From 7a05aeb9e204a6353ff3784162a3a9cb28eec483 Mon Sep 17 00:00:00 2001
From: Davide Italiano <davide@freebsd.org>
Date: Thu, 15 Dec 2016 23:48:07 +0000
Subject: [PATCH] [SimplifyLibCalls] Add a test to make sure we lower fls(0)
 correctly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289895 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/InstCombine/fls.ll | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/test/Transforms/InstCombine/fls.ll b/test/Transforms/InstCombine/fls.ll
index bf608b35dff..9ccc56aa6bc 100644
--- a/test/Transforms/InstCombine/fls.ll
+++ b/test/Transforms/InstCombine/fls.ll
@@ -43,6 +43,15 @@ define i32 @flsnotconst(i64 %z) {
   ret i32 %goo
 }
 
+; Make sure we lower fls(0) to 0 and not to `undef`.
+; CHECK-LABEL: define i32 @flszero(
+; CHECK: ret i32 0
+; CHECK: }
+define i32 @flszero() {
+  %zero = call i32 @fls(i32 0)
+  ret i32 %zero
+}
+
 declare i32 @fls(i32)
 declare i32 @flsl(i64)
 declare i32 @flsll(i64)
-- 
2.50.0