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