From: Nirav Dave <niravd@google.com>
Date: Fri, 29 Mar 2019 18:50:22 +0000 (+0000)
Subject: [DAG] Avoid redundancy in StoreMerge TokenFactor generation.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b1825c3ad88467636f04904c10a5b1da31920175;p=llvm

[DAG] Avoid redundancy in StoreMerge TokenFactor generation.

Avoid generating redundant TokenFactor when all merged stores have
the same chain.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357299 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 2cd698eb7e0..13e1e96cc92 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -14514,9 +14514,9 @@ SDValue DAGCombiner::getMergeStoreChains(SmallVectorImpl<MemOpLink> &StoreNodes,
     Visited.insert(StoreNodes[i].MemNode);
   }
 
-  // don't include nodes that are children
+  // don't include nodes that are children or repeated nodes.
   for (unsigned i = 0; i < NumStores; ++i) {
-    if (Visited.count(StoreNodes[i].MemNode->getChain().getNode()) == 0)
+    if (Visited.insert(StoreNodes[i].MemNode->getChain().getNode()).second)
       Chains.push_back(StoreNodes[i].MemNode->getChain());
   }