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| author | Manman Ren <mren@apple.com> | 2012-07-07 03:34:46 +0000 |
|---|---|---|
| committer | Manman Ren <mren@apple.com> | 2012-07-07 03:34:46 +0000 |
| commit | 2d4215f75949448d5207ec67b11878741a708fbe (patch) | |
| tree | a41f6d1f7fa6643e1aee92b9aace18b4fc24d03d /test/CodeGen/X86/jump_sign.ll | |
| parent | 845b4c2f0b2b3f0ec468ac863550b25708279180 (diff) | |
| download | llvm-2d4215f75949448d5207ec67b11878741a708fbe.tar.gz llvm-2d4215f75949448d5207ec67b11878741a708fbe.tar.bz2 llvm-2d4215f75949448d5207ec67b11878741a708fbe.tar.xz | |
X86: Fix optimizeCompare to correctly check safe condition.
It is safe if EFLAGS is killed or re-defined.
When we are done with the basic block, check whether EFLAGS is live-out.
Do not optimize away cmp if EFLAGS is live-out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159888 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/X86/jump_sign.ll')
| -rw-r--r-- | test/CodeGen/X86/jump_sign.ll | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/test/CodeGen/X86/jump_sign.ll b/test/CodeGen/X86/jump_sign.ll index 567490b59e..e84f49c8a1 100644 --- a/test/CodeGen/X86/jump_sign.ll +++ b/test/CodeGen/X86/jump_sign.ll @@ -102,6 +102,24 @@ entry: %cond = select i1 %cmp, i32 %b, i32 %sub ret i32 %cond } +; If EFLAGS is live-out, we can't remove cmp if there exists +; a swapped sub. +define i32 @l2(i32 %a, i32 %b) nounwind { +entry: +; CHECK: l2: +; CHECK: cmp + %cmp = icmp eq i32 %b, %a + %sub = sub nsw i32 %a, %b + br i1 %cmp, label %if.then, label %if.else + +if.then: + %cmp2 = icmp sgt i32 %b, %a + %sel = select i1 %cmp2, i32 %sub, i32 %a + ret i32 %sel + +if.else: + ret i32 %sub +} ; rdar://11540023 define i32 @n(i32 %x, i32 %y) nounwind { entry: |