[llvm] 046b4a5 - [DAGCombiner] reduce code duplication in getStoreMergeCandidates; NFC

[Sanjay Patel via llvm-commits]

Author: Sanjay Patel
Date: 2020-08-17T15:37:55-04:00
New Revision: 046b4a550a8185745e1f6cf0246fb589cf6ba9d0

URL: https://github.com/llvm/llvm-project/commit/046b4a550a8185745e1f6cf0246fb589cf6ba9d0
DIFF: https://github.com/llvm/llvm-project/commit/046b4a550a8185745e1f6cf0246fb589cf6ba9d0.diff

LOG: [DAGCombiner] reduce code duplication in getStoreMergeCandidates; NFC

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8ad19e7b539f..e4b9d6b8c4a5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -16200,6 +16200,19 @@ void DAGCombiner::getStoreMergeCandidates(
            RootCount->second.second > StoreMergeDependenceLimit;
   };
 
+  auto TryToAddCandidate = [&](SDNode::use_iterator UseIter) {
+    // This must be a chain use.
+    if (UseIter.getOperandNo() != 0)
+      return;
+    if (auto *OtherStore = dyn_cast<StoreSDNode>(*UseIter)) {
+      BaseIndexOffset Ptr;
+      int64_t PtrDiff;
+      if (CandidateMatch(OtherStore, Ptr, PtrDiff) &&
+          !OverLimitInDependenceCheck(OtherStore, RootNode))
+        StoreNodes.push_back(MemOpLink(OtherStore, PtrDiff));
+    }
+  };
+
   // We looking for a root node which is an ancestor to all mergable
   // stores. We search up through a load, to our root and then down
   // through all children. For instance we will find Store{1,2,3} if
@@ -16219,31 +16232,20 @@ void DAGCombiner::getStoreMergeCandidates(
   RootNode = St->getChain().getNode();
 
   unsigned NumNodesExplored = 0;
-  if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(RootNode)) {
+  if (auto *Ldn = dyn_cast<LoadSDNode>(RootNode)) {
     RootNode = Ldn->getChain().getNode();
     for (auto I = RootNode->use_begin(), E = RootNode->use_end();
-         I != E && NumNodesExplored < 1024; ++I, ++NumNodesExplored)
-      if (I.getOperandNo() == 0 && isa<LoadSDNode>(*I)) // walk down chain
+         I != E && NumNodesExplored < 1024; ++I, ++NumNodesExplored) {
+      if (I.getOperandNo() == 0 && isa<LoadSDNode>(*I)) { // walk down chain
         for (auto I2 = (*I)->use_begin(), E2 = (*I)->use_end(); I2 != E2; ++I2)
-          if (I2.getOperandNo() == 0)
-            if (StoreSDNode *OtherST = dyn_cast<StoreSDNode>(*I2)) {
-              BaseIndexOffset Ptr;
-              int64_t PtrDiff;
-              if (CandidateMatch(OtherST, Ptr, PtrDiff) &&
-                  !OverLimitInDependenceCheck(OtherST, RootNode))
-                StoreNodes.push_back(MemOpLink(OtherST, PtrDiff));
-            }
-  } else
+          TryToAddCandidate(I2);
+      }
+    }
+  } else {
     for (auto I = RootNode->use_begin(), E = RootNode->use_end();
          I != E && NumNodesExplored < 1024; ++I, ++NumNodesExplored)
-      if (I.getOperandNo() == 0)
-        if (StoreSDNode *OtherST = dyn_cast<StoreSDNode>(*I)) {
-          BaseIndexOffset Ptr;
-          int64_t PtrDiff;
-          if (CandidateMatch(OtherST, Ptr, PtrDiff) &&
-              !OverLimitInDependenceCheck(OtherST, RootNode))
-            StoreNodes.push_back(MemOpLink(OtherST, PtrDiff));
-        }
+      TryToAddCandidate(I);
+  }
 }
 
 // We need to check that merging these stores does not cause a loop in