1 files changed, 44 insertions, 0 deletions
diff --git a/test/Transforms/Mem2Reg/pr24179.ll b/test/Transforms/Mem2Reg/pr24179.ll
new file mode 100644
index 0000000000000..e4216ce4daa17
--- /dev/null
+++ b/test/Transforms/Mem2Reg/pr24179.ll
@@ -0,0 +1,44 @@
+; RUN: opt -mem2reg < %s -S | FileCheck %s
+
+declare i32 @def(i32)
+declare i1 @use(i32)
+
+; Special case of a single-BB alloca does not apply here since the load
+; is affected by the following store. Expect this case to be identified
+; and a PHI node to be created.
+define void @test1() {
+; CHECK-LABEL: @test1(
+ entry:
+  %t = alloca i32
+  br label %loop
+
+ loop:
+  %v = load i32, i32* %t
+  %c = call i1 @use(i32 %v)
+; CHECK: [[PHI:%.*]] = phi i32 [ undef, %entry ], [ %n, %loop ]
+; CHECK: call i1 @use(i32 [[PHI]])
+  %n = call i32 @def(i32 7)
+  store i32 %n, i32* %t
+  br i1 %c, label %loop, label %exit
+
+ exit:
+  ret void
+}
+
+; Same as above, except there is no following store. The alloca should just be
+; replaced with an undef
+define void @test2() {
+; CHECK-LABEL: @test2(
+ entry:
+  %t = alloca i32
+  br label %loop
+
+ loop:
+  %v = load i32, i32* %t
+  %c = call i1 @use(i32 %v)
+; CHECK: %c = call i1 @use(i32 undef)
+  br i1 %c, label %loop, label %exit
+
+ exit:
+  ret void
+}