LowerBitSets: Don't bother to do any work if the llvm.bitset.test intrinsic is unused.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259625 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/LowerBitSets.cpp b/lib/Transforms/IPO/LowerBitSets.cpp
index 92eaf9f..7b9879c 100644 (file)
--- a/lib/Transforms/IPO/LowerBitSets.cpp
+++ b/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.