forked from OSchip/llvm-project
80 lines
1.7 KiB
LLVM
80 lines
1.7 KiB
LLVM
; This test makes sure that these instructions are properly eliminated.
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;
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; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine -disable-output &&
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; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine | llvm-dis | not grep phi
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implementation
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int %test1(int %A, bool %b) {
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BB0: br bool %b, label %BB1, label %BB2
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BB1:
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%B = phi int [%A, %BB0] ; Combine away one argument PHI nodes
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ret int %B
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BB2:
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ret int %A
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}
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int %test2(int %A, bool %b) {
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BB0: br bool %b, label %BB1, label %BB2
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BB1:
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br label %BB2
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BB2:
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%B = phi int [%A, %BB0], [%A, %BB1] ; Combine away PHI nodes with same values
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ret int %B
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}
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int %test3(int %A, bool %b) {
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BB0: br label %Loop
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Loop:
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%B = phi int [%A, %BB0], [%B, %Loop] ; PHI has same value always.
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br bool %b, label %Loop, label %Exit
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Exit:
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ret int %B
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}
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int %test4(bool %b) {
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BB0: ret int 7 ; Loop is unreachable
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Loop:
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%B = phi int [%B, %L2], [%B, %Loop] ; PHI has same value always.
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br bool %b, label %L2, label %Loop
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L2:
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br label %Loop
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}
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int %test5(int %A, bool %b) {
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BB0: br label %Loop
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Loop:
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%B = phi int [%A, %BB0], [undef, %Loop] ; PHI has same value always.
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br bool %b, label %Loop, label %Exit
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Exit:
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ret int %B
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}
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uint %test6(int %A, bool %b) {
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BB0:
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%X = cast int %A to uint
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br bool %b, label %BB1, label %BB2
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BB1:
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%Y = cast int %A to uint
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br label %BB2
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BB2:
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%B = phi uint [%X, %BB0], [%Y, %BB1] ;; Suck casts into phi
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ret uint %B
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}
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int %test7(int %A, bool %b) {
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BB0: br label %Loop
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Loop:
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%B = phi int [%A, %BB0], [%C, %Loop] ; PHI is dead.
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%C = add int %B, 123
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br bool %b, label %Loop, label %Exit
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Exit:
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ret int 0
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}
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