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| author | Manman Ren <mren@apple.com> | 2012-05-31 17:20:29 +0000 |
|---|---|---|
| committer | Manman Ren <mren@apple.com> | 2012-05-31 17:20:29 +0000 |
| commit | 91c5346d91973a1d3458a20f8c6b0e899b732e38 (patch) | |
| tree | eb29d9f46d2f9184cb248413cc98369f6179c089 /test/CodeGen/X86/jump_sign.ll | |
| parent | 5ddc04caf25a649963c99be02646c3a9fc88d514 (diff) | |
| download | llvm-91c5346d91973a1d3458a20f8c6b0e899b732e38.tar.gz llvm-91c5346d91973a1d3458a20f8c6b0e899b732e38.tar.bz2 llvm-91c5346d91973a1d3458a20f8c6b0e899b732e38.tar.xz | |
X86: replace SUB with CMP if possible
This patch will optimize the following
movq %rdi, %rax
subq %rsi, %rax
cmovsq %rsi, %rdi
movq %rdi, %rax
to
cmpq %rsi, %rdi
cmovsq %rsi, %rdi
movq %rdi, %rax
Perform this optimization if the actual result of SUB is not used.
rdar: 11540023
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157755 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/X86/jump_sign.ll')
| -rw-r--r-- | test/CodeGen/X86/jump_sign.ll | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/test/CodeGen/X86/jump_sign.ll b/test/CodeGen/X86/jump_sign.ll index 94cbe5d193..cf5408e071 100644 --- a/test/CodeGen/X86/jump_sign.ll +++ b/test/CodeGen/X86/jump_sign.ll @@ -83,3 +83,14 @@ entry: %cond = select i1 %cmp, i32 %sub, i32 0 ret i32 %cond } +; rdar://11540023 +define i64 @n(i64 %x, i64 %y) nounwind { +entry: +; CHECK: n: +; CHECK-NOT: sub +; CHECK: cmp + %sub = sub nsw i64 %x, %y + %cmp = icmp slt i64 %sub, 0 + %y.x = select i1 %cmp, i64 %y, i64 %x + ret i64 %y.x +} |