1 files changed, 54 insertions, 0 deletions
diff --git a/llvm/test/Transforms/TailCallElim/inf-recursion.ll b/llvm/test/Transforms/TailCallElim/inf-recursion.ll
new file mode 100644
index 00000000000..650ac48823d
--- /dev/null
+++ b/llvm/test/Transforms/TailCallElim/inf-recursion.ll
@@ -0,0 +1,54 @@
+; RUN: opt < %s -tailcallelim -verify-dom-info -S | FileCheck %s
+
+; Don't turn this into an infinite loop, this is probably the implementation
+; of fabs and we expect the codegen to lower fabs.
+; CHECK: @fabs(double %f)
+; CHECK: call
+; CHECK: ret
+
+define double @fabs(double %f) {
+entry:
+        %tmp2 = call double @fabs( double %f )          ; <double> [#uses=1]
+        ret double %tmp2
+}
+
+; Do turn other calls into infinite loops though.
+
+; CHECK-LABEL: define double @foo(
+; CHECK-NOT: call
+; CHECK: }
+define double @foo(double %f) {
+        %t= call double @foo(double %f)
+        ret double %t
+}
+
+; CHECK-LABEL: define float @fabsf(
+; CHECK-NOT: call
+; CHECK: }
+define float @fabsf(float %f) {
+        %t= call float @fabsf(float 2.0)
+        ret float %t
+}
+
+declare x86_fp80 @fabsl(x86_fp80 %f)
+
+; Don't crash while transforming a function with infinite recursion.
+define i32 @PR22704(i1 %bool) {
+entry:
+  br i1 %bool, label %t, label %f
+
+t:
+  %call1 = call i32 @PR22704(i1 1)
+  br label %return
+
+f:
+  %call = call i32 @PR22704(i1 1)
+  br label %return
+
+return:
+  ret i32 0
+
+; CHECK-LABEL: @PR22704(
+; CHECK:       %bool.tr = phi i1 [ %bool, %entry ], [ true, %t ], [ true, %f ]
+; CHECK:       br i1 %bool.tr, label %t, label %f
+}