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; This test makes sure that these instructions are properly eliminated.
;
; RUN: opt < %s -instcombine -S | not grep phi
define i32 @test1(i32 %A, i1 %b) {
BB0:
br i1 %b, label %BB1, label %BB2
BB1: ; preds = %BB0
; Combine away one argument PHI nodes
%B = phi i32 [ %A, %BB0 ] ; <i32> [#uses=1]
ret i32 %B
BB2: ; preds = %BB0
ret i32 %A
}
define i32 @test2(i32 %A, i1 %b) {
BB0:
br i1 %b, label %BB1, label %BB2
BB1: ; preds = %BB0
br label %BB2
BB2: ; preds = %BB1, %BB0
; Combine away PHI nodes with same values
%B = phi i32 [ %A, %BB0 ], [ %A, %BB1 ] ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test3(i32 %A, i1 %b) {
BB0:
br label %Loop
Loop: ; preds = %Loop, %BB0
; PHI has same value always.
%B = phi i32 [ %A, %BB0 ], [ %B, %Loop ] ; <i32> [#uses=2]
br i1 %b, label %Loop, label %Exit
Exit: ; preds = %Loop
ret i32 %B
}
define i32 @test4(i1 %b) {
BB0:
; Loop is unreachable
ret i32 7
Loop: ; preds = %L2, %Loop
; PHI has same value always.
%B = phi i32 [ %B, %L2 ], [ %B, %Loop ] ; <i32> [#uses=2]
br i1 %b, label %L2, label %Loop
L2: ; preds = %Loop
br label %Loop
}
define i32 @test5(i32 %A, i1 %b) {
BB0:
br label %Loop
Loop: ; preds = %Loop, %BB0
; PHI has same value always.
%B = phi i32 [ %A, %BB0 ], [ undef, %Loop ] ; <i32> [#uses=1]
br i1 %b, label %Loop, label %Exit
Exit: ; preds = %Loop
ret i32 %B
}
define i32 @test6(i32 %A, i1 %b) {
BB0:
%X = bitcast i32 %A to i32 ; <i32> [#uses=1]
br i1 %b, label %BB1, label %BB2
BB1: ; preds = %BB0
%Y = bitcast i32 %A to i32 ; <i32> [#uses=1]
br label %BB2
BB2: ; preds = %BB1, %BB0
;; Suck casts into phi
%B = phi i32 [ %X, %BB0 ], [ %Y, %BB1 ] ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test7(i32 %A, i1 %b) {
BB0:
br label %Loop
Loop: ; preds = %Loop, %BB0
; PHI is dead.
%B = phi i32 [ %A, %BB0 ], [ %C, %Loop ] ; <i32> [#uses=1]
%C = add i32 %B, 123 ; <i32> [#uses=1]
br i1 %b, label %Loop, label %Exit
Exit: ; preds = %Loop
ret i32 0
}
define i32* @test8({ i32, i32 } *%A, i1 %b) {
BB0:
%X = getelementptr { i32, i32 } *%A, i32 0, i32 1
br i1 %b, label %BB1, label %BB2
BB1:
%Y = getelementptr { i32, i32 } *%A, i32 0, i32 1
br label %BB2
BB2:
;; Suck GEPs into phi
%B = phi i32* [ %X, %BB0 ], [ %Y, %BB1 ]
ret i32* %B
}
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