[LegalizeVectorOps] Pass the post-UpdateNodeOperands version of Op to…

… ExpandLoad/ExpandStore

UpdateNodeOperands might CSE to another existing node. So we should make sure we're legalizing that node otherwise we might fail to hook up the operands properly. I've moved the result registration up to the caller to avoid having to pass both Result and Op into the functions where it might be confusing which is which.

This address 2 other issues pointed out in D71861.

Differential Revision: https://reviews.llvm.org/D72021

llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp

@@ -130,7 +130,7 @@ class VectorLegalizer {
   /// supported by the target.
   SDValue ExpandVSELECT(SDValue Op);
   SDValue ExpandSELECT(SDValue Op);
-  SDValue ExpandLoad(SDValue Op);
+  std::pair<SDValue, SDValue> ExpandLoad(SDValue Op);
   SDValue ExpandStore(SDValue Op);
   SDValue ExpandFNEG(SDValue Op);
   SDValue ExpandFSUB(SDValue Op);
@@ -265,9 +265,13 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
           return TranslateLegalizeResults(Op, Lowered);
         }
         LLVM_FALLTHROUGH;
-      case TargetLowering::Expand:
+      case TargetLowering::Expand: {
         Changed = true;
-        return ExpandLoad(Op);
+        std::pair<SDValue, SDValue> Tmp = ExpandLoad(Result);
+        AddLegalizedOperand(Op.getValue(0), Tmp.first);
+        AddLegalizedOperand(Op.getValue(1), Tmp.second);
+        return Op.getResNo() ? Tmp.first : Tmp.second;
+      }
       }
     }
   } else if (Op.getOpcode() == ISD::STORE) {
@@ -290,9 +294,12 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
         }
         return TranslateLegalizeResults(Op, Lowered);
       }
-      case TargetLowering::Expand:
+      case TargetLowering::Expand: {
         Changed = true;
-        return ExpandStore(Op);
+        SDValue Chain = ExpandStore(Result);
+        AddLegalizedOperand(Op, Chain);
+        return Chain;
+      }
       }
     }
   }
@@ -633,7 +640,7 @@ SDValue VectorLegalizer::PromoteFP_TO_INT(SDValue Op) {
   return Promoted;
 }
 
-SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
+std::pair<SDValue, SDValue> VectorLegalizer::ExpandLoad(SDValue Op) {
   LoadSDNode *LD = cast<LoadSDNode>(Op.getNode());
 
   EVT SrcVT = LD->getMemoryVT();
@@ -760,16 +767,12 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
     std::tie(Value, NewChain) = TLI.scalarizeVectorLoad(LD, DAG);
   }
 
-  AddLegalizedOperand(Op.getValue(0), Value);
-  AddLegalizedOperand(Op.getValue(1), NewChain);
-
-  return (Op.getResNo() ? NewChain : Value);
+  return std::make_pair(Value, NewChain);
 }
 
 SDValue VectorLegalizer::ExpandStore(SDValue Op) {
   StoreSDNode *ST = cast<StoreSDNode>(Op.getNode());
   SDValue TF = TLI.scalarizeVectorStore(ST, DAG);
-  AddLegalizedOperand(Op, TF);
   return TF;
 }