1 files changed, 79 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/phi.ll b/llvm/test/Transforms/InstCombine/phi.ll
new file mode 100644
index 00000000000..44841b76431
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/phi.ll
@@ -0,0 +1,79 @@
+; This test makes sure that these instructions are properly eliminated.
+;
+
+; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine -disable-output &&
+; RUN: llvm-upgrade < %s | llvm-as | 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
+}
+
+int %test7(int %A, bool %b) {
+BB0: br label %Loop
+
+Loop:
+        %B = phi int [%A, %BB0], [%C, %Loop]    ; PHI is dead.
+	%C = add int %B, 123
+        br bool %b, label %Loop, label %Exit
+Exit:
+        ret int 0
+}
+