[llvm] r337708 - [Legalize] Elide MERGE_VALUES created by scalarizeVectorLoad.

[Nirav Dave via llvm-commits]

Author: niravd
Date: Mon Jul 23 09:43:42 2018
New Revision: 337708

URL: http://llvm.org/viewvc/llvm-project?rev=337708&view=rev
Log:
[Legalize] Elide MERGE_VALUES created by scalarizeVectorLoad.

scalarizeVectorLoad creates MERGE_VALUES nodes which are immediately
decomposed in expandLoad. Elide the node in these cases.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp?rev=337708&r1=337707&r2=337708&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp Mon Jul 23 09:43:42 2018
@@ -680,9 +680,14 @@ SDValue VectorLegalizer::ExpandLoad(SDVa
     Value = DAG.getBuildVector(Op.getNode()->getValueType(0), dl, Vals);
   } else {
     SDValue Scalarized = TLI.scalarizeVectorLoad(LD, DAG);
-
-    NewChain = Scalarized.getValue(1);
-    Value = Scalarized.getValue(0);
+    // Skip past MERGE_VALUE node if known.
+    if (Scalarized->getOpcode() == ISD::MERGE_VALUES) {
+      NewChain = Scalarized.getOperand(1);
+      Value = Scalarized.getOperand(0);
+    } else {
+      NewChain = Scalarized.getValue(1);
+      Value = Scalarized.getValue(0);
+    }
   }
 
   AddLegalizedOperand(Op.getValue(0), Value);

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=337708&r1=337707&r2=337708&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Mon Jul 23 09:43:42 2018
@@ -3984,6 +3984,8 @@ TargetLowering::expandUnalignedLoad(Load
       if (!isOperationLegalOrCustom(ISD::LOAD, intVT)) {
         // Scalarize the load and let the individual components be handled.
         SDValue Scalarized = scalarizeVectorLoad(LD, DAG);
+        if (Scalarized->getOpcode() == ISD::MERGE_VALUES)
+	  return std::make_pair(Scalarized.getOperand(0), Scalarized.getOperand(1));
         return std::make_pair(Scalarized.getValue(0), Scalarized.getValue(1));
       }