MemCmpExpansion::getCompareLoadPairs - assert we find a comparison diff. NFCI.

Fix scan-build uninitialized warning and assert the final diff isn't null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361095 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/ExpandMemCmp.cpp b/lib/CodeGen/ExpandMemCmp.cpp
index a3a9790..06c171a 100644 (file)
--- a/lib/CodeGen/ExpandMemCmp.cpp
+++ b/lib/CodeGen/ExpandMemCmp.cpp
@@ -323,7 +323,7 @@ Value *MemCmpExpansion::getCompareLoadPairs(unsigned BlockIndex,
   assert(LoadIndex < getNumLoads() &&
          "getCompareLoadPairs() called with no remaining loads");
   std::vector<Value *> XorList, OrList;
   assert(LoadIndex < getNumLoads() &&
          "getCompareLoadPairs() called with no remaining loads");
   std::vector<Value *> XorList, OrList;

-  Value *Diff;
+  Value *Diff = nullptr;

 
   const unsigned NumLoads =
       std::min(getNumLoads() - LoadIndex, NumLoadsPerBlockForZeroCmp);
 
   const unsigned NumLoads =
       std::min(getNumLoads() - LoadIndex, NumLoadsPerBlockForZeroCmp);


@@ -400,6 +400,8 @@ Value *MemCmpExpansion::getCompareLoadPairs(unsigned BlockIndex,
     while (OrList.size() != 1) {
       OrList = pairWiseOr(OrList);
     }
     while (OrList.size() != 1) {
       OrList = pairWiseOr(OrList);
     }

+
+    assert(Diff && "Failed to find comparison diff");

     Cmp = Builder.CreateICmpNE(OrList[0], ConstantInt::get(Diff->getType(), 0));
   }
 
     Cmp = Builder.CreateICmpNE(OrList[0], ConstantInt::get(Diff->getType(), 0));
   }