; This test makes sure that these instructions are properly eliminated. ; ; RUN: llvm-as < %s | opt -instcombine | llvm-dis | 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 ] ; [#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 ] ; [#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 ] ; [#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 ] ; [#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 ] ; [#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 ; [#uses=1] br i1 %b, label %BB1, label %BB2 BB1: ; preds = %BB0 %Y = bitcast i32 %A to i32 ; [#uses=1] br label %BB2 BB2: ; preds = %BB1, %BB0 ;; Suck casts into phi %B = phi i32 [ %X, %BB0 ], [ %Y, %BB1 ] ; [#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 ] ; [#uses=1] %C = add i32 %B, 123 ; [#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 }