Add a testcase for r135123.
Part of rdar://9761830
llvm-svn: 135133
diff --git a/llvm/test/CodeGen/ARM/fold-const.ll b/llvm/test/CodeGen/ARM/fold-const.ll
new file mode 100644
index 0000000..227e4e8
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/fold-const.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -march=arm -mattr=+v7 | FileCheck %s
+
+define i32 @f(i32 %a) nounwind readnone optsize ssp {
+entry:
+ %conv = zext i32 %a to i64
+ %tmp1 = tail call i64 @llvm.ctlz.i64(i64 %conv)
+; CHECK: clz
+; CHECK-NOT: adds
+ %cast = trunc i64 %tmp1 to i32
+ %sub = sub nsw i32 63, %cast
+ ret i32 %sub
+}
+
+declare i64 @llvm.ctlz.i64(i64) nounwind readnone