forked from OSchip/llvm-project
43 lines
1.1 KiB
LLVM
43 lines
1.1 KiB
LLVM
; Test that LICM uses basicaa to do alias analysis, which is capable of
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; disambiguating some obvious cases. If LICM is able to disambiguate the
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; two pointers, then the load should be hoisted, and the store sunk. Thus
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; the loop becomes empty and can be deleted by ADCE.
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; RUN: llvm-upgrade < %s | llvm-as | opt -basicaa -licm --adce | llvm-dis | not grep Loop
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%A = global int 7
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%B = global int 8
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%C = global [2 x int ] [ int 4, int 8 ]
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implementation
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int %test(bool %c) {
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%Atmp = load int* %A
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br label %Loop
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Loop:
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%ToRemove = load int* %A
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store int %Atmp, int* %B ; Store cannot alias %A
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br bool %c, label %Out, label %Loop
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Out:
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%X = sub int %ToRemove, %Atmp
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ret int %X
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}
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int %test2(bool %c) {
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br label %Loop
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Loop:
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%AVal = load int* %A
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%C0 = getelementptr [2 x int ]* %C, long 0, long 0
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store int %AVal, int* %C0 ; Store cannot alias %A
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%BVal = load int* %B
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%C1 = getelementptr [2 x int ]* %C, long 0, long 1
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store int %BVal, int* %C1 ; Store cannot alias %A, %B, or %C0
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br bool %c, label %Out, label %Loop
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Out:
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%X = sub int %AVal, %BVal
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ret int %X
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}
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