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| author | Jakub Jelinek <jakub@redhat.com> | 2007-12-14 19:00:39 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2007-12-14 19:00:39 +0100 |
| commit | 18117c0574ff93712f6b1710c5bdd70b68695637 (patch) | |
| tree | c4441421464bc00c96de471a7e07b6a70025b6e9 /gcc/config | |
| parent | 05c219bb4943a1ebfc30df747e1d97897b3494a1 (diff) | |
| download | gcc-18117c0574ff93712f6b1710c5bdd70b68695637.zip gcc-18117c0574ff93712f6b1710c5bdd70b68695637.tar.gz gcc-18117c0574ff93712f6b1710c5bdd70b68695637.tar.bz2 | |
re PR target/29978 (redundant jumps)
PR target/29978
* config/i386/i386.c (ix86_expand_branch): Optimize LE/LEU/GT/GTU
DImode comparisons against constant with all 1's in the lower word.
* gcc.target/i386/pr29978.c: New test.
From-SVN: r130938
Diffstat (limited to 'gcc/config')
| -rw-r--r-- | gcc/config/i386/i386.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index fcae077..95a3496 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -12093,16 +12093,28 @@ ix86_expand_branch (enum rtx_code code, rtx label) /* Otherwise, if we are doing less-than or greater-or-equal-than, op1 is a constant and the low word is zero, then we can just - examine the high word. */ + examine the high word. Similarly for low word -1 and + less-or-equal-than or greater-than. */ - if (CONST_INT_P (hi[1]) && lo[1] == const0_rtx) + if (CONST_INT_P (hi[1])) switch (code) { case LT: case LTU: case GE: case GEU: - ix86_compare_op0 = hi[0]; - ix86_compare_op1 = hi[1]; - ix86_expand_branch (code, label); - return; + if (lo[1] == const0_rtx) + { + ix86_compare_op0 = hi[0]; + ix86_compare_op1 = hi[1]; + ix86_expand_branch (code, label); + return; + } + case LE: case LEU: case GT: case GTU: + if (lo[1] == constm1_rtx) + { + ix86_compare_op0 = hi[0]; + ix86_compare_op1 = hi[1]; + ix86_expand_branch (code, label); + return; + } default: break; } |