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| author | Shuxin Yang <shuxin.llvm@gmail.com> | 2012-10-31 23:11:48 +0000 |
|---|---|---|
| committer | Shuxin Yang <shuxin.llvm@gmail.com> | 2012-10-31 23:11:48 +0000 |
| commit | a5526a9bffbd62a14d576f583c206a8a781cc2f1 (patch) | |
| tree | e58a6a7c0baec3b6f947d8df16933e36fdc374ac /test | |
| parent | e57b2cbce652d45ed5516e52ad82991bfa03cfd7 (diff) | |
| download | external_llvm-a5526a9bffbd62a14d576f583c206a8a781cc2f1.zip external_llvm-a5526a9bffbd62a14d576f583c206a8a781cc2f1.tar.gz external_llvm-a5526a9bffbd62a14d576f583c206a8a781cc2f1.tar.bz2 | |
(For X86) Enhancement to add-carray/sub-borrow (adc/sbb) optimization.
The adc/sbb optimization is to able to convert following expression
into a single adc/sbb instruction:
(ult) ... = x + 1 // where the ult is unsigned-less-than comparison
(ult) ... = x - 1
This change is to flip the "x >u y" (i.e. ugt comparison) in order
to expose the adc/sbb opportunity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167180 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/CodeGen/X86/add-of-carry.ll | 13 | ||||
| -rw-r--r-- | test/CodeGen/X86/jump_sign.ll | 1 |
2 files changed, 13 insertions, 1 deletions
diff --git a/test/CodeGen/X86/add-of-carry.ll b/test/CodeGen/X86/add-of-carry.ll index a4abccb..4e30f2b 100644 --- a/test/CodeGen/X86/add-of-carry.ll +++ b/test/CodeGen/X86/add-of-carry.ll @@ -30,4 +30,17 @@ entry: ret i32 %z.0 } +; <rdar://problem/12579915> +define i32 @test3(i32 %x, i32 %y, i32 %res) nounwind uwtable readnone ssp { +entry: + %cmp = icmp ugt i32 %x, %y + %dec = sext i1 %cmp to i32 + %dec.res = add nsw i32 %dec, %res + ret i32 %dec.res +; CHECK: test3: +; CHECK: cmpl +; CHECK: sbbl +; CHECK: ret +} + declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32) nounwind readnone diff --git a/test/CodeGen/X86/jump_sign.ll b/test/CodeGen/X86/jump_sign.ll index 78d9e06..0e34222 100644 --- a/test/CodeGen/X86/jump_sign.ll +++ b/test/CodeGen/X86/jump_sign.ll @@ -219,7 +219,6 @@ entry: ; by sbb, we should not optimize cmp away. define i32 @q(i32 %j.4, i32 %w, i32 %el) { ; CHECK: q: -; CHECK: sub ; CHECK: cmp ; CHECK-NEXT: sbb %tmp532 = add i32 %j.4, %w |