forked from OSchip/llvm-project
47 lines
907 B
LLVM
47 lines
907 B
LLVM
; Test that GCSE uses basicaa to do alias analysis, which is capable of
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; disambiguating some obvious cases. All loads should be removable in
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; this testcase.
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; RUN: opt < %s -basicaa -gvn -instcombine -dce -S \
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; RUN: | not grep load
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@A = global i32 7
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@B = global i32 8
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define i32 @test() {
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%A1 = load i32* @A
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store i32 123, i32* @B ; Store cannot alias @A
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%A2 = load i32* @A
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%X = sub i32 %A1, %A2
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ret i32 %X
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}
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define i32 @test2() {
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%A1 = load i32* @A
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br label %Loop
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Loop:
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%AP = phi i32 [0, %0], [%X, %Loop]
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store i32 %AP, i32* @B ; Store cannot alias @A
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%A2 = load i32* @A
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%X = sub i32 %A1, %A2
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%c = icmp eq i32 %X, 0
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br i1 %c, label %out, label %Loop
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out:
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ret i32 %X
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}
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declare void @external()
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define i32 @test3() {
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%X = alloca i32
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store i32 7, i32* %X
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call void @external()
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%V = load i32* %X
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ret i32 %V
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}
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