1 files changed, 115 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/phi.ll b/test/Transforms/InstCombine/phi.ll
new file mode 100644
index 0000000000000..4efbb79d9d4ee
--- /dev/null
+++ b/test/Transforms/InstCombine/phi.ll
@@ -0,0 +1,115 @@
+; 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 ]               ; <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
+}
+
+