[SDAG] Handle LowerOperation returning its input consistently

[oota-llvm.git] / lib / CodeGen / SelectionDAG / LegalizeVectorOps.cpp

diff --git a/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index 3a8c276e26181c2b913153eaefb0b886626242f5..03c2734a9e40386684da0da5af46f834a2987b66 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -207,6 +207,8 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
         return TranslateLegalizeResults(Op, Result);
       case TargetLowering::Custom:
         if (SDValue Lowered = TLI.LowerOperation(Result, DAG)) {
+          if (Lowered == Result)
+            return TranslateLegalizeResults(Op, Lowered);
           Changed = true;
           if (Lowered->getNumValues() != Op->getNumValues()) {
             // This expanded to something other than the load. Assume the
@@ -232,9 +234,11 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
       default: llvm_unreachable("This action is not supported yet!");
       case TargetLowering::Legal:
         return TranslateLegalizeResults(Op, Result);
-      case TargetLowering::Custom:
-        Changed = true;
-        return TranslateLegalizeResults(Op, TLI.LowerOperation(Result, DAG));
+      case TargetLowering::Custom: {
+        SDValue Lowered = TLI.LowerOperation(Result, DAG);
+        Changed = Lowered != Result;
+        return TranslateLegalizeResults(Op, Lowered);
+      }
       case TargetLowering::Expand:
         Changed = true;
         return LegalizeOp(ExpandStore(Op));
@@ -512,7 +516,8 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
         ScalarLoad = DAG.getLoad(WideVT, dl, Chain, BasePTR,
                                  LD->getPointerInfo().getWithOffset(Offset),
                                  LD->isVolatile(), LD->isNonTemporal(),
-                                 LD->isInvariant(), LD->getAlignment(),
+                                 LD->isInvariant(),
+                                 MinAlign(LD->getAlignment(), Offset),
                                  LD->getAAInfo());
       } else {
         EVT LoadVT = WideVT;
@@ -524,7 +529,8 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
                                     LD->getPointerInfo().getWithOffset(Offset),
                                     LoadVT, LD->isVolatile(),
                                     LD->isNonTemporal(), LD->isInvariant(),
-                                    LD->getAlignment(), LD->getAAInfo());
+                                    MinAlign(LD->getAlignment(), Offset),
+                                    LD->getAAInfo());
       }
 
       RemainingBytes -= LoadBytes;
@@ -595,7 +601,7 @@ SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
                 Chain, BasePTR, LD->getPointerInfo().getWithOffset(Idx * Stride),
                 SrcVT.getScalarType(),
                 LD->isVolatile(), LD->isNonTemporal(), LD->isInvariant(),
-                LD->getAlignment(), LD->getAAInfo());
+                MinAlign(LD->getAlignment(), Idx * Stride), LD->getAAInfo());
 
       BasePTR = DAG.getNode(ISD::ADD, dl, BasePTR.getValueType(), BasePTR,
                          DAG.getConstant(Stride, BasePTR.getValueType()));
@@ -654,7 +660,8 @@ SDValue VectorLegalizer::ExpandStore(SDValue Op) {
     // This scalar TruncStore may be illegal, but we legalize it later.
     SDValue Store = DAG.getTruncStore(Chain, dl, Ex, BasePTR,
                ST->getPointerInfo().getWithOffset(Idx*Stride), MemSclVT,
-               isVolatile, isNonTemporal, Alignment, AAInfo);
+               isVolatile, isNonTemporal, MinAlign(Alignment, Idx*Stride),
+               AAInfo);
 
     BasePTR = DAG.getNode(ISD::ADD, dl, BasePTR.getValueType(), BasePTR,
                                DAG.getConstant(Stride, BasePTR.getValueType()));