diff options
| author | Roger Sayle <roger@eyesopen.com> | 2003-01-23 02:57:26 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2003-01-23 02:57:26 +0000 |
| commit | 34ee7f8278d155d6d128f6af19b10ed35fa8f3d5 (patch) | |
| tree | e350e7cda96af13a3c7a7347f5f121cef549541c /gcc/cse.c | |
| parent | 94edc4abdc1de8d0c77421354eabf3bfc3de0c91 (diff) | |
| download | gcc-34ee7f8278d155d6d128f6af19b10ed35fa8f3d5.zip gcc-34ee7f8278d155d6d128f6af19b10ed35fa8f3d5.tar.gz gcc-34ee7f8278d155d6d128f6af19b10ed35fa8f3d5.tar.bz2 | |
re PR rtl-optimization/8423 (CSE1 not propagating __builtin_constant_p enough)
PR optimization/8423
* cse.c (fold_rtx): Only eliminate a CONSTANT_P_RTX to 1 when
its argument is constant, or 0 if !flag_gcse.
* simplify-rtx.c (simplify_rtx): Convert CONSTANT_P_RTX to 1
if it's argument is constant.
* gcse.c (want_to_gcse_p): Ignore CONSTANT_P_RTX nodes.
(hash_scan_set): Don't record CONSTANT_P_RTX expressions.
(do_local_cprop): Don't propagate CONSTANT_P_RTX constants.
* builtins.c (purge_builtin_constant_p): New function to force
instantiation of any remaining CONSTANT_P_RTX nodes.
* rtl.h (purge_builtin_constant_p): Prototype here.
* toplev.c (rest_of_compilation): Invoke purge_builtin_constant_p
pass after GCSE and before loop.
(flag_gcse): No longer static.
* flags.h (flag_gcse): Prototype here.
From-SVN: r61642
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 11 |
1 files changed, 8 insertions, 3 deletions
@@ -1,6 +1,6 @@ /* Common subexpression elimination for GNU compiler. Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998 - 1999, 2000, 2001, 2002 Free Software Foundation, Inc. + 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. This file is part of GCC. @@ -4332,9 +4332,14 @@ fold_rtx (x, insn) break; case 'x': - /* Always eliminate CONSTANT_P_RTX at this stage. */ + /* Eliminate CONSTANT_P_RTX if its constant. */ if (code == CONSTANT_P_RTX) - return (const_arg0 ? const1_rtx : const0_rtx); + { + if (const_arg0) + return const1_rtx; + if (!flag_gcse) + return const0_rtx; + } break; } |