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Diffstat (limited to 'test/Transforms/PhaseOrdering/basic.ll')
| -rw-r--r-- | test/Transforms/PhaseOrdering/basic.ll | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/test/Transforms/PhaseOrdering/basic.ll b/test/Transforms/PhaseOrdering/basic.ll index 2d52ae50df..88ebca0a9c 100644 --- a/test/Transforms/PhaseOrdering/basic.ll +++ b/test/Transforms/PhaseOrdering/basic.ll @@ -22,3 +22,30 @@ define void @test1() nounwind ssp { ; CHECK: @test1 ; CHECK-NEXT: ret void } + +; This function exposes a phase ordering problem when InstCombine is +; turning %add into a bitmask, making it difficult to spot a 0 return value. +; +; It it also important that %add is expressed as a multiple of %div so scalar +; evolution can recognize it. +define i32 @test2(i32 %a, i32* %p) nounwind uwtable ssp { +entry: + %div = udiv i32 %a, 4 + %arrayidx = getelementptr inbounds i32* %p, i64 0 + store i32 %div, i32* %arrayidx, align 4 + %add = add i32 %div, %div + %arrayidx1 = getelementptr inbounds i32* %p, i64 1 + store i32 %add, i32* %arrayidx1, align 4 + %arrayidx2 = getelementptr inbounds i32* %p, i64 1 + %0 = load i32* %arrayidx2, align 4 + %arrayidx3 = getelementptr inbounds i32* %p, i64 0 + %1 = load i32* %arrayidx3, align 4 + %mul = mul i32 2, %1 + %sub = sub i32 %0, %mul + ret i32 %sub + +; CHECK: @test2 +; CHECK: %div = lshr i32 %a, 2 +; CHECK: %add = shl nuw nsw i32 %div, 1 +; CHECK: ret i32 0 +} |