Fortify r152675 a bit. Although I'm not able to come up with a test case that would trigger the truncation case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152678 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 66c04b4..e3c14b0 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -7204,7 +7204,7 @@
// If the result of load has to be truncated, then it's not necessarily
// profitable.
- if (NVT.bitsLT(LVT))
+ if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
return SDValue();
if (InVec.getOpcode() == ISD::BITCAST) {
@@ -7308,6 +7308,7 @@
// use of the load; that's okay because we don't want to perform this
// transformation in other cases anyway.
SDValue Load;
+ SDValue Chain;
if (NVT.bitsGT(LVT)) {
// If the result type of vextract is wider than the load, then issue an
// extending load instead.
@@ -7316,14 +7317,21 @@
Load = DAG.getExtLoad(ExtType, N->getDebugLoc(), NVT, LN0->getChain(),
NewPtr, LN0->getPointerInfo().getWithOffset(PtrOff),
LVT, LN0->isVolatile(), LN0->isNonTemporal(),Align);
- } else
+ Chain = Load.getValue(1);
+ } else {
Load = DAG.getLoad(LVT, N->getDebugLoc(), LN0->getChain(), NewPtr,
LN0->getPointerInfo().getWithOffset(PtrOff),
LN0->isVolatile(), LN0->isNonTemporal(),
LN0->isInvariant(), Align);
+ Chain = Load.getValue(1);
+ if (NVT.bitsLT(LVT))
+ Load = DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), NVT, Load);
+ else
+ Load = DAG.getNode(ISD::BITCAST, N->getDebugLoc(), NVT, Load);
+ }
WorkListRemover DeadNodes(*this);
SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
- SDValue To[] = { Load.getValue(0), Load.getValue(1) };
+ SDValue To[] = { Load, Chain };
DAG.ReplaceAllUsesOfValuesWith(From, To, 2, &DeadNodes);
// Since we're explcitly calling ReplaceAllUses, add the new node to the
// worklist explicitly as well.