From 0c0d7e2d0fbe58eb69db383ace48e68ecfd6f050 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Wed, 3 Feb 2016 03:48:46 +0000
Subject: [PATCH] LowerBitSets: Don't bother to do any work if the
 llvm.bitset.test intrinsic is unused.

llvm-svn: 259625
---
 llvm/lib/Transforms/IPO/LowerBitSets.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/IPO/LowerBitSets.cpp b/llvm/lib/Transforms/IPO/LowerBitSets.cpp
index 92eaf9f..7b9879c 100644
--- a/llvm/lib/Transforms/IPO/LowerBitSets.cpp
+++ b/llvm/lib/Transforms/IPO/LowerBitSets.cpp
@@ -920,7 +920,7 @@ void LowerBitSets::buildBitSetsFromDisjointSet(
 bool LowerBitSets::buildBitSets() {
   Function *BitSetTestFunc =
       M->getFunction(Intrinsic::getName(Intrinsic::bitset_test));
-  if (!BitSetTestFunc)
+  if (!BitSetTestFunc || BitSetTestFunc->use_empty())
     return false;
 
   // Equivalence class set containing bitsets and the globals they reference.
-- 
2.7.4