Enhance logic in X86DAGToDAGISel::PreprocessForRMW which move load inside callseq_start to allow it to be folded into a call. It was not considering the cases where a token factor is between the load and the callseq_start.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63022 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index c1d886c..04ba430 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -432,14 +432,27 @@
/// MoveBelowCallSeqStart - Replace CALLSEQ_START operand with load's chain
/// operand and move load below the call's chain operand.
static void MoveBelowCallSeqStart(SelectionDAG *CurDAG, SDValue Load,
- SDValue Call, SDValue Chain) {
+ SDValue Call, SDValue CallSeqStart) {
SmallVector<SDValue, 8> Ops;
- for (unsigned i = 0, e = Chain.getNode()->getNumOperands(); i != e; ++i)
- if (Load.getNode() == Chain.getOperand(i).getNode())
- Ops.push_back(Load.getOperand(0));
- else
- Ops.push_back(Chain.getOperand(i));
- CurDAG->UpdateNodeOperands(Chain, &Ops[0], Ops.size());
+ SDValue Chain = CallSeqStart.getOperand(0);
+ if (Chain.getNode() == Load.getNode())
+ Ops.push_back(Load.getOperand(0));
+ else {
+ assert(Chain.getOpcode() == ISD::TokenFactor &&
+ "Unexpected CallSeqStart chain operand");
+ for (unsigned i = 0, e = Chain.getNumOperands(); i != e; ++i)
+ if (Chain.getOperand(i).getNode() == Load.getNode())
+ Ops.push_back(Load.getOperand(0));
+ else
+ Ops.push_back(Chain.getOperand(i));
+ SDValue NewChain =
+ CurDAG->getNode(ISD::TokenFactor, MVT::Other, &Ops[0], Ops.size());
+ Ops.clear();
+ Ops.push_back(NewChain);
+ }
+ for (unsigned i = 1, e = CallSeqStart.getNumOperands(); i != e; ++i)
+ Ops.push_back(CallSeqStart.getOperand(i));
+ CurDAG->UpdateNodeOperands(CallSeqStart, &Ops[0], Ops.size());
CurDAG->UpdateNodeOperands(Load, Call.getOperand(0),
Load.getOperand(1), Load.getOperand(2));
Ops.clear();
@@ -468,7 +481,13 @@
return false;
Chain = Chain.getOperand(0);
}
- return Chain.getOperand(0).getNode() == Callee.getNode();
+
+ if (Chain.getOperand(0).getNode() == Callee.getNode())
+ return true;
+ if (Chain.getOperand(0).getOpcode() == ISD::TokenFactor &&
+ Callee.getValue(1).isOperandOf(Chain.getOperand(0).getNode()))
+ return true;
+ return false;
}