From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Sat, 18 May 2019 11:31:48 +0000 (+0000)
Subject: MemCmpExpansion::getCompareLoadPairs - assert we find a comparison diff. NFCI.
X-Git-Tag: android-x86-9.0-r1~3246
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=a77280973d22b32ebd0e244ad4649946f71fa778;p=android-x86%2Fexternal-llvm.git

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 a3a979008dc..06c171a457b 100644
--- 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;
-  Value *Diff;
+  Value *Diff = nullptr;
 
   const unsigned NumLoads =
       std::min(getNumLoads() - LoadIndex, NumLoadsPerBlockForZeroCmp);
@@ -400,6 +400,8 @@ Value *MemCmpExpansion::getCompareLoadPairs(unsigned BlockIndex,
     while (OrList.size() != 1) {
       OrList = pairWiseOr(OrList);
     }
+
+    assert(Diff && "Failed to find comparison diff");
     Cmp = Builder.CreateICmpNE(OrList[0], ConstantInt::get(Diff->getType(), 0));
   }