4b66e1c091
* fix-header.c (recognized_extern, recognized_function): Constify
a char*.
* lcm.c (compute_laterin): Remove unused variable `temp_bitmap'.
(pre_edge_lcm): Mark parameter `file' with ATTRIBUTE_UNUSED.
(compute_available): Remove unused variable `last'.
(compute_nearerout): Remove unused variable `temp_bitmap'.
(pre_edge_rev_lcm): Mark parameter `file' with ATTRIBUTE_UNUSED.
Remove unused variable `x'.
* scan.h (recognized_function, recognized_extern): Constify a
char*.
* simplify-rtx.c (simplify_rtx): Remove unused variable `new'.
From-SVN: r30380
1951 lines
53 KiB
C
1951 lines
53 KiB
C
/* Common subexpression elimination for GNU compiler.
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Copyright (C) 1987, 88, 89, 92-7, 1998, 1999 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License 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 GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "config.h"
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/* stdio.h must precede rtl.h for FFS. */
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#include "system.h"
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#include <setjmp.h>
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#include "rtl.h"
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#include "tm_p.h"
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#include "regs.h"
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#include "hard-reg-set.h"
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#include "flags.h"
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#include "real.h"
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#include "insn-config.h"
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#include "recog.h"
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#include "function.h"
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#include "expr.h"
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#include "toplev.h"
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#include "output.h"
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/* Simplification and canonicalization of RTL. */
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/* Nonzero if X has the form (PLUS frame-pointer integer). We check for
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virtual regs here because the simplify_*_operation routines are called
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by integrate.c, which is called before virtual register instantiation.
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?!? FIXED_BASE_PLUS_P and NONZERO_BASE_PLUS_P need to move into
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a header file so that their definitions can be shared with the
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simplification routines in simplify-rtx.c. Until then, do not
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change these macros without also changing the copy in simplify-rtx.c. */
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#define FIXED_BASE_PLUS_P(X) \
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((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \
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|| ((X) == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])\
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|| (X) == virtual_stack_vars_rtx \
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|| (X) == virtual_incoming_args_rtx \
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|| (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
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&& (XEXP (X, 0) == frame_pointer_rtx \
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|| XEXP (X, 0) == hard_frame_pointer_rtx \
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|| ((X) == arg_pointer_rtx \
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&& fixed_regs[ARG_POINTER_REGNUM]) \
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|| XEXP (X, 0) == virtual_stack_vars_rtx \
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|| XEXP (X, 0) == virtual_incoming_args_rtx)) \
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|| GET_CODE (X) == ADDRESSOF)
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/* Similar, but also allows reference to the stack pointer.
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This used to include FIXED_BASE_PLUS_P, however, we can't assume that
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arg_pointer_rtx by itself is nonzero, because on at least one machine,
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the i960, the arg pointer is zero when it is unused. */
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#define NONZERO_BASE_PLUS_P(X) \
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((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \
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|| (X) == virtual_stack_vars_rtx \
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|| (X) == virtual_incoming_args_rtx \
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|| (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
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&& (XEXP (X, 0) == frame_pointer_rtx \
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|| XEXP (X, 0) == hard_frame_pointer_rtx \
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|| ((X) == arg_pointer_rtx \
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&& fixed_regs[ARG_POINTER_REGNUM]) \
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|| XEXP (X, 0) == virtual_stack_vars_rtx \
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|| XEXP (X, 0) == virtual_incoming_args_rtx)) \
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|| (X) == stack_pointer_rtx \
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|| (X) == virtual_stack_dynamic_rtx \
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|| (X) == virtual_outgoing_args_rtx \
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|| (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
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&& (XEXP (X, 0) == stack_pointer_rtx \
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|| XEXP (X, 0) == virtual_stack_dynamic_rtx \
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|| XEXP (X, 0) == virtual_outgoing_args_rtx)) \
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|| GET_CODE (X) == ADDRESSOF)
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static rtx simplify_plus_minus PROTO((enum rtx_code, enum machine_mode,
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rtx, rtx));
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static void check_fold_consts PROTO((PTR));
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/* Make a binary operation by properly ordering the operands and
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seeing if the expression folds. */
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rtx
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simplify_gen_binary (code, mode, op0, op1)
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enum rtx_code code;
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enum machine_mode mode;
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rtx op0, op1;
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{
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rtx tem;
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/* Put complex operands first and constants second if commutative. */
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if (GET_RTX_CLASS (code) == 'c'
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&& ((CONSTANT_P (op0) && GET_CODE (op1) != CONST_INT)
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|| (GET_RTX_CLASS (GET_CODE (op0)) == 'o'
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&& GET_RTX_CLASS (GET_CODE (op1)) != 'o')
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|| (GET_CODE (op0) == SUBREG
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&& GET_RTX_CLASS (GET_CODE (SUBREG_REG (op0))) == 'o'
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&& GET_RTX_CLASS (GET_CODE (op1)) != 'o')))
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tem = op0, op0 = op1, op1 = tem;
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/* If this simplifies, do it. */
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tem = simplify_binary_operation (code, mode, op0, op1);
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if (tem)
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return tem;
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/* Handle addition and subtraction of CONST_INT specially. Otherwise,
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just form the operation. */
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if (code == PLUS && GET_CODE (op1) == CONST_INT
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&& GET_MODE (op0) != VOIDmode)
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return plus_constant (op0, INTVAL (op1));
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else if (code == MINUS && GET_CODE (op1) == CONST_INT
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&& GET_MODE (op0) != VOIDmode)
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return plus_constant (op0, - INTVAL (op1));
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else
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return gen_rtx_fmt_ee (code, mode, op0, op1);
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}
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/* Try to simplify a unary operation CODE whose output mode is to be
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MODE with input operand OP whose mode was originally OP_MODE.
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Return zero if no simplification can be made. */
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rtx
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simplify_unary_operation (code, mode, op, op_mode)
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enum rtx_code code;
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enum machine_mode mode;
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rtx op;
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enum machine_mode op_mode;
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{
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register int width = GET_MODE_BITSIZE (mode);
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/* The order of these tests is critical so that, for example, we don't
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check the wrong mode (input vs. output) for a conversion operation,
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such as FIX. At some point, this should be simplified. */
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#if !defined(REAL_IS_NOT_DOUBLE) || defined(REAL_ARITHMETIC)
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if (code == FLOAT && GET_MODE (op) == VOIDmode
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&& (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT))
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{
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HOST_WIDE_INT hv, lv;
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REAL_VALUE_TYPE d;
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if (GET_CODE (op) == CONST_INT)
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lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0;
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else
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lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op);
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#ifdef REAL_ARITHMETIC
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REAL_VALUE_FROM_INT (d, lv, hv, mode);
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#else
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if (hv < 0)
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{
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d = (double) (~ hv);
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d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
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* (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
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d += (double) (unsigned HOST_WIDE_INT) (~ lv);
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d = (- d - 1.0);
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}
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else
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{
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d = (double) hv;
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d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
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* (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
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d += (double) (unsigned HOST_WIDE_INT) lv;
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}
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#endif /* REAL_ARITHMETIC */
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d = real_value_truncate (mode, d);
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return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
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}
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else if (code == UNSIGNED_FLOAT && GET_MODE (op) == VOIDmode
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&& (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT))
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{
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HOST_WIDE_INT hv, lv;
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REAL_VALUE_TYPE d;
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if (GET_CODE (op) == CONST_INT)
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lv = INTVAL (op), hv = INTVAL (op) < 0 ? -1 : 0;
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else
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lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op);
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if (op_mode == VOIDmode)
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{
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/* We don't know how to interpret negative-looking numbers in
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this case, so don't try to fold those. */
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if (hv < 0)
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return 0;
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}
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else if (GET_MODE_BITSIZE (op_mode) >= HOST_BITS_PER_WIDE_INT * 2)
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;
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else
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hv = 0, lv &= GET_MODE_MASK (op_mode);
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#ifdef REAL_ARITHMETIC
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REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode);
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#else
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d = (double) (unsigned HOST_WIDE_INT) hv;
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d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
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* (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
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d += (double) (unsigned HOST_WIDE_INT) lv;
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#endif /* REAL_ARITHMETIC */
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d = real_value_truncate (mode, d);
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return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
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}
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#endif
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if (GET_CODE (op) == CONST_INT
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&& width <= HOST_BITS_PER_WIDE_INT && width > 0)
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{
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register HOST_WIDE_INT arg0 = INTVAL (op);
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register HOST_WIDE_INT val;
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switch (code)
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{
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case NOT:
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val = ~ arg0;
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break;
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case NEG:
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val = - arg0;
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break;
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case ABS:
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val = (arg0 >= 0 ? arg0 : - arg0);
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break;
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case FFS:
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/* Don't use ffs here. Instead, get low order bit and then its
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number. If arg0 is zero, this will return 0, as desired. */
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arg0 &= GET_MODE_MASK (mode);
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val = exact_log2 (arg0 & (- arg0)) + 1;
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break;
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case TRUNCATE:
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val = arg0;
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break;
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case ZERO_EXTEND:
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if (op_mode == VOIDmode)
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op_mode = mode;
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if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT)
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{
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/* If we were really extending the mode,
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we would have to distinguish between zero-extension
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and sign-extension. */
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if (width != GET_MODE_BITSIZE (op_mode))
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abort ();
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val = arg0;
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}
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else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT)
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val = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode));
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else
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return 0;
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break;
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case SIGN_EXTEND:
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if (op_mode == VOIDmode)
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op_mode = mode;
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if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT)
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{
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/* If we were really extending the mode,
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we would have to distinguish between zero-extension
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and sign-extension. */
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if (width != GET_MODE_BITSIZE (op_mode))
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abort ();
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val = arg0;
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}
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else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT)
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{
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val
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= arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode));
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if (val
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& ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (op_mode) - 1)))
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val -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
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}
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else
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return 0;
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break;
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case SQRT:
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return 0;
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default:
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abort ();
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}
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val = trunc_int_for_mode (val, mode);
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return GEN_INT (val);
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}
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/* We can do some operations on integer CONST_DOUBLEs. Also allow
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for a DImode operation on a CONST_INT. */
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else if (GET_MODE (op) == VOIDmode && width <= HOST_BITS_PER_INT * 2
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&& (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT))
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{
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HOST_WIDE_INT l1, h1, lv, hv;
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if (GET_CODE (op) == CONST_DOUBLE)
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l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op);
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else
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l1 = INTVAL (op), h1 = l1 < 0 ? -1 : 0;
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switch (code)
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{
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case NOT:
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lv = ~ l1;
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hv = ~ h1;
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break;
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case NEG:
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neg_double (l1, h1, &lv, &hv);
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break;
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case ABS:
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if (h1 < 0)
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neg_double (l1, h1, &lv, &hv);
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else
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lv = l1, hv = h1;
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break;
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case FFS:
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hv = 0;
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if (l1 == 0)
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lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & (-h1)) + 1;
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else
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lv = exact_log2 (l1 & (-l1)) + 1;
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break;
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case TRUNCATE:
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/* This is just a change-of-mode, so do nothing. */
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lv = l1, hv = h1;
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break;
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case ZERO_EXTEND:
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if (op_mode == VOIDmode
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|| GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT)
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return 0;
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hv = 0;
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lv = l1 & GET_MODE_MASK (op_mode);
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break;
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case SIGN_EXTEND:
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if (op_mode == VOIDmode
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|| GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT)
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return 0;
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else
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{
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lv = l1 & GET_MODE_MASK (op_mode);
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if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT
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&& (lv & ((HOST_WIDE_INT) 1
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<< (GET_MODE_BITSIZE (op_mode) - 1))) != 0)
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lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
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hv = (lv < 0) ? ~ (HOST_WIDE_INT) 0 : 0;
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}
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break;
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case SQRT:
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return 0;
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default:
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return 0;
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}
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return immed_double_const (lv, hv, mode);
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}
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#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
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else if (GET_CODE (op) == CONST_DOUBLE
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&& GET_MODE_CLASS (mode) == MODE_FLOAT)
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{
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REAL_VALUE_TYPE d;
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jmp_buf handler;
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rtx x;
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if (setjmp (handler))
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/* There used to be a warning here, but that is inadvisable.
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People may want to cause traps, and the natural way
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to do it should not get a warning. */
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return 0;
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set_float_handler (handler);
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REAL_VALUE_FROM_CONST_DOUBLE (d, op);
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switch (code)
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{
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case NEG:
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d = REAL_VALUE_NEGATE (d);
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break;
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case ABS:
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if (REAL_VALUE_NEGATIVE (d))
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d = REAL_VALUE_NEGATE (d);
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break;
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case FLOAT_TRUNCATE:
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d = real_value_truncate (mode, d);
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break;
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case FLOAT_EXTEND:
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/* All this does is change the mode. */
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break;
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case FIX:
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d = REAL_VALUE_RNDZINT (d);
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break;
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case UNSIGNED_FIX:
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d = REAL_VALUE_UNSIGNED_RNDZINT (d);
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break;
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case SQRT:
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return 0;
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default:
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abort ();
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}
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x = CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
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set_float_handler (NULL_PTR);
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return x;
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}
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|
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else if (GET_CODE (op) == CONST_DOUBLE
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&& GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT
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||
&& GET_MODE_CLASS (mode) == MODE_INT
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&& width <= HOST_BITS_PER_WIDE_INT && width > 0)
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{
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REAL_VALUE_TYPE d;
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jmp_buf handler;
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HOST_WIDE_INT val;
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|
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if (setjmp (handler))
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return 0;
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set_float_handler (handler);
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REAL_VALUE_FROM_CONST_DOUBLE (d, op);
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switch (code)
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{
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case FIX:
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val = REAL_VALUE_FIX (d);
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break;
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case UNSIGNED_FIX:
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val = REAL_VALUE_UNSIGNED_FIX (d);
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break;
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default:
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abort ();
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}
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set_float_handler (NULL_PTR);
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val = trunc_int_for_mode (val, mode);
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return GEN_INT (val);
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}
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#endif
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/* This was formerly used only for non-IEEE float.
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eggert@twinsun.com says it is safe for IEEE also. */
|
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else
|
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{
|
||
/* There are some simplifications we can do even if the operands
|
||
aren't constant. */
|
||
switch (code)
|
||
{
|
||
case NEG:
|
||
case NOT:
|
||
/* (not (not X)) == X, similarly for NEG. */
|
||
if (GET_CODE (op) == code)
|
||
return XEXP (op, 0);
|
||
break;
|
||
|
||
case SIGN_EXTEND:
|
||
/* (sign_extend (truncate (minus (label_ref L1) (label_ref L2))))
|
||
becomes just the MINUS if its mode is MODE. This allows
|
||
folding switch statements on machines using casesi (such as
|
||
the Vax). */
|
||
if (GET_CODE (op) == TRUNCATE
|
||
&& GET_MODE (XEXP (op, 0)) == mode
|
||
&& GET_CODE (XEXP (op, 0)) == MINUS
|
||
&& GET_CODE (XEXP (XEXP (op, 0), 0)) == LABEL_REF
|
||
&& GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF)
|
||
return XEXP (op, 0);
|
||
|
||
#ifdef POINTERS_EXTEND_UNSIGNED
|
||
if (! POINTERS_EXTEND_UNSIGNED
|
||
&& mode == Pmode && GET_MODE (op) == ptr_mode
|
||
&& CONSTANT_P (op))
|
||
return convert_memory_address (Pmode, op);
|
||
#endif
|
||
break;
|
||
|
||
#ifdef POINTERS_EXTEND_UNSIGNED
|
||
case ZERO_EXTEND:
|
||
if (POINTERS_EXTEND_UNSIGNED
|
||
&& mode == Pmode && GET_MODE (op) == ptr_mode
|
||
&& CONSTANT_P (op))
|
||
return convert_memory_address (Pmode, op);
|
||
break;
|
||
#endif
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/* Simplify a binary operation CODE with result mode MODE, operating on OP0
|
||
and OP1. Return 0 if no simplification is possible.
|
||
|
||
Don't use this for relational operations such as EQ or LT.
|
||
Use simplify_relational_operation instead. */
|
||
|
||
rtx
|
||
simplify_binary_operation (code, mode, op0, op1)
|
||
enum rtx_code code;
|
||
enum machine_mode mode;
|
||
rtx op0, op1;
|
||
{
|
||
register HOST_WIDE_INT arg0, arg1, arg0s, arg1s;
|
||
HOST_WIDE_INT val;
|
||
int width = GET_MODE_BITSIZE (mode);
|
||
rtx tem;
|
||
|
||
/* Relational operations don't work here. We must know the mode
|
||
of the operands in order to do the comparison correctly.
|
||
Assuming a full word can give incorrect results.
|
||
Consider comparing 128 with -128 in QImode. */
|
||
|
||
if (GET_RTX_CLASS (code) == '<')
|
||
abort ();
|
||
|
||
#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
|
||
if (GET_MODE_CLASS (mode) == MODE_FLOAT
|
||
&& GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE
|
||
&& mode == GET_MODE (op0) && mode == GET_MODE (op1))
|
||
{
|
||
REAL_VALUE_TYPE f0, f1, value;
|
||
jmp_buf handler;
|
||
|
||
if (setjmp (handler))
|
||
return 0;
|
||
|
||
set_float_handler (handler);
|
||
|
||
REAL_VALUE_FROM_CONST_DOUBLE (f0, op0);
|
||
REAL_VALUE_FROM_CONST_DOUBLE (f1, op1);
|
||
f0 = real_value_truncate (mode, f0);
|
||
f1 = real_value_truncate (mode, f1);
|
||
|
||
#ifdef REAL_ARITHMETIC
|
||
#ifndef REAL_INFINITY
|
||
if (code == DIV && REAL_VALUES_EQUAL (f1, dconst0))
|
||
return 0;
|
||
#endif
|
||
REAL_ARITHMETIC (value, rtx_to_tree_code (code), f0, f1);
|
||
#else
|
||
switch (code)
|
||
{
|
||
case PLUS:
|
||
value = f0 + f1;
|
||
break;
|
||
case MINUS:
|
||
value = f0 - f1;
|
||
break;
|
||
case MULT:
|
||
value = f0 * f1;
|
||
break;
|
||
case DIV:
|
||
#ifndef REAL_INFINITY
|
||
if (f1 == 0)
|
||
return 0;
|
||
#endif
|
||
value = f0 / f1;
|
||
break;
|
||
case SMIN:
|
||
value = MIN (f0, f1);
|
||
break;
|
||
case SMAX:
|
||
value = MAX (f0, f1);
|
||
break;
|
||
default:
|
||
abort ();
|
||
}
|
||
#endif
|
||
|
||
value = real_value_truncate (mode, value);
|
||
set_float_handler (NULL_PTR);
|
||
return CONST_DOUBLE_FROM_REAL_VALUE (value, mode);
|
||
}
|
||
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
|
||
|
||
/* We can fold some multi-word operations. */
|
||
if (GET_MODE_CLASS (mode) == MODE_INT
|
||
&& width == HOST_BITS_PER_WIDE_INT * 2
|
||
&& (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT)
|
||
&& (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT))
|
||
{
|
||
HOST_WIDE_INT l1, l2, h1, h2, lv, hv;
|
||
|
||
if (GET_CODE (op0) == CONST_DOUBLE)
|
||
l1 = CONST_DOUBLE_LOW (op0), h1 = CONST_DOUBLE_HIGH (op0);
|
||
else
|
||
l1 = INTVAL (op0), h1 = l1 < 0 ? -1 : 0;
|
||
|
||
if (GET_CODE (op1) == CONST_DOUBLE)
|
||
l2 = CONST_DOUBLE_LOW (op1), h2 = CONST_DOUBLE_HIGH (op1);
|
||
else
|
||
l2 = INTVAL (op1), h2 = l2 < 0 ? -1 : 0;
|
||
|
||
switch (code)
|
||
{
|
||
case MINUS:
|
||
/* A - B == A + (-B). */
|
||
neg_double (l2, h2, &lv, &hv);
|
||
l2 = lv, h2 = hv;
|
||
|
||
/* .. fall through ... */
|
||
|
||
case PLUS:
|
||
add_double (l1, h1, l2, h2, &lv, &hv);
|
||
break;
|
||
|
||
case MULT:
|
||
mul_double (l1, h1, l2, h2, &lv, &hv);
|
||
break;
|
||
|
||
case DIV: case MOD: case UDIV: case UMOD:
|
||
/* We'd need to include tree.h to do this and it doesn't seem worth
|
||
it. */
|
||
return 0;
|
||
|
||
case AND:
|
||
lv = l1 & l2, hv = h1 & h2;
|
||
break;
|
||
|
||
case IOR:
|
||
lv = l1 | l2, hv = h1 | h2;
|
||
break;
|
||
|
||
case XOR:
|
||
lv = l1 ^ l2, hv = h1 ^ h2;
|
||
break;
|
||
|
||
case SMIN:
|
||
if (h1 < h2
|
||
|| (h1 == h2
|
||
&& ((unsigned HOST_WIDE_INT) l1
|
||
< (unsigned HOST_WIDE_INT) l2)))
|
||
lv = l1, hv = h1;
|
||
else
|
||
lv = l2, hv = h2;
|
||
break;
|
||
|
||
case SMAX:
|
||
if (h1 > h2
|
||
|| (h1 == h2
|
||
&& ((unsigned HOST_WIDE_INT) l1
|
||
> (unsigned HOST_WIDE_INT) l2)))
|
||
lv = l1, hv = h1;
|
||
else
|
||
lv = l2, hv = h2;
|
||
break;
|
||
|
||
case UMIN:
|
||
if ((unsigned HOST_WIDE_INT) h1 < (unsigned HOST_WIDE_INT) h2
|
||
|| (h1 == h2
|
||
&& ((unsigned HOST_WIDE_INT) l1
|
||
< (unsigned HOST_WIDE_INT) l2)))
|
||
lv = l1, hv = h1;
|
||
else
|
||
lv = l2, hv = h2;
|
||
break;
|
||
|
||
case UMAX:
|
||
if ((unsigned HOST_WIDE_INT) h1 > (unsigned HOST_WIDE_INT) h2
|
||
|| (h1 == h2
|
||
&& ((unsigned HOST_WIDE_INT) l1
|
||
> (unsigned HOST_WIDE_INT) l2)))
|
||
lv = l1, hv = h1;
|
||
else
|
||
lv = l2, hv = h2;
|
||
break;
|
||
|
||
case LSHIFTRT: case ASHIFTRT:
|
||
case ASHIFT:
|
||
case ROTATE: case ROTATERT:
|
||
#ifdef SHIFT_COUNT_TRUNCATED
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
l2 &= (GET_MODE_BITSIZE (mode) - 1), h2 = 0;
|
||
#endif
|
||
|
||
if (h2 != 0 || l2 < 0 || l2 >= GET_MODE_BITSIZE (mode))
|
||
return 0;
|
||
|
||
if (code == LSHIFTRT || code == ASHIFTRT)
|
||
rshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv,
|
||
code == ASHIFTRT);
|
||
else if (code == ASHIFT)
|
||
lshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, 1);
|
||
else if (code == ROTATE)
|
||
lrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv);
|
||
else /* code == ROTATERT */
|
||
rrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv);
|
||
break;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
|
||
return immed_double_const (lv, hv, mode);
|
||
}
|
||
|
||
if (GET_CODE (op0) != CONST_INT || GET_CODE (op1) != CONST_INT
|
||
|| width > HOST_BITS_PER_WIDE_INT || width == 0)
|
||
{
|
||
/* Even if we can't compute a constant result,
|
||
there are some cases worth simplifying. */
|
||
|
||
switch (code)
|
||
{
|
||
case PLUS:
|
||
/* In IEEE floating point, x+0 is not the same as x. Similarly
|
||
for the other optimizations below. */
|
||
if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
|
||
&& FLOAT_MODE_P (mode) && ! flag_fast_math)
|
||
break;
|
||
|
||
if (op1 == CONST0_RTX (mode))
|
||
return op0;
|
||
|
||
/* ((-a) + b) -> (b - a) and similarly for (a + (-b)) */
|
||
if (GET_CODE (op0) == NEG)
|
||
return simplify_gen_binary (MINUS, mode, op1, XEXP (op0, 0));
|
||
else if (GET_CODE (op1) == NEG)
|
||
return simplify_gen_binary (MINUS, mode, op0, XEXP (op1, 0));
|
||
|
||
/* Handle both-operands-constant cases. We can only add
|
||
CONST_INTs to constants since the sum of relocatable symbols
|
||
can't be handled by most assemblers. Don't add CONST_INT
|
||
to CONST_INT since overflow won't be computed properly if wider
|
||
than HOST_BITS_PER_WIDE_INT. */
|
||
|
||
if (CONSTANT_P (op0) && GET_MODE (op0) != VOIDmode
|
||
&& GET_CODE (op1) == CONST_INT)
|
||
return plus_constant (op0, INTVAL (op1));
|
||
else if (CONSTANT_P (op1) && GET_MODE (op1) != VOIDmode
|
||
&& GET_CODE (op0) == CONST_INT)
|
||
return plus_constant (op1, INTVAL (op0));
|
||
|
||
/* See if this is something like X * C - X or vice versa or
|
||
if the multiplication is written as a shift. If so, we can
|
||
distribute and make a new multiply, shift, or maybe just
|
||
have X (if C is 2 in the example above). But don't make
|
||
real multiply if we didn't have one before. */
|
||
|
||
if (! FLOAT_MODE_P (mode))
|
||
{
|
||
HOST_WIDE_INT coeff0 = 1, coeff1 = 1;
|
||
rtx lhs = op0, rhs = op1;
|
||
int had_mult = 0;
|
||
|
||
if (GET_CODE (lhs) == NEG)
|
||
coeff0 = -1, lhs = XEXP (lhs, 0);
|
||
else if (GET_CODE (lhs) == MULT
|
||
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT)
|
||
{
|
||
coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0);
|
||
had_mult = 1;
|
||
}
|
||
else if (GET_CODE (lhs) == ASHIFT
|
||
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT
|
||
&& INTVAL (XEXP (lhs, 1)) >= 0
|
||
&& INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
|
||
lhs = XEXP (lhs, 0);
|
||
}
|
||
|
||
if (GET_CODE (rhs) == NEG)
|
||
coeff1 = -1, rhs = XEXP (rhs, 0);
|
||
else if (GET_CODE (rhs) == MULT
|
||
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT)
|
||
{
|
||
coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0);
|
||
had_mult = 1;
|
||
}
|
||
else if (GET_CODE (rhs) == ASHIFT
|
||
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT
|
||
&& INTVAL (XEXP (rhs, 1)) >= 0
|
||
&& INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
|
||
rhs = XEXP (rhs, 0);
|
||
}
|
||
|
||
if (rtx_equal_p (lhs, rhs))
|
||
{
|
||
tem = simplify_gen_binary (MULT, mode, lhs,
|
||
GEN_INT (coeff0 + coeff1));
|
||
return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem;
|
||
}
|
||
}
|
||
|
||
/* If one of the operands is a PLUS or a MINUS, see if we can
|
||
simplify this by the associative law.
|
||
Don't use the associative law for floating point.
|
||
The inaccuracy makes it nonassociative,
|
||
and subtle programs can break if operations are associated. */
|
||
|
||
if (INTEGRAL_MODE_P (mode)
|
||
&& (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS
|
||
|| GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS)
|
||
&& (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
|
||
return tem;
|
||
break;
|
||
|
||
case COMPARE:
|
||
#ifdef HAVE_cc0
|
||
/* Convert (compare FOO (const_int 0)) to FOO unless we aren't
|
||
using cc0, in which case we want to leave it as a COMPARE
|
||
so we can distinguish it from a register-register-copy.
|
||
|
||
In IEEE floating point, x-0 is not the same as x. */
|
||
|
||
if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
|
||
|| ! FLOAT_MODE_P (mode) || flag_fast_math)
|
||
&& op1 == CONST0_RTX (mode))
|
||
return op0;
|
||
#else
|
||
/* Do nothing here. */
|
||
#endif
|
||
break;
|
||
|
||
case MINUS:
|
||
/* None of these optimizations can be done for IEEE
|
||
floating point. */
|
||
if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
|
||
&& FLOAT_MODE_P (mode) && ! flag_fast_math)
|
||
break;
|
||
|
||
/* We can't assume x-x is 0 even with non-IEEE floating point,
|
||
but since it is zero except in very strange circumstances, we
|
||
will treat it as zero with -ffast-math. */
|
||
if (rtx_equal_p (op0, op1)
|
||
&& ! side_effects_p (op0)
|
||
&& (! FLOAT_MODE_P (mode) || flag_fast_math))
|
||
return CONST0_RTX (mode);
|
||
|
||
/* Change subtraction from zero into negation. */
|
||
if (op0 == CONST0_RTX (mode))
|
||
return gen_rtx_NEG (mode, op1);
|
||
|
||
/* (-1 - a) is ~a. */
|
||
if (op0 == constm1_rtx)
|
||
return gen_rtx_NOT (mode, op1);
|
||
|
||
/* Subtracting 0 has no effect. */
|
||
if (op1 == CONST0_RTX (mode))
|
||
return op0;
|
||
|
||
/* See if this is something like X * C - X or vice versa or
|
||
if the multiplication is written as a shift. If so, we can
|
||
distribute and make a new multiply, shift, or maybe just
|
||
have X (if C is 2 in the example above). But don't make
|
||
real multiply if we didn't have one before. */
|
||
|
||
if (! FLOAT_MODE_P (mode))
|
||
{
|
||
HOST_WIDE_INT coeff0 = 1, coeff1 = 1;
|
||
rtx lhs = op0, rhs = op1;
|
||
int had_mult = 0;
|
||
|
||
if (GET_CODE (lhs) == NEG)
|
||
coeff0 = -1, lhs = XEXP (lhs, 0);
|
||
else if (GET_CODE (lhs) == MULT
|
||
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT)
|
||
{
|
||
coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0);
|
||
had_mult = 1;
|
||
}
|
||
else if (GET_CODE (lhs) == ASHIFT
|
||
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT
|
||
&& INTVAL (XEXP (lhs, 1)) >= 0
|
||
&& INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
|
||
lhs = XEXP (lhs, 0);
|
||
}
|
||
|
||
if (GET_CODE (rhs) == NEG)
|
||
coeff1 = - 1, rhs = XEXP (rhs, 0);
|
||
else if (GET_CODE (rhs) == MULT
|
||
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT)
|
||
{
|
||
coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0);
|
||
had_mult = 1;
|
||
}
|
||
else if (GET_CODE (rhs) == ASHIFT
|
||
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT
|
||
&& INTVAL (XEXP (rhs, 1)) >= 0
|
||
&& INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
|
||
rhs = XEXP (rhs, 0);
|
||
}
|
||
|
||
if (rtx_equal_p (lhs, rhs))
|
||
{
|
||
tem = simplify_gen_binary (MULT, mode, lhs,
|
||
GEN_INT (coeff0 - coeff1));
|
||
return (GET_CODE (tem) == MULT && ! had_mult) ? 0 : tem;
|
||
}
|
||
}
|
||
|
||
/* (a - (-b)) -> (a + b). */
|
||
if (GET_CODE (op1) == NEG)
|
||
return simplify_gen_binary (PLUS, mode, op0, XEXP (op1, 0));
|
||
|
||
/* If one of the operands is a PLUS or a MINUS, see if we can
|
||
simplify this by the associative law.
|
||
Don't use the associative law for floating point.
|
||
The inaccuracy makes it nonassociative,
|
||
and subtle programs can break if operations are associated. */
|
||
|
||
if (INTEGRAL_MODE_P (mode)
|
||
&& (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS
|
||
|| GET_CODE (op1) == PLUS || GET_CODE (op1) == MINUS)
|
||
&& (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
|
||
return tem;
|
||
|
||
/* Don't let a relocatable value get a negative coeff. */
|
||
if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode)
|
||
return plus_constant (op0, - INTVAL (op1));
|
||
|
||
/* (x - (x & y)) -> (x & ~y) */
|
||
if (GET_CODE (op1) == AND)
|
||
{
|
||
if (rtx_equal_p (op0, XEXP (op1, 0)))
|
||
return simplify_gen_binary (AND, mode, op0,
|
||
gen_rtx_NOT (mode, XEXP (op1, 1)));
|
||
if (rtx_equal_p (op0, XEXP (op1, 1)))
|
||
return simplify_gen_binary (AND, mode, op0,
|
||
gen_rtx_NOT (mode, XEXP (op1, 0)));
|
||
}
|
||
break;
|
||
|
||
case MULT:
|
||
if (op1 == constm1_rtx)
|
||
{
|
||
tem = simplify_unary_operation (NEG, mode, op0, mode);
|
||
|
||
return tem ? tem : gen_rtx_NEG (mode, op0);
|
||
}
|
||
|
||
/* In IEEE floating point, x*0 is not always 0. */
|
||
if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
|
||
|| ! FLOAT_MODE_P (mode) || flag_fast_math)
|
||
&& op1 == CONST0_RTX (mode)
|
||
&& ! side_effects_p (op0))
|
||
return op1;
|
||
|
||
/* In IEEE floating point, x*1 is not equivalent to x for nans.
|
||
However, ANSI says we can drop signals,
|
||
so we can do this anyway. */
|
||
if (op1 == CONST1_RTX (mode))
|
||
return op0;
|
||
|
||
/* Convert multiply by constant power of two into shift unless
|
||
we are still generating RTL. This test is a kludge. */
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (val = exact_log2 (INTVAL (op1))) >= 0
|
||
/* If the mode is larger than the host word size, and the
|
||
uppermost bit is set, then this isn't a power of two due
|
||
to implicit sign extension. */
|
||
&& (width <= HOST_BITS_PER_WIDE_INT
|
||
|| val != HOST_BITS_PER_WIDE_INT - 1)
|
||
&& ! rtx_equal_function_value_matters)
|
||
return gen_rtx_ASHIFT (mode, op0, GEN_INT (val));
|
||
|
||
if (GET_CODE (op1) == CONST_DOUBLE
|
||
&& GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT)
|
||
{
|
||
REAL_VALUE_TYPE d;
|
||
jmp_buf handler;
|
||
int op1is2, op1ism1;
|
||
|
||
if (setjmp (handler))
|
||
return 0;
|
||
|
||
set_float_handler (handler);
|
||
REAL_VALUE_FROM_CONST_DOUBLE (d, op1);
|
||
op1is2 = REAL_VALUES_EQUAL (d, dconst2);
|
||
op1ism1 = REAL_VALUES_EQUAL (d, dconstm1);
|
||
set_float_handler (NULL_PTR);
|
||
|
||
/* x*2 is x+x and x*(-1) is -x */
|
||
if (op1is2 && GET_MODE (op0) == mode)
|
||
return gen_rtx_PLUS (mode, op0, copy_rtx (op0));
|
||
|
||
else if (op1ism1 && GET_MODE (op0) == mode)
|
||
return gen_rtx_NEG (mode, op0);
|
||
}
|
||
break;
|
||
|
||
case IOR:
|
||
if (op1 == const0_rtx)
|
||
return op0;
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode))
|
||
return op1;
|
||
if (rtx_equal_p (op0, op1) && ! side_effects_p (op0))
|
||
return op0;
|
||
/* A | (~A) -> -1 */
|
||
if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1))
|
||
|| (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0)))
|
||
&& ! side_effects_p (op0)
|
||
&& GET_MODE_CLASS (mode) != MODE_CC)
|
||
return constm1_rtx;
|
||
break;
|
||
|
||
case XOR:
|
||
if (op1 == const0_rtx)
|
||
return op0;
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode))
|
||
return gen_rtx_NOT (mode, op0);
|
||
if (op0 == op1 && ! side_effects_p (op0)
|
||
&& GET_MODE_CLASS (mode) != MODE_CC)
|
||
return const0_rtx;
|
||
break;
|
||
|
||
case AND:
|
||
if (op1 == const0_rtx && ! side_effects_p (op0))
|
||
return const0_rtx;
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (INTVAL (op1) & GET_MODE_MASK (mode)) == GET_MODE_MASK (mode))
|
||
return op0;
|
||
if (op0 == op1 && ! side_effects_p (op0)
|
||
&& GET_MODE_CLASS (mode) != MODE_CC)
|
||
return op0;
|
||
/* A & (~A) -> 0 */
|
||
if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1))
|
||
|| (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0)))
|
||
&& ! side_effects_p (op0)
|
||
&& GET_MODE_CLASS (mode) != MODE_CC)
|
||
return const0_rtx;
|
||
break;
|
||
|
||
case UDIV:
|
||
/* Convert divide by power of two into shift (divide by 1 handled
|
||
below). */
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (arg1 = exact_log2 (INTVAL (op1))) > 0)
|
||
return gen_rtx_LSHIFTRT (mode, op0, GEN_INT (arg1));
|
||
|
||
/* ... fall through ... */
|
||
|
||
case DIV:
|
||
if (op1 == CONST1_RTX (mode))
|
||
return op0;
|
||
|
||
/* In IEEE floating point, 0/x is not always 0. */
|
||
if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
|
||
|| ! FLOAT_MODE_P (mode) || flag_fast_math)
|
||
&& op0 == CONST0_RTX (mode)
|
||
&& ! side_effects_p (op1))
|
||
return op0;
|
||
|
||
#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
|
||
/* Change division by a constant into multiplication. Only do
|
||
this with -ffast-math until an expert says it is safe in
|
||
general. */
|
||
else if (GET_CODE (op1) == CONST_DOUBLE
|
||
&& GET_MODE_CLASS (GET_MODE (op1)) == MODE_FLOAT
|
||
&& op1 != CONST0_RTX (mode)
|
||
&& flag_fast_math)
|
||
{
|
||
REAL_VALUE_TYPE d;
|
||
REAL_VALUE_FROM_CONST_DOUBLE (d, op1);
|
||
|
||
if (! REAL_VALUES_EQUAL (d, dconst0))
|
||
{
|
||
#if defined (REAL_ARITHMETIC)
|
||
REAL_ARITHMETIC (d, rtx_to_tree_code (DIV), dconst1, d);
|
||
return gen_rtx_MULT (mode, op0,
|
||
CONST_DOUBLE_FROM_REAL_VALUE (d, mode));
|
||
#else
|
||
return
|
||
gen_rtx_MULT (mode, op0,
|
||
CONST_DOUBLE_FROM_REAL_VALUE (1./d, mode));
|
||
#endif
|
||
}
|
||
}
|
||
#endif
|
||
break;
|
||
|
||
case UMOD:
|
||
/* Handle modulus by power of two (mod with 1 handled below). */
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& exact_log2 (INTVAL (op1)) > 0)
|
||
return gen_rtx_AND (mode, op0, GEN_INT (INTVAL (op1) - 1));
|
||
|
||
/* ... fall through ... */
|
||
|
||
case MOD:
|
||
if ((op0 == const0_rtx || op1 == const1_rtx)
|
||
&& ! side_effects_p (op0) && ! side_effects_p (op1))
|
||
return const0_rtx;
|
||
break;
|
||
|
||
case ROTATERT:
|
||
case ROTATE:
|
||
/* Rotating ~0 always results in ~0. */
|
||
if (GET_CODE (op0) == CONST_INT && width <= HOST_BITS_PER_WIDE_INT
|
||
&& (unsigned HOST_WIDE_INT) INTVAL (op0) == GET_MODE_MASK (mode)
|
||
&& ! side_effects_p (op1))
|
||
return op0;
|
||
|
||
/* ... fall through ... */
|
||
|
||
case ASHIFT:
|
||
case ASHIFTRT:
|
||
case LSHIFTRT:
|
||
if (op1 == const0_rtx)
|
||
return op0;
|
||
if (op0 == const0_rtx && ! side_effects_p (op1))
|
||
return op0;
|
||
break;
|
||
|
||
case SMIN:
|
||
if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT
|
||
&& INTVAL (op1) == (HOST_WIDE_INT) 1 << (width -1)
|
||
&& ! side_effects_p (op0))
|
||
return op1;
|
||
else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0))
|
||
return op0;
|
||
break;
|
||
|
||
case SMAX:
|
||
if (width <= HOST_BITS_PER_WIDE_INT && GET_CODE (op1) == CONST_INT
|
||
&& ((unsigned HOST_WIDE_INT) INTVAL (op1)
|
||
== (unsigned HOST_WIDE_INT) GET_MODE_MASK (mode) >> 1)
|
||
&& ! side_effects_p (op0))
|
||
return op1;
|
||
else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0))
|
||
return op0;
|
||
break;
|
||
|
||
case UMIN:
|
||
if (op1 == const0_rtx && ! side_effects_p (op0))
|
||
return op1;
|
||
else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0))
|
||
return op0;
|
||
break;
|
||
|
||
case UMAX:
|
||
if (op1 == constm1_rtx && ! side_effects_p (op0))
|
||
return op1;
|
||
else if (rtx_equal_p (op0, op1) && ! side_effects_p (op0))
|
||
return op0;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Get the integer argument values in two forms:
|
||
zero-extended in ARG0, ARG1 and sign-extended in ARG0S, ARG1S. */
|
||
|
||
arg0 = INTVAL (op0);
|
||
arg1 = INTVAL (op1);
|
||
|
||
if (width < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
arg0 &= ((HOST_WIDE_INT) 1 << width) - 1;
|
||
arg1 &= ((HOST_WIDE_INT) 1 << width) - 1;
|
||
|
||
arg0s = arg0;
|
||
if (arg0s & ((HOST_WIDE_INT) 1 << (width - 1)))
|
||
arg0s |= ((HOST_WIDE_INT) (-1) << width);
|
||
|
||
arg1s = arg1;
|
||
if (arg1s & ((HOST_WIDE_INT) 1 << (width - 1)))
|
||
arg1s |= ((HOST_WIDE_INT) (-1) << width);
|
||
}
|
||
else
|
||
{
|
||
arg0s = arg0;
|
||
arg1s = arg1;
|
||
}
|
||
|
||
/* Compute the value of the arithmetic. */
|
||
|
||
switch (code)
|
||
{
|
||
case PLUS:
|
||
val = arg0s + arg1s;
|
||
break;
|
||
|
||
case MINUS:
|
||
val = arg0s - arg1s;
|
||
break;
|
||
|
||
case MULT:
|
||
val = arg0s * arg1s;
|
||
break;
|
||
|
||
case DIV:
|
||
if (arg1s == 0)
|
||
return 0;
|
||
val = arg0s / arg1s;
|
||
break;
|
||
|
||
case MOD:
|
||
if (arg1s == 0)
|
||
return 0;
|
||
val = arg0s % arg1s;
|
||
break;
|
||
|
||
case UDIV:
|
||
if (arg1 == 0)
|
||
return 0;
|
||
val = (unsigned HOST_WIDE_INT) arg0 / arg1;
|
||
break;
|
||
|
||
case UMOD:
|
||
if (arg1 == 0)
|
||
return 0;
|
||
val = (unsigned HOST_WIDE_INT) arg0 % arg1;
|
||
break;
|
||
|
||
case AND:
|
||
val = arg0 & arg1;
|
||
break;
|
||
|
||
case IOR:
|
||
val = arg0 | arg1;
|
||
break;
|
||
|
||
case XOR:
|
||
val = arg0 ^ arg1;
|
||
break;
|
||
|
||
case LSHIFTRT:
|
||
/* If shift count is undefined, don't fold it; let the machine do
|
||
what it wants. But truncate it if the machine will do that. */
|
||
if (arg1 < 0)
|
||
return 0;
|
||
|
||
#ifdef SHIFT_COUNT_TRUNCATED
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
arg1 %= width;
|
||
#endif
|
||
|
||
val = ((unsigned HOST_WIDE_INT) arg0) >> arg1;
|
||
break;
|
||
|
||
case ASHIFT:
|
||
if (arg1 < 0)
|
||
return 0;
|
||
|
||
#ifdef SHIFT_COUNT_TRUNCATED
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
arg1 %= width;
|
||
#endif
|
||
|
||
val = ((unsigned HOST_WIDE_INT) arg0) << arg1;
|
||
break;
|
||
|
||
case ASHIFTRT:
|
||
if (arg1 < 0)
|
||
return 0;
|
||
|
||
#ifdef SHIFT_COUNT_TRUNCATED
|
||
if (SHIFT_COUNT_TRUNCATED)
|
||
arg1 %= width;
|
||
#endif
|
||
|
||
val = arg0s >> arg1;
|
||
|
||
/* Bootstrap compiler may not have sign extended the right shift.
|
||
Manually extend the sign to insure bootstrap cc matches gcc. */
|
||
if (arg0s < 0 && arg1 > 0)
|
||
val |= ((HOST_WIDE_INT) -1) << (HOST_BITS_PER_WIDE_INT - arg1);
|
||
|
||
break;
|
||
|
||
case ROTATERT:
|
||
if (arg1 < 0)
|
||
return 0;
|
||
|
||
arg1 %= width;
|
||
val = ((((unsigned HOST_WIDE_INT) arg0) << (width - arg1))
|
||
| (((unsigned HOST_WIDE_INT) arg0) >> arg1));
|
||
break;
|
||
|
||
case ROTATE:
|
||
if (arg1 < 0)
|
||
return 0;
|
||
|
||
arg1 %= width;
|
||
val = ((((unsigned HOST_WIDE_INT) arg0) << arg1)
|
||
| (((unsigned HOST_WIDE_INT) arg0) >> (width - arg1)));
|
||
break;
|
||
|
||
case COMPARE:
|
||
/* Do nothing here. */
|
||
return 0;
|
||
|
||
case SMIN:
|
||
val = arg0s <= arg1s ? arg0s : arg1s;
|
||
break;
|
||
|
||
case UMIN:
|
||
val = ((unsigned HOST_WIDE_INT) arg0
|
||
<= (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1);
|
||
break;
|
||
|
||
case SMAX:
|
||
val = arg0s > arg1s ? arg0s : arg1s;
|
||
break;
|
||
|
||
case UMAX:
|
||
val = ((unsigned HOST_WIDE_INT) arg0
|
||
> (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1);
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
val = trunc_int_for_mode (val, mode);
|
||
|
||
return GEN_INT (val);
|
||
}
|
||
|
||
/* Simplify a PLUS or MINUS, at least one of whose operands may be another
|
||
PLUS or MINUS.
|
||
|
||
Rather than test for specific case, we do this by a brute-force method
|
||
and do all possible simplifications until no more changes occur. Then
|
||
we rebuild the operation. */
|
||
|
||
static rtx
|
||
simplify_plus_minus (code, mode, op0, op1)
|
||
enum rtx_code code;
|
||
enum machine_mode mode;
|
||
rtx op0, op1;
|
||
{
|
||
rtx ops[8];
|
||
int negs[8];
|
||
rtx result, tem;
|
||
int n_ops = 2, input_ops = 2, input_consts = 0, n_consts = 0;
|
||
int first = 1, negate = 0, changed;
|
||
int i, j;
|
||
|
||
bzero ((char *) ops, sizeof ops);
|
||
|
||
/* Set up the two operands and then expand them until nothing has been
|
||
changed. If we run out of room in our array, give up; this should
|
||
almost never happen. */
|
||
|
||
ops[0] = op0, ops[1] = op1, negs[0] = 0, negs[1] = (code == MINUS);
|
||
|
||
changed = 1;
|
||
while (changed)
|
||
{
|
||
changed = 0;
|
||
|
||
for (i = 0; i < n_ops; i++)
|
||
switch (GET_CODE (ops[i]))
|
||
{
|
||
case PLUS:
|
||
case MINUS:
|
||
if (n_ops == 7)
|
||
return 0;
|
||
|
||
ops[n_ops] = XEXP (ops[i], 1);
|
||
negs[n_ops++] = GET_CODE (ops[i]) == MINUS ? !negs[i] : negs[i];
|
||
ops[i] = XEXP (ops[i], 0);
|
||
input_ops++;
|
||
changed = 1;
|
||
break;
|
||
|
||
case NEG:
|
||
ops[i] = XEXP (ops[i], 0);
|
||
negs[i] = ! negs[i];
|
||
changed = 1;
|
||
break;
|
||
|
||
case CONST:
|
||
ops[i] = XEXP (ops[i], 0);
|
||
input_consts++;
|
||
changed = 1;
|
||
break;
|
||
|
||
case NOT:
|
||
/* ~a -> (-a - 1) */
|
||
if (n_ops != 7)
|
||
{
|
||
ops[n_ops] = constm1_rtx;
|
||
negs[n_ops++] = negs[i];
|
||
ops[i] = XEXP (ops[i], 0);
|
||
negs[i] = ! negs[i];
|
||
changed = 1;
|
||
}
|
||
break;
|
||
|
||
case CONST_INT:
|
||
if (negs[i])
|
||
ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0, changed = 1;
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* If we only have two operands, we can't do anything. */
|
||
if (n_ops <= 2)
|
||
return 0;
|
||
|
||
/* Now simplify each pair of operands until nothing changes. The first
|
||
time through just simplify constants against each other. */
|
||
|
||
changed = 1;
|
||
while (changed)
|
||
{
|
||
changed = first;
|
||
|
||
for (i = 0; i < n_ops - 1; i++)
|
||
for (j = i + 1; j < n_ops; j++)
|
||
if (ops[i] != 0 && ops[j] != 0
|
||
&& (! first || (CONSTANT_P (ops[i]) && CONSTANT_P (ops[j]))))
|
||
{
|
||
rtx lhs = ops[i], rhs = ops[j];
|
||
enum rtx_code ncode = PLUS;
|
||
|
||
if (negs[i] && ! negs[j])
|
||
lhs = ops[j], rhs = ops[i], ncode = MINUS;
|
||
else if (! negs[i] && negs[j])
|
||
ncode = MINUS;
|
||
|
||
tem = simplify_binary_operation (ncode, mode, lhs, rhs);
|
||
if (tem)
|
||
{
|
||
ops[i] = tem, ops[j] = 0;
|
||
negs[i] = negs[i] && negs[j];
|
||
if (GET_CODE (tem) == NEG)
|
||
ops[i] = XEXP (tem, 0), negs[i] = ! negs[i];
|
||
|
||
if (GET_CODE (ops[i]) == CONST_INT && negs[i])
|
||
ops[i] = GEN_INT (- INTVAL (ops[i])), negs[i] = 0;
|
||
changed = 1;
|
||
}
|
||
}
|
||
|
||
first = 0;
|
||
}
|
||
|
||
/* Pack all the operands to the lower-numbered entries and give up if
|
||
we didn't reduce the number of operands we had. Make sure we
|
||
count a CONST as two operands. If we have the same number of
|
||
operands, but have made more CONSTs than we had, this is also
|
||
an improvement, so accept it. */
|
||
|
||
for (i = 0, j = 0; j < n_ops; j++)
|
||
if (ops[j] != 0)
|
||
{
|
||
ops[i] = ops[j], negs[i++] = negs[j];
|
||
if (GET_CODE (ops[j]) == CONST)
|
||
n_consts++;
|
||
}
|
||
|
||
if (i + n_consts > input_ops
|
||
|| (i + n_consts == input_ops && n_consts <= input_consts))
|
||
return 0;
|
||
|
||
n_ops = i;
|
||
|
||
/* If we have a CONST_INT, put it last. */
|
||
for (i = 0; i < n_ops - 1; i++)
|
||
if (GET_CODE (ops[i]) == CONST_INT)
|
||
{
|
||
tem = ops[n_ops - 1], ops[n_ops - 1] = ops[i] , ops[i] = tem;
|
||
j = negs[n_ops - 1], negs[n_ops - 1] = negs[i], negs[i] = j;
|
||
}
|
||
|
||
/* Put a non-negated operand first. If there aren't any, make all
|
||
operands positive and negate the whole thing later. */
|
||
for (i = 0; i < n_ops && negs[i]; i++)
|
||
;
|
||
|
||
if (i == n_ops)
|
||
{
|
||
for (i = 0; i < n_ops; i++)
|
||
negs[i] = 0;
|
||
negate = 1;
|
||
}
|
||
else if (i != 0)
|
||
{
|
||
tem = ops[0], ops[0] = ops[i], ops[i] = tem;
|
||
j = negs[0], negs[0] = negs[i], negs[i] = j;
|
||
}
|
||
|
||
/* Now make the result by performing the requested operations. */
|
||
result = ops[0];
|
||
for (i = 1; i < n_ops; i++)
|
||
result = simplify_gen_binary (negs[i] ? MINUS : PLUS, mode, result, ops[i]);
|
||
|
||
return negate ? gen_rtx_NEG (mode, result) : result;
|
||
}
|
||
|
||
struct cfc_args
|
||
{
|
||
rtx op0, op1; /* Input */
|
||
int equal, op0lt, op1lt; /* Output */
|
||
};
|
||
|
||
static void
|
||
check_fold_consts (data)
|
||
PTR data;
|
||
{
|
||
struct cfc_args *args = (struct cfc_args *) data;
|
||
REAL_VALUE_TYPE d0, d1;
|
||
|
||
REAL_VALUE_FROM_CONST_DOUBLE (d0, args->op0);
|
||
REAL_VALUE_FROM_CONST_DOUBLE (d1, args->op1);
|
||
args->equal = REAL_VALUES_EQUAL (d0, d1);
|
||
args->op0lt = REAL_VALUES_LESS (d0, d1);
|
||
args->op1lt = REAL_VALUES_LESS (d1, d0);
|
||
}
|
||
|
||
/* Like simplify_binary_operation except used for relational operators.
|
||
MODE is the mode of the operands, not that of the result. If MODE
|
||
is VOIDmode, both operands must also be VOIDmode and we compare the
|
||
operands in "infinite precision".
|
||
|
||
If no simplification is possible, this function returns zero. Otherwise,
|
||
it returns either const_true_rtx or const0_rtx. */
|
||
|
||
rtx
|
||
simplify_relational_operation (code, mode, op0, op1)
|
||
enum rtx_code code;
|
||
enum machine_mode mode;
|
||
rtx op0, op1;
|
||
{
|
||
int equal, op0lt, op0ltu, op1lt, op1ltu;
|
||
rtx tem;
|
||
|
||
/* If op0 is a compare, extract the comparison arguments from it. */
|
||
if (GET_CODE (op0) == COMPARE && op1 == const0_rtx)
|
||
op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
|
||
|
||
/* We can't simplify MODE_CC values since we don't know what the
|
||
actual comparison is. */
|
||
if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC
|
||
#ifdef HAVE_cc0
|
||
|| op0 == cc0_rtx
|
||
#endif
|
||
)
|
||
return 0;
|
||
|
||
/* For integer comparisons of A and B maybe we can simplify A - B and can
|
||
then simplify a comparison of that with zero. If A and B are both either
|
||
a register or a CONST_INT, this can't help; testing for these cases will
|
||
prevent infinite recursion here and speed things up.
|
||
|
||
If CODE is an unsigned comparison, then we can never do this optimization,
|
||
because it gives an incorrect result if the subtraction wraps around zero.
|
||
ANSI C defines unsigned operations such that they never overflow, and
|
||
thus such cases can not be ignored. */
|
||
|
||
if (INTEGRAL_MODE_P (mode) && op1 != const0_rtx
|
||
&& ! ((GET_CODE (op0) == REG || GET_CODE (op0) == CONST_INT)
|
||
&& (GET_CODE (op1) == REG || GET_CODE (op1) == CONST_INT))
|
||
&& 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1))
|
||
&& code != GTU && code != GEU && code != LTU && code != LEU)
|
||
return simplify_relational_operation (signed_condition (code),
|
||
mode, tem, const0_rtx);
|
||
|
||
/* For non-IEEE floating-point, if the two operands are equal, we know the
|
||
result. */
|
||
if (rtx_equal_p (op0, op1)
|
||
&& (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
|
||
|| ! FLOAT_MODE_P (GET_MODE (op0)) || flag_fast_math))
|
||
equal = 1, op0lt = 0, op0ltu = 0, op1lt = 0, op1ltu = 0;
|
||
|
||
/* If the operands are floating-point constants, see if we can fold
|
||
the result. */
|
||
#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
|
||
else if (GET_CODE (op0) == CONST_DOUBLE && GET_CODE (op1) == CONST_DOUBLE
|
||
&& GET_MODE_CLASS (GET_MODE (op0)) == MODE_FLOAT)
|
||
{
|
||
struct cfc_args args;
|
||
|
||
/* Setup input for check_fold_consts() */
|
||
args.op0 = op0;
|
||
args.op1 = op1;
|
||
|
||
if (do_float_handler(check_fold_consts, (PTR) &args) == 0)
|
||
/* We got an exception from check_fold_consts() */
|
||
return 0;
|
||
|
||
/* Receive output from check_fold_consts() */
|
||
equal = args.equal;
|
||
op0lt = op0ltu = args.op0lt;
|
||
op1lt = op1ltu = args.op1lt;
|
||
}
|
||
#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
|
||
|
||
/* Otherwise, see if the operands are both integers. */
|
||
else if ((GET_MODE_CLASS (mode) == MODE_INT || mode == VOIDmode)
|
||
&& (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT)
|
||
&& (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT))
|
||
{
|
||
int width = GET_MODE_BITSIZE (mode);
|
||
HOST_WIDE_INT l0s, h0s, l1s, h1s;
|
||
unsigned HOST_WIDE_INT l0u, h0u, l1u, h1u;
|
||
|
||
/* Get the two words comprising each integer constant. */
|
||
if (GET_CODE (op0) == CONST_DOUBLE)
|
||
{
|
||
l0u = l0s = CONST_DOUBLE_LOW (op0);
|
||
h0u = h0s = CONST_DOUBLE_HIGH (op0);
|
||
}
|
||
else
|
||
{
|
||
l0u = l0s = INTVAL (op0);
|
||
h0u = h0s = l0s < 0 ? -1 : 0;
|
||
}
|
||
|
||
if (GET_CODE (op1) == CONST_DOUBLE)
|
||
{
|
||
l1u = l1s = CONST_DOUBLE_LOW (op1);
|
||
h1u = h1s = CONST_DOUBLE_HIGH (op1);
|
||
}
|
||
else
|
||
{
|
||
l1u = l1s = INTVAL (op1);
|
||
h1u = h1s = l1s < 0 ? -1 : 0;
|
||
}
|
||
|
||
/* If WIDTH is nonzero and smaller than HOST_BITS_PER_WIDE_INT,
|
||
we have to sign or zero-extend the values. */
|
||
if (width != 0 && width <= HOST_BITS_PER_WIDE_INT)
|
||
h0u = h1u = 0, h0s = l0s < 0 ? -1 : 0, h1s = l1s < 0 ? -1 : 0;
|
||
|
||
if (width != 0 && width < HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
l0u &= ((HOST_WIDE_INT) 1 << width) - 1;
|
||
l1u &= ((HOST_WIDE_INT) 1 << width) - 1;
|
||
|
||
if (l0s & ((HOST_WIDE_INT) 1 << (width - 1)))
|
||
l0s |= ((HOST_WIDE_INT) (-1) << width);
|
||
|
||
if (l1s & ((HOST_WIDE_INT) 1 << (width - 1)))
|
||
l1s |= ((HOST_WIDE_INT) (-1) << width);
|
||
}
|
||
|
||
equal = (h0u == h1u && l0u == l1u);
|
||
op0lt = (h0s < h1s || (h0s == h1s && l0s < l1s));
|
||
op1lt = (h1s < h0s || (h1s == h0s && l1s < l0s));
|
||
op0ltu = (h0u < h1u || (h0u == h1u && l0u < l1u));
|
||
op1ltu = (h1u < h0u || (h1u == h0u && l1u < l0u));
|
||
}
|
||
|
||
/* Otherwise, there are some code-specific tests we can make. */
|
||
else
|
||
{
|
||
switch (code)
|
||
{
|
||
case EQ:
|
||
/* References to the frame plus a constant or labels cannot
|
||
be zero, but a SYMBOL_REF can due to #pragma weak. */
|
||
if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx)
|
||
|| GET_CODE (op0) == LABEL_REF)
|
||
#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
|
||
/* On some machines, the ap reg can be 0 sometimes. */
|
||
&& op0 != arg_pointer_rtx
|
||
#endif
|
||
)
|
||
return const0_rtx;
|
||
break;
|
||
|
||
case NE:
|
||
if (((NONZERO_BASE_PLUS_P (op0) && op1 == const0_rtx)
|
||
|| GET_CODE (op0) == LABEL_REF)
|
||
#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
|
||
&& op0 != arg_pointer_rtx
|
||
#endif
|
||
)
|
||
return const_true_rtx;
|
||
break;
|
||
|
||
case GEU:
|
||
/* Unsigned values are never negative. */
|
||
if (op1 == const0_rtx)
|
||
return const_true_rtx;
|
||
break;
|
||
|
||
case LTU:
|
||
if (op1 == const0_rtx)
|
||
return const0_rtx;
|
||
break;
|
||
|
||
case LEU:
|
||
/* Unsigned values are never greater than the largest
|
||
unsigned value. */
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (unsigned HOST_WIDE_INT) INTVAL (op1) == GET_MODE_MASK (mode)
|
||
&& INTEGRAL_MODE_P (mode))
|
||
return const_true_rtx;
|
||
break;
|
||
|
||
case GTU:
|
||
if (GET_CODE (op1) == CONST_INT
|
||
&& (unsigned HOST_WIDE_INT) INTVAL (op1) == GET_MODE_MASK (mode)
|
||
&& INTEGRAL_MODE_P (mode))
|
||
return const0_rtx;
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* If we reach here, EQUAL, OP0LT, OP0LTU, OP1LT, and OP1LTU are set
|
||
as appropriate. */
|
||
switch (code)
|
||
{
|
||
case EQ:
|
||
return equal ? const_true_rtx : const0_rtx;
|
||
case NE:
|
||
return ! equal ? const_true_rtx : const0_rtx;
|
||
case LT:
|
||
return op0lt ? const_true_rtx : const0_rtx;
|
||
case GT:
|
||
return op1lt ? const_true_rtx : const0_rtx;
|
||
case LTU:
|
||
return op0ltu ? const_true_rtx : const0_rtx;
|
||
case GTU:
|
||
return op1ltu ? const_true_rtx : const0_rtx;
|
||
case LE:
|
||
return equal || op0lt ? const_true_rtx : const0_rtx;
|
||
case GE:
|
||
return equal || op1lt ? const_true_rtx : const0_rtx;
|
||
case LEU:
|
||
return equal || op0ltu ? const_true_rtx : const0_rtx;
|
||
case GEU:
|
||
return equal || op1ltu ? const_true_rtx : const0_rtx;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Simplify CODE, an operation with result mode MODE and three operands,
|
||
OP0, OP1, and OP2. OP0_MODE was the mode of OP0 before it became
|
||
a constant. Return 0 if no simplifications is possible. */
|
||
|
||
rtx
|
||
simplify_ternary_operation (code, mode, op0_mode, op0, op1, op2)
|
||
enum rtx_code code;
|
||
enum machine_mode mode, op0_mode;
|
||
rtx op0, op1, op2;
|
||
{
|
||
int width = GET_MODE_BITSIZE (mode);
|
||
|
||
/* VOIDmode means "infinite" precision. */
|
||
if (width == 0)
|
||
width = HOST_BITS_PER_WIDE_INT;
|
||
|
||
switch (code)
|
||
{
|
||
case SIGN_EXTRACT:
|
||
case ZERO_EXTRACT:
|
||
if (GET_CODE (op0) == CONST_INT
|
||
&& GET_CODE (op1) == CONST_INT
|
||
&& GET_CODE (op2) == CONST_INT
|
||
&& INTVAL (op1) + INTVAL (op2) <= GET_MODE_BITSIZE (op0_mode)
|
||
&& width <= HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
/* Extracting a bit-field from a constant */
|
||
HOST_WIDE_INT val = INTVAL (op0);
|
||
|
||
if (BITS_BIG_ENDIAN)
|
||
val >>= (GET_MODE_BITSIZE (op0_mode)
|
||
- INTVAL (op2) - INTVAL (op1));
|
||
else
|
||
val >>= INTVAL (op2);
|
||
|
||
if (HOST_BITS_PER_WIDE_INT != INTVAL (op1))
|
||
{
|
||
/* First zero-extend. */
|
||
val &= ((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1;
|
||
/* If desired, propagate sign bit. */
|
||
if (code == SIGN_EXTRACT
|
||
&& (val & ((HOST_WIDE_INT) 1 << (INTVAL (op1) - 1))))
|
||
val |= ~ (((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1);
|
||
}
|
||
|
||
/* Clear the bits that don't belong in our mode,
|
||
unless they and our sign bit are all one.
|
||
So we get either a reasonable negative value or a reasonable
|
||
unsigned value for this mode. */
|
||
if (width < HOST_BITS_PER_WIDE_INT
|
||
&& ((val & ((HOST_WIDE_INT) (-1) << (width - 1)))
|
||
!= ((HOST_WIDE_INT) (-1) << (width - 1))))
|
||
val &= ((HOST_WIDE_INT) 1 << width) - 1;
|
||
|
||
return GEN_INT (val);
|
||
}
|
||
break;
|
||
|
||
case IF_THEN_ELSE:
|
||
if (GET_CODE (op0) == CONST_INT)
|
||
return op0 != const0_rtx ? op1 : op2;
|
||
|
||
/* Convert a == b ? b : a to "a". */
|
||
if (GET_CODE (op0) == NE && ! side_effects_p (op0)
|
||
&& rtx_equal_p (XEXP (op0, 0), op1)
|
||
&& rtx_equal_p (XEXP (op0, 1), op2))
|
||
return op1;
|
||
else if (GET_CODE (op0) == EQ && ! side_effects_p (op0)
|
||
&& rtx_equal_p (XEXP (op0, 1), op1)
|
||
&& rtx_equal_p (XEXP (op0, 0), op2))
|
||
return op2;
|
||
else if (GET_RTX_CLASS (GET_CODE (op0)) == '<' && ! side_effects_p (op0))
|
||
{
|
||
rtx temp;
|
||
temp = simplify_relational_operation (GET_CODE (op0), op0_mode,
|
||
XEXP (op0, 0), XEXP (op0, 1));
|
||
/* See if any simplifications were possible. */
|
||
if (temp == const0_rtx)
|
||
return op2;
|
||
else if (temp == const1_rtx)
|
||
return op1;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Simplify X, an rtx expression.
|
||
|
||
Return the simplified expression or NULL if no simplifications
|
||
were possible.
|
||
|
||
This is the preferred entry point into the simplification routines;
|
||
however, we still allow passes to call the more specific routines.
|
||
|
||
Right now GCC has three (yes, three) major bodies of RTL simplficiation
|
||
code that need to be unified.
|
||
|
||
1. fold_rtx in cse.c. This code uses various CSE specific
|
||
information to aid in RTL simplification.
|
||
|
||
2. simplify_rtx in combine.c. Similar to fold_rtx, except that
|
||
it uses combine specific information to aid in RTL
|
||
simplification.
|
||
|
||
3. The routines in this file.
|
||
|
||
|
||
Long term we want to only have one body of simplification code; to
|
||
get to that state I recommend the following steps:
|
||
|
||
1. Pour over fold_rtx & simplify_rtx and move any simplifications
|
||
which are not pass dependent state into these routines.
|
||
|
||
2. As code is moved by #1, change fold_rtx & simplify_rtx to
|
||
use this routine whenever possible.
|
||
|
||
3. Allow for pass dependent state to be provided to these
|
||
routines and add simplifications based on the pass dependent
|
||
state. Remove code from cse.c & combine.c that becomes
|
||
redundant/dead.
|
||
|
||
It will take time, but ultimately the compiler will be easier to
|
||
maintain and improve. It's totally silly that when we add a
|
||
simplification that it needs to be added to 4 places (3 for RTL
|
||
simplification and 1 for tree simplification. */
|
||
|
||
rtx
|
||
simplify_rtx (x)
|
||
rtx x;
|
||
{
|
||
enum rtx_code code;
|
||
enum machine_mode mode;
|
||
|
||
mode = GET_MODE (x);
|
||
code = GET_CODE (x);
|
||
|
||
switch (GET_RTX_CLASS (code))
|
||
{
|
||
case '1':
|
||
return simplify_unary_operation (code, mode,
|
||
XEXP (x, 0), GET_MODE (XEXP (x, 0)));
|
||
case '2':
|
||
case 'c':
|
||
return simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1));
|
||
|
||
case '3':
|
||
case 'b':
|
||
return simplify_ternary_operation (code, mode, GET_MODE (XEXP (x, 0)),
|
||
XEXP (x, 0), XEXP (x, 1), XEXP (x, 2));
|
||
|
||
case '<':
|
||
return simplify_relational_operation (code, GET_MODE (XEXP (x, 0)),
|
||
XEXP (x, 0), XEXP (x, 1));
|
||
default:
|
||
return NULL;
|
||
}
|
||
}
|