d3d6f724f2
2007-02-15 Andrew Pinski <andrew_pinski@playstation.sony.com>
PR middle-end/30729
* stmt.c (warn_if_unused_value): VA_ARG_EXPR has side
effects unknown to this function, return early.
2007-02-15 Andrew Pinski <andrew_pinski@playstation.sony.com>
PR middle-end/30729
* gcc.dg/Wunused-value-2.c: New testcase.
From-SVN: r122027
3308 lines
97 KiB
C
3308 lines
97 KiB
C
/* Expands front end tree to back end RTL for GCC
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Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
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1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
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Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA. */
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/* This file handles the generation of rtl code from tree structure
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above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
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The functions whose names start with `expand_' are called by the
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expander to generate RTL instructions for various kinds of constructs. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "rtl.h"
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#include "hard-reg-set.h"
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#include "tree.h"
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#include "tm_p.h"
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#include "flags.h"
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#include "except.h"
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#include "function.h"
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#include "insn-config.h"
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#include "expr.h"
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#include "libfuncs.h"
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#include "recog.h"
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#include "machmode.h"
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#include "toplev.h"
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#include "output.h"
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#include "ggc.h"
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#include "langhooks.h"
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#include "predict.h"
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#include "optabs.h"
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#include "target.h"
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#include "regs.h"
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/* Functions and data structures for expanding case statements. */
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/* Case label structure, used to hold info on labels within case
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statements. We handle "range" labels; for a single-value label
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as in C, the high and low limits are the same.
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We start with a vector of case nodes sorted in ascending order, and
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the default label as the last element in the vector. Before expanding
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to RTL, we transform this vector into a list linked via the RIGHT
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fields in the case_node struct. Nodes with higher case values are
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later in the list.
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Switch statements can be output in three forms. A branch table is
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used if there are more than a few labels and the labels are dense
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within the range between the smallest and largest case value. If a
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branch table is used, no further manipulations are done with the case
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node chain.
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The alternative to the use of a branch table is to generate a series
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of compare and jump insns. When that is done, we use the LEFT, RIGHT,
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and PARENT fields to hold a binary tree. Initially the tree is
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totally unbalanced, with everything on the right. We balance the tree
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with nodes on the left having lower case values than the parent
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and nodes on the right having higher values. We then output the tree
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in order.
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For very small, suitable switch statements, we can generate a series
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of simple bit test and branches instead. */
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struct case_node GTY(())
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{
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struct case_node *left; /* Left son in binary tree */
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struct case_node *right; /* Right son in binary tree; also node chain */
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struct case_node *parent; /* Parent of node in binary tree */
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tree low; /* Lowest index value for this label */
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tree high; /* Highest index value for this label */
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tree code_label; /* Label to jump to when node matches */
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};
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typedef struct case_node case_node;
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typedef struct case_node *case_node_ptr;
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/* These are used by estimate_case_costs and balance_case_nodes. */
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/* This must be a signed type, and non-ANSI compilers lack signed char. */
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static short cost_table_[129];
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static int use_cost_table;
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static int cost_table_initialized;
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/* Special care is needed because we allow -1, but TREE_INT_CST_LOW
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is unsigned. */
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#define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]
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static int n_occurrences (int, const char *);
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static bool tree_conflicts_with_clobbers_p (tree, HARD_REG_SET *);
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static void expand_nl_goto_receiver (void);
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static bool check_operand_nalternatives (tree, tree);
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static bool check_unique_operand_names (tree, tree);
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static char *resolve_operand_name_1 (char *, tree, tree);
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static void expand_null_return_1 (void);
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static void expand_value_return (rtx);
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static int estimate_case_costs (case_node_ptr);
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static bool lshift_cheap_p (void);
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static int case_bit_test_cmp (const void *, const void *);
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static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx);
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static void balance_case_nodes (case_node_ptr *, case_node_ptr);
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static int node_has_low_bound (case_node_ptr, tree);
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static int node_has_high_bound (case_node_ptr, tree);
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static int node_is_bounded (case_node_ptr, tree);
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static void emit_case_nodes (rtx, case_node_ptr, rtx, tree);
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static struct case_node *add_case_node (struct case_node *, tree,
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tree, tree, tree);
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/* Return the rtx-label that corresponds to a LABEL_DECL,
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creating it if necessary. */
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rtx
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label_rtx (tree label)
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{
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gcc_assert (TREE_CODE (label) == LABEL_DECL);
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if (!DECL_RTL_SET_P (label))
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{
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rtx r = gen_label_rtx ();
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SET_DECL_RTL (label, r);
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if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
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LABEL_PRESERVE_P (r) = 1;
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}
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return DECL_RTL (label);
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}
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/* As above, but also put it on the forced-reference list of the
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function that contains it. */
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rtx
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force_label_rtx (tree label)
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{
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rtx ref = label_rtx (label);
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tree function = decl_function_context (label);
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struct function *p;
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gcc_assert (function);
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if (function != current_function_decl)
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p = find_function_data (function);
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else
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p = cfun;
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p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref,
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p->expr->x_forced_labels);
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return ref;
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}
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/* Add an unconditional jump to LABEL as the next sequential instruction. */
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void
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emit_jump (rtx label)
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{
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do_pending_stack_adjust ();
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emit_jump_insn (gen_jump (label));
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emit_barrier ();
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}
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/* Emit code to jump to the address
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specified by the pointer expression EXP. */
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void
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expand_computed_goto (tree exp)
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{
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rtx x = expand_normal (exp);
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x = convert_memory_address (Pmode, x);
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do_pending_stack_adjust ();
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emit_indirect_jump (x);
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}
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/* Handle goto statements and the labels that they can go to. */
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/* Specify the location in the RTL code of a label LABEL,
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which is a LABEL_DECL tree node.
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This is used for the kind of label that the user can jump to with a
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goto statement, and for alternatives of a switch or case statement.
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RTL labels generated for loops and conditionals don't go through here;
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they are generated directly at the RTL level, by other functions below.
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Note that this has nothing to do with defining label *names*.
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Languages vary in how they do that and what that even means. */
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void
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expand_label (tree label)
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{
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rtx label_r = label_rtx (label);
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do_pending_stack_adjust ();
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emit_label (label_r);
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if (DECL_NAME (label))
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LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
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if (DECL_NONLOCAL (label))
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{
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expand_nl_goto_receiver ();
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nonlocal_goto_handler_labels
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= gen_rtx_EXPR_LIST (VOIDmode, label_r,
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nonlocal_goto_handler_labels);
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}
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if (FORCED_LABEL (label))
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forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
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if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
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maybe_set_first_label_num (label_r);
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}
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/* Generate RTL code for a `goto' statement with target label LABEL.
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LABEL should be a LABEL_DECL tree node that was or will later be
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defined with `expand_label'. */
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void
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expand_goto (tree label)
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{
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#ifdef ENABLE_CHECKING
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/* Check for a nonlocal goto to a containing function. Should have
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gotten translated to __builtin_nonlocal_goto. */
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tree context = decl_function_context (label);
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gcc_assert (!context || context == current_function_decl);
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#endif
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emit_jump (label_rtx (label));
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}
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/* Return the number of times character C occurs in string S. */
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static int
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n_occurrences (int c, const char *s)
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{
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int n = 0;
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while (*s)
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n += (*s++ == c);
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return n;
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}
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/* Generate RTL for an asm statement (explicit assembler code).
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STRING is a STRING_CST node containing the assembler code text,
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or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
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insn is volatile; don't optimize it. */
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static void
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expand_asm (tree string, int vol)
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{
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rtx body;
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if (TREE_CODE (string) == ADDR_EXPR)
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string = TREE_OPERAND (string, 0);
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body = gen_rtx_ASM_INPUT (VOIDmode,
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ggc_strdup (TREE_STRING_POINTER (string)));
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MEM_VOLATILE_P (body) = vol;
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emit_insn (body);
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}
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/* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
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OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
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inputs and NOUTPUTS outputs to this extended-asm. Upon return,
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*ALLOWS_MEM will be TRUE iff the constraint allows the use of a
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memory operand. Similarly, *ALLOWS_REG will be TRUE iff the
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constraint allows the use of a register operand. And, *IS_INOUT
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will be true if the operand is read-write, i.e., if it is used as
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an input as well as an output. If *CONSTRAINT_P is not in
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canonical form, it will be made canonical. (Note that `+' will be
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replaced with `=' as part of this process.)
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Returns TRUE if all went well; FALSE if an error occurred. */
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bool
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parse_output_constraint (const char **constraint_p, int operand_num,
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int ninputs, int noutputs, bool *allows_mem,
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bool *allows_reg, bool *is_inout)
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{
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const char *constraint = *constraint_p;
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const char *p;
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/* Assume the constraint doesn't allow the use of either a register
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or memory. */
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*allows_mem = false;
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*allows_reg = false;
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/* Allow the `=' or `+' to not be at the beginning of the string,
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since it wasn't explicitly documented that way, and there is a
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large body of code that puts it last. Swap the character to
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the front, so as not to uglify any place else. */
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p = strchr (constraint, '=');
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if (!p)
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p = strchr (constraint, '+');
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/* If the string doesn't contain an `=', issue an error
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message. */
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if (!p)
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{
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error ("output operand constraint lacks %<=%>");
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return false;
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}
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/* If the constraint begins with `+', then the operand is both read
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from and written to. */
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*is_inout = (*p == '+');
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/* Canonicalize the output constraint so that it begins with `='. */
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if (p != constraint || *is_inout)
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{
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char *buf;
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size_t c_len = strlen (constraint);
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if (p != constraint)
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warning (0, "output constraint %qc for operand %d "
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"is not at the beginning",
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*p, operand_num);
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/* Make a copy of the constraint. */
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buf = alloca (c_len + 1);
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strcpy (buf, constraint);
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/* Swap the first character and the `=' or `+'. */
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buf[p - constraint] = buf[0];
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/* Make sure the first character is an `='. (Until we do this,
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it might be a `+'.) */
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buf[0] = '=';
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/* Replace the constraint with the canonicalized string. */
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*constraint_p = ggc_alloc_string (buf, c_len);
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constraint = *constraint_p;
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}
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/* Loop through the constraint string. */
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for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
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switch (*p)
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{
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case '+':
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case '=':
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error ("operand constraint contains incorrectly positioned "
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"%<+%> or %<=%>");
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return false;
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case '%':
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if (operand_num + 1 == ninputs + noutputs)
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{
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error ("%<%%%> constraint used with last operand");
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return false;
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}
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break;
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case 'V': case 'm': case 'o':
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*allows_mem = true;
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break;
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case '?': case '!': case '*': case '&': case '#':
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case 'E': case 'F': case 'G': case 'H':
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case 's': case 'i': case 'n':
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case 'I': case 'J': case 'K': case 'L': case 'M':
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case 'N': case 'O': case 'P': case ',':
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break;
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case '0': case '1': case '2': case '3': case '4':
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case '5': case '6': case '7': case '8': case '9':
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case '[':
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error ("matching constraint not valid in output operand");
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return false;
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case '<': case '>':
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/* ??? Before flow, auto inc/dec insns are not supposed to exist,
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excepting those that expand_call created. So match memory
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and hope. */
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*allows_mem = true;
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break;
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case 'g': case 'X':
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*allows_reg = true;
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*allows_mem = true;
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break;
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|
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case 'p': case 'r':
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*allows_reg = true;
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break;
|
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|
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default:
|
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if (!ISALPHA (*p))
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break;
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if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS)
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*allows_reg = true;
|
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#ifdef EXTRA_CONSTRAINT_STR
|
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else if (EXTRA_ADDRESS_CONSTRAINT (*p, p))
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*allows_reg = true;
|
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else if (EXTRA_MEMORY_CONSTRAINT (*p, p))
|
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*allows_mem = true;
|
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else
|
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{
|
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/* Otherwise we can't assume anything about the nature of
|
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the constraint except that it isn't purely registers.
|
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Treat it like "g" and hope for the best. */
|
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*allows_reg = true;
|
||
*allows_mem = true;
|
||
}
|
||
#endif
|
||
break;
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Similar, but for input constraints. */
|
||
|
||
bool
|
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parse_input_constraint (const char **constraint_p, int input_num,
|
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int ninputs, int noutputs, int ninout,
|
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const char * const * constraints,
|
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bool *allows_mem, bool *allows_reg)
|
||
{
|
||
const char *constraint = *constraint_p;
|
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const char *orig_constraint = constraint;
|
||
size_t c_len = strlen (constraint);
|
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size_t j;
|
||
bool saw_match = false;
|
||
|
||
/* Assume the constraint doesn't allow the use of either
|
||
a register or memory. */
|
||
*allows_mem = false;
|
||
*allows_reg = false;
|
||
|
||
/* Make sure constraint has neither `=', `+', nor '&'. */
|
||
|
||
for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j))
|
||
switch (constraint[j])
|
||
{
|
||
case '+': case '=': case '&':
|
||
if (constraint == orig_constraint)
|
||
{
|
||
error ("input operand constraint contains %qc", constraint[j]);
|
||
return false;
|
||
}
|
||
break;
|
||
|
||
case '%':
|
||
if (constraint == orig_constraint
|
||
&& input_num + 1 == ninputs - ninout)
|
||
{
|
||
error ("%<%%%> constraint used with last operand");
|
||
return false;
|
||
}
|
||
break;
|
||
|
||
case 'V': case 'm': case 'o':
|
||
*allows_mem = true;
|
||
break;
|
||
|
||
case '<': case '>':
|
||
case '?': case '!': case '*': case '#':
|
||
case 'E': case 'F': case 'G': case 'H':
|
||
case 's': case 'i': case 'n':
|
||
case 'I': case 'J': case 'K': case 'L': case 'M':
|
||
case 'N': case 'O': case 'P': case ',':
|
||
break;
|
||
|
||
/* Whether or not a numeric constraint allows a register is
|
||
decided by the matching constraint, and so there is no need
|
||
to do anything special with them. We must handle them in
|
||
the default case, so that we don't unnecessarily force
|
||
operands to memory. */
|
||
case '0': case '1': case '2': case '3': case '4':
|
||
case '5': case '6': case '7': case '8': case '9':
|
||
{
|
||
char *end;
|
||
unsigned long match;
|
||
|
||
saw_match = true;
|
||
|
||
match = strtoul (constraint + j, &end, 10);
|
||
if (match >= (unsigned long) noutputs)
|
||
{
|
||
error ("matching constraint references invalid operand number");
|
||
return false;
|
||
}
|
||
|
||
/* Try and find the real constraint for this dup. Only do this
|
||
if the matching constraint is the only alternative. */
|
||
if (*end == '\0'
|
||
&& (j == 0 || (j == 1 && constraint[0] == '%')))
|
||
{
|
||
constraint = constraints[match];
|
||
*constraint_p = constraint;
|
||
c_len = strlen (constraint);
|
||
j = 0;
|
||
/* ??? At the end of the loop, we will skip the first part of
|
||
the matched constraint. This assumes not only that the
|
||
other constraint is an output constraint, but also that
|
||
the '=' or '+' come first. */
|
||
break;
|
||
}
|
||
else
|
||
j = end - constraint;
|
||
/* Anticipate increment at end of loop. */
|
||
j--;
|
||
}
|
||
/* Fall through. */
|
||
|
||
case 'p': case 'r':
|
||
*allows_reg = true;
|
||
break;
|
||
|
||
case 'g': case 'X':
|
||
*allows_reg = true;
|
||
*allows_mem = true;
|
||
break;
|
||
|
||
default:
|
||
if (! ISALPHA (constraint[j]))
|
||
{
|
||
error ("invalid punctuation %qc in constraint", constraint[j]);
|
||
return false;
|
||
}
|
||
if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j)
|
||
!= NO_REGS)
|
||
*allows_reg = true;
|
||
#ifdef EXTRA_CONSTRAINT_STR
|
||
else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j))
|
||
*allows_reg = true;
|
||
else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j))
|
||
*allows_mem = true;
|
||
else
|
||
{
|
||
/* Otherwise we can't assume anything about the nature of
|
||
the constraint except that it isn't purely registers.
|
||
Treat it like "g" and hope for the best. */
|
||
*allows_reg = true;
|
||
*allows_mem = true;
|
||
}
|
||
#endif
|
||
break;
|
||
}
|
||
|
||
if (saw_match && !*allows_reg)
|
||
warning (0, "matching constraint does not allow a register");
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Return DECL iff there's an overlap between *REGS and DECL, where DECL
|
||
can be an asm-declared register. Called via walk_tree. */
|
||
|
||
static tree
|
||
decl_overlaps_hard_reg_set_p (tree *declp, int *walk_subtrees ATTRIBUTE_UNUSED,
|
||
void *data)
|
||
{
|
||
tree decl = *declp;
|
||
const HARD_REG_SET *regs = data;
|
||
|
||
if (TREE_CODE (decl) == VAR_DECL)
|
||
{
|
||
if (DECL_HARD_REGISTER (decl)
|
||
&& REG_P (DECL_RTL (decl))
|
||
&& REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
rtx reg = DECL_RTL (decl);
|
||
unsigned int regno;
|
||
|
||
for (regno = REGNO (reg);
|
||
regno < (REGNO (reg)
|
||
+ hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]);
|
||
regno++)
|
||
if (TEST_HARD_REG_BIT (*regs, regno))
|
||
return decl;
|
||
}
|
||
walk_subtrees = 0;
|
||
}
|
||
else if (TYPE_P (decl) || TREE_CODE (decl) == PARM_DECL)
|
||
walk_subtrees = 0;
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* If there is an overlap between *REGS and DECL, return the first overlap
|
||
found. */
|
||
tree
|
||
tree_overlaps_hard_reg_set (tree decl, HARD_REG_SET *regs)
|
||
{
|
||
return walk_tree (&decl, decl_overlaps_hard_reg_set_p, regs, NULL);
|
||
}
|
||
|
||
/* Check for overlap between registers marked in CLOBBERED_REGS and
|
||
anything inappropriate in T. Emit error and return the register
|
||
variable definition for error, NULL_TREE for ok. */
|
||
|
||
static bool
|
||
tree_conflicts_with_clobbers_p (tree t, HARD_REG_SET *clobbered_regs)
|
||
{
|
||
/* Conflicts between asm-declared register variables and the clobber
|
||
list are not allowed. */
|
||
tree overlap = tree_overlaps_hard_reg_set (t, clobbered_regs);
|
||
|
||
if (overlap)
|
||
{
|
||
error ("asm-specifier for variable %qs conflicts with asm clobber list",
|
||
IDENTIFIER_POINTER (DECL_NAME (overlap)));
|
||
|
||
/* Reset registerness to stop multiple errors emitted for a single
|
||
variable. */
|
||
DECL_REGISTER (overlap) = 0;
|
||
return true;
|
||
}
|
||
|
||
return false;
|
||
}
|
||
|
||
/* Generate RTL for an asm statement with arguments.
|
||
STRING is the instruction template.
|
||
OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
|
||
Each output or input has an expression in the TREE_VALUE and
|
||
and a tree list in TREE_PURPOSE which in turn contains a constraint
|
||
name in TREE_VALUE (or NULL_TREE) and a constraint string
|
||
in TREE_PURPOSE.
|
||
CLOBBERS is a list of STRING_CST nodes each naming a hard register
|
||
that is clobbered by this insn.
|
||
|
||
Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
|
||
Some elements of OUTPUTS may be replaced with trees representing temporary
|
||
values. The caller should copy those temporary values to the originally
|
||
specified lvalues.
|
||
|
||
VOL nonzero means the insn is volatile; don't optimize it. */
|
||
|
||
static void
|
||
expand_asm_operands (tree string, tree outputs, tree inputs,
|
||
tree clobbers, int vol, location_t locus)
|
||
{
|
||
rtvec argvec, constraintvec;
|
||
rtx body;
|
||
int ninputs = list_length (inputs);
|
||
int noutputs = list_length (outputs);
|
||
int ninout;
|
||
int nclobbers;
|
||
HARD_REG_SET clobbered_regs;
|
||
int clobber_conflict_found = 0;
|
||
tree tail;
|
||
tree t;
|
||
int i;
|
||
/* Vector of RTX's of evaluated output operands. */
|
||
rtx *output_rtx = alloca (noutputs * sizeof (rtx));
|
||
int *inout_opnum = alloca (noutputs * sizeof (int));
|
||
rtx *real_output_rtx = alloca (noutputs * sizeof (rtx));
|
||
enum machine_mode *inout_mode
|
||
= alloca (noutputs * sizeof (enum machine_mode));
|
||
const char **constraints
|
||
= alloca ((noutputs + ninputs) * sizeof (const char *));
|
||
int old_generating_concat_p = generating_concat_p;
|
||
|
||
/* An ASM with no outputs needs to be treated as volatile, for now. */
|
||
if (noutputs == 0)
|
||
vol = 1;
|
||
|
||
if (! check_operand_nalternatives (outputs, inputs))
|
||
return;
|
||
|
||
string = resolve_asm_operand_names (string, outputs, inputs);
|
||
|
||
/* Collect constraints. */
|
||
i = 0;
|
||
for (t = outputs; t ; t = TREE_CHAIN (t), i++)
|
||
constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
|
||
for (t = inputs; t ; t = TREE_CHAIN (t), i++)
|
||
constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
|
||
|
||
/* Sometimes we wish to automatically clobber registers across an asm.
|
||
Case in point is when the i386 backend moved from cc0 to a hard reg --
|
||
maintaining source-level compatibility means automatically clobbering
|
||
the flags register. */
|
||
clobbers = targetm.md_asm_clobbers (outputs, inputs, clobbers);
|
||
|
||
/* Count the number of meaningful clobbered registers, ignoring what
|
||
we would ignore later. */
|
||
nclobbers = 0;
|
||
CLEAR_HARD_REG_SET (clobbered_regs);
|
||
for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
const char *regname;
|
||
|
||
if (TREE_VALUE (tail) == error_mark_node)
|
||
return;
|
||
regname = TREE_STRING_POINTER (TREE_VALUE (tail));
|
||
|
||
i = decode_reg_name (regname);
|
||
if (i >= 0 || i == -4)
|
||
++nclobbers;
|
||
else if (i == -2)
|
||
error ("unknown register name %qs in %<asm%>", regname);
|
||
|
||
/* Mark clobbered registers. */
|
||
if (i >= 0)
|
||
{
|
||
/* Clobbering the PIC register is an error. */
|
||
if (i == (int) PIC_OFFSET_TABLE_REGNUM)
|
||
{
|
||
error ("PIC register %qs clobbered in %<asm%>", regname);
|
||
return;
|
||
}
|
||
|
||
SET_HARD_REG_BIT (clobbered_regs, i);
|
||
}
|
||
}
|
||
|
||
/* First pass over inputs and outputs checks validity and sets
|
||
mark_addressable if needed. */
|
||
|
||
ninout = 0;
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
tree val = TREE_VALUE (tail);
|
||
tree type = TREE_TYPE (val);
|
||
const char *constraint;
|
||
bool is_inout;
|
||
bool allows_reg;
|
||
bool allows_mem;
|
||
|
||
/* If there's an erroneous arg, emit no insn. */
|
||
if (type == error_mark_node)
|
||
return;
|
||
|
||
/* Try to parse the output constraint. If that fails, there's
|
||
no point in going further. */
|
||
constraint = constraints[i];
|
||
if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
|
||
&allows_mem, &allows_reg, &is_inout))
|
||
return;
|
||
|
||
if (! allows_reg
|
||
&& (allows_mem
|
||
|| is_inout
|
||
|| (DECL_P (val)
|
||
&& REG_P (DECL_RTL (val))
|
||
&& GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
|
||
lang_hooks.mark_addressable (val);
|
||
|
||
if (is_inout)
|
||
ninout++;
|
||
}
|
||
|
||
ninputs += ninout;
|
||
if (ninputs + noutputs > MAX_RECOG_OPERANDS)
|
||
{
|
||
error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS);
|
||
return;
|
||
}
|
||
|
||
for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
|
||
{
|
||
bool allows_reg, allows_mem;
|
||
const char *constraint;
|
||
|
||
/* If there's an erroneous arg, emit no insn, because the ASM_INPUT
|
||
would get VOIDmode and that could cause a crash in reload. */
|
||
if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
|
||
return;
|
||
|
||
constraint = constraints[i + noutputs];
|
||
if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
|
||
constraints, &allows_mem, &allows_reg))
|
||
return;
|
||
|
||
if (! allows_reg && allows_mem)
|
||
lang_hooks.mark_addressable (TREE_VALUE (tail));
|
||
}
|
||
|
||
/* Second pass evaluates arguments. */
|
||
|
||
ninout = 0;
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
tree val = TREE_VALUE (tail);
|
||
tree type = TREE_TYPE (val);
|
||
bool is_inout;
|
||
bool allows_reg;
|
||
bool allows_mem;
|
||
rtx op;
|
||
bool ok;
|
||
|
||
ok = parse_output_constraint (&constraints[i], i, ninputs,
|
||
noutputs, &allows_mem, &allows_reg,
|
||
&is_inout);
|
||
gcc_assert (ok);
|
||
|
||
/* If an output operand is not a decl or indirect ref and our constraint
|
||
allows a register, make a temporary to act as an intermediate.
|
||
Make the asm insn write into that, then our caller will copy it to
|
||
the real output operand. Likewise for promoted variables. */
|
||
|
||
generating_concat_p = 0;
|
||
|
||
real_output_rtx[i] = NULL_RTX;
|
||
if ((TREE_CODE (val) == INDIRECT_REF
|
||
&& allows_mem)
|
||
|| (DECL_P (val)
|
||
&& (allows_mem || REG_P (DECL_RTL (val)))
|
||
&& ! (REG_P (DECL_RTL (val))
|
||
&& GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
|
||
|| ! allows_reg
|
||
|| is_inout)
|
||
{
|
||
op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
|
||
if (MEM_P (op))
|
||
op = validize_mem (op);
|
||
|
||
if (! allows_reg && !MEM_P (op))
|
||
error ("output number %d not directly addressable", i);
|
||
if ((! allows_mem && MEM_P (op))
|
||
|| GET_CODE (op) == CONCAT)
|
||
{
|
||
real_output_rtx[i] = op;
|
||
op = gen_reg_rtx (GET_MODE (op));
|
||
if (is_inout)
|
||
emit_move_insn (op, real_output_rtx[i]);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
op = assign_temp (type, 0, 0, 1);
|
||
op = validize_mem (op);
|
||
TREE_VALUE (tail) = make_tree (type, op);
|
||
}
|
||
output_rtx[i] = op;
|
||
|
||
generating_concat_p = old_generating_concat_p;
|
||
|
||
if (is_inout)
|
||
{
|
||
inout_mode[ninout] = TYPE_MODE (type);
|
||
inout_opnum[ninout++] = i;
|
||
}
|
||
|
||
if (tree_conflicts_with_clobbers_p (val, &clobbered_regs))
|
||
clobber_conflict_found = 1;
|
||
}
|
||
|
||
/* Make vectors for the expression-rtx, constraint strings,
|
||
and named operands. */
|
||
|
||
argvec = rtvec_alloc (ninputs);
|
||
constraintvec = rtvec_alloc (ninputs);
|
||
|
||
body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
|
||
: GET_MODE (output_rtx[0])),
|
||
ggc_strdup (TREE_STRING_POINTER (string)),
|
||
empty_string, 0, argvec, constraintvec,
|
||
locus);
|
||
|
||
MEM_VOLATILE_P (body) = vol;
|
||
|
||
/* Eval the inputs and put them into ARGVEC.
|
||
Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
|
||
|
||
for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
|
||
{
|
||
bool allows_reg, allows_mem;
|
||
const char *constraint;
|
||
tree val, type;
|
||
rtx op;
|
||
bool ok;
|
||
|
||
constraint = constraints[i + noutputs];
|
||
ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
|
||
constraints, &allows_mem, &allows_reg);
|
||
gcc_assert (ok);
|
||
|
||
generating_concat_p = 0;
|
||
|
||
val = TREE_VALUE (tail);
|
||
type = TREE_TYPE (val);
|
||
/* EXPAND_INITIALIZER will not generate code for valid initializer
|
||
constants, but will still generate code for other types of operand.
|
||
This is the behavior we want for constant constraints. */
|
||
op = expand_expr (val, NULL_RTX, VOIDmode,
|
||
allows_reg ? EXPAND_NORMAL
|
||
: allows_mem ? EXPAND_MEMORY
|
||
: EXPAND_INITIALIZER);
|
||
|
||
/* Never pass a CONCAT to an ASM. */
|
||
if (GET_CODE (op) == CONCAT)
|
||
op = force_reg (GET_MODE (op), op);
|
||
else if (MEM_P (op))
|
||
op = validize_mem (op);
|
||
|
||
if (asm_operand_ok (op, constraint) <= 0)
|
||
{
|
||
if (allows_reg && TYPE_MODE (type) != BLKmode)
|
||
op = force_reg (TYPE_MODE (type), op);
|
||
else if (!allows_mem)
|
||
warning (0, "asm operand %d probably doesn%'t match constraints",
|
||
i + noutputs);
|
||
else if (MEM_P (op))
|
||
{
|
||
/* We won't recognize either volatile memory or memory
|
||
with a queued address as available a memory_operand
|
||
at this point. Ignore it: clearly this *is* a memory. */
|
||
}
|
||
else
|
||
{
|
||
warning (0, "use of memory input without lvalue in "
|
||
"asm operand %d is deprecated", i + noutputs);
|
||
|
||
if (CONSTANT_P (op))
|
||
{
|
||
rtx mem = force_const_mem (TYPE_MODE (type), op);
|
||
if (mem)
|
||
op = validize_mem (mem);
|
||
else
|
||
op = force_reg (TYPE_MODE (type), op);
|
||
}
|
||
if (REG_P (op)
|
||
|| GET_CODE (op) == SUBREG
|
||
|| GET_CODE (op) == CONCAT)
|
||
{
|
||
tree qual_type = build_qualified_type (type,
|
||
(TYPE_QUALS (type)
|
||
| TYPE_QUAL_CONST));
|
||
rtx memloc = assign_temp (qual_type, 1, 1, 1);
|
||
memloc = validize_mem (memloc);
|
||
emit_move_insn (memloc, op);
|
||
op = memloc;
|
||
}
|
||
}
|
||
}
|
||
|
||
generating_concat_p = old_generating_concat_p;
|
||
ASM_OPERANDS_INPUT (body, i) = op;
|
||
|
||
ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
|
||
= gen_rtx_ASM_INPUT (TYPE_MODE (type),
|
||
ggc_strdup (constraints[i + noutputs]));
|
||
|
||
if (tree_conflicts_with_clobbers_p (val, &clobbered_regs))
|
||
clobber_conflict_found = 1;
|
||
}
|
||
|
||
/* Protect all the operands from the queue now that they have all been
|
||
evaluated. */
|
||
|
||
generating_concat_p = 0;
|
||
|
||
/* For in-out operands, copy output rtx to input rtx. */
|
||
for (i = 0; i < ninout; i++)
|
||
{
|
||
int j = inout_opnum[i];
|
||
char buffer[16];
|
||
|
||
ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
|
||
= output_rtx[j];
|
||
|
||
sprintf (buffer, "%d", j);
|
||
ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
|
||
= gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
|
||
}
|
||
|
||
generating_concat_p = old_generating_concat_p;
|
||
|
||
/* Now, for each output, construct an rtx
|
||
(set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
|
||
ARGVEC CONSTRAINTS OPNAMES))
|
||
If there is more than one, put them inside a PARALLEL. */
|
||
|
||
if (noutputs == 1 && nclobbers == 0)
|
||
{
|
||
ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]);
|
||
emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
|
||
}
|
||
|
||
else if (noutputs == 0 && nclobbers == 0)
|
||
{
|
||
/* No output operands: put in a raw ASM_OPERANDS rtx. */
|
||
emit_insn (body);
|
||
}
|
||
|
||
else
|
||
{
|
||
rtx obody = body;
|
||
int num = noutputs;
|
||
|
||
if (num == 0)
|
||
num = 1;
|
||
|
||
body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
|
||
|
||
/* For each output operand, store a SET. */
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
XVECEXP (body, 0, i)
|
||
= gen_rtx_SET (VOIDmode,
|
||
output_rtx[i],
|
||
gen_rtx_ASM_OPERANDS
|
||
(GET_MODE (output_rtx[i]),
|
||
ggc_strdup (TREE_STRING_POINTER (string)),
|
||
ggc_strdup (constraints[i]),
|
||
i, argvec, constraintvec, locus));
|
||
|
||
MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
|
||
}
|
||
|
||
/* If there are no outputs (but there are some clobbers)
|
||
store the bare ASM_OPERANDS into the PARALLEL. */
|
||
|
||
if (i == 0)
|
||
XVECEXP (body, 0, i++) = obody;
|
||
|
||
/* Store (clobber REG) for each clobbered register specified. */
|
||
|
||
for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
|
||
{
|
||
const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
|
||
int j = decode_reg_name (regname);
|
||
rtx clobbered_reg;
|
||
|
||
if (j < 0)
|
||
{
|
||
if (j == -3) /* `cc', which is not a register */
|
||
continue;
|
||
|
||
if (j == -4) /* `memory', don't cache memory across asm */
|
||
{
|
||
XVECEXP (body, 0, i++)
|
||
= gen_rtx_CLOBBER (VOIDmode,
|
||
gen_rtx_MEM
|
||
(BLKmode,
|
||
gen_rtx_SCRATCH (VOIDmode)));
|
||
continue;
|
||
}
|
||
|
||
/* Ignore unknown register, error already signaled. */
|
||
continue;
|
||
}
|
||
|
||
/* Use QImode since that's guaranteed to clobber just one reg. */
|
||
clobbered_reg = gen_rtx_REG (QImode, j);
|
||
|
||
/* Do sanity check for overlap between clobbers and respectively
|
||
input and outputs that hasn't been handled. Such overlap
|
||
should have been detected and reported above. */
|
||
if (!clobber_conflict_found)
|
||
{
|
||
int opno;
|
||
|
||
/* We test the old body (obody) contents to avoid tripping
|
||
over the under-construction body. */
|
||
for (opno = 0; opno < noutputs; opno++)
|
||
if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno]))
|
||
internal_error ("asm clobber conflict with output operand");
|
||
|
||
for (opno = 0; opno < ninputs - ninout; opno++)
|
||
if (reg_overlap_mentioned_p (clobbered_reg,
|
||
ASM_OPERANDS_INPUT (obody, opno)))
|
||
internal_error ("asm clobber conflict with input operand");
|
||
}
|
||
|
||
XVECEXP (body, 0, i++)
|
||
= gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
|
||
}
|
||
|
||
emit_insn (body);
|
||
}
|
||
|
||
/* For any outputs that needed reloading into registers, spill them
|
||
back to where they belong. */
|
||
for (i = 0; i < noutputs; ++i)
|
||
if (real_output_rtx[i])
|
||
emit_move_insn (real_output_rtx[i], output_rtx[i]);
|
||
|
||
free_temp_slots ();
|
||
}
|
||
|
||
void
|
||
expand_asm_expr (tree exp)
|
||
{
|
||
int noutputs, i;
|
||
tree outputs, tail;
|
||
tree *o;
|
||
|
||
if (ASM_INPUT_P (exp))
|
||
{
|
||
expand_asm (ASM_STRING (exp), ASM_VOLATILE_P (exp));
|
||
return;
|
||
}
|
||
|
||
outputs = ASM_OUTPUTS (exp);
|
||
noutputs = list_length (outputs);
|
||
/* o[I] is the place that output number I should be written. */
|
||
o = (tree *) alloca (noutputs * sizeof (tree));
|
||
|
||
/* Record the contents of OUTPUTS before it is modified. */
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
o[i] = TREE_VALUE (tail);
|
||
|
||
/* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
|
||
OUTPUTS some trees for where the values were actually stored. */
|
||
expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp),
|
||
ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp),
|
||
input_location);
|
||
|
||
/* Copy all the intermediate outputs into the specified outputs. */
|
||
for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
|
||
{
|
||
if (o[i] != TREE_VALUE (tail))
|
||
{
|
||
expand_assignment (o[i], TREE_VALUE (tail));
|
||
free_temp_slots ();
|
||
|
||
/* Restore the original value so that it's correct the next
|
||
time we expand this function. */
|
||
TREE_VALUE (tail) = o[i];
|
||
}
|
||
}
|
||
}
|
||
|
||
/* A subroutine of expand_asm_operands. Check that all operands have
|
||
the same number of alternatives. Return true if so. */
|
||
|
||
static bool
|
||
check_operand_nalternatives (tree outputs, tree inputs)
|
||
{
|
||
if (outputs || inputs)
|
||
{
|
||
tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
|
||
int nalternatives
|
||
= n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
|
||
tree next = inputs;
|
||
|
||
if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
|
||
{
|
||
error ("too many alternatives in %<asm%>");
|
||
return false;
|
||
}
|
||
|
||
tmp = outputs;
|
||
while (tmp)
|
||
{
|
||
const char *constraint
|
||
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
|
||
|
||
if (n_occurrences (',', constraint) != nalternatives)
|
||
{
|
||
error ("operand constraints for %<asm%> differ "
|
||
"in number of alternatives");
|
||
return false;
|
||
}
|
||
|
||
if (TREE_CHAIN (tmp))
|
||
tmp = TREE_CHAIN (tmp);
|
||
else
|
||
tmp = next, next = 0;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* A subroutine of expand_asm_operands. Check that all operand names
|
||
are unique. Return true if so. We rely on the fact that these names
|
||
are identifiers, and so have been canonicalized by get_identifier,
|
||
so all we need are pointer comparisons. */
|
||
|
||
static bool
|
||
check_unique_operand_names (tree outputs, tree inputs)
|
||
{
|
||
tree i, j;
|
||
|
||
for (i = outputs; i ; i = TREE_CHAIN (i))
|
||
{
|
||
tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
|
||
if (! i_name)
|
||
continue;
|
||
|
||
for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
|
||
if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
|
||
goto failure;
|
||
}
|
||
|
||
for (i = inputs; i ; i = TREE_CHAIN (i))
|
||
{
|
||
tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
|
||
if (! i_name)
|
||
continue;
|
||
|
||
for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
|
||
if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
|
||
goto failure;
|
||
for (j = outputs; j ; j = TREE_CHAIN (j))
|
||
if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
|
||
goto failure;
|
||
}
|
||
|
||
return true;
|
||
|
||
failure:
|
||
error ("duplicate asm operand name %qs",
|
||
TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
|
||
return false;
|
||
}
|
||
|
||
/* A subroutine of expand_asm_operands. Resolve the names of the operands
|
||
in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
|
||
STRING and in the constraints to those numbers. */
|
||
|
||
tree
|
||
resolve_asm_operand_names (tree string, tree outputs, tree inputs)
|
||
{
|
||
char *buffer;
|
||
char *p;
|
||
const char *c;
|
||
tree t;
|
||
|
||
check_unique_operand_names (outputs, inputs);
|
||
|
||
/* Substitute [<name>] in input constraint strings. There should be no
|
||
named operands in output constraints. */
|
||
for (t = inputs; t ; t = TREE_CHAIN (t))
|
||
{
|
||
c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
|
||
if (strchr (c, '[') != NULL)
|
||
{
|
||
p = buffer = xstrdup (c);
|
||
while ((p = strchr (p, '[')) != NULL)
|
||
p = resolve_operand_name_1 (p, outputs, inputs);
|
||
TREE_VALUE (TREE_PURPOSE (t))
|
||
= build_string (strlen (buffer), buffer);
|
||
free (buffer);
|
||
}
|
||
}
|
||
|
||
/* Now check for any needed substitutions in the template. */
|
||
c = TREE_STRING_POINTER (string);
|
||
while ((c = strchr (c, '%')) != NULL)
|
||
{
|
||
if (c[1] == '[')
|
||
break;
|
||
else if (ISALPHA (c[1]) && c[2] == '[')
|
||
break;
|
||
else
|
||
{
|
||
c += 1;
|
||
continue;
|
||
}
|
||
}
|
||
|
||
if (c)
|
||
{
|
||
/* OK, we need to make a copy so we can perform the substitutions.
|
||
Assume that we will not need extra space--we get to remove '['
|
||
and ']', which means we cannot have a problem until we have more
|
||
than 999 operands. */
|
||
buffer = xstrdup (TREE_STRING_POINTER (string));
|
||
p = buffer + (c - TREE_STRING_POINTER (string));
|
||
|
||
while ((p = strchr (p, '%')) != NULL)
|
||
{
|
||
if (p[1] == '[')
|
||
p += 1;
|
||
else if (ISALPHA (p[1]) && p[2] == '[')
|
||
p += 2;
|
||
else
|
||
{
|
||
p += 1;
|
||
continue;
|
||
}
|
||
|
||
p = resolve_operand_name_1 (p, outputs, inputs);
|
||
}
|
||
|
||
string = build_string (strlen (buffer), buffer);
|
||
free (buffer);
|
||
}
|
||
|
||
return string;
|
||
}
|
||
|
||
/* A subroutine of resolve_operand_names. P points to the '[' for a
|
||
potential named operand of the form [<name>]. In place, replace
|
||
the name and brackets with a number. Return a pointer to the
|
||
balance of the string after substitution. */
|
||
|
||
static char *
|
||
resolve_operand_name_1 (char *p, tree outputs, tree inputs)
|
||
{
|
||
char *q;
|
||
int op;
|
||
tree t;
|
||
size_t len;
|
||
|
||
/* Collect the operand name. */
|
||
q = strchr (p, ']');
|
||
if (!q)
|
||
{
|
||
error ("missing close brace for named operand");
|
||
return strchr (p, '\0');
|
||
}
|
||
len = q - p - 1;
|
||
|
||
/* Resolve the name to a number. */
|
||
for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
|
||
{
|
||
tree name = TREE_PURPOSE (TREE_PURPOSE (t));
|
||
if (name)
|
||
{
|
||
const char *c = TREE_STRING_POINTER (name);
|
||
if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
|
||
goto found;
|
||
}
|
||
}
|
||
for (t = inputs; t ; t = TREE_CHAIN (t), op++)
|
||
{
|
||
tree name = TREE_PURPOSE (TREE_PURPOSE (t));
|
||
if (name)
|
||
{
|
||
const char *c = TREE_STRING_POINTER (name);
|
||
if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
|
||
goto found;
|
||
}
|
||
}
|
||
|
||
*q = '\0';
|
||
error ("undefined named operand %qs", p + 1);
|
||
op = 0;
|
||
found:
|
||
|
||
/* Replace the name with the number. Unfortunately, not all libraries
|
||
get the return value of sprintf correct, so search for the end of the
|
||
generated string by hand. */
|
||
sprintf (p, "%d", op);
|
||
p = strchr (p, '\0');
|
||
|
||
/* Verify the no extra buffer space assumption. */
|
||
gcc_assert (p <= q);
|
||
|
||
/* Shift the rest of the buffer down to fill the gap. */
|
||
memmove (p, q + 1, strlen (q + 1) + 1);
|
||
|
||
return p;
|
||
}
|
||
|
||
/* Generate RTL to evaluate the expression EXP. */
|
||
|
||
void
|
||
expand_expr_stmt (tree exp)
|
||
{
|
||
rtx value;
|
||
tree type;
|
||
|
||
value = expand_expr (exp, const0_rtx, VOIDmode, 0);
|
||
if (GIMPLE_TUPLE_P (exp))
|
||
type = void_type_node;
|
||
else
|
||
type = TREE_TYPE (exp);
|
||
|
||
/* If all we do is reference a volatile value in memory,
|
||
copy it to a register to be sure it is actually touched. */
|
||
if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp))
|
||
{
|
||
if (TYPE_MODE (type) == VOIDmode)
|
||
;
|
||
else if (TYPE_MODE (type) != BLKmode)
|
||
value = copy_to_reg (value);
|
||
else
|
||
{
|
||
rtx lab = gen_label_rtx ();
|
||
|
||
/* Compare the value with itself to reference it. */
|
||
emit_cmp_and_jump_insns (value, value, EQ,
|
||
expand_normal (TYPE_SIZE (type)),
|
||
BLKmode, 0, lab);
|
||
emit_label (lab);
|
||
}
|
||
}
|
||
|
||
/* Free any temporaries used to evaluate this expression. */
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* Warn if EXP contains any computations whose results are not used.
|
||
Return 1 if a warning is printed; 0 otherwise. LOCUS is the
|
||
(potential) location of the expression. */
|
||
|
||
int
|
||
warn_if_unused_value (tree exp, location_t locus)
|
||
{
|
||
restart:
|
||
if (TREE_USED (exp) || TREE_NO_WARNING (exp))
|
||
return 0;
|
||
|
||
/* Don't warn about void constructs. This includes casting to void,
|
||
void function calls, and statement expressions with a final cast
|
||
to void. */
|
||
if (VOID_TYPE_P (TREE_TYPE (exp)))
|
||
return 0;
|
||
|
||
if (EXPR_HAS_LOCATION (exp))
|
||
locus = EXPR_LOCATION (exp);
|
||
|
||
switch (TREE_CODE (exp))
|
||
{
|
||
case PREINCREMENT_EXPR:
|
||
case POSTINCREMENT_EXPR:
|
||
case PREDECREMENT_EXPR:
|
||
case POSTDECREMENT_EXPR:
|
||
case MODIFY_EXPR:
|
||
case GIMPLE_MODIFY_STMT:
|
||
case INIT_EXPR:
|
||
case TARGET_EXPR:
|
||
case CALL_EXPR:
|
||
case TRY_CATCH_EXPR:
|
||
case WITH_CLEANUP_EXPR:
|
||
case EXIT_EXPR:
|
||
case VA_ARG_EXPR:
|
||
return 0;
|
||
|
||
case BIND_EXPR:
|
||
/* For a binding, warn if no side effect within it. */
|
||
exp = BIND_EXPR_BODY (exp);
|
||
goto restart;
|
||
|
||
case SAVE_EXPR:
|
||
exp = TREE_OPERAND (exp, 0);
|
||
goto restart;
|
||
|
||
case TRUTH_ORIF_EXPR:
|
||
case TRUTH_ANDIF_EXPR:
|
||
/* In && or ||, warn if 2nd operand has no side effect. */
|
||
exp = TREE_OPERAND (exp, 1);
|
||
goto restart;
|
||
|
||
case COMPOUND_EXPR:
|
||
if (warn_if_unused_value (TREE_OPERAND (exp, 0), locus))
|
||
return 1;
|
||
/* Let people do `(foo (), 0)' without a warning. */
|
||
if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
|
||
return 0;
|
||
exp = TREE_OPERAND (exp, 1);
|
||
goto restart;
|
||
|
||
case COND_EXPR:
|
||
/* If this is an expression with side effects, don't warn; this
|
||
case commonly appears in macro expansions. */
|
||
if (TREE_SIDE_EFFECTS (exp))
|
||
return 0;
|
||
goto warn;
|
||
|
||
case INDIRECT_REF:
|
||
/* Don't warn about automatic dereferencing of references, since
|
||
the user cannot control it. */
|
||
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
|
||
{
|
||
exp = TREE_OPERAND (exp, 0);
|
||
goto restart;
|
||
}
|
||
/* Fall through. */
|
||
|
||
default:
|
||
/* Referencing a volatile value is a side effect, so don't warn. */
|
||
if ((DECL_P (exp) || REFERENCE_CLASS_P (exp))
|
||
&& TREE_THIS_VOLATILE (exp))
|
||
return 0;
|
||
|
||
/* If this is an expression which has no operands, there is no value
|
||
to be unused. There are no such language-independent codes,
|
||
but front ends may define such. */
|
||
if (EXPRESSION_CLASS_P (exp) && TREE_OPERAND_LENGTH (exp) == 0)
|
||
return 0;
|
||
|
||
warn:
|
||
warning (0, "%Hvalue computed is not used", &locus);
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
|
||
/* Generate RTL to return from the current function, with no value.
|
||
(That is, we do not do anything about returning any value.) */
|
||
|
||
void
|
||
expand_null_return (void)
|
||
{
|
||
/* If this function was declared to return a value, but we
|
||
didn't, clobber the return registers so that they are not
|
||
propagated live to the rest of the function. */
|
||
clobber_return_register ();
|
||
|
||
expand_null_return_1 ();
|
||
}
|
||
|
||
/* Generate RTL to return directly from the current function.
|
||
(That is, we bypass any return value.) */
|
||
|
||
void
|
||
expand_naked_return (void)
|
||
{
|
||
rtx end_label;
|
||
|
||
clear_pending_stack_adjust ();
|
||
do_pending_stack_adjust ();
|
||
|
||
end_label = naked_return_label;
|
||
if (end_label == 0)
|
||
end_label = naked_return_label = gen_label_rtx ();
|
||
|
||
emit_jump (end_label);
|
||
}
|
||
|
||
/* Generate RTL to return from the current function, with value VAL. */
|
||
|
||
static void
|
||
expand_value_return (rtx val)
|
||
{
|
||
/* Copy the value to the return location
|
||
unless it's already there. */
|
||
|
||
rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
|
||
if (return_reg != val)
|
||
{
|
||
tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
|
||
if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
|
||
{
|
||
int unsignedp = TYPE_UNSIGNED (type);
|
||
enum machine_mode old_mode
|
||
= DECL_MODE (DECL_RESULT (current_function_decl));
|
||
enum machine_mode mode
|
||
= promote_mode (type, old_mode, &unsignedp, 1);
|
||
|
||
if (mode != old_mode)
|
||
val = convert_modes (mode, old_mode, val, unsignedp);
|
||
}
|
||
if (GET_CODE (return_reg) == PARALLEL)
|
||
emit_group_load (return_reg, val, type, int_size_in_bytes (type));
|
||
else
|
||
emit_move_insn (return_reg, val);
|
||
}
|
||
|
||
expand_null_return_1 ();
|
||
}
|
||
|
||
/* Output a return with no value. */
|
||
|
||
static void
|
||
expand_null_return_1 (void)
|
||
{
|
||
clear_pending_stack_adjust ();
|
||
do_pending_stack_adjust ();
|
||
emit_jump (return_label);
|
||
}
|
||
|
||
/* Generate RTL to evaluate the expression RETVAL and return it
|
||
from the current function. */
|
||
|
||
void
|
||
expand_return (tree retval)
|
||
{
|
||
rtx result_rtl;
|
||
rtx val = 0;
|
||
tree retval_rhs;
|
||
|
||
/* If function wants no value, give it none. */
|
||
if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
|
||
{
|
||
expand_normal (retval);
|
||
expand_null_return ();
|
||
return;
|
||
}
|
||
|
||
if (retval == error_mark_node)
|
||
{
|
||
/* Treat this like a return of no value from a function that
|
||
returns a value. */
|
||
expand_null_return ();
|
||
return;
|
||
}
|
||
else if ((TREE_CODE (retval) == GIMPLE_MODIFY_STMT
|
||
|| TREE_CODE (retval) == INIT_EXPR)
|
||
&& TREE_CODE (GENERIC_TREE_OPERAND (retval, 0)) == RESULT_DECL)
|
||
retval_rhs = GENERIC_TREE_OPERAND (retval, 1);
|
||
else
|
||
retval_rhs = retval;
|
||
|
||
result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
|
||
|
||
/* If we are returning the RESULT_DECL, then the value has already
|
||
been stored into it, so we don't have to do anything special. */
|
||
if (TREE_CODE (retval_rhs) == RESULT_DECL)
|
||
expand_value_return (result_rtl);
|
||
|
||
/* If the result is an aggregate that is being returned in one (or more)
|
||
registers, load the registers here. The compiler currently can't handle
|
||
copying a BLKmode value into registers. We could put this code in a
|
||
more general area (for use by everyone instead of just function
|
||
call/return), but until this feature is generally usable it is kept here
|
||
(and in expand_call). */
|
||
|
||
else if (retval_rhs != 0
|
||
&& TYPE_MODE (GENERIC_TREE_TYPE (retval_rhs)) == BLKmode
|
||
&& REG_P (result_rtl))
|
||
{
|
||
int i;
|
||
unsigned HOST_WIDE_INT bitpos, xbitpos;
|
||
unsigned HOST_WIDE_INT padding_correction = 0;
|
||
unsigned HOST_WIDE_INT bytes
|
||
= int_size_in_bytes (TREE_TYPE (retval_rhs));
|
||
int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
|
||
unsigned int bitsize
|
||
= MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
|
||
rtx *result_pseudos = alloca (sizeof (rtx) * n_regs);
|
||
rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
|
||
rtx result_val = expand_normal (retval_rhs);
|
||
enum machine_mode tmpmode, result_reg_mode;
|
||
|
||
if (bytes == 0)
|
||
{
|
||
expand_null_return ();
|
||
return;
|
||
}
|
||
|
||
/* If the structure doesn't take up a whole number of words, see
|
||
whether the register value should be padded on the left or on
|
||
the right. Set PADDING_CORRECTION to the number of padding
|
||
bits needed on the left side.
|
||
|
||
In most ABIs, the structure will be returned at the least end of
|
||
the register, which translates to right padding on little-endian
|
||
targets and left padding on big-endian targets. The opposite
|
||
holds if the structure is returned at the most significant
|
||
end of the register. */
|
||
if (bytes % UNITS_PER_WORD != 0
|
||
&& (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
|
||
? !BYTES_BIG_ENDIAN
|
||
: BYTES_BIG_ENDIAN))
|
||
padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
|
||
* BITS_PER_UNIT));
|
||
|
||
/* Copy the structure BITSIZE bits at a time. */
|
||
for (bitpos = 0, xbitpos = padding_correction;
|
||
bitpos < bytes * BITS_PER_UNIT;
|
||
bitpos += bitsize, xbitpos += bitsize)
|
||
{
|
||
/* We need a new destination pseudo each time xbitpos is
|
||
on a word boundary and when xbitpos == padding_correction
|
||
(the first time through). */
|
||
if (xbitpos % BITS_PER_WORD == 0
|
||
|| xbitpos == padding_correction)
|
||
{
|
||
/* Generate an appropriate register. */
|
||
dst = gen_reg_rtx (word_mode);
|
||
result_pseudos[xbitpos / BITS_PER_WORD] = dst;
|
||
|
||
/* Clear the destination before we move anything into it. */
|
||
emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
|
||
}
|
||
|
||
/* We need a new source operand each time bitpos is on a word
|
||
boundary. */
|
||
if (bitpos % BITS_PER_WORD == 0)
|
||
src = operand_subword_force (result_val,
|
||
bitpos / BITS_PER_WORD,
|
||
BLKmode);
|
||
|
||
/* Use bitpos for the source extraction (left justified) and
|
||
xbitpos for the destination store (right justified). */
|
||
store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
|
||
extract_bit_field (src, bitsize,
|
||
bitpos % BITS_PER_WORD, 1,
|
||
NULL_RTX, word_mode, word_mode));
|
||
}
|
||
|
||
tmpmode = GET_MODE (result_rtl);
|
||
if (tmpmode == BLKmode)
|
||
{
|
||
/* Find the smallest integer mode large enough to hold the
|
||
entire structure and use that mode instead of BLKmode
|
||
on the USE insn for the return register. */
|
||
for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
|
||
tmpmode != VOIDmode;
|
||
tmpmode = GET_MODE_WIDER_MODE (tmpmode))
|
||
/* Have we found a large enough mode? */
|
||
if (GET_MODE_SIZE (tmpmode) >= bytes)
|
||
break;
|
||
|
||
/* A suitable mode should have been found. */
|
||
gcc_assert (tmpmode != VOIDmode);
|
||
|
||
PUT_MODE (result_rtl, tmpmode);
|
||
}
|
||
|
||
if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
|
||
result_reg_mode = word_mode;
|
||
else
|
||
result_reg_mode = tmpmode;
|
||
result_reg = gen_reg_rtx (result_reg_mode);
|
||
|
||
for (i = 0; i < n_regs; i++)
|
||
emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
|
||
result_pseudos[i]);
|
||
|
||
if (tmpmode != result_reg_mode)
|
||
result_reg = gen_lowpart (tmpmode, result_reg);
|
||
|
||
expand_value_return (result_reg);
|
||
}
|
||
else if (retval_rhs != 0
|
||
&& !VOID_TYPE_P (TREE_TYPE (retval_rhs))
|
||
&& (REG_P (result_rtl)
|
||
|| (GET_CODE (result_rtl) == PARALLEL)))
|
||
{
|
||
/* Calculate the return value into a temporary (usually a pseudo
|
||
reg). */
|
||
tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
|
||
tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
|
||
|
||
val = assign_temp (nt, 0, 0, 1);
|
||
val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
|
||
val = force_not_mem (val);
|
||
/* Return the calculated value. */
|
||
expand_value_return (val);
|
||
}
|
||
else
|
||
{
|
||
/* No hard reg used; calculate value into hard return reg. */
|
||
expand_expr (retval, const0_rtx, VOIDmode, 0);
|
||
expand_value_return (result_rtl);
|
||
}
|
||
}
|
||
|
||
/* Given a pointer to a BLOCK node return nonzero if (and only if) the node
|
||
in question represents the outermost pair of curly braces (i.e. the "body
|
||
block") of a function or method.
|
||
|
||
For any BLOCK node representing a "body block" of a function or method, the
|
||
BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
|
||
represents the outermost (function) scope for the function or method (i.e.
|
||
the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
|
||
*that* node in turn will point to the relevant FUNCTION_DECL node. */
|
||
|
||
int
|
||
is_body_block (tree stmt)
|
||
{
|
||
if (lang_hooks.no_body_blocks)
|
||
return 0;
|
||
|
||
if (TREE_CODE (stmt) == BLOCK)
|
||
{
|
||
tree parent = BLOCK_SUPERCONTEXT (stmt);
|
||
|
||
if (parent && TREE_CODE (parent) == BLOCK)
|
||
{
|
||
tree grandparent = BLOCK_SUPERCONTEXT (parent);
|
||
|
||
if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Emit code to restore vital registers at the beginning of a nonlocal goto
|
||
handler. */
|
||
static void
|
||
expand_nl_goto_receiver (void)
|
||
{
|
||
/* Clobber the FP when we get here, so we have to make sure it's
|
||
marked as used by this function. */
|
||
emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
|
||
|
||
/* Mark the static chain as clobbered here so life information
|
||
doesn't get messed up for it. */
|
||
emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx));
|
||
|
||
#ifdef HAVE_nonlocal_goto
|
||
if (! HAVE_nonlocal_goto)
|
||
#endif
|
||
/* First adjust our frame pointer to its actual value. It was
|
||
previously set to the start of the virtual area corresponding to
|
||
the stacked variables when we branched here and now needs to be
|
||
adjusted to the actual hardware fp value.
|
||
|
||
Assignments are to virtual registers are converted by
|
||
instantiate_virtual_regs into the corresponding assignment
|
||
to the underlying register (fp in this case) that makes
|
||
the original assignment true.
|
||
So the following insn will actually be
|
||
decrementing fp by STARTING_FRAME_OFFSET. */
|
||
emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
|
||
|
||
#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
|
||
if (fixed_regs[ARG_POINTER_REGNUM])
|
||
{
|
||
#ifdef ELIMINABLE_REGS
|
||
/* If the argument pointer can be eliminated in favor of the
|
||
frame pointer, we don't need to restore it. We assume here
|
||
that if such an elimination is present, it can always be used.
|
||
This is the case on all known machines; if we don't make this
|
||
assumption, we do unnecessary saving on many machines. */
|
||
static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
|
||
size_t i;
|
||
|
||
for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
|
||
if (elim_regs[i].from == ARG_POINTER_REGNUM
|
||
&& elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
|
||
break;
|
||
|
||
if (i == ARRAY_SIZE (elim_regs))
|
||
#endif
|
||
{
|
||
/* Now restore our arg pointer from the address at which it
|
||
was saved in our stack frame. */
|
||
emit_move_insn (virtual_incoming_args_rtx,
|
||
copy_to_reg (get_arg_pointer_save_area (cfun)));
|
||
}
|
||
}
|
||
#endif
|
||
|
||
#ifdef HAVE_nonlocal_goto_receiver
|
||
if (HAVE_nonlocal_goto_receiver)
|
||
emit_insn (gen_nonlocal_goto_receiver ());
|
||
#endif
|
||
|
||
/* @@@ This is a kludge. Not all machine descriptions define a blockage
|
||
insn, but we must not allow the code we just generated to be reordered
|
||
by scheduling. Specifically, the update of the frame pointer must
|
||
happen immediately, not later. So emit an ASM_INPUT to act as blockage
|
||
insn. */
|
||
emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
|
||
}
|
||
|
||
/* Generate RTL for the automatic variable declaration DECL.
|
||
(Other kinds of declarations are simply ignored if seen here.) */
|
||
|
||
void
|
||
expand_decl (tree decl)
|
||
{
|
||
tree type;
|
||
|
||
type = TREE_TYPE (decl);
|
||
|
||
/* For a CONST_DECL, set mode, alignment, and sizes from those of the
|
||
type in case this node is used in a reference. */
|
||
if (TREE_CODE (decl) == CONST_DECL)
|
||
{
|
||
DECL_MODE (decl) = TYPE_MODE (type);
|
||
DECL_ALIGN (decl) = TYPE_ALIGN (type);
|
||
DECL_SIZE (decl) = TYPE_SIZE (type);
|
||
DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
|
||
return;
|
||
}
|
||
|
||
/* Otherwise, only automatic variables need any expansion done. Static and
|
||
external variables, and external functions, will be handled by
|
||
`assemble_variable' (called from finish_decl). TYPE_DECL requires
|
||
nothing. PARM_DECLs are handled in `assign_parms'. */
|
||
if (TREE_CODE (decl) != VAR_DECL)
|
||
return;
|
||
|
||
if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
|
||
return;
|
||
|
||
/* Create the RTL representation for the variable. */
|
||
|
||
if (type == error_mark_node)
|
||
SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));
|
||
|
||
else if (DECL_SIZE (decl) == 0)
|
||
/* Variable with incomplete type. */
|
||
{
|
||
rtx x;
|
||
if (DECL_INITIAL (decl) == 0)
|
||
/* Error message was already done; now avoid a crash. */
|
||
x = gen_rtx_MEM (BLKmode, const0_rtx);
|
||
else
|
||
/* An initializer is going to decide the size of this array.
|
||
Until we know the size, represent its address with a reg. */
|
||
x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
|
||
|
||
set_mem_attributes (x, decl, 1);
|
||
SET_DECL_RTL (decl, x);
|
||
}
|
||
else if (use_register_for_decl (decl))
|
||
{
|
||
/* Automatic variable that can go in a register. */
|
||
int unsignedp = TYPE_UNSIGNED (type);
|
||
enum machine_mode reg_mode
|
||
= promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
|
||
|
||
SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));
|
||
|
||
/* Note if the object is a user variable. */
|
||
if (!DECL_ARTIFICIAL (decl))
|
||
{
|
||
mark_user_reg (DECL_RTL (decl));
|
||
|
||
/* Trust user variables which have a pointer type to really
|
||
be pointers. Do not trust compiler generated temporaries
|
||
as our type system is totally busted as it relates to
|
||
pointer arithmetic which translates into lots of compiler
|
||
generated objects with pointer types, but which are not really
|
||
pointers. */
|
||
if (POINTER_TYPE_P (type))
|
||
mark_reg_pointer (DECL_RTL (decl),
|
||
TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
|
||
}
|
||
}
|
||
|
||
else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
|
||
&& ! (flag_stack_check && ! STACK_CHECK_BUILTIN
|
||
&& 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
|
||
STACK_CHECK_MAX_VAR_SIZE)))
|
||
{
|
||
/* Variable of fixed size that goes on the stack. */
|
||
rtx oldaddr = 0;
|
||
rtx addr;
|
||
rtx x;
|
||
|
||
/* If we previously made RTL for this decl, it must be an array
|
||
whose size was determined by the initializer.
|
||
The old address was a register; set that register now
|
||
to the proper address. */
|
||
if (DECL_RTL_SET_P (decl))
|
||
{
|
||
gcc_assert (MEM_P (DECL_RTL (decl)));
|
||
gcc_assert (REG_P (XEXP (DECL_RTL (decl), 0)));
|
||
oldaddr = XEXP (DECL_RTL (decl), 0);
|
||
}
|
||
|
||
/* Set alignment we actually gave this decl. */
|
||
DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
|
||
: GET_MODE_BITSIZE (DECL_MODE (decl)));
|
||
DECL_USER_ALIGN (decl) = 0;
|
||
|
||
x = assign_temp (decl, 1, 1, 1);
|
||
set_mem_attributes (x, decl, 1);
|
||
SET_DECL_RTL (decl, x);
|
||
|
||
if (oldaddr)
|
||
{
|
||
addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
|
||
if (addr != oldaddr)
|
||
emit_move_insn (oldaddr, addr);
|
||
}
|
||
}
|
||
else
|
||
/* Dynamic-size object: must push space on the stack. */
|
||
{
|
||
rtx address, size, x;
|
||
|
||
/* Record the stack pointer on entry to block, if have
|
||
not already done so. */
|
||
do_pending_stack_adjust ();
|
||
|
||
/* Compute the variable's size, in bytes. This will expand any
|
||
needed SAVE_EXPRs for the first time. */
|
||
size = expand_normal (DECL_SIZE_UNIT (decl));
|
||
free_temp_slots ();
|
||
|
||
/* Allocate space on the stack for the variable. Note that
|
||
DECL_ALIGN says how the variable is to be aligned and we
|
||
cannot use it to conclude anything about the alignment of
|
||
the size. */
|
||
address = allocate_dynamic_stack_space (size, NULL_RTX,
|
||
TYPE_ALIGN (TREE_TYPE (decl)));
|
||
|
||
/* Reference the variable indirect through that rtx. */
|
||
x = gen_rtx_MEM (DECL_MODE (decl), address);
|
||
set_mem_attributes (x, decl, 1);
|
||
SET_DECL_RTL (decl, x);
|
||
|
||
|
||
/* Indicate the alignment we actually gave this variable. */
|
||
#ifdef STACK_BOUNDARY
|
||
DECL_ALIGN (decl) = STACK_BOUNDARY;
|
||
#else
|
||
DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
|
||
#endif
|
||
DECL_USER_ALIGN (decl) = 0;
|
||
}
|
||
}
|
||
|
||
/* Emit code to save the current value of stack. */
|
||
rtx
|
||
expand_stack_save (void)
|
||
{
|
||
rtx ret = NULL_RTX;
|
||
|
||
do_pending_stack_adjust ();
|
||
emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX);
|
||
return ret;
|
||
}
|
||
|
||
/* Emit code to restore the current value of stack. */
|
||
void
|
||
expand_stack_restore (tree var)
|
||
{
|
||
rtx sa = DECL_RTL (var);
|
||
|
||
emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX);
|
||
}
|
||
|
||
/* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
|
||
DECL_ELTS is the list of elements that belong to DECL's type.
|
||
In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
|
||
|
||
void
|
||
expand_anon_union_decl (tree decl, tree cleanup ATTRIBUTE_UNUSED,
|
||
tree decl_elts)
|
||
{
|
||
rtx x;
|
||
tree t;
|
||
|
||
/* If any of the elements are addressable, so is the entire union. */
|
||
for (t = decl_elts; t; t = TREE_CHAIN (t))
|
||
if (TREE_ADDRESSABLE (TREE_VALUE (t)))
|
||
{
|
||
TREE_ADDRESSABLE (decl) = 1;
|
||
break;
|
||
}
|
||
|
||
expand_decl (decl);
|
||
x = DECL_RTL (decl);
|
||
|
||
/* Go through the elements, assigning RTL to each. */
|
||
for (t = decl_elts; t; t = TREE_CHAIN (t))
|
||
{
|
||
tree decl_elt = TREE_VALUE (t);
|
||
enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
|
||
rtx decl_rtl;
|
||
|
||
/* If any of the elements are addressable, so is the entire
|
||
union. */
|
||
if (TREE_USED (decl_elt))
|
||
TREE_USED (decl) = 1;
|
||
|
||
/* Propagate the union's alignment to the elements. */
|
||
DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
|
||
DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
|
||
|
||
/* If the element has BLKmode and the union doesn't, the union is
|
||
aligned such that the element doesn't need to have BLKmode, so
|
||
change the element's mode to the appropriate one for its size. */
|
||
if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
|
||
DECL_MODE (decl_elt) = mode
|
||
= mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
|
||
|
||
if (mode == GET_MODE (x))
|
||
decl_rtl = x;
|
||
else if (MEM_P (x))
|
||
/* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
|
||
instead create a new MEM rtx with the proper mode. */
|
||
decl_rtl = adjust_address_nv (x, mode, 0);
|
||
else
|
||
{
|
||
gcc_assert (REG_P (x));
|
||
decl_rtl = gen_lowpart_SUBREG (mode, x);
|
||
}
|
||
SET_DECL_RTL (decl_elt, decl_rtl);
|
||
}
|
||
}
|
||
|
||
/* Do the insertion of a case label into case_list. The labels are
|
||
fed to us in descending order from the sorted vector of case labels used
|
||
in the tree part of the middle end. So the list we construct is
|
||
sorted in ascending order. The bounds on the case range, LOW and HIGH,
|
||
are converted to case's index type TYPE. */
|
||
|
||
static struct case_node *
|
||
add_case_node (struct case_node *head, tree type, tree low, tree high,
|
||
tree label)
|
||
{
|
||
tree min_value, max_value;
|
||
struct case_node *r;
|
||
|
||
gcc_assert (TREE_CODE (low) == INTEGER_CST);
|
||
gcc_assert (!high || TREE_CODE (high) == INTEGER_CST);
|
||
|
||
min_value = TYPE_MIN_VALUE (type);
|
||
max_value = TYPE_MAX_VALUE (type);
|
||
|
||
/* If there's no HIGH value, then this is not a case range; it's
|
||
just a simple case label. But that's just a degenerate case
|
||
range.
|
||
If the bounds are equal, turn this into the one-value case. */
|
||
if (!high || tree_int_cst_equal (low, high))
|
||
{
|
||
/* If the simple case value is unreachable, ignore it. */
|
||
if ((TREE_CODE (min_value) == INTEGER_CST
|
||
&& tree_int_cst_compare (low, min_value) < 0)
|
||
|| (TREE_CODE (max_value) == INTEGER_CST
|
||
&& tree_int_cst_compare (low, max_value) > 0))
|
||
return head;
|
||
low = fold_convert (type, low);
|
||
high = low;
|
||
}
|
||
else
|
||
{
|
||
/* If the entire case range is unreachable, ignore it. */
|
||
if ((TREE_CODE (min_value) == INTEGER_CST
|
||
&& tree_int_cst_compare (high, min_value) < 0)
|
||
|| (TREE_CODE (max_value) == INTEGER_CST
|
||
&& tree_int_cst_compare (low, max_value) > 0))
|
||
return head;
|
||
|
||
/* If the lower bound is less than the index type's minimum
|
||
value, truncate the range bounds. */
|
||
if (TREE_CODE (min_value) == INTEGER_CST
|
||
&& tree_int_cst_compare (low, min_value) < 0)
|
||
low = min_value;
|
||
low = fold_convert (type, low);
|
||
|
||
/* If the upper bound is greater than the index type's maximum
|
||
value, truncate the range bounds. */
|
||
if (TREE_CODE (max_value) == INTEGER_CST
|
||
&& tree_int_cst_compare (high, max_value) > 0)
|
||
high = max_value;
|
||
high = fold_convert (type, high);
|
||
}
|
||
|
||
|
||
/* Add this label to the chain. Make sure to drop overflow flags. */
|
||
r = ggc_alloc (sizeof (struct case_node));
|
||
r->low = build_int_cst_wide (TREE_TYPE (low), TREE_INT_CST_LOW (low),
|
||
TREE_INT_CST_HIGH (low));
|
||
r->high = build_int_cst_wide (TREE_TYPE (high), TREE_INT_CST_LOW (high),
|
||
TREE_INT_CST_HIGH (high));
|
||
r->code_label = label;
|
||
r->parent = r->left = NULL;
|
||
r->right = head;
|
||
return r;
|
||
}
|
||
|
||
/* Maximum number of case bit tests. */
|
||
#define MAX_CASE_BIT_TESTS 3
|
||
|
||
/* By default, enable case bit tests on targets with ashlsi3. */
|
||
#ifndef CASE_USE_BIT_TESTS
|
||
#define CASE_USE_BIT_TESTS (ashl_optab->handlers[word_mode].insn_code \
|
||
!= CODE_FOR_nothing)
|
||
#endif
|
||
|
||
|
||
/* A case_bit_test represents a set of case nodes that may be
|
||
selected from using a bit-wise comparison. HI and LO hold
|
||
the integer to be tested against, LABEL contains the label
|
||
to jump to upon success and BITS counts the number of case
|
||
nodes handled by this test, typically the number of bits
|
||
set in HI:LO. */
|
||
|
||
struct case_bit_test
|
||
{
|
||
HOST_WIDE_INT hi;
|
||
HOST_WIDE_INT lo;
|
||
rtx label;
|
||
int bits;
|
||
};
|
||
|
||
/* Determine whether "1 << x" is relatively cheap in word_mode. */
|
||
|
||
static
|
||
bool lshift_cheap_p (void)
|
||
{
|
||
static bool init = false;
|
||
static bool cheap = true;
|
||
|
||
if (!init)
|
||
{
|
||
rtx reg = gen_rtx_REG (word_mode, 10000);
|
||
int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET);
|
||
cheap = cost < COSTS_N_INSNS (3);
|
||
init = true;
|
||
}
|
||
|
||
return cheap;
|
||
}
|
||
|
||
/* Comparison function for qsort to order bit tests by decreasing
|
||
number of case nodes, i.e. the node with the most cases gets
|
||
tested first. */
|
||
|
||
static int
|
||
case_bit_test_cmp (const void *p1, const void *p2)
|
||
{
|
||
const struct case_bit_test *d1 = p1;
|
||
const struct case_bit_test *d2 = p2;
|
||
|
||
if (d2->bits != d1->bits)
|
||
return d2->bits - d1->bits;
|
||
|
||
/* Stabilize the sort. */
|
||
return CODE_LABEL_NUMBER (d2->label) - CODE_LABEL_NUMBER (d1->label);
|
||
}
|
||
|
||
/* Expand a switch statement by a short sequence of bit-wise
|
||
comparisons. "switch(x)" is effectively converted into
|
||
"if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
|
||
integer constants.
|
||
|
||
INDEX_EXPR is the value being switched on, which is of
|
||
type INDEX_TYPE. MINVAL is the lowest case value of in
|
||
the case nodes, of INDEX_TYPE type, and RANGE is highest
|
||
value minus MINVAL, also of type INDEX_TYPE. NODES is
|
||
the set of case nodes, and DEFAULT_LABEL is the label to
|
||
branch to should none of the cases match.
|
||
|
||
There *MUST* be MAX_CASE_BIT_TESTS or less unique case
|
||
node targets. */
|
||
|
||
static void
|
||
emit_case_bit_tests (tree index_type, tree index_expr, tree minval,
|
||
tree range, case_node_ptr nodes, rtx default_label)
|
||
{
|
||
struct case_bit_test test[MAX_CASE_BIT_TESTS];
|
||
enum machine_mode mode;
|
||
rtx expr, index, label;
|
||
unsigned int i,j,lo,hi;
|
||
struct case_node *n;
|
||
unsigned int count;
|
||
|
||
count = 0;
|
||
for (n = nodes; n; n = n->right)
|
||
{
|
||
label = label_rtx (n->code_label);
|
||
for (i = 0; i < count; i++)
|
||
if (label == test[i].label)
|
||
break;
|
||
|
||
if (i == count)
|
||
{
|
||
gcc_assert (count < MAX_CASE_BIT_TESTS);
|
||
test[i].hi = 0;
|
||
test[i].lo = 0;
|
||
test[i].label = label;
|
||
test[i].bits = 1;
|
||
count++;
|
||
}
|
||
else
|
||
test[i].bits++;
|
||
|
||
lo = tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
|
||
n->low, minval), 1);
|
||
hi = tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
|
||
n->high, minval), 1);
|
||
for (j = lo; j <= hi; j++)
|
||
if (j >= HOST_BITS_PER_WIDE_INT)
|
||
test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT);
|
||
else
|
||
test[i].lo |= (HOST_WIDE_INT) 1 << j;
|
||
}
|
||
|
||
qsort (test, count, sizeof(*test), case_bit_test_cmp);
|
||
|
||
index_expr = fold_build2 (MINUS_EXPR, index_type,
|
||
fold_convert (index_type, index_expr),
|
||
fold_convert (index_type, minval));
|
||
index = expand_normal (index_expr);
|
||
do_pending_stack_adjust ();
|
||
|
||
mode = TYPE_MODE (index_type);
|
||
expr = expand_normal (range);
|
||
emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1,
|
||
default_label);
|
||
|
||
index = convert_to_mode (word_mode, index, 0);
|
||
index = expand_binop (word_mode, ashl_optab, const1_rtx,
|
||
index, NULL_RTX, 1, OPTAB_WIDEN);
|
||
|
||
for (i = 0; i < count; i++)
|
||
{
|
||
expr = immed_double_const (test[i].lo, test[i].hi, word_mode);
|
||
expr = expand_binop (word_mode, and_optab, index, expr,
|
||
NULL_RTX, 1, OPTAB_WIDEN);
|
||
emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX,
|
||
word_mode, 1, test[i].label);
|
||
}
|
||
|
||
emit_jump (default_label);
|
||
}
|
||
|
||
#ifndef HAVE_casesi
|
||
#define HAVE_casesi 0
|
||
#endif
|
||
|
||
#ifndef HAVE_tablejump
|
||
#define HAVE_tablejump 0
|
||
#endif
|
||
|
||
/* Terminate a case (Pascal/Ada) or switch (C) statement
|
||
in which ORIG_INDEX is the expression to be tested.
|
||
If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
|
||
type as given in the source before any compiler conversions.
|
||
Generate the code to test it and jump to the right place. */
|
||
|
||
void
|
||
expand_case (tree exp)
|
||
{
|
||
tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
|
||
rtx default_label = 0;
|
||
struct case_node *n;
|
||
unsigned int count, uniq;
|
||
rtx index;
|
||
rtx table_label;
|
||
int ncases;
|
||
rtx *labelvec;
|
||
int i, fail;
|
||
rtx before_case, end, lab;
|
||
|
||
tree vec = SWITCH_LABELS (exp);
|
||
tree orig_type = TREE_TYPE (exp);
|
||
tree index_expr = SWITCH_COND (exp);
|
||
tree index_type = TREE_TYPE (index_expr);
|
||
int unsignedp = TYPE_UNSIGNED (index_type);
|
||
|
||
/* The insn after which the case dispatch should finally
|
||
be emitted. Zero for a dummy. */
|
||
rtx start;
|
||
|
||
/* A list of case labels; it is first built as a list and it may then
|
||
be rearranged into a nearly balanced binary tree. */
|
||
struct case_node *case_list = 0;
|
||
|
||
/* Label to jump to if no case matches. */
|
||
tree default_label_decl;
|
||
|
||
/* The switch body is lowered in gimplify.c, we should never have
|
||
switches with a non-NULL SWITCH_BODY here. */
|
||
gcc_assert (!SWITCH_BODY (exp));
|
||
gcc_assert (SWITCH_LABELS (exp));
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* An ERROR_MARK occurs for various reasons including invalid data type. */
|
||
if (index_type != error_mark_node)
|
||
{
|
||
tree elt;
|
||
bitmap label_bitmap;
|
||
|
||
/* cleanup_tree_cfg removes all SWITCH_EXPR with their index
|
||
expressions being INTEGER_CST. */
|
||
gcc_assert (TREE_CODE (index_expr) != INTEGER_CST);
|
||
|
||
/* The default case is at the end of TREE_VEC. */
|
||
elt = TREE_VEC_ELT (vec, TREE_VEC_LENGTH (vec) - 1);
|
||
gcc_assert (!CASE_HIGH (elt));
|
||
gcc_assert (!CASE_LOW (elt));
|
||
default_label_decl = CASE_LABEL (elt);
|
||
|
||
for (i = TREE_VEC_LENGTH (vec) - 1; --i >= 0; )
|
||
{
|
||
tree low, high;
|
||
elt = TREE_VEC_ELT (vec, i);
|
||
|
||
low = CASE_LOW (elt);
|
||
gcc_assert (low);
|
||
high = CASE_HIGH (elt);
|
||
|
||
/* Discard empty ranges. */
|
||
if (high && INT_CST_LT (high, low))
|
||
continue;
|
||
|
||
case_list = add_case_node (case_list, index_type, low, high,
|
||
CASE_LABEL (elt));
|
||
}
|
||
|
||
|
||
before_case = start = get_last_insn ();
|
||
default_label = label_rtx (default_label_decl);
|
||
|
||
/* Get upper and lower bounds of case values. */
|
||
|
||
uniq = 0;
|
||
count = 0;
|
||
label_bitmap = BITMAP_ALLOC (NULL);
|
||
for (n = case_list; n; n = n->right)
|
||
{
|
||
/* Count the elements and track the largest and smallest
|
||
of them (treating them as signed even if they are not). */
|
||
if (count++ == 0)
|
||
{
|
||
minval = n->low;
|
||
maxval = n->high;
|
||
}
|
||
else
|
||
{
|
||
if (INT_CST_LT (n->low, minval))
|
||
minval = n->low;
|
||
if (INT_CST_LT (maxval, n->high))
|
||
maxval = n->high;
|
||
}
|
||
/* A range counts double, since it requires two compares. */
|
||
if (! tree_int_cst_equal (n->low, n->high))
|
||
count++;
|
||
|
||
/* If we have not seen this label yet, then increase the
|
||
number of unique case node targets seen. */
|
||
lab = label_rtx (n->code_label);
|
||
if (!bitmap_bit_p (label_bitmap, CODE_LABEL_NUMBER (lab)))
|
||
{
|
||
bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab));
|
||
uniq++;
|
||
}
|
||
}
|
||
|
||
BITMAP_FREE (label_bitmap);
|
||
|
||
/* cleanup_tree_cfg removes all SWITCH_EXPR with a single
|
||
destination, such as one with a default case only. However,
|
||
it doesn't remove cases that are out of range for the switch
|
||
type, so we may still get a zero here. */
|
||
if (count == 0)
|
||
{
|
||
emit_jump (default_label);
|
||
return;
|
||
}
|
||
|
||
/* Compute span of values. */
|
||
range = fold_build2 (MINUS_EXPR, index_type, maxval, minval);
|
||
|
||
/* Try implementing this switch statement by a short sequence of
|
||
bit-wise comparisons. However, we let the binary-tree case
|
||
below handle constant index expressions. */
|
||
if (CASE_USE_BIT_TESTS
|
||
&& ! TREE_CONSTANT (index_expr)
|
||
&& compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
|
||
&& compare_tree_int (range, 0) > 0
|
||
&& lshift_cheap_p ()
|
||
&& ((uniq == 1 && count >= 3)
|
||
|| (uniq == 2 && count >= 5)
|
||
|| (uniq == 3 && count >= 6)))
|
||
{
|
||
/* Optimize the case where all the case values fit in a
|
||
word without having to subtract MINVAL. In this case,
|
||
we can optimize away the subtraction. */
|
||
if (compare_tree_int (minval, 0) > 0
|
||
&& compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
|
||
{
|
||
minval = build_int_cst (index_type, 0);
|
||
range = maxval;
|
||
}
|
||
emit_case_bit_tests (index_type, index_expr, minval, range,
|
||
case_list, default_label);
|
||
}
|
||
|
||
/* If range of values is much bigger than number of values,
|
||
make a sequence of conditional branches instead of a dispatch.
|
||
If the switch-index is a constant, do it this way
|
||
because we can optimize it. */
|
||
|
||
else if (count < case_values_threshold ()
|
||
|| compare_tree_int (range,
|
||
(optimize_size ? 3 : 10) * count) > 0
|
||
/* RANGE may be signed, and really large ranges will show up
|
||
as negative numbers. */
|
||
|| compare_tree_int (range, 0) < 0
|
||
#ifndef ASM_OUTPUT_ADDR_DIFF_ELT
|
||
|| flag_pic
|
||
#endif
|
||
|| !flag_jump_tables
|
||
|| TREE_CONSTANT (index_expr)
|
||
/* If neither casesi or tablejump is available, we can
|
||
only go this way. */
|
||
|| (!HAVE_casesi && !HAVE_tablejump))
|
||
{
|
||
index = expand_normal (index_expr);
|
||
|
||
/* If the index is a short or char that we do not have
|
||
an insn to handle comparisons directly, convert it to
|
||
a full integer now, rather than letting each comparison
|
||
generate the conversion. */
|
||
|
||
if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
|
||
&& ! have_insn_for (COMPARE, GET_MODE (index)))
|
||
{
|
||
enum machine_mode wider_mode;
|
||
for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
|
||
wider_mode = GET_MODE_WIDER_MODE (wider_mode))
|
||
if (have_insn_for (COMPARE, wider_mode))
|
||
{
|
||
index = convert_to_mode (wider_mode, index, unsignedp);
|
||
break;
|
||
}
|
||
}
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
if (MEM_P (index))
|
||
index = copy_to_reg (index);
|
||
|
||
/* We generate a binary decision tree to select the
|
||
appropriate target code. This is done as follows:
|
||
|
||
The list of cases is rearranged into a binary tree,
|
||
nearly optimal assuming equal probability for each case.
|
||
|
||
The tree is transformed into RTL, eliminating
|
||
redundant test conditions at the same time.
|
||
|
||
If program flow could reach the end of the
|
||
decision tree an unconditional jump to the
|
||
default code is emitted. */
|
||
|
||
use_cost_table
|
||
= (TREE_CODE (orig_type) != ENUMERAL_TYPE
|
||
&& estimate_case_costs (case_list));
|
||
balance_case_nodes (&case_list, NULL);
|
||
emit_case_nodes (index, case_list, default_label, index_type);
|
||
emit_jump (default_label);
|
||
}
|
||
else
|
||
{
|
||
table_label = gen_label_rtx ();
|
||
if (! try_casesi (index_type, index_expr, minval, range,
|
||
table_label, default_label))
|
||
{
|
||
bool ok;
|
||
|
||
/* Index jumptables from zero for suitable values of
|
||
minval to avoid a subtraction. */
|
||
if (! optimize_size
|
||
&& compare_tree_int (minval, 0) > 0
|
||
&& compare_tree_int (minval, 3) < 0)
|
||
{
|
||
minval = build_int_cst (index_type, 0);
|
||
range = maxval;
|
||
}
|
||
|
||
ok = try_tablejump (index_type, index_expr, minval, range,
|
||
table_label, default_label);
|
||
gcc_assert (ok);
|
||
}
|
||
|
||
/* Get table of labels to jump to, in order of case index. */
|
||
|
||
ncases = tree_low_cst (range, 0) + 1;
|
||
labelvec = alloca (ncases * sizeof (rtx));
|
||
memset (labelvec, 0, ncases * sizeof (rtx));
|
||
|
||
for (n = case_list; n; n = n->right)
|
||
{
|
||
/* Compute the low and high bounds relative to the minimum
|
||
value since that should fit in a HOST_WIDE_INT while the
|
||
actual values may not. */
|
||
HOST_WIDE_INT i_low
|
||
= tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
|
||
n->low, minval), 1);
|
||
HOST_WIDE_INT i_high
|
||
= tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
|
||
n->high, minval), 1);
|
||
HOST_WIDE_INT i;
|
||
|
||
for (i = i_low; i <= i_high; i ++)
|
||
labelvec[i]
|
||
= gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
|
||
}
|
||
|
||
/* Fill in the gaps with the default. */
|
||
for (i = 0; i < ncases; i++)
|
||
if (labelvec[i] == 0)
|
||
labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
|
||
|
||
/* Output the table. */
|
||
emit_label (table_label);
|
||
|
||
if (CASE_VECTOR_PC_RELATIVE || flag_pic)
|
||
emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
|
||
gen_rtx_LABEL_REF (Pmode, table_label),
|
||
gen_rtvec_v (ncases, labelvec),
|
||
const0_rtx, const0_rtx));
|
||
else
|
||
emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
|
||
gen_rtvec_v (ncases, labelvec)));
|
||
|
||
/* Record no drop-through after the table. */
|
||
emit_barrier ();
|
||
}
|
||
|
||
before_case = NEXT_INSN (before_case);
|
||
end = get_last_insn ();
|
||
fail = squeeze_notes (&before_case, &end);
|
||
gcc_assert (!fail);
|
||
reorder_insns (before_case, end, start);
|
||
}
|
||
|
||
free_temp_slots ();
|
||
}
|
||
|
||
/* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */
|
||
|
||
static void
|
||
do_jump_if_equal (enum machine_mode mode, rtx op0, rtx op1, rtx label,
|
||
int unsignedp)
|
||
{
|
||
do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode,
|
||
NULL_RTX, NULL_RTX, label);
|
||
}
|
||
|
||
/* Not all case values are encountered equally. This function
|
||
uses a heuristic to weight case labels, in cases where that
|
||
looks like a reasonable thing to do.
|
||
|
||
Right now, all we try to guess is text, and we establish the
|
||
following weights:
|
||
|
||
chars above space: 16
|
||
digits: 16
|
||
default: 12
|
||
space, punct: 8
|
||
tab: 4
|
||
newline: 2
|
||
other "\" chars: 1
|
||
remaining chars: 0
|
||
|
||
If we find any cases in the switch that are not either -1 or in the range
|
||
of valid ASCII characters, or are control characters other than those
|
||
commonly used with "\", don't treat this switch scanning text.
|
||
|
||
Return 1 if these nodes are suitable for cost estimation, otherwise
|
||
return 0. */
|
||
|
||
static int
|
||
estimate_case_costs (case_node_ptr node)
|
||
{
|
||
tree min_ascii = integer_minus_one_node;
|
||
tree max_ascii = build_int_cst (TREE_TYPE (node->high), 127);
|
||
case_node_ptr n;
|
||
int i;
|
||
|
||
/* If we haven't already made the cost table, make it now. Note that the
|
||
lower bound of the table is -1, not zero. */
|
||
|
||
if (! cost_table_initialized)
|
||
{
|
||
cost_table_initialized = 1;
|
||
|
||
for (i = 0; i < 128; i++)
|
||
{
|
||
if (ISALNUM (i))
|
||
COST_TABLE (i) = 16;
|
||
else if (ISPUNCT (i))
|
||
COST_TABLE (i) = 8;
|
||
else if (ISCNTRL (i))
|
||
COST_TABLE (i) = -1;
|
||
}
|
||
|
||
COST_TABLE (' ') = 8;
|
||
COST_TABLE ('\t') = 4;
|
||
COST_TABLE ('\0') = 4;
|
||
COST_TABLE ('\n') = 2;
|
||
COST_TABLE ('\f') = 1;
|
||
COST_TABLE ('\v') = 1;
|
||
COST_TABLE ('\b') = 1;
|
||
}
|
||
|
||
/* See if all the case expressions look like text. It is text if the
|
||
constant is >= -1 and the highest constant is <= 127. Do all comparisons
|
||
as signed arithmetic since we don't want to ever access cost_table with a
|
||
value less than -1. Also check that none of the constants in a range
|
||
are strange control characters. */
|
||
|
||
for (n = node; n; n = n->right)
|
||
{
|
||
if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
|
||
return 0;
|
||
|
||
for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
|
||
i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
|
||
if (COST_TABLE (i) < 0)
|
||
return 0;
|
||
}
|
||
|
||
/* All interesting values are within the range of interesting
|
||
ASCII characters. */
|
||
return 1;
|
||
}
|
||
|
||
/* Take an ordered list of case nodes
|
||
and transform them into a near optimal binary tree,
|
||
on the assumption that any target code selection value is as
|
||
likely as any other.
|
||
|
||
The transformation is performed by splitting the ordered
|
||
list into two equal sections plus a pivot. The parts are
|
||
then attached to the pivot as left and right branches. Each
|
||
branch is then transformed recursively. */
|
||
|
||
static void
|
||
balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
|
||
{
|
||
case_node_ptr np;
|
||
|
||
np = *head;
|
||
if (np)
|
||
{
|
||
int cost = 0;
|
||
int i = 0;
|
||
int ranges = 0;
|
||
case_node_ptr *npp;
|
||
case_node_ptr left;
|
||
|
||
/* Count the number of entries on branch. Also count the ranges. */
|
||
|
||
while (np)
|
||
{
|
||
if (!tree_int_cst_equal (np->low, np->high))
|
||
{
|
||
ranges++;
|
||
if (use_cost_table)
|
||
cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
|
||
}
|
||
|
||
if (use_cost_table)
|
||
cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
|
||
|
||
i++;
|
||
np = np->right;
|
||
}
|
||
|
||
if (i > 2)
|
||
{
|
||
/* Split this list if it is long enough for that to help. */
|
||
npp = head;
|
||
left = *npp;
|
||
if (use_cost_table)
|
||
{
|
||
/* Find the place in the list that bisects the list's total cost,
|
||
Here I gets half the total cost. */
|
||
int n_moved = 0;
|
||
i = (cost + 1) / 2;
|
||
while (1)
|
||
{
|
||
/* Skip nodes while their cost does not reach that amount. */
|
||
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
|
||
i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
|
||
i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
|
||
if (i <= 0)
|
||
break;
|
||
npp = &(*npp)->right;
|
||
n_moved += 1;
|
||
}
|
||
if (n_moved == 0)
|
||
{
|
||
/* Leave this branch lopsided, but optimize left-hand
|
||
side and fill in `parent' fields for right-hand side. */
|
||
np = *head;
|
||
np->parent = parent;
|
||
balance_case_nodes (&np->left, np);
|
||
for (; np->right; np = np->right)
|
||
np->right->parent = np;
|
||
return;
|
||
}
|
||
}
|
||
/* If there are just three nodes, split at the middle one. */
|
||
else if (i == 3)
|
||
npp = &(*npp)->right;
|
||
else
|
||
{
|
||
/* Find the place in the list that bisects the list's total cost,
|
||
where ranges count as 2.
|
||
Here I gets half the total cost. */
|
||
i = (i + ranges + 1) / 2;
|
||
while (1)
|
||
{
|
||
/* Skip nodes while their cost does not reach that amount. */
|
||
if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
|
||
i--;
|
||
i--;
|
||
if (i <= 0)
|
||
break;
|
||
npp = &(*npp)->right;
|
||
}
|
||
}
|
||
*head = np = *npp;
|
||
*npp = 0;
|
||
np->parent = parent;
|
||
np->left = left;
|
||
|
||
/* Optimize each of the two split parts. */
|
||
balance_case_nodes (&np->left, np);
|
||
balance_case_nodes (&np->right, np);
|
||
}
|
||
else
|
||
{
|
||
/* Else leave this branch as one level,
|
||
but fill in `parent' fields. */
|
||
np = *head;
|
||
np->parent = parent;
|
||
for (; np->right; np = np->right)
|
||
np->right->parent = np;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Search the parent sections of the case node tree
|
||
to see if a test for the lower bound of NODE would be redundant.
|
||
INDEX_TYPE is the type of the index expression.
|
||
|
||
The instructions to generate the case decision tree are
|
||
output in the same order as nodes are processed so it is
|
||
known that if a parent node checks the range of the current
|
||
node minus one that the current node is bounded at its lower
|
||
span. Thus the test would be redundant. */
|
||
|
||
static int
|
||
node_has_low_bound (case_node_ptr node, tree index_type)
|
||
{
|
||
tree low_minus_one;
|
||
case_node_ptr pnode;
|
||
|
||
/* If the lower bound of this node is the lowest value in the index type,
|
||
we need not test it. */
|
||
|
||
if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
|
||
return 1;
|
||
|
||
/* If this node has a left branch, the value at the left must be less
|
||
than that at this node, so it cannot be bounded at the bottom and
|
||
we need not bother testing any further. */
|
||
|
||
if (node->left)
|
||
return 0;
|
||
|
||
low_minus_one = fold_build2 (MINUS_EXPR, TREE_TYPE (node->low),
|
||
node->low,
|
||
build_int_cst (TREE_TYPE (node->low), 1));
|
||
|
||
/* If the subtraction above overflowed, we can't verify anything.
|
||
Otherwise, look for a parent that tests our value - 1. */
|
||
|
||
if (! tree_int_cst_lt (low_minus_one, node->low))
|
||
return 0;
|
||
|
||
for (pnode = node->parent; pnode; pnode = pnode->parent)
|
||
if (tree_int_cst_equal (low_minus_one, pnode->high))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Search the parent sections of the case node tree
|
||
to see if a test for the upper bound of NODE would be redundant.
|
||
INDEX_TYPE is the type of the index expression.
|
||
|
||
The instructions to generate the case decision tree are
|
||
output in the same order as nodes are processed so it is
|
||
known that if a parent node checks the range of the current
|
||
node plus one that the current node is bounded at its upper
|
||
span. Thus the test would be redundant. */
|
||
|
||
static int
|
||
node_has_high_bound (case_node_ptr node, tree index_type)
|
||
{
|
||
tree high_plus_one;
|
||
case_node_ptr pnode;
|
||
|
||
/* If there is no upper bound, obviously no test is needed. */
|
||
|
||
if (TYPE_MAX_VALUE (index_type) == NULL)
|
||
return 1;
|
||
|
||
/* If the upper bound of this node is the highest value in the type
|
||
of the index expression, we need not test against it. */
|
||
|
||
if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
|
||
return 1;
|
||
|
||
/* If this node has a right branch, the value at the right must be greater
|
||
than that at this node, so it cannot be bounded at the top and
|
||
we need not bother testing any further. */
|
||
|
||
if (node->right)
|
||
return 0;
|
||
|
||
high_plus_one = fold_build2 (PLUS_EXPR, TREE_TYPE (node->high),
|
||
node->high,
|
||
build_int_cst (TREE_TYPE (node->high), 1));
|
||
|
||
/* If the addition above overflowed, we can't verify anything.
|
||
Otherwise, look for a parent that tests our value + 1. */
|
||
|
||
if (! tree_int_cst_lt (node->high, high_plus_one))
|
||
return 0;
|
||
|
||
for (pnode = node->parent; pnode; pnode = pnode->parent)
|
||
if (tree_int_cst_equal (high_plus_one, pnode->low))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Search the parent sections of the
|
||
case node tree to see if both tests for the upper and lower
|
||
bounds of NODE would be redundant. */
|
||
|
||
static int
|
||
node_is_bounded (case_node_ptr node, tree index_type)
|
||
{
|
||
return (node_has_low_bound (node, index_type)
|
||
&& node_has_high_bound (node, index_type));
|
||
}
|
||
|
||
/* Emit step-by-step code to select a case for the value of INDEX.
|
||
The thus generated decision tree follows the form of the
|
||
case-node binary tree NODE, whose nodes represent test conditions.
|
||
INDEX_TYPE is the type of the index of the switch.
|
||
|
||
Care is taken to prune redundant tests from the decision tree
|
||
by detecting any boundary conditions already checked by
|
||
emitted rtx. (See node_has_high_bound, node_has_low_bound
|
||
and node_is_bounded, above.)
|
||
|
||
Where the test conditions can be shown to be redundant we emit
|
||
an unconditional jump to the target code. As a further
|
||
optimization, the subordinates of a tree node are examined to
|
||
check for bounded nodes. In this case conditional and/or
|
||
unconditional jumps as a result of the boundary check for the
|
||
current node are arranged to target the subordinates associated
|
||
code for out of bound conditions on the current node.
|
||
|
||
We can assume that when control reaches the code generated here,
|
||
the index value has already been compared with the parents
|
||
of this node, and determined to be on the same side of each parent
|
||
as this node is. Thus, if this node tests for the value 51,
|
||
and a parent tested for 52, we don't need to consider
|
||
the possibility of a value greater than 51. If another parent
|
||
tests for the value 50, then this node need not test anything. */
|
||
|
||
static void
|
||
emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
|
||
tree index_type)
|
||
{
|
||
/* If INDEX has an unsigned type, we must make unsigned branches. */
|
||
int unsignedp = TYPE_UNSIGNED (index_type);
|
||
enum machine_mode mode = GET_MODE (index);
|
||
enum machine_mode imode = TYPE_MODE (index_type);
|
||
|
||
/* Handle indices detected as constant during RTL expansion. */
|
||
if (mode == VOIDmode)
|
||
mode = imode;
|
||
|
||
/* See if our parents have already tested everything for us.
|
||
If they have, emit an unconditional jump for this node. */
|
||
if (node_is_bounded (node, index_type))
|
||
emit_jump (label_rtx (node->code_label));
|
||
|
||
else if (tree_int_cst_equal (node->low, node->high))
|
||
{
|
||
/* Node is single valued. First see if the index expression matches
|
||
this node and then check our children, if any. */
|
||
|
||
do_jump_if_equal (mode, index,
|
||
convert_modes (mode, imode,
|
||
expand_normal (node->low),
|
||
unsignedp),
|
||
label_rtx (node->code_label), unsignedp);
|
||
|
||
if (node->right != 0 && node->left != 0)
|
||
{
|
||
/* This node has children on both sides.
|
||
Dispatch to one side or the other
|
||
by comparing the index value with this node's value.
|
||
If one subtree is bounded, check that one first,
|
||
so we can avoid real branches in the tree. */
|
||
|
||
if (node_is_bounded (node->right, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
label_rtx (node->right->code_label));
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
|
||
else if (node_is_bounded (node->left, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
LT, NULL_RTX, mode, unsignedp,
|
||
label_rtx (node->left->code_label));
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
|
||
/* If both children are single-valued cases with no
|
||
children, finish up all the work. This way, we can save
|
||
one ordered comparison. */
|
||
else if (tree_int_cst_equal (node->right->low, node->right->high)
|
||
&& node->right->left == 0
|
||
&& node->right->right == 0
|
||
&& tree_int_cst_equal (node->left->low, node->left->high)
|
||
&& node->left->left == 0
|
||
&& node->left->right == 0)
|
||
{
|
||
/* Neither node is bounded. First distinguish the two sides;
|
||
then emit the code for one side at a time. */
|
||
|
||
/* See if the value matches what the right hand side
|
||
wants. */
|
||
do_jump_if_equal (mode, index,
|
||
convert_modes (mode, imode,
|
||
expand_normal (node->right->low),
|
||
unsignedp),
|
||
label_rtx (node->right->code_label),
|
||
unsignedp);
|
||
|
||
/* See if the value matches what the left hand side
|
||
wants. */
|
||
do_jump_if_equal (mode, index,
|
||
convert_modes (mode, imode,
|
||
expand_normal (node->left->low),
|
||
unsignedp),
|
||
label_rtx (node->left->code_label),
|
||
unsignedp);
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Neither node is bounded. First distinguish the two sides;
|
||
then emit the code for one side at a time. */
|
||
|
||
tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
|
||
/* See if the value is on the right. */
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
label_rtx (test_label));
|
||
|
||
/* Value must be on the left.
|
||
Handle the left-hand subtree. */
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
/* If left-hand subtree does nothing,
|
||
go to default. */
|
||
emit_jump (default_label);
|
||
|
||
/* Code branches here for the right-hand subtree. */
|
||
expand_label (test_label);
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
}
|
||
|
||
else if (node->right != 0 && node->left == 0)
|
||
{
|
||
/* Here we have a right child but no left so we issue a conditional
|
||
branch to default and process the right child.
|
||
|
||
Omit the conditional branch to default if the right child
|
||
does not have any children and is single valued; it would
|
||
cost too much space to save so little time. */
|
||
|
||
if (node->right->right || node->right->left
|
||
|| !tree_int_cst_equal (node->right->low, node->right->high))
|
||
{
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
LT, NULL_RTX, mode, unsignedp,
|
||
default_label);
|
||
}
|
||
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
else
|
||
/* We cannot process node->right normally
|
||
since we haven't ruled out the numbers less than
|
||
this node's value. So handle node->right explicitly. */
|
||
do_jump_if_equal (mode, index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->right->low),
|
||
unsignedp),
|
||
label_rtx (node->right->code_label), unsignedp);
|
||
}
|
||
|
||
else if (node->right == 0 && node->left != 0)
|
||
{
|
||
/* Just one subtree, on the left. */
|
||
if (node->left->left || node->left->right
|
||
|| !tree_int_cst_equal (node->left->low, node->left->high))
|
||
{
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
default_label);
|
||
}
|
||
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
else
|
||
/* We cannot process node->left normally
|
||
since we haven't ruled out the numbers less than
|
||
this node's value. So handle node->left explicitly. */
|
||
do_jump_if_equal (mode, index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->left->low),
|
||
unsignedp),
|
||
label_rtx (node->left->code_label), unsignedp);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Node is a range. These cases are very similar to those for a single
|
||
value, except that we do not start by testing whether this node
|
||
is the one to branch to. */
|
||
|
||
if (node->right != 0 && node->left != 0)
|
||
{
|
||
/* Node has subtrees on both sides.
|
||
If the right-hand subtree is bounded,
|
||
test for it first, since we can go straight there.
|
||
Otherwise, we need to make a branch in the control structure,
|
||
then handle the two subtrees. */
|
||
tree test_label = 0;
|
||
|
||
if (node_is_bounded (node->right, index_type))
|
||
/* Right hand node is fully bounded so we can eliminate any
|
||
testing and branch directly to the target code. */
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
label_rtx (node->right->code_label));
|
||
else
|
||
{
|
||
/* Right hand node requires testing.
|
||
Branch to a label where we will handle it later. */
|
||
|
||
test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
label_rtx (test_label));
|
||
}
|
||
|
||
/* Value belongs to this node or to the left-hand subtree. */
|
||
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->low),
|
||
unsignedp),
|
||
GE, NULL_RTX, mode, unsignedp,
|
||
label_rtx (node->code_label));
|
||
|
||
/* Handle the left-hand subtree. */
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
|
||
/* If right node had to be handled later, do that now. */
|
||
|
||
if (test_label)
|
||
{
|
||
/* If the left-hand subtree fell through,
|
||
don't let it fall into the right-hand subtree. */
|
||
emit_jump (default_label);
|
||
|
||
expand_label (test_label);
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
}
|
||
|
||
else if (node->right != 0 && node->left == 0)
|
||
{
|
||
/* Deal with values to the left of this node,
|
||
if they are possible. */
|
||
if (!node_has_low_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->low),
|
||
unsignedp),
|
||
LT, NULL_RTX, mode, unsignedp,
|
||
default_label);
|
||
}
|
||
|
||
/* Value belongs to this node or to the right-hand subtree. */
|
||
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
LE, NULL_RTX, mode, unsignedp,
|
||
label_rtx (node->code_label));
|
||
|
||
emit_case_nodes (index, node->right, default_label, index_type);
|
||
}
|
||
|
||
else if (node->right == 0 && node->left != 0)
|
||
{
|
||
/* Deal with values to the right of this node,
|
||
if they are possible. */
|
||
if (!node_has_high_bound (node, index_type))
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
default_label);
|
||
}
|
||
|
||
/* Value belongs to this node or to the left-hand subtree. */
|
||
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->low),
|
||
unsignedp),
|
||
GE, NULL_RTX, mode, unsignedp,
|
||
label_rtx (node->code_label));
|
||
|
||
emit_case_nodes (index, node->left, default_label, index_type);
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Node has no children so we check low and high bounds to remove
|
||
redundant tests. Only one of the bounds can exist,
|
||
since otherwise this node is bounded--a case tested already. */
|
||
int high_bound = node_has_high_bound (node, index_type);
|
||
int low_bound = node_has_low_bound (node, index_type);
|
||
|
||
if (!high_bound && low_bound)
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->high),
|
||
unsignedp),
|
||
GT, NULL_RTX, mode, unsignedp,
|
||
default_label);
|
||
}
|
||
|
||
else if (!low_bound && high_bound)
|
||
{
|
||
emit_cmp_and_jump_insns (index,
|
||
convert_modes
|
||
(mode, imode,
|
||
expand_normal (node->low),
|
||
unsignedp),
|
||
LT, NULL_RTX, mode, unsignedp,
|
||
default_label);
|
||
}
|
||
else if (!low_bound && !high_bound)
|
||
{
|
||
/* Widen LOW and HIGH to the same width as INDEX. */
|
||
tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
|
||
tree low = build1 (CONVERT_EXPR, type, node->low);
|
||
tree high = build1 (CONVERT_EXPR, type, node->high);
|
||
rtx low_rtx, new_index, new_bound;
|
||
|
||
/* Instead of doing two branches, emit one unsigned branch for
|
||
(index-low) > (high-low). */
|
||
low_rtx = expand_expr (low, NULL_RTX, mode, EXPAND_NORMAL);
|
||
new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
|
||
NULL_RTX, unsignedp,
|
||
OPTAB_WIDEN);
|
||
new_bound = expand_expr (fold_build2 (MINUS_EXPR, type,
|
||
high, low),
|
||
NULL_RTX, mode, EXPAND_NORMAL);
|
||
|
||
emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
|
||
mode, 1, default_label);
|
||
}
|
||
|
||
emit_jump (label_rtx (node->code_label));
|
||
}
|
||
}
|
||
}
|