Don't set kill flags on uses of CopyFromReg nodes. InstrEmitter doesn't
create separate virtual registers for CopyFromReg values, so uses of
them don't necessarily kill the value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103519 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index a5db63b..929287a 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -297,15 +297,22 @@
}
// If this value has only one use, that use is a kill. This is a
- // conservative approximation. Tied operands are never killed, so we need
- // to check that. And that means we need to determine the index of the
- // operand.
- unsigned Idx = MI->getNumOperands();
- while (Idx > 0 &&
- MI->getOperand(Idx-1).isReg() && MI->getOperand(Idx-1).isImplicit())
- --Idx;
- bool isTied = MI->getDesc().getOperandConstraint(Idx, TOI::TIED_TO) != -1;
- bool isKill = Op.hasOneUse() && !isTied && !IsDebug;
+ // conservative approximation. InstrEmitter does trivial coalescing
+ // with CopyFromReg nodes, so don't emit kill flags for them.
+ // Tied operands are never killed, so we need to check that. And that
+ // means we need to determine the index of the operand.
+ bool isKill = Op.hasOneUse() &&
+ Op.getNode()->getOpcode() != ISD::CopyFromReg &&
+ !IsDebug;
+ if (isKill) {
+ unsigned Idx = MI->getNumOperands();
+ while (Idx > 0 &&
+ MI->getOperand(Idx-1).isReg() && MI->getOperand(Idx-1).isImplicit())
+ --Idx;
+ bool isTied = MI->getDesc().getOperandConstraint(Idx, TOI::TIED_TO) != -1;
+ if (isTied)
+ isKill = false;
+ }
MI->addOperand(MachineOperand::CreateReg(VReg, isOptDef,
false/*isImp*/, isKill,