor their sign.
|
||
In this situation, there is only one case we can return true for.
|
||
X - 0 is the same as X unless rounding towards -infinity is
|
||
supported. */
|
||
return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
|
||
}
|
||
|
||
/* Subroutine of fold() that checks comparisons of built-in math
|
||
functions against real constants.
|
||
|
||
FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
|
||
operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
|
||
is the type of the result and ARG0 and ARG1 are the operands of the
|
||
comparison. ARG1 must be a TREE_REAL_CST.
|
||
|
||
The function returns the constant folded tree if a simplification
|
||
can be made, and NULL_TREE otherwise. */
|
||
|
||
static tree
|
||
fold_mathfn_compare (fcode, code, type, arg0, arg1)
|
||
enum built_in_function fcode;
|
||
enum tree_code code;
|
||
tree type, arg0, arg1;
|
||
{
|
||
REAL_VALUE_TYPE c;
|
||
|
||
if (fcode == BUILT_IN_SQRT
|
||
|| fcode == BUILT_IN_SQRTF
|
||
|| fcode == BUILT_IN_SQRTL)
|
||
{
|
||
tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
|
||
enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
|
||
|
||
c = TREE_REAL_CST (arg1);
|
||
if (REAL_VALUE_NEGATIVE (c))
|
||
{
|
||
/* sqrt(x) < y is always false, if y is negative. */
|
||
if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
|
||
return omit_one_operand (type,
|
||
convert (type, integer_zero_node),
|
||
arg);
|
||
|
||
/* sqrt(x) > y is always true, if y is negative and we
|
||
don't care about NaNs, i.e. negative values of x. */
|
||
if (code == NE_EXPR || !HONOR_NANS (mode))
|
||
return omit_one_operand (type,
|
||
convert (type, integer_one_node),
|
||
arg);
|
||
|
||
/* sqrt(x) > y is the same as x >= 0, if y is negative. */
|
||
return fold (build (GE_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg), dconst0)));
|
||
}
|
||
else if (code == GT_EXPR || code == GE_EXPR)
|
||
{
|
||
REAL_VALUE_TYPE c2;
|
||
|
||
REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
|
||
real_convert (&c2, mode, &c2);
|
||
|
||
if (REAL_VALUE_ISINF (c2))
|
||
{
|
||
/* sqrt(x) > y is x == +Inf, when y is very large. */
|
||
if (HONOR_INFINITIES (mode))
|
||
return fold (build (EQ_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg), c2)));
|
||
|
||
/* sqrt(x) > y is always false, when y is very large
|
||
and we don't care about infinities. */
|
||
return omit_one_operand (type,
|
||
convert (type, integer_zero_node),
|
||
arg);
|
||
}
|
||
|
||
/* sqrt(x) > c is the same as x > c*c. */
|
||
return fold (build (code, type, arg,
|
||
build_real (TREE_TYPE (arg), c2)));
|
||
}
|
||
else if (code == LT_EXPR || code == LE_EXPR)
|
||
{
|
||
REAL_VALUE_TYPE c2;
|
||
|
||
REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
|
||
real_convert (&c2, mode, &c2);
|
||
|
||
if (REAL_VALUE_ISINF (c2))
|
||
{
|
||
/* sqrt(x) < y is always true, when y is a very large
|
||
value and we don't care about NaNs or Infinities. */
|
||
if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
|
||
return omit_one_operand (type,
|
||
convert (type, integer_one_node),
|
||
arg);
|
||
|
||
/* sqrt(x) < y is x != +Inf when y is very large and we
|
||
don't care about NaNs. */
|
||
if (! HONOR_NANS (mode))
|
||
return fold (build (NE_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg), c2)));
|
||
|
||
/* sqrt(x) < y is x >= 0 when y is very large and we
|
||
don't care about Infinities. */
|
||
if (! HONOR_INFINITIES (mode))
|
||
return fold (build (GE_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg), dconst0)));
|
||
|
||
/* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
|
||
if ((*lang_hooks.decls.global_bindings_p) () != 0
|
||
|| CONTAINS_PLACEHOLDER_P (arg))
|
||
return NULL_TREE;
|
||
|
||
arg = save_expr (arg);
|
||
return fold (build (TRUTH_ANDIF_EXPR, type,
|
||
fold (build (GE_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg),
|
||
dconst0))),
|
||
fold (build (NE_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg),
|
||
c2)))));
|
||
}
|
||
|
||
/* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
|
||
if (! HONOR_NANS (mode))
|
||
return fold (build (code, type, arg,
|
||
build_real (TREE_TYPE (arg), c2)));
|
||
|
||
/* sqrt(x) < c is the same as x >= 0 && x < c*c. */
|
||
if ((*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ! CONTAINS_PLACEHOLDER_P (arg))
|
||
{
|
||
arg = save_expr (arg);
|
||
return fold (build (TRUTH_ANDIF_EXPR, type,
|
||
fold (build (GE_EXPR, type, arg,
|
||
build_real (TREE_TYPE (arg),
|
||
dconst0))),
|
||
fold (build (code, type, arg,
|
||
build_real (TREE_TYPE (arg),
|
||
c2)))));
|
||
}
|
||
}
|
||
}
|
||
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Subroutine of fold() that optimizes comparisons against Infinities,
|
||
either +Inf or -Inf.
|
||
|
||
CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
|
||
GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
|
||
are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
|
||
|
||
The function returns the constant folded tree if a simplification
|
||
can be made, and NULL_TREE otherwise. */
|
||
|
||
static tree
|
||
fold_inf_compare (code, type, arg0, arg1)
|
||
enum tree_code code;
|
||
tree type, arg0, arg1;
|
||
{
|
||
enum machine_mode mode;
|
||
REAL_VALUE_TYPE max;
|
||
tree temp;
|
||
bool neg;
|
||
|
||
mode = TYPE_MODE (TREE_TYPE (arg0));
|
||
|
||
/* For negative infinity swap the sense of the comparison. */
|
||
neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
|
||
if (neg)
|
||
code = swap_tree_comparison (code);
|
||
|
||
switch (code)
|
||
{
|
||
case GT_EXPR:
|
||
/* x > +Inf is always false, if with ignore sNANs. */
|
||
if (HONOR_SNANS (mode))
|
||
return NULL_TREE;
|
||
return omit_one_operand (type,
|
||
convert (type, integer_zero_node),
|
||
arg0);
|
||
|
||
case LE_EXPR:
|
||
/* x <= +Inf is always true, if we don't case about NaNs. */
|
||
if (! HONOR_NANS (mode))
|
||
return omit_one_operand (type,
|
||
convert (type, integer_one_node),
|
||
arg0);
|
||
|
||
/* x <= +Inf is the same as x == x, i.e. isfinite(x). */
|
||
if ((*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ! CONTAINS_PLACEHOLDER_P (arg0))
|
||
{
|
||
arg0 = save_expr (arg0);
|
||
return fold (build (EQ_EXPR, type, arg0, arg0));
|
||
}
|
||
break;
|
||
|
||
case EQ_EXPR:
|
||
case GE_EXPR:
|
||
/* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
|
||
real_maxval (&max, neg, mode);
|
||
return fold (build (neg ? LT_EXPR : GT_EXPR, type,
|
||
arg0, build_real (TREE_TYPE (arg0), max)));
|
||
|
||
case LT_EXPR:
|
||
/* x < +Inf is always equal to x <= DBL_MAX. */
|
||
real_maxval (&max, neg, mode);
|
||
return fold (build (neg ? GE_EXPR : LE_EXPR, type,
|
||
arg0, build_real (TREE_TYPE (arg0), max)));
|
||
|
||
case NE_EXPR:
|
||
/* x != +Inf is always equal to !(x > DBL_MAX). */
|
||
real_maxval (&max, neg, mode);
|
||
if (! HONOR_NANS (mode))
|
||
return fold (build (neg ? GE_EXPR : LE_EXPR, type,
|
||
arg0, build_real (TREE_TYPE (arg0), max)));
|
||
temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
|
||
arg0, build_real (TREE_TYPE (arg0), max)));
|
||
return fold (build1 (TRUTH_NOT_EXPR, type, temp));
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Perform constant folding and related simplification of EXPR.
|
||
The related simplifications include x*1 => x, x*0 => 0, etc.,
|
||
and application of the associative law.
|
||
NOP_EXPR conversions may be removed freely (as long as we
|
||
are careful not to change the C type of the overall expression)
|
||
We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
|
||
but we can constant-fold them if they have constant operands. */
|
||
|
||
tree
|
||
fold (expr)
|
||
tree expr;
|
||
{
|
||
tree t = expr;
|
||
tree t1 = NULL_TREE;
|
||
tree tem;
|
||
tree type = TREE_TYPE (expr);
|
||
tree arg0 = NULL_TREE, arg1 = NULL_TREE;
|
||
enum tree_code code = TREE_CODE (t);
|
||
int kind = TREE_CODE_CLASS (code);
|
||
int invert;
|
||
/* WINS will be nonzero when the switch is done
|
||
if all operands are constant. */
|
||
int wins = 1;
|
||
|
||
/* Don't try to process an RTL_EXPR since its operands aren't trees.
|
||
Likewise for a SAVE_EXPR that's already been evaluated. */
|
||
if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
|
||
return t;
|
||
|
||
/* Return right away if a constant. */
|
||
if (kind == 'c')
|
||
return t;
|
||
|
||
#ifdef MAX_INTEGER_COMPUTATION_MODE
|
||
check_max_integer_computation_mode (expr);
|
||
#endif
|
||
|
||
if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
|
||
{
|
||
tree subop;
|
||
|
||
/* Special case for conversion ops that can have fixed point args. */
|
||
arg0 = TREE_OPERAND (t, 0);
|
||
|
||
/* Don't use STRIP_NOPS, because signedness of argument type matters. */
|
||
if (arg0 != 0)
|
||
STRIP_SIGN_NOPS (arg0);
|
||
|
||
if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
|
||
subop = TREE_REALPART (arg0);
|
||
else
|
||
subop = arg0;
|
||
|
||
if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
|
||
&& TREE_CODE (subop) != REAL_CST
|
||
)
|
||
/* Note that TREE_CONSTANT isn't enough:
|
||
static var addresses are constant but we can't
|
||
do arithmetic on them. */
|
||
wins = 0;
|
||
}
|
||
else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
|
||
{
|
||
int len = first_rtl_op (code);
|
||
int i;
|
||
for (i = 0; i < len; i++)
|
||
{
|
||
tree op = TREE_OPERAND (t, i);
|
||
tree subop;
|
||
|
||
if (op == 0)
|
||
continue; /* Valid for CALL_EXPR, at least. */
|
||
|
||
if (kind == '<' || code == RSHIFT_EXPR)
|
||
{
|
||
/* Signedness matters here. Perhaps we can refine this
|
||
later. */
|
||
STRIP_SIGN_NOPS (op);
|
||
}
|
||
else
|
||
/* Strip any conversions that don't change the mode. */
|
||
STRIP_NOPS (op);
|
||
|
||
if (TREE_CODE (op) == COMPLEX_CST)
|
||
subop = TREE_REALPART (op);
|
||
else
|
||
subop = op;
|
||
|
||
if (TREE_CODE (subop) != INTEGER_CST
|
||
&& TREE_CODE (subop) != REAL_CST)
|
||
/* Note that TREE_CONSTANT isn't enough:
|
||
static var addresses are constant but we can't
|
||
do arithmetic on them. */
|
||
wins = 0;
|
||
|
||
if (i == 0)
|
||
arg0 = op;
|
||
else if (i == 1)
|
||
arg1 = op;
|
||
}
|
||
}
|
||
|
||
/* If this is a commutative operation, and ARG0 is a constant, move it
|
||
to ARG1 to reduce the number of tests below. */
|
||
if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
|
||
|| code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
|
||
|| code == BIT_AND_EXPR)
|
||
&& (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
|
||
{
|
||
tem = arg0; arg0 = arg1; arg1 = tem;
|
||
|
||
tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
|
||
TREE_OPERAND (t, 1) = tem;
|
||
}
|
||
|
||
/* Now WINS is set as described above,
|
||
ARG0 is the first operand of EXPR,
|
||
and ARG1 is the second operand (if it has more than one operand).
|
||
|
||
First check for cases where an arithmetic operation is applied to a
|
||
compound, conditional, or comparison operation. Push the arithmetic
|
||
operation inside the compound or conditional to see if any folding
|
||
can then be done. Convert comparison to conditional for this purpose.
|
||
The also optimizes non-constant cases that used to be done in
|
||
expand_expr.
|
||
|
||
Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
|
||
one of the operands is a comparison and the other is a comparison, a
|
||
BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
|
||
code below would make the expression more complex. Change it to a
|
||
TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
|
||
TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
|
||
|
||
if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
|
||
|| code == EQ_EXPR || code == NE_EXPR)
|
||
&& ((truth_value_p (TREE_CODE (arg0))
|
||
&& (truth_value_p (TREE_CODE (arg1))
|
||
|| (TREE_CODE (arg1) == BIT_AND_EXPR
|
||
&& integer_onep (TREE_OPERAND (arg1, 1)))))
|
||
|| (truth_value_p (TREE_CODE (arg1))
|
||
&& (truth_value_p (TREE_CODE (arg0))
|
||
|| (TREE_CODE (arg0) == BIT_AND_EXPR
|
||
&& integer_onep (TREE_OPERAND (arg0, 1)))))))
|
||
{
|
||
t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
|
||
: code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
|
||
: TRUTH_XOR_EXPR,
|
||
type, arg0, arg1));
|
||
|
||
if (code == EQ_EXPR)
|
||
t = invert_truthvalue (t);
|
||
|
||
return t;
|
||
}
|
||
|
||
if (TREE_CODE_CLASS (code) == '1')
|
||
{
|
||
if (TREE_CODE (arg0) == COMPOUND_EXPR)
|
||
return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
|
||
else if (TREE_CODE (arg0) == COND_EXPR)
|
||
{
|
||
tree arg01 = TREE_OPERAND (arg0, 1);
|
||
tree arg02 = TREE_OPERAND (arg0, 2);
|
||
if (! VOID_TYPE_P (TREE_TYPE (arg01)))
|
||
arg01 = fold (build1 (code, type, arg01));
|
||
if (! VOID_TYPE_P (TREE_TYPE (arg02)))
|
||
arg02 = fold (build1 (code, type, arg02));
|
||
t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
arg01, arg02));
|
||
|
||
/* If this was a conversion, and all we did was to move into
|
||
inside the COND_EXPR, bring it back out. But leave it if
|
||
it is a conversion from integer to integer and the
|
||
result precision is no wider than a word since such a
|
||
conversion is cheap and may be optimized away by combine,
|
||
while it couldn't if it were outside the COND_EXPR. Then return
|
||
so we don't get into an infinite recursion loop taking the
|
||
conversion out and then back in. */
|
||
|
||
if ((code == NOP_EXPR || code == CONVERT_EXPR
|
||
|| code == NON_LVALUE_EXPR)
|
||
&& TREE_CODE (t) == COND_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (t, 1)) == code
|
||
&& TREE_CODE (TREE_OPERAND (t, 2)) == code
|
||
&& ! VOID_TYPE_P (TREE_OPERAND (t, 1))
|
||
&& ! VOID_TYPE_P (TREE_OPERAND (t, 2))
|
||
&& (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
|
||
== TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
|
||
&& ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
|
||
&& (INTEGRAL_TYPE_P
|
||
(TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
|
||
&& TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
|
||
t = build1 (code, type,
|
||
build (COND_EXPR,
|
||
TREE_TYPE (TREE_OPERAND
|
||
(TREE_OPERAND (t, 1), 0)),
|
||
TREE_OPERAND (t, 0),
|
||
TREE_OPERAND (TREE_OPERAND (t, 1), 0),
|
||
TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
|
||
return t;
|
||
}
|
||
else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
|
||
return fold (build (COND_EXPR, type, arg0,
|
||
fold (build1 (code, type, integer_one_node)),
|
||
fold (build1 (code, type, integer_zero_node))));
|
||
}
|
||
else if (TREE_CODE_CLASS (code) == '<'
|
||
&& TREE_CODE (arg0) == COMPOUND_EXPR)
|
||
return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
|
||
else if (TREE_CODE_CLASS (code) == '<'
|
||
&& TREE_CODE (arg1) == COMPOUND_EXPR)
|
||
return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
|
||
fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
|
||
else if (TREE_CODE_CLASS (code) == '2'
|
||
|| TREE_CODE_CLASS (code) == '<')
|
||
{
|
||
if (TREE_CODE (arg1) == COMPOUND_EXPR
|
||
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
|
||
&& ! TREE_SIDE_EFFECTS (arg0))
|
||
return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
|
||
fold (build (code, type,
|
||
arg0, TREE_OPERAND (arg1, 1))));
|
||
else if ((TREE_CODE (arg1) == COND_EXPR
|
||
|| (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
|
||
&& TREE_CODE_CLASS (code) != '<'))
|
||
&& (TREE_CODE (arg0) != COND_EXPR
|
||
|| count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
|
||
&& (! TREE_SIDE_EFFECTS (arg0)
|
||
|| ((*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ! CONTAINS_PLACEHOLDER_P (arg0))))
|
||
return
|
||
fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
|
||
/*cond_first_p=*/0);
|
||
else if (TREE_CODE (arg0) == COMPOUND_EXPR)
|
||
return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
|
||
else if ((TREE_CODE (arg0) == COND_EXPR
|
||
|| (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
|
||
&& TREE_CODE_CLASS (code) != '<'))
|
||
&& (TREE_CODE (arg1) != COND_EXPR
|
||
|| count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
|
||
&& (! TREE_SIDE_EFFECTS (arg1)
|
||
|| ((*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ! CONTAINS_PLACEHOLDER_P (arg1))))
|
||
return
|
||
fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
|
||
/*cond_first_p=*/1);
|
||
}
|
||
|
||
switch (code)
|
||
{
|
||
case INTEGER_CST:
|
||
case REAL_CST:
|
||
case VECTOR_CST:
|
||
case STRING_CST:
|
||
case COMPLEX_CST:
|
||
case CONSTRUCTOR:
|
||
return t;
|
||
|
||
case CONST_DECL:
|
||
return fold (DECL_INITIAL (t));
|
||
|
||
case NOP_EXPR:
|
||
case FLOAT_EXPR:
|
||
case CONVERT_EXPR:
|
||
case FIX_TRUNC_EXPR:
|
||
/* Other kinds of FIX are not handled properly by fold_convert. */
|
||
|
||
if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
|
||
return TREE_OPERAND (t, 0);
|
||
|
||
/* Handle cases of two conversions in a row. */
|
||
if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
|
||
|| TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
|
||
{
|
||
tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
|
||
tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
|
||
tree final_type = TREE_TYPE (t);
|
||
int inside_int = INTEGRAL_TYPE_P (inside_type);
|
||
int inside_ptr = POINTER_TYPE_P (inside_type);
|
||
int inside_float = FLOAT_TYPE_P (inside_type);
|
||
unsigned int inside_prec = TYPE_PRECISION (inside_type);
|
||
int inside_unsignedp = TREE_UNSIGNED (inside_type);
|
||
int inter_int = INTEGRAL_TYPE_P (inter_type);
|
||
int inter_ptr = POINTER_TYPE_P (inter_type);
|
||
int inter_float = FLOAT_TYPE_P (inter_type);
|
||
unsigned int inter_prec = TYPE_PRECISION (inter_type);
|
||
int inter_unsignedp = TREE_UNSIGNED (inter_type);
|
||
int final_int = INTEGRAL_TYPE_P (final_type);
|
||
int final_ptr = POINTER_TYPE_P (final_type);
|
||
int final_float = FLOAT_TYPE_P (final_type);
|
||
unsigned int final_prec = TYPE_PRECISION (final_type);
|
||
int final_unsignedp = TREE_UNSIGNED (final_type);
|
||
|
||
/* In addition to the cases of two conversions in a row
|
||
handled below, if we are converting something to its own
|
||
type via an object of identical or wider precision, neither
|
||
conversion is needed. */
|
||
if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
|
||
&& ((inter_int && final_int) || (inter_float && final_float))
|
||
&& inter_prec >= final_prec)
|
||
return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
|
||
|
||
/* Likewise, if the intermediate and final types are either both
|
||
float or both integer, we don't need the middle conversion if
|
||
it is wider than the final type and doesn't change the signedness
|
||
(for integers). Avoid this if the final type is a pointer
|
||
since then we sometimes need the inner conversion. Likewise if
|
||
the outer has a precision not equal to the size of its mode. */
|
||
if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
|
||
|| (inter_float && inside_float))
|
||
&& inter_prec >= inside_prec
|
||
&& (inter_float || inter_unsignedp == inside_unsignedp)
|
||
&& ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
|
||
&& TYPE_MODE (final_type) == TYPE_MODE (inter_type))
|
||
&& ! final_ptr)
|
||
return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
|
||
|
||
/* If we have a sign-extension of a zero-extended value, we can
|
||
replace that by a single zero-extension. */
|
||
if (inside_int && inter_int && final_int
|
||
&& inside_prec < inter_prec && inter_prec < final_prec
|
||
&& inside_unsignedp && !inter_unsignedp)
|
||
return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
|
||
|
||
/* Two conversions in a row are not needed unless:
|
||
- some conversion is floating-point (overstrict for now), or
|
||
- the intermediate type is narrower than both initial and
|
||
final, or
|
||
- the intermediate type and innermost type differ in signedness,
|
||
and the outermost type is wider than the intermediate, or
|
||
- the initial type is a pointer type and the precisions of the
|
||
intermediate and final types differ, or
|
||
- the final type is a pointer type and the precisions of the
|
||
initial and intermediate types differ. */
|
||
if (! inside_float && ! inter_float && ! final_float
|
||
&& (inter_prec > inside_prec || inter_prec > final_prec)
|
||
&& ! (inside_int && inter_int
|
||
&& inter_unsignedp != inside_unsignedp
|
||
&& inter_prec < final_prec)
|
||
&& ((inter_unsignedp && inter_prec > inside_prec)
|
||
== (final_unsignedp && final_prec > inter_prec))
|
||
&& ! (inside_ptr && inter_prec != final_prec)
|
||
&& ! (final_ptr && inside_prec != inter_prec)
|
||
&& ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
|
||
&& TYPE_MODE (final_type) == TYPE_MODE (inter_type))
|
||
&& ! final_ptr)
|
||
return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
|
||
}
|
||
|
||
if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
|
||
&& TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
|
||
/* Detect assigning a bitfield. */
|
||
&& !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
|
||
&& DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
|
||
{
|
||
/* Don't leave an assignment inside a conversion
|
||
unless assigning a bitfield. */
|
||
tree prev = TREE_OPERAND (t, 0);
|
||
TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
|
||
/* First do the assignment, then return converted constant. */
|
||
t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
|
||
TREE_USED (t) = 1;
|
||
return t;
|
||
}
|
||
|
||
/* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
|
||
constants (if x has signed type, the sign bit cannot be set
|
||
in c). This folds extension into the BIT_AND_EXPR. */
|
||
if (INTEGRAL_TYPE_P (TREE_TYPE (t))
|
||
&& TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
|
||
&& TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
|
||
{
|
||
tree and = TREE_OPERAND (t, 0);
|
||
tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
|
||
int change = 0;
|
||
|
||
if (TREE_UNSIGNED (TREE_TYPE (and))
|
||
|| (TYPE_PRECISION (TREE_TYPE (t))
|
||
<= TYPE_PRECISION (TREE_TYPE (and))))
|
||
change = 1;
|
||
else if (TYPE_PRECISION (TREE_TYPE (and1))
|
||
<= HOST_BITS_PER_WIDE_INT
|
||
&& host_integerp (and1, 1))
|
||
{
|
||
unsigned HOST_WIDE_INT cst;
|
||
|
||
cst = tree_low_cst (and1, 1);
|
||
cst &= (HOST_WIDE_INT) -1
|
||
<< (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
|
||
change = (cst == 0);
|
||
#ifdef LOAD_EXTEND_OP
|
||
if (change
|
||
&& (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
|
||
== ZERO_EXTEND))
|
||
{
|
||
tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
|
||
and0 = convert (uns, and0);
|
||
and1 = convert (uns, and1);
|
||
}
|
||
#endif
|
||
}
|
||
if (change)
|
||
return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
|
||
convert (TREE_TYPE (t), and0),
|
||
convert (TREE_TYPE (t), and1)));
|
||
}
|
||
|
||
if (!wins)
|
||
{
|
||
TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
|
||
return t;
|
||
}
|
||
return fold_convert (t, arg0);
|
||
|
||
case VIEW_CONVERT_EXPR:
|
||
if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
|
||
return build1 (VIEW_CONVERT_EXPR, type,
|
||
TREE_OPERAND (TREE_OPERAND (t, 0), 0));
|
||
return t;
|
||
|
||
case COMPONENT_REF:
|
||
if (TREE_CODE (arg0) == CONSTRUCTOR
|
||
&& ! type_contains_placeholder_p (TREE_TYPE (arg0)))
|
||
{
|
||
tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
|
||
if (m)
|
||
t = TREE_VALUE (m);
|
||
}
|
||
return t;
|
||
|
||
case RANGE_EXPR:
|
||
TREE_CONSTANT (t) = wins;
|
||
return t;
|
||
|
||
case NEGATE_EXPR:
|
||
if (wins)
|
||
{
|
||
if (TREE_CODE (arg0) == INTEGER_CST)
|
||
{
|
||
unsigned HOST_WIDE_INT low;
|
||
HOST_WIDE_INT high;
|
||
int overflow = neg_double (TREE_INT_CST_LOW (arg0),
|
||
TREE_INT_CST_HIGH (arg0),
|
||
&low, &high);
|
||
t = build_int_2 (low, high);
|
||
TREE_TYPE (t) = type;
|
||
TREE_OVERFLOW (t)
|
||
= (TREE_OVERFLOW (arg0)
|
||
| force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
|
||
TREE_CONSTANT_OVERFLOW (t)
|
||
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
|
||
}
|
||
else if (TREE_CODE (arg0) == REAL_CST)
|
||
t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
|
||
}
|
||
else if (TREE_CODE (arg0) == NEGATE_EXPR)
|
||
return TREE_OPERAND (arg0, 0);
|
||
/* Convert -((double)float) into (double)(-float). */
|
||
else if (TREE_CODE (arg0) == NOP_EXPR
|
||
&& TREE_CODE (type) == REAL_TYPE)
|
||
{
|
||
tree targ0 = strip_float_extensions (arg0);
|
||
if (targ0 != arg0)
|
||
return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
|
||
|
||
}
|
||
|
||
/* Convert - (a - b) to (b - a) for non-floating-point. */
|
||
else if (TREE_CODE (arg0) == MINUS_EXPR
|
||
&& (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
|
||
return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg0, 0));
|
||
|
||
return t;
|
||
|
||
case ABS_EXPR:
|
||
if (wins)
|
||
{
|
||
if (TREE_CODE (arg0) == INTEGER_CST)
|
||
{
|
||
/* If the value is unsigned, then the absolute value is
|
||
the same as the ordinary value. */
|
||
if (TREE_UNSIGNED (type))
|
||
return arg0;
|
||
/* Similarly, if the value is non-negative. */
|
||
else if (INT_CST_LT (integer_minus_one_node, arg0))
|
||
return arg0;
|
||
/* If the value is negative, then the absolute value is
|
||
its negation. */
|
||
else
|
||
{
|
||
unsigned HOST_WIDE_INT low;
|
||
HOST_WIDE_INT high;
|
||
int overflow = neg_double (TREE_INT_CST_LOW (arg0),
|
||
TREE_INT_CST_HIGH (arg0),
|
||
&low, &high);
|
||
t = build_int_2 (low, high);
|
||
TREE_TYPE (t) = type;
|
||
TREE_OVERFLOW (t)
|
||
= (TREE_OVERFLOW (arg0)
|
||
| force_fit_type (t, overflow));
|
||
TREE_CONSTANT_OVERFLOW (t)
|
||
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
|
||
}
|
||
}
|
||
else if (TREE_CODE (arg0) == REAL_CST)
|
||
{
|
||
if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
|
||
t = build_real (type,
|
||
REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
|
||
}
|
||
}
|
||
else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR)
|
||
return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
|
||
/* Convert fabs((double)float) into (double)fabsf(float). */
|
||
else if (TREE_CODE (arg0) == NOP_EXPR
|
||
&& TREE_CODE (type) == REAL_TYPE)
|
||
{
|
||
tree targ0 = strip_float_extensions (arg0);
|
||
if (targ0 != arg0)
|
||
return convert (type, build1 (ABS_EXPR, TREE_TYPE (targ0), targ0));
|
||
|
||
}
|
||
else
|
||
{
|
||
/* fabs(sqrt(x)) = sqrt(x) and fabs(exp(x)) = exp(x). */
|
||
enum built_in_function fcode = builtin_mathfn_code (arg0);
|
||
if (fcode == BUILT_IN_SQRT
|
||
|| fcode == BUILT_IN_SQRTF
|
||
|| fcode == BUILT_IN_SQRTL
|
||
|| fcode == BUILT_IN_EXP
|
||
|| fcode == BUILT_IN_EXPF
|
||
|| fcode == BUILT_IN_EXPL)
|
||
t = arg0;
|
||
}
|
||
return t;
|
||
|
||
case CONJ_EXPR:
|
||
if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
|
||
return convert (type, arg0);
|
||
else if (TREE_CODE (arg0) == COMPLEX_EXPR)
|
||
return build (COMPLEX_EXPR, type,
|
||
TREE_OPERAND (arg0, 0),
|
||
negate_expr (TREE_OPERAND (arg0, 1)));
|
||
else if (TREE_CODE (arg0) == COMPLEX_CST)
|
||
return build_complex (type, TREE_REALPART (arg0),
|
||
negate_expr (TREE_IMAGPART (arg0)));
|
||
else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
|
||
return fold (build (TREE_CODE (arg0), type,
|
||
fold (build1 (CONJ_EXPR, type,
|
||
TREE_OPERAND (arg0, 0))),
|
||
fold (build1 (CONJ_EXPR,
|
||
type, TREE_OPERAND (arg0, 1)))));
|
||
else if (TREE_CODE (arg0) == CONJ_EXPR)
|
||
return TREE_OPERAND (arg0, 0);
|
||
return t;
|
||
|
||
case BIT_NOT_EXPR:
|
||
if (wins)
|
||
{
|
||
t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
|
||
~ TREE_INT_CST_HIGH (arg0));
|
||
TREE_TYPE (t) = type;
|
||
force_fit_type (t, 0);
|
||
TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
|
||
TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
|
||
}
|
||
else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
|
||
return TREE_OPERAND (arg0, 0);
|
||
return t;
|
||
|
||
case PLUS_EXPR:
|
||
/* A + (-B) -> A - B */
|
||
if (TREE_CODE (arg1) == NEGATE_EXPR)
|
||
return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
|
||
/* (-A) + B -> B - A */
|
||
if (TREE_CODE (arg0) == NEGATE_EXPR)
|
||
return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
|
||
else if (! FLOAT_TYPE_P (type))
|
||
{
|
||
if (integer_zerop (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* If we are adding two BIT_AND_EXPR's, both of which are and'ing
|
||
with a constant, and the two constants have no bits in common,
|
||
we should treat this as a BIT_IOR_EXPR since this may produce more
|
||
simplifications. */
|
||
if (TREE_CODE (arg0) == BIT_AND_EXPR
|
||
&& TREE_CODE (arg1) == BIT_AND_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
|
||
&& TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
|
||
&& integer_zerop (const_binop (BIT_AND_EXPR,
|
||
TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg1, 1), 0)))
|
||
{
|
||
code = BIT_IOR_EXPR;
|
||
goto bit_ior;
|
||
}
|
||
|
||
/* Reassociate (plus (plus (mult) (foo)) (mult)) as
|
||
(plus (plus (mult) (mult)) (foo)) so that we can
|
||
take advantage of the factoring cases below. */
|
||
if ((TREE_CODE (arg0) == PLUS_EXPR
|
||
&& TREE_CODE (arg1) == MULT_EXPR)
|
||
|| (TREE_CODE (arg1) == PLUS_EXPR
|
||
&& TREE_CODE (arg0) == MULT_EXPR))
|
||
{
|
||
tree parg0, parg1, parg, marg;
|
||
|
||
if (TREE_CODE (arg0) == PLUS_EXPR)
|
||
parg = arg0, marg = arg1;
|
||
else
|
||
parg = arg1, marg = arg0;
|
||
parg0 = TREE_OPERAND (parg, 0);
|
||
parg1 = TREE_OPERAND (parg, 1);
|
||
STRIP_NOPS (parg0);
|
||
STRIP_NOPS (parg1);
|
||
|
||
if (TREE_CODE (parg0) == MULT_EXPR
|
||
&& TREE_CODE (parg1) != MULT_EXPR)
|
||
return fold (build (PLUS_EXPR, type,
|
||
fold (build (PLUS_EXPR, type,
|
||
convert (type, parg0),
|
||
convert (type, marg))),
|
||
convert (type, parg1)));
|
||
if (TREE_CODE (parg0) != MULT_EXPR
|
||
&& TREE_CODE (parg1) == MULT_EXPR)
|
||
return fold (build (PLUS_EXPR, type,
|
||
fold (build (PLUS_EXPR, type,
|
||
convert (type, parg1),
|
||
convert (type, marg))),
|
||
convert (type, parg0)));
|
||
}
|
||
|
||
if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
|
||
{
|
||
tree arg00, arg01, arg10, arg11;
|
||
tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
|
||
|
||
/* (A * C) + (B * C) -> (A+B) * C.
|
||
We are most concerned about the case where C is a constant,
|
||
but other combinations show up during loop reduction. Since
|
||
it is not difficult, try all four possibilities. */
|
||
|
||
arg00 = TREE_OPERAND (arg0, 0);
|
||
arg01 = TREE_OPERAND (arg0, 1);
|
||
arg10 = TREE_OPERAND (arg1, 0);
|
||
arg11 = TREE_OPERAND (arg1, 1);
|
||
same = NULL_TREE;
|
||
|
||
if (operand_equal_p (arg01, arg11, 0))
|
||
same = arg01, alt0 = arg00, alt1 = arg10;
|
||
else if (operand_equal_p (arg00, arg10, 0))
|
||
same = arg00, alt0 = arg01, alt1 = arg11;
|
||
else if (operand_equal_p (arg00, arg11, 0))
|
||
same = arg00, alt0 = arg01, alt1 = arg10;
|
||
else if (operand_equal_p (arg01, arg10, 0))
|
||
same = arg01, alt0 = arg00, alt1 = arg11;
|
||
|
||
/* No identical multiplicands; see if we can find a common
|
||
power-of-two factor in non-power-of-two multiplies. This
|
||
can help in multi-dimensional array access. */
|
||
else if (TREE_CODE (arg01) == INTEGER_CST
|
||
&& TREE_CODE (arg11) == INTEGER_CST
|
||
&& TREE_INT_CST_HIGH (arg01) == 0
|
||
&& TREE_INT_CST_HIGH (arg11) == 0)
|
||
{
|
||
HOST_WIDE_INT int01, int11, tmp;
|
||
int01 = TREE_INT_CST_LOW (arg01);
|
||
int11 = TREE_INT_CST_LOW (arg11);
|
||
|
||
/* Move min of absolute values to int11. */
|
||
if ((int01 >= 0 ? int01 : -int01)
|
||
< (int11 >= 0 ? int11 : -int11))
|
||
{
|
||
tmp = int01, int01 = int11, int11 = tmp;
|
||
alt0 = arg00, arg00 = arg10, arg10 = alt0;
|
||
alt0 = arg01, arg01 = arg11, arg11 = alt0;
|
||
}
|
||
|
||
if (exact_log2 (int11) > 0 && int01 % int11 == 0)
|
||
{
|
||
alt0 = fold (build (MULT_EXPR, type, arg00,
|
||
build_int_2 (int01 / int11, 0)));
|
||
alt1 = arg10;
|
||
same = arg11;
|
||
}
|
||
}
|
||
|
||
if (same)
|
||
return fold (build (MULT_EXPR, type,
|
||
fold (build (PLUS_EXPR, type, alt0, alt1)),
|
||
same));
|
||
}
|
||
}
|
||
|
||
/* See if ARG1 is zero and X + ARG1 reduces to X. */
|
||
else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* Likewise if the operands are reversed. */
|
||
else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
|
||
return non_lvalue (convert (type, arg1));
|
||
|
||
bit_rotate:
|
||
/* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
|
||
is a rotate of A by C1 bits. */
|
||
/* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
|
||
is a rotate of A by B bits. */
|
||
{
|
||
enum tree_code code0, code1;
|
||
code0 = TREE_CODE (arg0);
|
||
code1 = TREE_CODE (arg1);
|
||
if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
|
||
|| (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0), 0)
|
||
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
|
||
{
|
||
tree tree01, tree11;
|
||
enum tree_code code01, code11;
|
||
|
||
tree01 = TREE_OPERAND (arg0, 1);
|
||
tree11 = TREE_OPERAND (arg1, 1);
|
||
STRIP_NOPS (tree01);
|
||
STRIP_NOPS (tree11);
|
||
code01 = TREE_CODE (tree01);
|
||
code11 = TREE_CODE (tree11);
|
||
if (code01 == INTEGER_CST
|
||
&& code11 == INTEGER_CST
|
||
&& TREE_INT_CST_HIGH (tree01) == 0
|
||
&& TREE_INT_CST_HIGH (tree11) == 0
|
||
&& ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
|
||
== TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
|
||
return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
code0 == LSHIFT_EXPR ? tree01 : tree11);
|
||
else if (code11 == MINUS_EXPR)
|
||
{
|
||
tree tree110, tree111;
|
||
tree110 = TREE_OPERAND (tree11, 0);
|
||
tree111 = TREE_OPERAND (tree11, 1);
|
||
STRIP_NOPS (tree110);
|
||
STRIP_NOPS (tree111);
|
||
if (TREE_CODE (tree110) == INTEGER_CST
|
||
&& 0 == compare_tree_int (tree110,
|
||
TYPE_PRECISION
|
||
(TREE_TYPE (TREE_OPERAND
|
||
(arg0, 0))))
|
||
&& operand_equal_p (tree01, tree111, 0))
|
||
return build ((code0 == LSHIFT_EXPR
|
||
? LROTATE_EXPR
|
||
: RROTATE_EXPR),
|
||
type, TREE_OPERAND (arg0, 0), tree01);
|
||
}
|
||
else if (code01 == MINUS_EXPR)
|
||
{
|
||
tree tree010, tree011;
|
||
tree010 = TREE_OPERAND (tree01, 0);
|
||
tree011 = TREE_OPERAND (tree01, 1);
|
||
STRIP_NOPS (tree010);
|
||
STRIP_NOPS (tree011);
|
||
if (TREE_CODE (tree010) == INTEGER_CST
|
||
&& 0 == compare_tree_int (tree010,
|
||
TYPE_PRECISION
|
||
(TREE_TYPE (TREE_OPERAND
|
||
(arg0, 0))))
|
||
&& operand_equal_p (tree11, tree011, 0))
|
||
return build ((code0 != LSHIFT_EXPR
|
||
? LROTATE_EXPR
|
||
: RROTATE_EXPR),
|
||
type, TREE_OPERAND (arg0, 0), tree11);
|
||
}
|
||
}
|
||
}
|
||
|
||
associate:
|
||
/* In most languages, can't associate operations on floats through
|
||
parentheses. Rather than remember where the parentheses were, we
|
||
don't associate floats at all. It shouldn't matter much. However,
|
||
associating multiplications is only very slightly inaccurate, so do
|
||
that if -funsafe-math-optimizations is specified. */
|
||
|
||
if (! wins
|
||
&& (! FLOAT_TYPE_P (type)
|
||
|| (flag_unsafe_math_optimizations && code == MULT_EXPR)))
|
||
{
|
||
tree var0, con0, lit0, minus_lit0;
|
||
tree var1, con1, lit1, minus_lit1;
|
||
|
||
/* Split both trees into variables, constants, and literals. Then
|
||
associate each group together, the constants with literals,
|
||
then the result with variables. This increases the chances of
|
||
literals being recombined later and of generating relocatable
|
||
expressions for the sum of a constant and literal. */
|
||
var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
|
||
var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
|
||
code == MINUS_EXPR);
|
||
|
||
/* Only do something if we found more than two objects. Otherwise,
|
||
nothing has changed and we risk infinite recursion. */
|
||
if (2 < ((var0 != 0) + (var1 != 0)
|
||
+ (con0 != 0) + (con1 != 0)
|
||
+ (lit0 != 0) + (lit1 != 0)
|
||
+ (minus_lit0 != 0) + (minus_lit1 != 0)))
|
||
{
|
||
/* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
|
||
if (code == MINUS_EXPR)
|
||
code = PLUS_EXPR;
|
||
|
||
var0 = associate_trees (var0, var1, code, type);
|
||
con0 = associate_trees (con0, con1, code, type);
|
||
lit0 = associate_trees (lit0, lit1, code, type);
|
||
minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
|
||
|
||
/* Preserve the MINUS_EXPR if the negative part of the literal is
|
||
greater than the positive part. Otherwise, the multiplicative
|
||
folding code (i.e extract_muldiv) may be fooled in case
|
||
unsigned constants are substracted, like in the following
|
||
example: ((X*2 + 4) - 8U)/2. */
|
||
if (minus_lit0 && lit0)
|
||
{
|
||
if (tree_int_cst_lt (lit0, minus_lit0))
|
||
{
|
||
minus_lit0 = associate_trees (minus_lit0, lit0,
|
||
MINUS_EXPR, type);
|
||
lit0 = 0;
|
||
}
|
||
else
|
||
{
|
||
lit0 = associate_trees (lit0, minus_lit0,
|
||
MINUS_EXPR, type);
|
||
minus_lit0 = 0;
|
||
}
|
||
}
|
||
if (minus_lit0)
|
||
{
|
||
if (con0 == 0)
|
||
return convert (type, associate_trees (var0, minus_lit0,
|
||
MINUS_EXPR, type));
|
||
else
|
||
{
|
||
con0 = associate_trees (con0, minus_lit0,
|
||
MINUS_EXPR, type);
|
||
return convert (type, associate_trees (var0, con0,
|
||
PLUS_EXPR, type));
|
||
}
|
||
}
|
||
|
||
con0 = associate_trees (con0, lit0, code, type);
|
||
return convert (type, associate_trees (var0, con0, code, type));
|
||
}
|
||
}
|
||
|
||
binary:
|
||
if (wins)
|
||
t1 = const_binop (code, arg0, arg1, 0);
|
||
if (t1 != NULL_TREE)
|
||
{
|
||
/* The return value should always have
|
||
the same type as the original expression. */
|
||
if (TREE_TYPE (t1) != TREE_TYPE (t))
|
||
t1 = convert (TREE_TYPE (t), t1);
|
||
|
||
return t1;
|
||
}
|
||
return t;
|
||
|
||
case MINUS_EXPR:
|
||
/* A - (-B) -> A + B */
|
||
if (TREE_CODE (arg1) == NEGATE_EXPR)
|
||
return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
|
||
/* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
|
||
if (TREE_CODE (arg0) == NEGATE_EXPR
|
||
&& (FLOAT_TYPE_P (type)
|
||
|| (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
|
||
&& negate_expr_p (arg1)
|
||
&& (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
|
||
&& (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
|
||
return fold (build (MINUS_EXPR, type, negate_expr (arg1),
|
||
TREE_OPERAND (arg0, 0)));
|
||
|
||
if (! FLOAT_TYPE_P (type))
|
||
{
|
||
if (! wins && integer_zerop (arg0))
|
||
return negate_expr (convert (type, arg1));
|
||
if (integer_zerop (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
|
||
about the case where C is a constant, just try one of the
|
||
four possibilities. */
|
||
|
||
if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg1, 1), 0))
|
||
return fold (build (MULT_EXPR, type,
|
||
fold (build (MINUS_EXPR, type,
|
||
TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0))),
|
||
TREE_OPERAND (arg0, 1)));
|
||
|
||
/* Fold A - (A & B) into ~B & A. */
|
||
if (!TREE_SIDE_EFFECTS (arg0)
|
||
&& TREE_CODE (arg1) == BIT_AND_EXPR)
|
||
{
|
||
if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
|
||
return fold (build (BIT_AND_EXPR, type,
|
||
fold (build1 (BIT_NOT_EXPR, type,
|
||
TREE_OPERAND (arg1, 0))),
|
||
arg0));
|
||
if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
|
||
return fold (build (BIT_AND_EXPR, type,
|
||
fold (build1 (BIT_NOT_EXPR, type,
|
||
TREE_OPERAND (arg1, 1))),
|
||
arg0));
|
||
}
|
||
}
|
||
|
||
/* See if ARG1 is zero and X - ARG1 reduces to X. */
|
||
else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
|
||
ARG0 is zero and X + ARG0 reduces to X, since that would mean
|
||
(-ARG1 + ARG0) reduces to -ARG1. */
|
||
else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
|
||
return negate_expr (convert (type, arg1));
|
||
|
||
/* Fold &x - &x. This can happen from &x.foo - &x.
|
||
This is unsafe for certain floats even in non-IEEE formats.
|
||
In IEEE, it is unsafe because it does wrong for NaNs.
|
||
Also note that operand_equal_p is always false if an operand
|
||
is volatile. */
|
||
|
||
if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
|
||
&& operand_equal_p (arg0, arg1, 0))
|
||
return convert (type, integer_zero_node);
|
||
|
||
goto associate;
|
||
|
||
case MULT_EXPR:
|
||
/* (-A) * (-B) -> A * B */
|
||
if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
|
||
return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0)));
|
||
|
||
if (! FLOAT_TYPE_P (type))
|
||
{
|
||
if (integer_zerop (arg1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
if (integer_onep (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* (a * (1 << b)) is (a << b) */
|
||
if (TREE_CODE (arg1) == LSHIFT_EXPR
|
||
&& integer_onep (TREE_OPERAND (arg1, 0)))
|
||
return fold (build (LSHIFT_EXPR, type, arg0,
|
||
TREE_OPERAND (arg1, 1)));
|
||
if (TREE_CODE (arg0) == LSHIFT_EXPR
|
||
&& integer_onep (TREE_OPERAND (arg0, 0)))
|
||
return fold (build (LSHIFT_EXPR, type, arg1,
|
||
TREE_OPERAND (arg0, 1)));
|
||
|
||
if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
|
||
convert (type, arg1),
|
||
code, NULL_TREE)))
|
||
return convert (type, tem);
|
||
|
||
}
|
||
else
|
||
{
|
||
/* Maybe fold x * 0 to 0. The expressions aren't the same
|
||
when x is NaN, since x * 0 is also NaN. Nor are they the
|
||
same in modes with signed zeros, since multiplying a
|
||
negative value by 0 gives -0, not +0. */
|
||
if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
|
||
&& !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
|
||
&& real_zerop (arg1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
/* In IEEE floating point, x*1 is not equivalent to x for snans. */
|
||
if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
|
||
&& real_onep (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* Transform x * -1.0 into -x. */
|
||
if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
|
||
&& real_minus_onep (arg1))
|
||
return fold (build1 (NEGATE_EXPR, type, arg0));
|
||
|
||
/* x*2 is x+x */
|
||
if (! wins && real_twop (arg1)
|
||
&& (*lang_hooks.decls.global_bindings_p) () == 0
|
||
&& ! CONTAINS_PLACEHOLDER_P (arg0))
|
||
{
|
||
tree arg = save_expr (arg0);
|
||
return fold (build (PLUS_EXPR, type, arg, arg));
|
||
}
|
||
|
||
if (flag_unsafe_math_optimizations)
|
||
{
|
||
enum built_in_function fcode0 = builtin_mathfn_code (arg0);
|
||
enum built_in_function fcode1 = builtin_mathfn_code (arg1);
|
||
|
||
/* Optimizations of sqrt(...)*sqrt(...). */
|
||
if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
|
||
|| (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
|
||
|| (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
|
||
{
|
||
tree sqrtfn, arg, arglist;
|
||
tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
|
||
tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
|
||
|
||
/* Optimize sqrt(x)*sqrt(x) as x. */
|
||
if (operand_equal_p (arg00, arg10, 0)
|
||
&& ! HONOR_SNANS (TYPE_MODE (type)))
|
||
return arg00;
|
||
|
||
/* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
|
||
sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
|
||
arg = fold (build (MULT_EXPR, type, arg00, arg10));
|
||
arglist = build_tree_list (NULL_TREE, arg);
|
||
return build_function_call_expr (sqrtfn, arglist);
|
||
}
|
||
|
||
/* Optimize exp(x)*exp(y) as exp(x+y). */
|
||
if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
|
||
|| (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
|
||
|| (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
|
||
{
|
||
tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
|
||
tree arg = build (PLUS_EXPR, type,
|
||
TREE_VALUE (TREE_OPERAND (arg0, 1)),
|
||
TREE_VALUE (TREE_OPERAND (arg1, 1)));
|
||
tree arglist = build_tree_list (NULL_TREE, fold (arg));
|
||
return build_function_call_expr (expfn, arglist);
|
||
}
|
||
|
||
/* Optimizations of pow(...)*pow(...). */
|
||
if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
|
||
|| (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
|
||
|| (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
|
||
{
|
||
tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
|
||
tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
|
||
1)));
|
||
tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
|
||
tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
|
||
1)));
|
||
|
||
/* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
|
||
if (operand_equal_p (arg01, arg11, 0))
|
||
{
|
||
tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
|
||
tree arg = build (MULT_EXPR, type, arg00, arg10);
|
||
tree arglist = tree_cons (NULL_TREE, fold (arg),
|
||
build_tree_list (NULL_TREE,
|
||
arg01));
|
||
return build_function_call_expr (powfn, arglist);
|
||
}
|
||
|
||
/* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
|
||
if (operand_equal_p (arg00, arg10, 0))
|
||
{
|
||
tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
|
||
tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
|
||
tree arglist = tree_cons (NULL_TREE, arg00,
|
||
build_tree_list (NULL_TREE,
|
||
arg));
|
||
return build_function_call_expr (powfn, arglist);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
goto associate;
|
||
|
||
case BIT_IOR_EXPR:
|
||
bit_ior:
|
||
if (integer_all_onesp (arg1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
if (integer_zerop (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
t1 = distribute_bit_expr (code, type, arg0, arg1);
|
||
if (t1 != NULL_TREE)
|
||
return t1;
|
||
|
||
/* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
|
||
|
||
This results in more efficient code for machines without a NAND
|
||
instruction. Combine will canonicalize to the first form
|
||
which will allow use of NAND instructions provided by the
|
||
backend if they exist. */
|
||
if (TREE_CODE (arg0) == BIT_NOT_EXPR
|
||
&& TREE_CODE (arg1) == BIT_NOT_EXPR)
|
||
{
|
||
return fold (build1 (BIT_NOT_EXPR, type,
|
||
build (BIT_AND_EXPR, type,
|
||
TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0))));
|
||
}
|
||
|
||
/* See if this can be simplified into a rotate first. If that
|
||
is unsuccessful continue in the association code. */
|
||
goto bit_rotate;
|
||
|
||
case BIT_XOR_EXPR:
|
||
if (integer_zerop (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
if (integer_all_onesp (arg1))
|
||
return fold (build1 (BIT_NOT_EXPR, type, arg0));
|
||
|
||
/* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
|
||
with a constant, and the two constants have no bits in common,
|
||
we should treat this as a BIT_IOR_EXPR since this may produce more
|
||
simplifications. */
|
||
if (TREE_CODE (arg0) == BIT_AND_EXPR
|
||
&& TREE_CODE (arg1) == BIT_AND_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
|
||
&& TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
|
||
&& integer_zerop (const_binop (BIT_AND_EXPR,
|
||
TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg1, 1), 0)))
|
||
{
|
||
code = BIT_IOR_EXPR;
|
||
goto bit_ior;
|
||
}
|
||
|
||
/* See if this can be simplified into a rotate first. If that
|
||
is unsuccessful continue in the association code. */
|
||
goto bit_rotate;
|
||
|
||
case BIT_AND_EXPR:
|
||
bit_and:
|
||
if (integer_all_onesp (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
if (integer_zerop (arg1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
t1 = distribute_bit_expr (code, type, arg0, arg1);
|
||
if (t1 != NULL_TREE)
|
||
return t1;
|
||
/* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
|
||
if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
|
||
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
|
||
{
|
||
unsigned int prec
|
||
= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
|
||
|
||
if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
|
||
&& (~TREE_INT_CST_LOW (arg1)
|
||
& (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
|
||
return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
|
||
}
|
||
|
||
/* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
|
||
|
||
This results in more efficient code for machines without a NOR
|
||
instruction. Combine will canonicalize to the first form
|
||
which will allow use of NOR instructions provided by the
|
||
backend if they exist. */
|
||
if (TREE_CODE (arg0) == BIT_NOT_EXPR
|
||
&& TREE_CODE (arg1) == BIT_NOT_EXPR)
|
||
{
|
||
return fold (build1 (BIT_NOT_EXPR, type,
|
||
build (BIT_IOR_EXPR, type,
|
||
TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0))));
|
||
}
|
||
|
||
goto associate;
|
||
|
||
case BIT_ANDTC_EXPR:
|
||
if (integer_all_onesp (arg0))
|
||
return non_lvalue (convert (type, arg1));
|
||
if (integer_zerop (arg0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
if (TREE_CODE (arg1) == INTEGER_CST)
|
||
{
|
||
arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
|
||
code = BIT_AND_EXPR;
|
||
goto bit_and;
|
||
}
|
||
goto binary;
|
||
|
||
case RDIV_EXPR:
|
||
/* Don't touch a floating-point divide by zero unless the mode
|
||
of the constant can represent infinity. */
|
||
if (TREE_CODE (arg1) == REAL_CST
|
||
&& !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
|
||
&& real_zerop (arg1))
|
||
return t;
|
||
|
||
/* (-A) / (-B) -> A / B */
|
||
if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
|
||
return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg1, 0)));
|
||
|
||
/* In IEEE floating point, x/1 is not equivalent to x for snans. */
|
||
if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
|
||
&& real_onep (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
|
||
/* If ARG1 is a constant, we can convert this to a multiply by the
|
||
reciprocal. This does not have the same rounding properties,
|
||
so only do this if -funsafe-math-optimizations. We can actually
|
||
always safely do it if ARG1 is a power of two, but it's hard to
|
||
tell if it is or not in a portable manner. */
|
||
if (TREE_CODE (arg1) == REAL_CST)
|
||
{
|
||
if (flag_unsafe_math_optimizations
|
||
&& 0 != (tem = const_binop (code, build_real (type, dconst1),
|
||
arg1, 0)))
|
||
return fold (build (MULT_EXPR, type, arg0, tem));
|
||
/* Find the reciprocal if optimizing and the result is exact. */
|
||
else if (optimize)
|
||
{
|
||
REAL_VALUE_TYPE r;
|
||
r = TREE_REAL_CST (arg1);
|
||
if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
|
||
{
|
||
tem = build_real (type, r);
|
||
return fold (build (MULT_EXPR, type, arg0, tem));
|
||
}
|
||
}
|
||
}
|
||
/* Convert A/B/C to A/(B*C). */
|
||
if (flag_unsafe_math_optimizations
|
||
&& TREE_CODE (arg0) == RDIV_EXPR)
|
||
{
|
||
return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
|
||
build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
|
||
arg1)));
|
||
}
|
||
/* Convert A/(B/C) to (A/B)*C. */
|
||
if (flag_unsafe_math_optimizations
|
||
&& TREE_CODE (arg1) == RDIV_EXPR)
|
||
{
|
||
return fold (build (MULT_EXPR, type,
|
||
build (RDIV_EXPR, type, arg0,
|
||
TREE_OPERAND (arg1, 0)),
|
||
TREE_OPERAND (arg1, 1)));
|
||
}
|
||
|
||
if (flag_unsafe_math_optimizations)
|
||
{
|
||
enum built_in_function fcode = builtin_mathfn_code (arg1);
|
||
/* Optimize x/exp(y) into x*exp(-y). */
|
||
if (fcode == BUILT_IN_EXP
|
||
|| fcode == BUILT_IN_EXPF
|
||
|| fcode == BUILT_IN_EXPL)
|
||
{
|
||
tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
|
||
tree arg = build1 (NEGATE_EXPR, type,
|
||
TREE_VALUE (TREE_OPERAND (arg1, 1)));
|
||
tree arglist = build_tree_list (NULL_TREE, fold (arg));
|
||
arg1 = build_function_call_expr (expfn, arglist);
|
||
return fold (build (MULT_EXPR, type, arg0, arg1));
|
||
}
|
||
|
||
/* Optimize x/pow(y,z) into x*pow(y,-z). */
|
||
if (fcode == BUILT_IN_POW
|
||
|| fcode == BUILT_IN_POWF
|
||
|| fcode == BUILT_IN_POWL)
|
||
{
|
||
tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
|
||
tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
|
||
tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
|
||
tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
|
||
tree arglist = tree_cons(NULL_TREE, arg10,
|
||
build_tree_list (NULL_TREE, neg11));
|
||
arg1 = build_function_call_expr (powfn, arglist);
|
||
return fold (build (MULT_EXPR, type, arg0, arg1));
|
||
}
|
||
}
|
||
goto binary;
|
||
|
||
case TRUNC_DIV_EXPR:
|
||
case ROUND_DIV_EXPR:
|
||
case FLOOR_DIV_EXPR:
|
||
case CEIL_DIV_EXPR:
|
||
case EXACT_DIV_EXPR:
|
||
if (integer_onep (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
if (integer_zerop (arg1))
|
||
return t;
|
||
|
||
/* If arg0 is a multiple of arg1, then rewrite to the fastest div
|
||
operation, EXACT_DIV_EXPR.
|
||
|
||
Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
|
||
At one time others generated faster code, it's not clear if they do
|
||
after the last round to changes to the DIV code in expmed.c. */
|
||
if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
|
||
&& multiple_of_p (type, arg0, arg1))
|
||
return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
|
||
|
||
if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
|
||
code, NULL_TREE)))
|
||
return convert (type, tem);
|
||
|
||
goto binary;
|
||
|
||
case CEIL_MOD_EXPR:
|
||
case FLOOR_MOD_EXPR:
|
||
case ROUND_MOD_EXPR:
|
||
case TRUNC_MOD_EXPR:
|
||
if (integer_onep (arg1))
|
||
return omit_one_operand (type, integer_zero_node, arg0);
|
||
if (integer_zerop (arg1))
|
||
return t;
|
||
|
||
if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
|
||
code, NULL_TREE)))
|
||
return convert (type, tem);
|
||
|
||
goto binary;
|
||
|
||
case LROTATE_EXPR:
|
||
case RROTATE_EXPR:
|
||
if (integer_all_onesp (arg0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
goto shift;
|
||
|
||
case RSHIFT_EXPR:
|
||
/* Optimize -1 >> x for arithmetic right shifts. */
|
||
if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
/* ... fall through ... */
|
||
|
||
case LSHIFT_EXPR:
|
||
shift:
|
||
if (integer_zerop (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
if (integer_zerop (arg0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
|
||
/* Since negative shift count is not well-defined,
|
||
don't try to compute it in the compiler. */
|
||
if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
|
||
return t;
|
||
/* Rewrite an LROTATE_EXPR by a constant into an
|
||
RROTATE_EXPR by a new constant. */
|
||
if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
|
||
{
|
||
TREE_SET_CODE (t, RROTATE_EXPR);
|
||
code = RROTATE_EXPR;
|
||
TREE_OPERAND (t, 1) = arg1
|
||
= const_binop
|
||
(MINUS_EXPR,
|
||
convert (TREE_TYPE (arg1),
|
||
build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
|
||
arg1, 0);
|
||
if (tree_int_cst_sgn (arg1) < 0)
|
||
return t;
|
||
}
|
||
|
||
/* If we have a rotate of a bit operation with the rotate count and
|
||
the second operand of the bit operation both constant,
|
||
permute the two operations. */
|
||
if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
|
||
&& (TREE_CODE (arg0) == BIT_AND_EXPR
|
||
|| TREE_CODE (arg0) == BIT_ANDTC_EXPR
|
||
|| TREE_CODE (arg0) == BIT_IOR_EXPR
|
||
|| TREE_CODE (arg0) == BIT_XOR_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
|
||
return fold (build (TREE_CODE (arg0), type,
|
||
fold (build (code, type,
|
||
TREE_OPERAND (arg0, 0), arg1)),
|
||
fold (build (code, type,
|
||
TREE_OPERAND (arg0, 1), arg1))));
|
||
|
||
/* Two consecutive rotates adding up to the width of the mode can
|
||
be ignored. */
|
||
if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
|
||
&& TREE_CODE (arg0) == RROTATE_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
|
||
&& TREE_INT_CST_HIGH (arg1) == 0
|
||
&& TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
|
||
&& ((TREE_INT_CST_LOW (arg1)
|
||
+ TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
|
||
== (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
|
||
return TREE_OPERAND (arg0, 0);
|
||
|
||
goto binary;
|
||
|
||
case MIN_EXPR:
|
||
if (operand_equal_p (arg0, arg1, 0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
if (INTEGRAL_TYPE_P (type)
|
||
&& operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
goto associate;
|
||
|
||
case MAX_EXPR:
|
||
if (operand_equal_p (arg0, arg1, 0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
if (INTEGRAL_TYPE_P (type)
|
||
&& TYPE_MAX_VALUE (type)
|
||
&& operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
goto associate;
|
||
|
||
case TRUTH_NOT_EXPR:
|
||
/* Note that the operand of this must be an int
|
||
and its values must be 0 or 1.
|
||
("true" is a fixed value perhaps depending on the language,
|
||
but we don't handle values other than 1 correctly yet.) */
|
||
tem = invert_truthvalue (arg0);
|
||
/* Avoid infinite recursion. */
|
||
if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
|
||
return t;
|
||
return convert (type, tem);
|
||
|
||
case TRUTH_ANDIF_EXPR:
|
||
/* Note that the operands of this must be ints
|
||
and their values must be 0 or 1.
|
||
("true" is a fixed value perhaps depending on the language.) */
|
||
/* If first arg is constant zero, return it. */
|
||
if (integer_zerop (arg0))
|
||
return convert (type, arg0);
|
||
case TRUTH_AND_EXPR:
|
||
/* If either arg is constant true, drop it. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
|
||
return non_lvalue (convert (type, arg1));
|
||
if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
|
||
/* Preserve sequence points. */
|
||
&& (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
|
||
return non_lvalue (convert (type, arg0));
|
||
/* If second arg is constant zero, result is zero, but first arg
|
||
must be evaluated. */
|
||
if (integer_zerop (arg1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
/* Likewise for first arg, but note that only the TRUTH_AND_EXPR
|
||
case will be handled here. */
|
||
if (integer_zerop (arg0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
|
||
truth_andor:
|
||
/* We only do these simplifications if we are optimizing. */
|
||
if (!optimize)
|
||
return t;
|
||
|
||
/* Check for things like (A || B) && (A || C). We can convert this
|
||
to A || (B && C). Note that either operator can be any of the four
|
||
truth and/or operations and the transformation will still be
|
||
valid. Also note that we only care about order for the
|
||
ANDIF and ORIF operators. If B contains side effects, this
|
||
might change the truth-value of A. */
|
||
if (TREE_CODE (arg0) == TREE_CODE (arg1)
|
||
&& (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
|
||
|| TREE_CODE (arg0) == TRUTH_ORIF_EXPR
|
||
|| TREE_CODE (arg0) == TRUTH_AND_EXPR
|
||
|| TREE_CODE (arg0) == TRUTH_OR_EXPR)
|
||
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
|
||
{
|
||
tree a00 = TREE_OPERAND (arg0, 0);
|
||
tree a01 = TREE_OPERAND (arg0, 1);
|
||
tree a10 = TREE_OPERAND (arg1, 0);
|
||
tree a11 = TREE_OPERAND (arg1, 1);
|
||
int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
|
||
|| TREE_CODE (arg0) == TRUTH_AND_EXPR)
|
||
&& (code == TRUTH_AND_EXPR
|
||
|| code == TRUTH_OR_EXPR));
|
||
|
||
if (operand_equal_p (a00, a10, 0))
|
||
return fold (build (TREE_CODE (arg0), type, a00,
|
||
fold (build (code, type, a01, a11))));
|
||
else if (commutative && operand_equal_p (a00, a11, 0))
|
||
return fold (build (TREE_CODE (arg0), type, a00,
|
||
fold (build (code, type, a01, a10))));
|
||
else if (commutative && operand_equal_p (a01, a10, 0))
|
||
return fold (build (TREE_CODE (arg0), type, a01,
|
||
fold (build (code, type, a00, a11))));
|
||
|
||
/* This case if tricky because we must either have commutative
|
||
operators or else A10 must not have side-effects. */
|
||
|
||
else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
|
||
&& operand_equal_p (a01, a11, 0))
|
||
return fold (build (TREE_CODE (arg0), type,
|
||
fold (build (code, type, a00, a10)),
|
||
a01));
|
||
}
|
||
|
||
/* See if we can build a range comparison. */
|
||
if (0 != (tem = fold_range_test (t)))
|
||
return tem;
|
||
|
||
/* Check for the possibility of merging component references. If our
|
||
lhs is another similar operation, try to merge its rhs with our
|
||
rhs. Then try to merge our lhs and rhs. */
|
||
if (TREE_CODE (arg0) == code
|
||
&& 0 != (tem = fold_truthop (code, type,
|
||
TREE_OPERAND (arg0, 1), arg1)))
|
||
return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
|
||
|
||
if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
|
||
return tem;
|
||
|
||
return t;
|
||
|
||
case TRUTH_ORIF_EXPR:
|
||
/* Note that the operands of this must be ints
|
||
and their values must be 0 or true.
|
||
("true" is a fixed value perhaps depending on the language.) */
|
||
/* If first arg is constant true, return it. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
|
||
return convert (type, arg0);
|
||
case TRUTH_OR_EXPR:
|
||
/* If either arg is constant zero, drop it. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
|
||
return non_lvalue (convert (type, arg1));
|
||
if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
|
||
/* Preserve sequence points. */
|
||
&& (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
|
||
return non_lvalue (convert (type, arg0));
|
||
/* If second arg is constant true, result is true, but we must
|
||
evaluate first arg. */
|
||
if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
|
||
return omit_one_operand (type, arg1, arg0);
|
||
/* Likewise for first arg, but note this only occurs here for
|
||
TRUTH_OR_EXPR. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
|
||
return omit_one_operand (type, arg0, arg1);
|
||
goto truth_andor;
|
||
|
||
case TRUTH_XOR_EXPR:
|
||
/* If either arg is constant zero, drop it. */
|
||
if (integer_zerop (arg0))
|
||
return non_lvalue (convert (type, arg1));
|
||
if (integer_zerop (arg1))
|
||
return non_lvalue (convert (type, arg0));
|
||
/* If either arg is constant true, this is a logical inversion. */
|
||
if (integer_onep (arg0))
|
||
return non_lvalue (convert (type, invert_truthvalue (arg1)));
|
||
if (integer_onep (arg1))
|
||
return non_lvalue (convert (type, invert_truthvalue (arg0)));
|
||
return t;
|
||
|
||
case EQ_EXPR:
|
||
case NE_EXPR:
|
||
case LT_EXPR:
|
||
case GT_EXPR:
|
||
case LE_EXPR:
|
||
case GE_EXPR:
|
||
/* If one arg is a real or integer constant, put it last. */
|
||
if ((TREE_CODE (arg0) == INTEGER_CST
|
||
&& TREE_CODE (arg1) != INTEGER_CST)
|
||
|| (TREE_CODE (arg0) == REAL_CST
|
||
&& TREE_CODE (arg0) != REAL_CST))
|
||
{
|
||
TREE_OPERAND (t, 0) = arg1;
|
||
TREE_OPERAND (t, 1) = arg0;
|
||
arg0 = TREE_OPERAND (t, 0);
|
||
arg1 = TREE_OPERAND (t, 1);
|
||
code = swap_tree_comparison (code);
|
||
TREE_SET_CODE (t, code);
|
||
}
|
||
|
||
if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
|
||
{
|
||
tree targ0 = strip_float_extensions (arg0);
|
||
tree targ1 = strip_float_extensions (arg1);
|
||
tree newtype = TREE_TYPE (targ0);
|
||
|
||
if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
|
||
newtype = TREE_TYPE (targ1);
|
||
|
||
/* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
|
||
if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
|
||
return fold (build (code, type, convert (newtype, targ0),
|
||
convert (newtype, targ1)));
|
||
|
||
/* (-a) CMP (-b) -> b CMP a */
|
||
if (TREE_CODE (arg0) == NEGATE_EXPR
|
||
&& TREE_CODE (arg1) == NEGATE_EXPR)
|
||
return fold (build (code, type, TREE_OPERAND (arg1, 0),
|
||
TREE_OPERAND (arg0, 0)));
|
||
|
||
if (TREE_CODE (arg1) == REAL_CST)
|
||
{
|
||
REAL_VALUE_TYPE cst;
|
||
cst = TREE_REAL_CST (arg1);
|
||
|
||
/* (-a) CMP CST -> a swap(CMP) (-CST) */
|
||
if (TREE_CODE (arg0) == NEGATE_EXPR)
|
||
return
|
||
fold (build (swap_tree_comparison (code), type,
|
||
TREE_OPERAND (arg0, 0),
|
||
build_real (TREE_TYPE (arg1),
|
||
REAL_VALUE_NEGATE (cst))));
|
||
|
||
/* IEEE doesn't distinguish +0 and -0 in comparisons. */
|
||
/* a CMP (-0) -> a CMP 0 */
|
||
if (REAL_VALUE_MINUS_ZERO (cst))
|
||
return fold (build (code, type, arg0,
|
||
build_real (TREE_TYPE (arg1), dconst0)));
|
||
|
||
/* x != NaN is always true, other ops are always false. */
|
||
if (REAL_VALUE_ISNAN (cst)
|
||
&& ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
|
||
{
|
||
t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
|
||
return omit_one_operand (type, convert (type, t), arg0);
|
||
}
|
||
|
||
/* Fold comparisons against infinity. */
|
||
if (REAL_VALUE_ISINF (cst))
|
||
{
|
||
tem = fold_inf_compare (code, type, arg0, arg1);
|
||
if (tem != NULL_TREE)
|
||
return tem;
|
||
}
|
||
}
|
||
|
||
/* If this is a comparison of a real constant with a PLUS_EXPR
|
||
or a MINUS_EXPR of a real constant, we can convert it into a
|
||
comparison with a revised real constant as long as no overflow
|
||
occurs when unsafe_math_optimizations are enabled. */
|
||
if (flag_unsafe_math_optimizations
|
||
&& TREE_CODE (arg1) == REAL_CST
|
||
&& (TREE_CODE (arg0) == PLUS_EXPR
|
||
|| TREE_CODE (arg0) == MINUS_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
|
||
&& 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
|
||
? MINUS_EXPR : PLUS_EXPR,
|
||
arg1, TREE_OPERAND (arg0, 1), 0))
|
||
&& ! TREE_CONSTANT_OVERFLOW (tem))
|
||
return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
|
||
|
||
/* Likewise, we can simplify a comparison of a real constant with
|
||
a MINUS_EXPR whose first operand is also a real constant, i.e.
|
||
(c1 - x) < c2 becomes x > c1-c2. */
|
||
if (flag_unsafe_math_optimizations
|
||
&& TREE_CODE (arg1) == REAL_CST
|
||
&& TREE_CODE (arg0) == MINUS_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
|
||
&& 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
|
||
arg1, 0))
|
||
&& ! TREE_CONSTANT_OVERFLOW (tem))
|
||
return fold (build (swap_tree_comparison (code), type,
|
||
TREE_OPERAND (arg0, 1), tem));
|
||
|
||
/* Fold comparisons against built-in math functions. */
|
||
if (TREE_CODE (arg1) == REAL_CST
|
||
&& flag_unsafe_math_optimizations
|
||
&& ! flag_errno_math)
|
||
{
|
||
enum built_in_function fcode = builtin_mathfn_code (arg0);
|
||
|
||
if (fcode != END_BUILTINS)
|
||
{
|
||
tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
|
||
if (tem != NULL_TREE)
|
||
return tem;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Convert foo++ == CONST into ++foo == CONST + INCR.
|
||
First, see if one arg is constant; find the constant arg
|
||
and the other one. */
|
||
{
|
||
tree constop = 0, varop = NULL_TREE;
|
||
int constopnum = -1;
|
||
|
||
if (TREE_CONSTANT (arg1))
|
||
constopnum = 1, constop = arg1, varop = arg0;
|
||
if (TREE_CONSTANT (arg0))
|
||
constopnum = 0, constop = arg0, varop = arg1;
|
||
|
||
if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
|
||
{
|
||
/* This optimization is invalid for ordered comparisons
|
||
if CONST+INCR overflows or if foo+incr might overflow.
|
||
This optimization is invalid for floating point due to rounding.
|
||
For pointer types we assume overflow doesn't happen. */
|
||
if (POINTER_TYPE_P (TREE_TYPE (varop))
|
||
|| (! FLOAT_TYPE_P (TREE_TYPE (varop))
|
||
&& (code == EQ_EXPR || code == NE_EXPR)))
|
||
{
|
||
tree newconst
|
||
= fold (build (PLUS_EXPR, TREE_TYPE (varop),
|
||
constop, TREE_OPERAND (varop, 1)));
|
||
|
||
/* Do not overwrite the current varop to be a preincrement,
|
||
create a new node so that we won't confuse our caller who
|
||
might create trees and throw them away, reusing the
|
||
arguments that they passed to build. This shows up in
|
||
the THEN or ELSE parts of ?: being postincrements. */
|
||
varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
|
||
TREE_OPERAND (varop, 0),
|
||
TREE_OPERAND (varop, 1));
|
||
|
||
/* If VAROP is a reference to a bitfield, we must mask
|
||
the constant by the width of the field. */
|
||
if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
|
||
&& DECL_BIT_FIELD(TREE_OPERAND
|
||
(TREE_OPERAND (varop, 0), 1)))
|
||
{
|
||
int size
|
||
= TREE_INT_CST_LOW (DECL_SIZE
|
||
(TREE_OPERAND
|
||
(TREE_OPERAND (varop, 0), 1)));
|
||
tree mask, unsigned_type;
|
||
unsigned int precision;
|
||
tree folded_compare;
|
||
|
||
/* First check whether the comparison would come out
|
||
always the same. If we don't do that we would
|
||
change the meaning with the masking. */
|
||
if (constopnum == 0)
|
||
folded_compare = fold (build (code, type, constop,
|
||
TREE_OPERAND (varop, 0)));
|
||
else
|
||
folded_compare = fold (build (code, type,
|
||
TREE_OPERAND (varop, 0),
|
||
constop));
|
||
if (integer_zerop (folded_compare)
|
||
|| integer_onep (folded_compare))
|
||
return omit_one_operand (type, folded_compare, varop);
|
||
|
||
unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
|
||
precision = TYPE_PRECISION (unsigned_type);
|
||
mask = build_int_2 (~0, ~0);
|
||
TREE_TYPE (mask) = unsigned_type;
|
||
force_fit_type (mask, 0);
|
||
mask = const_binop (RSHIFT_EXPR, mask,
|
||
size_int (precision - size), 0);
|
||
newconst = fold (build (BIT_AND_EXPR,
|
||
TREE_TYPE (varop), newconst,
|
||
convert (TREE_TYPE (varop),
|
||
mask)));
|
||
}
|
||
|
||
t = build (code, type,
|
||
(constopnum == 0) ? newconst : varop,
|
||
(constopnum == 1) ? newconst : varop);
|
||
return t;
|
||
}
|
||
}
|
||
else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
|
||
{
|
||
if (POINTER_TYPE_P (TREE_TYPE (varop))
|
||
|| (! FLOAT_TYPE_P (TREE_TYPE (varop))
|
||
&& (code == EQ_EXPR || code == NE_EXPR)))
|
||
{
|
||
tree newconst
|
||
= fold (build (MINUS_EXPR, TREE_TYPE (varop),
|
||
constop, TREE_OPERAND (varop, 1)));
|
||
|
||
/* Do not overwrite the current varop to be a predecrement,
|
||
create a new node so that we won't confuse our caller who
|
||
might create trees and throw them away, reusing the
|
||
arguments that they passed to build. This shows up in
|
||
the THEN or ELSE parts of ?: being postdecrements. */
|
||
varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
|
||
TREE_OPERAND (varop, 0),
|
||
TREE_OPERAND (varop, 1));
|
||
|
||
if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
|
||
&& DECL_BIT_FIELD(TREE_OPERAND
|
||
(TREE_OPERAND (varop, 0), 1)))
|
||
{
|
||
int size
|
||
= TREE_INT_CST_LOW (DECL_SIZE
|
||
(TREE_OPERAND
|
||
(TREE_OPERAND (varop, 0), 1)));
|
||
tree mask, unsigned_type;
|
||
unsigned int precision;
|
||
tree folded_compare;
|
||
|
||
if (constopnum == 0)
|
||
folded_compare = fold (build (code, type, constop,
|
||
TREE_OPERAND (varop, 0)));
|
||
else
|
||
folded_compare = fold (build (code, type,
|
||
TREE_OPERAND (varop, 0),
|
||
constop));
|
||
if (integer_zerop (folded_compare)
|
||
|| integer_onep (folded_compare))
|
||
return omit_one_operand (type, folded_compare, varop);
|
||
|
||
unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
|
||
precision = TYPE_PRECISION (unsigned_type);
|
||
mask = build_int_2 (~0, ~0);
|
||
TREE_TYPE (mask) = TREE_TYPE (varop);
|
||
force_fit_type (mask, 0);
|
||
mask = const_binop (RSHIFT_EXPR, mask,
|
||
size_int (precision - size), 0);
|
||
newconst = fold (build (BIT_AND_EXPR,
|
||
TREE_TYPE (varop), newconst,
|
||
convert (TREE_TYPE (varop),
|
||
mask)));
|
||
}
|
||
|
||
t = build (code, type,
|
||
(constopnum == 0) ? newconst : varop,
|
||
(constopnum == 1) ? newconst : varop);
|
||
return t;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
|
||
This transformation affects the cases which are handled in later
|
||
optimizations involving comparisons with non-negative constants. */
|
||
if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& TREE_CODE (arg0) != INTEGER_CST
|
||
&& tree_int_cst_sgn (arg1) > 0)
|
||
{
|
||
switch (code)
|
||
{
|
||
case GE_EXPR:
|
||
code = GT_EXPR;
|
||
arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1);
|
||
break;
|
||
|
||
case LT_EXPR:
|
||
code = LE_EXPR;
|
||
arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1);
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Comparisons with the highest or lowest possible integer of
|
||
the specified size will have known values. */
|
||
{
|
||
int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
|
||
|
||
if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& ! TREE_CONSTANT_OVERFLOW (arg1)
|
||
&& width <= HOST_BITS_PER_WIDE_INT
|
||
&& (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
|
||
|| POINTER_TYPE_P (TREE_TYPE (arg1))))
|
||
{
|
||
unsigned HOST_WIDE_INT signed_max;
|
||
unsigned HOST_WIDE_INT max, min;
|
||
|
||
signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
|
||
|
||
if (TREE_UNSIGNED (TREE_TYPE (arg1)))
|
||
{
|
||
max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
|
||
min = 0;
|
||
}
|
||
else
|
||
{
|
||
max = signed_max;
|
||
min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
|
||
}
|
||
|
||
if (TREE_INT_CST_HIGH (arg1) == 0
|
||
&& TREE_INT_CST_LOW (arg1) == max)
|
||
switch (code)
|
||
{
|
||
case GT_EXPR:
|
||
return omit_one_operand (type,
|
||
convert (type, integer_zero_node),
|
||
arg0);
|
||
case GE_EXPR:
|
||
code = EQ_EXPR;
|
||
TREE_SET_CODE (t, EQ_EXPR);
|
||
break;
|
||
case LE_EXPR:
|
||
return omit_one_operand (type,
|
||
convert (type, integer_one_node),
|
||
arg0);
|
||
case LT_EXPR:
|
||
code = NE_EXPR;
|
||
TREE_SET_CODE (t, NE_EXPR);
|
||
break;
|
||
|
||
/* The GE_EXPR and LT_EXPR cases above are not normally
|
||
reached because of previous transformations. */
|
||
|
||
default:
|
||
break;
|
||
}
|
||
else if (TREE_INT_CST_HIGH (arg1) == 0
|
||
&& TREE_INT_CST_LOW (arg1) == max - 1)
|
||
switch (code)
|
||
{
|
||
case GT_EXPR:
|
||
code = EQ_EXPR;
|
||
arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1);
|
||
break;
|
||
case LE_EXPR:
|
||
code = NE_EXPR;
|
||
arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1);
|
||
break;
|
||
default:
|
||
break;
|
||
}
|
||
else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
|
||
&& TREE_INT_CST_LOW (arg1) == min)
|
||
switch (code)
|
||
{
|
||
case LT_EXPR:
|
||
return omit_one_operand (type,
|
||
convert (type, integer_zero_node),
|
||
arg0);
|
||
case LE_EXPR:
|
||
code = EQ_EXPR;
|
||
TREE_SET_CODE (t, EQ_EXPR);
|
||
break;
|
||
|
||
case GE_EXPR:
|
||
return omit_one_operand (type,
|
||
convert (type, integer_one_node),
|
||
arg0);
|
||
case GT_EXPR:
|
||
code = NE_EXPR;
|
||
TREE_SET_CODE (t, NE_EXPR);
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
|
||
&& TREE_INT_CST_LOW (arg1) == min + 1)
|
||
switch (code)
|
||
{
|
||
case GE_EXPR:
|
||
code = NE_EXPR;
|
||
arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1);
|
||
break;
|
||
case LT_EXPR:
|
||
code = EQ_EXPR;
|
||
arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1);
|
||
break;
|
||
default:
|
||
break;
|
||
}
|
||
|
||
else if (TREE_INT_CST_HIGH (arg1) == 0
|
||
&& TREE_INT_CST_LOW (arg1) == signed_max
|
||
&& TREE_UNSIGNED (TREE_TYPE (arg1))
|
||
/* signed_type does not work on pointer types. */
|
||
&& INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
|
||
{
|
||
/* The following case also applies to X < signed_max+1
|
||
and X >= signed_max+1 because previous transformations. */
|
||
if (code == LE_EXPR || code == GT_EXPR)
|
||
{
|
||
tree st0, st1;
|
||
st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
|
||
st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
|
||
return fold
|
||
(build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
|
||
type, convert (st0, arg0),
|
||
convert (st1, integer_zero_node)));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
|
||
a MINUS_EXPR of a constant, we can convert it into a comparison with
|
||
a revised constant as long as no overflow occurs. */
|
||
if ((code == EQ_EXPR || code == NE_EXPR)
|
||
&& TREE_CODE (arg1) == INTEGER_CST
|
||
&& (TREE_CODE (arg0) == PLUS_EXPR
|
||
|| TREE_CODE (arg0) == MINUS_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
|
||
&& 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
|
||
? MINUS_EXPR : PLUS_EXPR,
|
||
arg1, TREE_OPERAND (arg0, 1), 0))
|
||
&& ! TREE_CONSTANT_OVERFLOW (tem))
|
||
return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
|
||
|
||
/* Similarly for a NEGATE_EXPR. */
|
||
else if ((code == EQ_EXPR || code == NE_EXPR)
|
||
&& TREE_CODE (arg0) == NEGATE_EXPR
|
||
&& TREE_CODE (arg1) == INTEGER_CST
|
||
&& 0 != (tem = negate_expr (arg1))
|
||
&& TREE_CODE (tem) == INTEGER_CST
|
||
&& ! TREE_CONSTANT_OVERFLOW (tem))
|
||
return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
|
||
|
||
/* If we have X - Y == 0, we can convert that to X == Y and similarly
|
||
for !=. Don't do this for ordered comparisons due to overflow. */
|
||
else if ((code == NE_EXPR || code == EQ_EXPR)
|
||
&& integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
|
||
return fold (build (code, type,
|
||
TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
|
||
|
||
/* If we are widening one operand of an integer comparison,
|
||
see if the other operand is similarly being widened. Perhaps we
|
||
can do the comparison in the narrower type. */
|
||
else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
|
||
&& TREE_CODE (arg0) == NOP_EXPR
|
||
&& (tem = get_unwidened (arg0, NULL_TREE)) != arg0
|
||
&& (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
|
||
&& (TREE_TYPE (t1) == TREE_TYPE (tem)
|
||
|| (TREE_CODE (t1) == INTEGER_CST
|
||
&& int_fits_type_p (t1, TREE_TYPE (tem)))))
|
||
return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
|
||
|
||
/* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
|
||
constant, we can simplify it. */
|
||
else if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& (TREE_CODE (arg0) == MIN_EXPR
|
||
|| TREE_CODE (arg0) == MAX_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
|
||
return optimize_minmax_comparison (t);
|
||
|
||
/* If we are comparing an ABS_EXPR with a constant, we can
|
||
convert all the cases into explicit comparisons, but they may
|
||
well not be faster than doing the ABS and one comparison.
|
||
But ABS (X) <= C is a range comparison, which becomes a subtraction
|
||
and a comparison, and is probably faster. */
|
||
else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
|
||
&& TREE_CODE (arg0) == ABS_EXPR
|
||
&& ! TREE_SIDE_EFFECTS (arg0)
|
||
&& (0 != (tem = negate_expr (arg1)))
|
||
&& TREE_CODE (tem) == INTEGER_CST
|
||
&& ! TREE_CONSTANT_OVERFLOW (tem))
|
||
return fold (build (TRUTH_ANDIF_EXPR, type,
|
||
build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
|
||
build (LE_EXPR, type,
|
||
TREE_OPERAND (arg0, 0), arg1)));
|
||
|
||
/* If this is an EQ or NE comparison with zero and ARG0 is
|
||
(1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
|
||
two operations, but the latter can be done in one less insn
|
||
on machines that have only two-operand insns or on which a
|
||
constant cannot be the first operand. */
|
||
if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
|
||
&& TREE_CODE (arg0) == BIT_AND_EXPR)
|
||
{
|
||
if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
|
||
&& integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
|
||
return
|
||
fold (build (code, type,
|
||
build (BIT_AND_EXPR, TREE_TYPE (arg0),
|
||
build (RSHIFT_EXPR,
|
||
TREE_TYPE (TREE_OPERAND (arg0, 0)),
|
||
TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
|
||
convert (TREE_TYPE (arg0),
|
||
integer_one_node)),
|
||
arg1));
|
||
else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
|
||
&& integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
|
||
return
|
||
fold (build (code, type,
|
||
build (BIT_AND_EXPR, TREE_TYPE (arg0),
|
||
build (RSHIFT_EXPR,
|
||
TREE_TYPE (TREE_OPERAND (arg0, 1)),
|
||
TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
|
||
convert (TREE_TYPE (arg0),
|
||
integer_one_node)),
|
||
arg1));
|
||
}
|
||
|
||
/* If this is an NE or EQ comparison of zero against the result of a
|
||
signed MOD operation whose second operand is a power of 2, make
|
||
the MOD operation unsigned since it is simpler and equivalent. */
|
||
if ((code == NE_EXPR || code == EQ_EXPR)
|
||
&& integer_zerop (arg1)
|
||
&& ! TREE_UNSIGNED (TREE_TYPE (arg0))
|
||
&& (TREE_CODE (arg0) == TRUNC_MOD_EXPR
|
||
|| TREE_CODE (arg0) == CEIL_MOD_EXPR
|
||
|| TREE_CODE (arg0) == FLOOR_MOD_EXPR
|
||
|| TREE_CODE (arg0) == ROUND_MOD_EXPR)
|
||
&& integer_pow2p (TREE_OPERAND (arg0, 1)))
|
||
{
|
||
tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
|
||
tree newmod = build (TREE_CODE (arg0), newtype,
|
||
convert (newtype, TREE_OPERAND (arg0, 0)),
|
||
convert (newtype, TREE_OPERAND (arg0, 1)));
|
||
|
||
return build (code, type, newmod, convert (newtype, arg1));
|
||
}
|
||
|
||
/* If this is an NE comparison of zero with an AND of one, remove the
|
||
comparison since the AND will give the correct value. */
|
||
if (code == NE_EXPR && integer_zerop (arg1)
|
||
&& TREE_CODE (arg0) == BIT_AND_EXPR
|
||
&& integer_onep (TREE_OPERAND (arg0, 1)))
|
||
return convert (type, arg0);
|
||
|
||
/* If we have (A & C) == C where C is a power of 2, convert this into
|
||
(A & C) != 0. Similarly for NE_EXPR. */
|
||
if ((code == EQ_EXPR || code == NE_EXPR)
|
||
&& TREE_CODE (arg0) == BIT_AND_EXPR
|
||
&& integer_pow2p (TREE_OPERAND (arg0, 1))
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
|
||
return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
|
||
arg0, integer_zero_node));
|
||
|
||
/* If we have (A & C) != 0 where C is the sign bit of A, convert
|
||
this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
|
||
if ((code == EQ_EXPR || code == NE_EXPR)
|
||
&& TREE_CODE (arg0) == BIT_AND_EXPR
|
||
&& integer_zerop (arg1))
|
||
{
|
||
tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg0, 1));
|
||
if (arg00 != NULL_TREE)
|
||
{
|
||
tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
|
||
return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
|
||
convert (stype, arg00),
|
||
convert (stype, integer_zero_node)));
|
||
}
|
||
}
|
||
|
||
/* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
|
||
and similarly for >= into !=. */
|
||
if ((code == LT_EXPR || code == GE_EXPR)
|
||
&& TREE_UNSIGNED (TREE_TYPE (arg0))
|
||
&& TREE_CODE (arg1) == LSHIFT_EXPR
|
||
&& integer_onep (TREE_OPERAND (arg1, 0)))
|
||
return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
|
||
build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
|
||
TREE_OPERAND (arg1, 1)),
|
||
convert (TREE_TYPE (arg0), integer_zero_node));
|
||
|
||
else if ((code == LT_EXPR || code == GE_EXPR)
|
||
&& TREE_UNSIGNED (TREE_TYPE (arg0))
|
||
&& (TREE_CODE (arg1) == NOP_EXPR
|
||
|| TREE_CODE (arg1) == CONVERT_EXPR)
|
||
&& TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
|
||
&& integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
|
||
return
|
||
build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
|
||
convert (TREE_TYPE (arg0),
|
||
build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
|
||
TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
|
||
convert (TREE_TYPE (arg0), integer_zero_node));
|
||
|
||
/* Simplify comparison of something with itself. (For IEEE
|
||
floating-point, we can only do some of these simplifications.) */
|
||
if (operand_equal_p (arg0, arg1, 0))
|
||
{
|
||
switch (code)
|
||
{
|
||
case EQ_EXPR:
|
||
case GE_EXPR:
|
||
case LE_EXPR:
|
||
if (! FLOAT_TYPE_P (TREE_TYPE (arg0)))
|
||
return constant_boolean_node (1, type);
|
||
code = EQ_EXPR;
|
||
TREE_SET_CODE (t, code);
|
||
break;
|
||
|
||
case NE_EXPR:
|
||
/* For NE, we can only do this simplification if integer. */
|
||
if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
|
||
break;
|
||
/* ... fall through ... */
|
||
case GT_EXPR:
|
||
case LT_EXPR:
|
||
return constant_boolean_node (0, type);
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* If we are comparing an expression that just has comparisons
|
||
of two integer values, arithmetic expressions of those comparisons,
|
||
and constants, we can simplify it. There are only three cases
|
||
to check: the two values can either be equal, the first can be
|
||
greater, or the second can be greater. Fold the expression for
|
||
those three values. Since each value must be 0 or 1, we have
|
||
eight possibilities, each of which corresponds to the constant 0
|
||
or 1 or one of the six possible comparisons.
|
||
|
||
This handles common cases like (a > b) == 0 but also handles
|
||
expressions like ((x > y) - (y > x)) > 0, which supposedly
|
||
occur in macroized code. */
|
||
|
||
if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
|
||
{
|
||
tree cval1 = 0, cval2 = 0;
|
||
int save_p = 0;
|
||
|
||
if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
|
||
/* Don't handle degenerate cases here; they should already
|
||
have been handled anyway. */
|
||
&& cval1 != 0 && cval2 != 0
|
||
&& ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
|
||
&& TREE_TYPE (cval1) == TREE_TYPE (cval2)
|
||
&& INTEGRAL_TYPE_P (TREE_TYPE (cval1))
|
||
&& TYPE_MAX_VALUE (TREE_TYPE (cval1))
|
||
&& TYPE_MAX_VALUE (TREE_TYPE (cval2))
|
||
&& ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
|
||
TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
|
||
{
|
||
tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
|
||
tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
|
||
|
||
/* We can't just pass T to eval_subst in case cval1 or cval2
|
||
was the same as ARG1. */
|
||
|
||
tree high_result
|
||
= fold (build (code, type,
|
||
eval_subst (arg0, cval1, maxval, cval2, minval),
|
||
arg1));
|
||
tree equal_result
|
||
= fold (build (code, type,
|
||
eval_subst (arg0, cval1, maxval, cval2, maxval),
|
||
arg1));
|
||
tree low_result
|
||
= fold (build (code, type,
|
||
eval_subst (arg0, cval1, minval, cval2, maxval),
|
||
arg1));
|
||
|
||
/* All three of these results should be 0 or 1. Confirm they
|
||
are. Then use those values to select the proper code
|
||
to use. */
|
||
|
||
if ((integer_zerop (high_result)
|
||
|| integer_onep (high_result))
|
||
&& (integer_zerop (equal_result)
|
||
|| integer_onep (equal_result))
|
||
&& (integer_zerop (low_result)
|
||
|| integer_onep (low_result)))
|
||
{
|
||
/* Make a 3-bit mask with the high-order bit being the
|
||
value for `>', the next for '=', and the low for '<'. */
|
||
switch ((integer_onep (high_result) * 4)
|
||
+ (integer_onep (equal_result) * 2)
|
||
+ integer_onep (low_result))
|
||
{
|
||
case 0:
|
||
/* Always false. */
|
||
return omit_one_operand (type, integer_zero_node, arg0);
|
||
case 1:
|
||
code = LT_EXPR;
|
||
break;
|
||
case 2:
|
||
code = EQ_EXPR;
|
||
break;
|
||
case 3:
|
||
code = LE_EXPR;
|
||
break;
|
||
case 4:
|
||
code = GT_EXPR;
|
||
break;
|
||
case 5:
|
||
code = NE_EXPR;
|
||
break;
|
||
case 6:
|
||
code = GE_EXPR;
|
||
break;
|
||
case 7:
|
||
/* Always true. */
|
||
return omit_one_operand (type, integer_one_node, arg0);
|
||
}
|
||
|
||
t = build (code, type, cval1, cval2);
|
||
if (save_p)
|
||
return save_expr (t);
|
||
else
|
||
return fold (t);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* If this is a comparison of a field, we may be able to simplify it. */
|
||
if (((TREE_CODE (arg0) == COMPONENT_REF
|
||
&& (*lang_hooks.can_use_bit_fields_p) ())
|
||
|| TREE_CODE (arg0) == BIT_FIELD_REF)
|
||
&& (code == EQ_EXPR || code == NE_EXPR)
|
||
/* Handle the constant case even without -O
|
||
to make sure the warnings are given. */
|
||
&& (optimize || TREE_CODE (arg1) == INTEGER_CST))
|
||
{
|
||
t1 = optimize_bit_field_compare (code, type, arg0, arg1);
|
||
return t1 ? t1 : t;
|
||
}
|
||
|
||
/* If this is a comparison of complex values and either or both sides
|
||
are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
|
||
comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
|
||
This may prevent needless evaluations. */
|
||
if ((code == EQ_EXPR || code == NE_EXPR)
|
||
&& TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
|
||
&& (TREE_CODE (arg0) == COMPLEX_EXPR
|
||
|| TREE_CODE (arg1) == COMPLEX_EXPR
|
||
|| TREE_CODE (arg0) == COMPLEX_CST
|
||
|| TREE_CODE (arg1) == COMPLEX_CST))
|
||
{
|
||
tree subtype = TREE_TYPE (TREE_TYPE (arg0));
|
||
tree real0, imag0, real1, imag1;
|
||
|
||
arg0 = save_expr (arg0);
|
||
arg1 = save_expr (arg1);
|
||
real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
|
||
imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
|
||
real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
|
||
imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
|
||
|
||
return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
|
||
: TRUTH_ORIF_EXPR),
|
||
type,
|
||
fold (build (code, type, real0, real1)),
|
||
fold (build (code, type, imag0, imag1))));
|
||
}
|
||
|
||
/* Optimize comparisons of strlen vs zero to a compare of the
|
||
first character of the string vs zero. To wit,
|
||
strlen(ptr) == 0 => *ptr == 0
|
||
strlen(ptr) != 0 => *ptr != 0
|
||
Other cases should reduce to one of these two (or a constant)
|
||
due to the return value of strlen being unsigned. */
|
||
if ((code == EQ_EXPR || code == NE_EXPR)
|
||
&& integer_zerop (arg1)
|
||
&& TREE_CODE (arg0) == CALL_EXPR
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
|
||
{
|
||
tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
|
||
tree arglist;
|
||
|
||
if (TREE_CODE (fndecl) == FUNCTION_DECL
|
||
&& DECL_BUILT_IN (fndecl)
|
||
&& DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
|
||
&& DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
|
||
&& (arglist = TREE_OPERAND (arg0, 1))
|
||
&& TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
|
||
&& ! TREE_CHAIN (arglist))
|
||
return fold (build (code, type,
|
||
build1 (INDIRECT_REF, char_type_node,
|
||
TREE_VALUE(arglist)),
|
||
integer_zero_node));
|
||
}
|
||
|
||
/* From here on, the only cases we handle are when the result is
|
||
known to be a constant.
|
||
|
||
To compute GT, swap the arguments and do LT.
|
||
To compute GE, do LT and invert the result.
|
||
To compute LE, swap the arguments, do LT and invert the result.
|
||
To compute NE, do EQ and invert the result.
|
||
|
||
Therefore, the code below must handle only EQ and LT. */
|
||
|
||
if (code == LE_EXPR || code == GT_EXPR)
|
||
{
|
||
tem = arg0, arg0 = arg1, arg1 = tem;
|
||
code = swap_tree_comparison (code);
|
||
}
|
||
|
||
/* Note that it is safe to invert for real values here because we
|
||
will check below in the one case that it matters. */
|
||
|
||
t1 = NULL_TREE;
|
||
invert = 0;
|
||
if (code == NE_EXPR || code == GE_EXPR)
|
||
{
|
||
invert = 1;
|
||
code = invert_tree_comparison (code);
|
||
}
|
||
|
||
/* Compute a result for LT or EQ if args permit;
|
||
otherwise return T. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
|
||
{
|
||
if (code == EQ_EXPR)
|
||
t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
|
||
else
|
||
t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
|
||
? INT_CST_LT_UNSIGNED (arg0, arg1)
|
||
: INT_CST_LT (arg0, arg1)),
|
||
0);
|
||
}
|
||
|
||
#if 0 /* This is no longer useful, but breaks some real code. */
|
||
/* Assume a nonexplicit constant cannot equal an explicit one,
|
||
since such code would be undefined anyway.
|
||
Exception: on sysvr4, using #pragma weak,
|
||
a label can come out as 0. */
|
||
else if (TREE_CODE (arg1) == INTEGER_CST
|
||
&& !integer_zerop (arg1)
|
||
&& TREE_CONSTANT (arg0)
|
||
&& TREE_CODE (arg0) == ADDR_EXPR
|
||
&& code == EQ_EXPR)
|
||
t1 = build_int_2 (0, 0);
|
||
#endif
|
||
/* Two real constants can be compared explicitly. */
|
||
else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
|
||
{
|
||
/* If either operand is a NaN, the result is false with two
|
||
exceptions: First, an NE_EXPR is true on NaNs, but that case
|
||
is already handled correctly since we will be inverting the
|
||
result for NE_EXPR. Second, if we had inverted a LE_EXPR
|
||
or a GE_EXPR into a LT_EXPR, we must return true so that it
|
||
will be inverted into false. */
|
||
|
||
if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
|
||
|| REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
|
||
t1 = build_int_2 (invert && code == LT_EXPR, 0);
|
||
|
||
else if (code == EQ_EXPR)
|
||
t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
|
||
TREE_REAL_CST (arg1)),
|
||
0);
|
||
else
|
||
t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
|
||
TREE_REAL_CST (arg1)),
|
||
0);
|
||
}
|
||
|
||
if (t1 == NULL_TREE)
|
||
return t;
|
||
|
||
if (invert)
|
||
TREE_INT_CST_LOW (t1) ^= 1;
|
||
|
||
TREE_TYPE (t1) = type;
|
||
if (TREE_CODE (type) == BOOLEAN_TYPE)
|
||
return (*lang_hooks.truthvalue_conversion) (t1);
|
||
return t1;
|
||
|
||
case COND_EXPR:
|
||
/* Pedantic ANSI C says that a conditional expression is never an lvalue,
|
||
so all simple results must be passed through pedantic_non_lvalue. */
|
||
if (TREE_CODE (arg0) == INTEGER_CST)
|
||
return pedantic_non_lvalue
|
||
(TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
|
||
else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
|
||
return pedantic_omit_one_operand (type, arg1, arg0);
|
||
|
||
/* If the second operand is zero, invert the comparison and swap
|
||
the second and third operands. Likewise if the second operand
|
||
is constant and the third is not or if the third operand is
|
||
equivalent to the first operand of the comparison. */
|
||
|
||
if (integer_zerop (arg1)
|
||
|| (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
|
||
|| (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
|
||
&& operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (t, 2),
|
||
TREE_OPERAND (arg0, 1))))
|
||
{
|
||
/* See if this can be inverted. If it can't, possibly because
|
||
it was a floating-point inequality comparison, don't do
|
||
anything. */
|
||
tem = invert_truthvalue (arg0);
|
||
|
||
if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
|
||
{
|
||
t = build (code, type, tem,
|
||
TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
|
||
arg0 = tem;
|
||
/* arg1 should be the first argument of the new T. */
|
||
arg1 = TREE_OPERAND (t, 1);
|
||
STRIP_NOPS (arg1);
|
||
}
|
||
}
|
||
|
||
/* If we have A op B ? A : C, we may be able to convert this to a
|
||
simpler expression, depending on the operation and the values
|
||
of B and C. Signed zeros prevent all of these transformations,
|
||
for reasons given above each one. */
|
||
|
||
if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
|
||
&& operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
|
||
arg1, TREE_OPERAND (arg0, 1))
|
||
&& !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
|
||
{
|
||
tree arg2 = TREE_OPERAND (t, 2);
|
||
enum tree_code comp_code = TREE_CODE (arg0);
|
||
|
||
STRIP_NOPS (arg2);
|
||
|
||
/* If we have A op 0 ? A : -A, consider applying the following
|
||
transformations:
|
||
|
||
A == 0? A : -A same as -A
|
||
A != 0? A : -A same as A
|
||
A >= 0? A : -A same as abs (A)
|
||
A > 0? A : -A same as abs (A)
|
||
A <= 0? A : -A same as -abs (A)
|
||
A < 0? A : -A same as -abs (A)
|
||
|
||
None of these transformations work for modes with signed
|
||
zeros. If A is +/-0, the first two transformations will
|
||
change the sign of the result (from +0 to -0, or vice
|
||
versa). The last four will fix the sign of the result,
|
||
even though the original expressions could be positive or
|
||
negative, depending on the sign of A.
|
||
|
||
Note that all these transformations are correct if A is
|
||
NaN, since the two alternatives (A and -A) are also NaNs. */
|
||
if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
|
||
? real_zerop (TREE_OPERAND (arg0, 1))
|
||
: integer_zerop (TREE_OPERAND (arg0, 1)))
|
||
&& TREE_CODE (arg2) == NEGATE_EXPR
|
||
&& operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
|
||
switch (comp_code)
|
||
{
|
||
case EQ_EXPR:
|
||
return
|
||
pedantic_non_lvalue
|
||
(convert (type,
|
||
negate_expr
|
||
(convert (TREE_TYPE (TREE_OPERAND (t, 1)),
|
||
arg1))));
|
||
case NE_EXPR:
|
||
return pedantic_non_lvalue (convert (type, arg1));
|
||
case GE_EXPR:
|
||
case GT_EXPR:
|
||
if (TREE_UNSIGNED (TREE_TYPE (arg1)))
|
||
arg1 = convert ((*lang_hooks.types.signed_type)
|
||
(TREE_TYPE (arg1)), arg1);
|
||
return pedantic_non_lvalue
|
||
(convert (type, fold (build1 (ABS_EXPR,
|
||
TREE_TYPE (arg1), arg1))));
|
||
case LE_EXPR:
|
||
case LT_EXPR:
|
||
if (TREE_UNSIGNED (TREE_TYPE (arg1)))
|
||
arg1 = convert ((lang_hooks.types.signed_type)
|
||
(TREE_TYPE (arg1)), arg1);
|
||
return pedantic_non_lvalue
|
||
(negate_expr (convert (type,
|
||
fold (build1 (ABS_EXPR,
|
||
TREE_TYPE (arg1),
|
||
arg1)))));
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
/* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
|
||
A == 0 ? A : 0 is always 0 unless A is -0. Note that
|
||
both transformations are correct when A is NaN: A != 0
|
||
is then true, and A == 0 is false. */
|
||
|
||
if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
|
||
{
|
||
if (comp_code == NE_EXPR)
|
||
return pedantic_non_lvalue (convert (type, arg1));
|
||
else if (comp_code == EQ_EXPR)
|
||
return pedantic_non_lvalue (convert (type, integer_zero_node));
|
||
}
|
||
|
||
/* Try some transformations of A op B ? A : B.
|
||
|
||
A == B? A : B same as B
|
||
A != B? A : B same as A
|
||
A >= B? A : B same as max (A, B)
|
||
A > B? A : B same as max (B, A)
|
||
A <= B? A : B same as min (A, B)
|
||
A < B? A : B same as min (B, A)
|
||
|
||
As above, these transformations don't work in the presence
|
||
of signed zeros. For example, if A and B are zeros of
|
||
opposite sign, the first two transformations will change
|
||
the sign of the result. In the last four, the original
|
||
expressions give different results for (A=+0, B=-0) and
|
||
(A=-0, B=+0), but the transformed expressions do not.
|
||
|
||
The first two transformations are correct if either A or B
|
||
is a NaN. In the first transformation, the condition will
|
||
be false, and B will indeed be chosen. In the case of the
|
||
second transformation, the condition A != B will be true,
|
||
and A will be chosen.
|
||
|
||
The conversions to max() and min() are not correct if B is
|
||
a number and A is not. The conditions in the original
|
||
expressions will be false, so all four give B. The min()
|
||
and max() versions would give a NaN instead. */
|
||
if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
|
||
arg2, TREE_OPERAND (arg0, 0)))
|
||
{
|
||
tree comp_op0 = TREE_OPERAND (arg0, 0);
|
||
tree comp_op1 = TREE_OPERAND (arg0, 1);
|
||
tree comp_type = TREE_TYPE (comp_op0);
|
||
|
||
/* Avoid adding NOP_EXPRs in case this is an lvalue. */
|
||
if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
|
||
{
|
||
comp_type = type;
|
||
comp_op0 = arg1;
|
||
comp_op1 = arg2;
|
||
}
|
||
|
||
switch (comp_code)
|
||
{
|
||
case EQ_EXPR:
|
||
return pedantic_non_lvalue (convert (type, arg2));
|
||
case NE_EXPR:
|
||
return pedantic_non_lvalue (convert (type, arg1));
|
||
case LE_EXPR:
|
||
case LT_EXPR:
|
||
/* In C++ a ?: expression can be an lvalue, so put the
|
||
operand which will be used if they are equal first
|
||
so that we can convert this back to the
|
||
corresponding COND_EXPR. */
|
||
if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
|
||
return pedantic_non_lvalue
|
||
(convert (type, fold (build (MIN_EXPR, comp_type,
|
||
(comp_code == LE_EXPR
|
||
? comp_op0 : comp_op1),
|
||
(comp_code == LE_EXPR
|
||
? comp_op1 : comp_op0)))));
|
||
break;
|
||
case GE_EXPR:
|
||
case GT_EXPR:
|
||
if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
|
||
return pedantic_non_lvalue
|
||
(convert (type, fold (build (MAX_EXPR, comp_type,
|
||
(comp_code == GE_EXPR
|
||
? comp_op0 : comp_op1),
|
||
(comp_code == GE_EXPR
|
||
? comp_op1 : comp_op0)))));
|
||
break;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
|
||
we might still be able to simplify this. For example,
|
||
if C1 is one less or one more than C2, this might have started
|
||
out as a MIN or MAX and been transformed by this function.
|
||
Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
|
||
|
||
if (INTEGRAL_TYPE_P (type)
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
|
||
&& TREE_CODE (arg2) == INTEGER_CST)
|
||
switch (comp_code)
|
||
{
|
||
case EQ_EXPR:
|
||
/* We can replace A with C1 in this case. */
|
||
arg1 = convert (type, TREE_OPERAND (arg0, 1));
|
||
t = build (code, type, TREE_OPERAND (t, 0), arg1,
|
||
TREE_OPERAND (t, 2));
|
||
break;
|
||
|
||
case LT_EXPR:
|
||
/* If C1 is C2 + 1, this is min(A, C2). */
|
||
if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
const_binop (PLUS_EXPR, arg2,
|
||
integer_one_node, 0), 1))
|
||
return pedantic_non_lvalue
|
||
(fold (build (MIN_EXPR, type, arg1, arg2)));
|
||
break;
|
||
|
||
case LE_EXPR:
|
||
/* If C1 is C2 - 1, this is min(A, C2). */
|
||
if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
const_binop (MINUS_EXPR, arg2,
|
||
integer_one_node, 0), 1))
|
||
return pedantic_non_lvalue
|
||
(fold (build (MIN_EXPR, type, arg1, arg2)));
|
||
break;
|
||
|
||
case GT_EXPR:
|
||
/* If C1 is C2 - 1, this is max(A, C2). */
|
||
if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
const_binop (MINUS_EXPR, arg2,
|
||
integer_one_node, 0), 1))
|
||
return pedantic_non_lvalue
|
||
(fold (build (MAX_EXPR, type, arg1, arg2)));
|
||
break;
|
||
|
||
case GE_EXPR:
|
||
/* If C1 is C2 + 1, this is max(A, C2). */
|
||
if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
|
||
&& operand_equal_p (TREE_OPERAND (arg0, 1),
|
||
const_binop (PLUS_EXPR, arg2,
|
||
integer_one_node, 0), 1))
|
||
return pedantic_non_lvalue
|
||
(fold (build (MAX_EXPR, type, arg1, arg2)));
|
||
break;
|
||
case NE_EXPR:
|
||
break;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* If the second operand is simpler than the third, swap them
|
||
since that produces better jump optimization results. */
|
||
if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
|
||
|| TREE_CODE (arg1) == SAVE_EXPR)
|
||
&& ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
|
||
|| DECL_P (TREE_OPERAND (t, 2))
|
||
|| TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
|
||
{
|
||
/* See if this can be inverted. If it can't, possibly because
|
||
it was a floating-point inequality comparison, don't do
|
||
anything. */
|
||
tem = invert_truthvalue (arg0);
|
||
|
||
if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
|
||
{
|
||
t = build (code, type, tem,
|
||
TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
|
||
arg0 = tem;
|
||
/* arg1 should be the first argument of the new T. */
|
||
arg1 = TREE_OPERAND (t, 1);
|
||
STRIP_NOPS (arg1);
|
||
}
|
||
}
|
||
|
||
/* Convert A ? 1 : 0 to simply A. */
|
||
if (integer_onep (TREE_OPERAND (t, 1))
|
||
&& integer_zerop (TREE_OPERAND (t, 2))
|
||
/* If we try to convert TREE_OPERAND (t, 0) to our type, the
|
||
call to fold will try to move the conversion inside
|
||
a COND, which will recurse. In that case, the COND_EXPR
|
||
is probably the best choice, so leave it alone. */
|
||
&& type == TREE_TYPE (arg0))
|
||
return pedantic_non_lvalue (arg0);
|
||
|
||
/* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
|
||
over COND_EXPR in cases such as floating point comparisons. */
|
||
if (integer_zerop (TREE_OPERAND (t, 1))
|
||
&& integer_onep (TREE_OPERAND (t, 2))
|
||
&& truth_value_p (TREE_CODE (arg0)))
|
||
return pedantic_non_lvalue (convert (type,
|
||
invert_truthvalue (arg0)));
|
||
|
||
/* Look for expressions of the form A & 2 ? 2 : 0. The result of this
|
||
operation is simply A & 2. */
|
||
|
||
if (integer_zerop (TREE_OPERAND (t, 2))
|
||
&& TREE_CODE (arg0) == NE_EXPR
|
||
&& integer_zerop (TREE_OPERAND (arg0, 1))
|
||
&& integer_pow2p (arg1)
|
||
&& TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
|
||
&& operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
|
||
arg1, 1))
|
||
return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
|
||
|
||
/* Convert A ? B : 0 into A && B if A and B are truth values. */
|
||
if (integer_zerop (TREE_OPERAND (t, 2))
|
||
&& truth_value_p (TREE_CODE (arg0))
|
||
&& truth_value_p (TREE_CODE (arg1)))
|
||
return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
|
||
arg0, arg1)));
|
||
|
||
/* Convert A ? B : 1 into !A || B if A and B are truth values. */
|
||
if (integer_onep (TREE_OPERAND (t, 2))
|
||
&& truth_value_p (TREE_CODE (arg0))
|
||
&& truth_value_p (TREE_CODE (arg1)))
|
||
{
|
||
/* Only perform transformation if ARG0 is easily inverted. */
|
||
tem = invert_truthvalue (arg0);
|
||
if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
|
||
return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
|
||
tem, arg1)));
|
||
}
|
||
|
||
return t;
|
||
|
||
case COMPOUND_EXPR:
|
||
/* When pedantic, a compound expression can be neither an lvalue
|
||
nor an integer constant expression. */
|
||
if (TREE_SIDE_EFFECTS (arg0) || pedantic)
|
||
return t;
|
||
/* Don't let (0, 0) be null pointer constant. */
|
||
if (integer_zerop (arg1))
|
||
return build1 (NOP_EXPR, type, arg1);
|
||
return convert (type, arg1);
|
||
|
||
case COMPLEX_EXPR:
|
||
if (wins)
|
||
return build_complex (type, arg0, arg1);
|
||
return t;
|
||
|
||
case REALPART_EXPR:
|
||
if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
|
||
return t;
|
||
else if (TREE_CODE (arg0) == COMPLEX_EXPR)
|
||
return omit_one_operand (type, TREE_OPERAND (arg0, 0),
|
||
TREE_OPERAND (arg0, 1));
|
||
else if (TREE_CODE (arg0) == COMPLEX_CST)
|
||
return TREE_REALPART (arg0);
|
||
else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
|
||
return fold (build (TREE_CODE (arg0), type,
|
||
fold (build1 (REALPART_EXPR, type,
|
||
TREE_OPERAND (arg0, 0))),
|
||
fold (build1 (REALPART_EXPR,
|
||
type, TREE_OPERAND (arg0, 1)))));
|
||
return t;
|
||
|
||
case IMAGPART_EXPR:
|
||
if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
|
||
return convert (type, integer_zero_node);
|
||
else if (TREE_CODE (arg0) == COMPLEX_EXPR)
|
||
return omit_one_operand (type, TREE_OPERAND (arg0, 1),
|
||
TREE_OPERAND (arg0, 0));
|
||
else if (TREE_CODE (arg0) == COMPLEX_CST)
|
||
return TREE_IMAGPART (arg0);
|
||
else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
|
||
return fold (build (TREE_CODE (arg0), type,
|
||
fold (build1 (IMAGPART_EXPR, type,
|
||
TREE_OPERAND (arg0, 0))),
|
||
fold (build1 (IMAGPART_EXPR, type,
|
||
TREE_OPERAND (arg0, 1)))));
|
||
return t;
|
||
|
||
/* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
|
||
appropriate. */
|
||
case CLEANUP_POINT_EXPR:
|
||
if (! has_cleanups (arg0))
|
||
return TREE_OPERAND (t, 0);
|
||
|
||
{
|
||
enum tree_code code0 = TREE_CODE (arg0);
|
||
int kind0 = TREE_CODE_CLASS (code0);
|
||
tree arg00 = TREE_OPERAND (arg0, 0);
|
||
tree arg01;
|
||
|
||
if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
|
||
return fold (build1 (code0, type,
|
||
fold (build1 (CLEANUP_POINT_EXPR,
|
||
TREE_TYPE (arg00), arg00))));
|
||
|
||
if (kind0 == '<' || kind0 == '2'
|
||
|| code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
|
||
|| code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
|
||
|| code0 == TRUTH_XOR_EXPR)
|
||
{
|
||
arg01 = TREE_OPERAND (arg0, 1);
|
||
|
||
if (TREE_CONSTANT (arg00)
|
||
|| ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
|
||
&& ! has_cleanups (arg00)))
|
||
return fold (build (code0, type, arg00,
|
||
fold (build1 (CLEANUP_POINT_EXPR,
|
||
TREE_TYPE (arg01), arg01))));
|
||
|
||
if (TREE_CONSTANT (arg01))
|
||
return fold (build (code0, type,
|
||
fold (build1 (CLEANUP_POINT_EXPR,
|
||
TREE_TYPE (arg00), arg00)),
|
||
arg01));
|
||
}
|
||
|
||
return t;
|
||
}
|
||
|
||
case CALL_EXPR:
|
||
/* Check for a built-in function. */
|
||
if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
|
||
&& (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
|
||
== FUNCTION_DECL)
|
||
&& DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
|
||
{
|
||
tree tmp = fold_builtin (expr);
|
||
if (tmp)
|
||
return tmp;
|
||
}
|
||
return t;
|
||
|
||
default:
|
||
return t;
|
||
} /* switch (code) */
|
||
}
|
||
|
||
/* Determine if first argument is a multiple of second argument. Return 0 if
|
||
it is not, or we cannot easily determined it to be.
|
||
|
||
An example of the sort of thing we care about (at this point; this routine
|
||
could surely be made more general, and expanded to do what the *_DIV_EXPR's
|
||
fold cases do now) is discovering that
|
||
|
||
SAVE_EXPR (I) * SAVE_EXPR (J * 8)
|
||
|
||
is a multiple of
|
||
|
||
SAVE_EXPR (J * 8)
|
||
|
||
when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
|
||
|
||
This code also handles discovering that
|
||
|
||
SAVE_EXPR (I) * SAVE_EXPR (J * 8)
|
||
|
||
is a multiple of 8 so we don't have to worry about dealing with a
|
||
possible remainder.
|
||
|
||
Note that we *look* inside a SAVE_EXPR only to determine how it was
|
||
calculated; it is not safe for fold to do much of anything else with the
|
||
internals of a SAVE_EXPR, since it cannot know when it will be evaluated
|
||
at run time. For example, the latter example above *cannot* be implemented
|
||
as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
|
||
evaluation time of the original SAVE_EXPR is not necessarily the same at
|
||
the time the new expression is evaluated. The only optimization of this
|
||
sort that would be valid is changing
|
||
|
||
SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
|
||
|
||
divided by 8 to
|
||
|
||
SAVE_EXPR (I) * SAVE_EXPR (J)
|
||
|
||
(where the same SAVE_EXPR (J) is used in the original and the
|
||
transformed version). */
|
||
|
||
static int
|
||
multiple_of_p (type, top, bottom)
|
||
tree type;
|
||
tree top;
|
||
tree bottom;
|
||
{
|
||
if (operand_equal_p (top, bottom, 0))
|
||
return 1;
|
||
|
||
if (TREE_CODE (type) != INTEGER_TYPE)
|
||
return 0;
|
||
|
||
switch (TREE_CODE (top))
|
||
{
|
||
case MULT_EXPR:
|
||
return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
|
||
|| multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
|
||
|
||
case PLUS_EXPR:
|
||
case MINUS_EXPR:
|
||
return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
|
||
&& multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
|
||
|
||
case LSHIFT_EXPR:
|
||
if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
|
||
{
|
||
tree op1, t1;
|
||
|
||
op1 = TREE_OPERAND (top, 1);
|
||
/* const_binop may not detect overflow correctly,
|
||
so check for it explicitly here. */
|
||
if (TYPE_PRECISION (TREE_TYPE (size_one_node))
|
||
> TREE_INT_CST_LOW (op1)
|
||
&& TREE_INT_CST_HIGH (op1) == 0
|
||
&& 0 != (t1 = convert (type,
|
||
const_binop (LSHIFT_EXPR, size_one_node,
|
||
op1, 0)))
|
||
&& ! TREE_OVERFLOW (t1))
|
||
return multiple_of_p (type, t1, bottom);
|
||
}
|
||
return 0;
|
||
|
||
case NOP_EXPR:
|
||
/* Can't handle conversions from non-integral or wider integral type. */
|
||
if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
|
||
|| (TYPE_PRECISION (type)
|
||
< TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
|
||
return 0;
|
||
|
||
/* .. fall through ... */
|
||
|
||
case SAVE_EXPR:
|
||
return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
|
||
|
||
case INTEGER_CST:
|
||
if (TREE_CODE (bottom) != INTEGER_CST
|
||
|| (TREE_UNSIGNED (type)
|
||
&& (tree_int_cst_sgn (top) < 0
|
||
|| tree_int_cst_sgn (bottom) < 0)))
|
||
return 0;
|
||
return integer_zerop (const_binop (TRUNC_MOD_EXPR,
|
||
top, bottom, 0));
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* Return true if `t' is known to be non-negative. */
|
||
|
||
int
|
||
tree_expr_nonnegative_p (t)
|
||
tree t;
|
||
{
|
||
switch (TREE_CODE (t))
|
||
{
|
||
case ABS_EXPR:
|
||
case FFS_EXPR:
|
||
case POPCOUNT_EXPR:
|
||
case PARITY_EXPR:
|
||
return 1;
|
||
|
||
case CLZ_EXPR:
|
||
case CTZ_EXPR:
|
||
/* These are undefined at zero. This is true even if
|
||
C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
|
||
computing here is a user-visible property. */
|
||
return 0;
|
||
|
||
case INTEGER_CST:
|
||
return tree_int_cst_sgn (t) >= 0;
|
||
case TRUNC_DIV_EXPR:
|
||
case CEIL_DIV_EXPR:
|
||
case FLOOR_DIV_EXPR:
|
||
case ROUND_DIV_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
|
||
&& tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
|
||
case TRUNC_MOD_EXPR:
|
||
case CEIL_MOD_EXPR:
|
||
case FLOOR_MOD_EXPR:
|
||
case ROUND_MOD_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
|
||
case COND_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
|
||
&& tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
|
||
case COMPOUND_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
|
||
case MIN_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
|
||
&& tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
|
||
case MAX_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
|
||
|| tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
|
||
case MODIFY_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
|
||
case BIND_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
|
||
case SAVE_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
|
||
case NON_LVALUE_EXPR:
|
||
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
|
||
case RTL_EXPR:
|
||
return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
|
||
|
||
default:
|
||
if (truth_value_p (TREE_CODE (t)))
|
||
/* Truth values evaluate to 0 or 1, which is nonnegative. */
|
||
return 1;
|
||
else
|
||
/* We don't know sign of `t', so be conservative and return false. */
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* Return true if `r' is known to be non-negative.
|
||
Only handles constants at the moment. */
|
||
|
||
int
|
||
rtl_expr_nonnegative_p (r)
|
||
rtx r;
|
||
{
|
||
switch (GET_CODE (r))
|
||
{
|
||
case CONST_INT:
|
||
return INTVAL (r) >= 0;
|
||
|
||
case CONST_DOUBLE:
|
||
if (GET_MODE (r) == VOIDmode)
|
||
return CONST_DOUBLE_HIGH (r) >= 0;
|
||
return 0;
|
||
|
||
case CONST_VECTOR:
|
||
{
|
||
int units, i;
|
||
rtx elt;
|
||
|
||
units = CONST_VECTOR_NUNITS (r);
|
||
|
||
for (i = 0; i < units; ++i)
|
||
{
|
||
elt = CONST_VECTOR_ELT (r, i);
|
||
if (!rtl_expr_nonnegative_p (elt))
|
||
return 0;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
case SYMBOL_REF:
|
||
case LABEL_REF:
|
||
/* These are always nonnegative. */
|
||
return 1;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
#include "gt-fold-const.h"
|