CreateVirtualRegisters does trivial copy coalescing. If a node def is used by a single CopyToReg, it reuses the virtual register assigned to the CopyToReg. This won't work for SDNode that is a clone or is itself cloned. Disable this optimization for those nodes or it can end up with non-SSA machine instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62356 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
index 282b533..7bb9bc2 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
@@ -46,7 +46,8 @@
/// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
/// implicit physical register output.
void ScheduleDAGSDNodes::EmitCopyFromReg(SDNode *Node, unsigned ResNo,
- bool IsClone, unsigned SrcReg,
+ bool IsClone, bool IsCloned,
+ unsigned SrcReg,
DenseMap<SDValue, unsigned> &VRBaseMap) {
unsigned VRBase = 0;
if (TargetRegisterInfo::isVirtualRegister(SrcReg)) {
@@ -64,44 +65,45 @@
// the CopyToReg'd destination register instead of creating a new vreg.
bool MatchReg = true;
const TargetRegisterClass *UseRC = NULL;
- for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
- UI != E; ++UI) {
- SDNode *User = *UI;
- bool Match = true;
- if (User->getOpcode() == ISD::CopyToReg &&
- User->getOperand(2).getNode() == Node &&
- User->getOperand(2).getResNo() == ResNo) {
- unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
- if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
- VRBase = DestReg;
- Match = false;
- } else if (DestReg != SrcReg)
- Match = false;
- } else {
- for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
- SDValue Op = User->getOperand(i);
- if (Op.getNode() != Node || Op.getResNo() != ResNo)
- continue;
- MVT VT = Node->getValueType(Op.getResNo());
- if (VT == MVT::Other || VT == MVT::Flag)
- continue;
- Match = false;
- if (User->isMachineOpcode()) {
- const TargetInstrDesc &II = TII->get(User->getMachineOpcode());
- const TargetRegisterClass *RC =
- getInstrOperandRegClass(TRI,TII,II,i+II.getNumDefs());
- if (!UseRC)
- UseRC = RC;
- else if (RC)
- assert(UseRC == RC &&
- "Multiple uses expecting different register classes!");
+ if (!IsClone && !IsCloned)
+ for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+ UI != E; ++UI) {
+ SDNode *User = *UI;
+ bool Match = true;
+ if (User->getOpcode() == ISD::CopyToReg &&
+ User->getOperand(2).getNode() == Node &&
+ User->getOperand(2).getResNo() == ResNo) {
+ unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
+ if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
+ VRBase = DestReg;
+ Match = false;
+ } else if (DestReg != SrcReg)
+ Match = false;
+ } else {
+ for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
+ SDValue Op = User->getOperand(i);
+ if (Op.getNode() != Node || Op.getResNo() != ResNo)
+ continue;
+ MVT VT = Node->getValueType(Op.getResNo());
+ if (VT == MVT::Other || VT == MVT::Flag)
+ continue;
+ Match = false;
+ if (User->isMachineOpcode()) {
+ const TargetInstrDesc &II = TII->get(User->getMachineOpcode());
+ const TargetRegisterClass *RC =
+ getInstrOperandRegClass(TRI,TII,II,i+II.getNumDefs());
+ if (!UseRC)
+ UseRC = RC;
+ else if (RC)
+ assert(UseRC == RC &&
+ "Multiple uses expecting different register classes!");
+ }
}
}
+ MatchReg &= Match;
+ if (VRBase)
+ break;
}
- MatchReg &= Match;
- if (VRBase)
- break;
- }
MVT VT = Node->getValueType(ResNo);
const TargetRegisterClass *SrcRC = 0, *DstRC = 0;
@@ -157,7 +159,8 @@
}
void ScheduleDAGSDNodes::CreateVirtualRegisters(SDNode *Node, MachineInstr *MI,
- const TargetInstrDesc &II, bool IsClone,
+ const TargetInstrDesc &II,
+ bool IsClone, bool IsCloned,
DenseMap<SDValue, unsigned> &VRBaseMap) {
assert(Node->getMachineOpcode() != TargetInstrInfo::IMPLICIT_DEF &&
"IMPLICIT_DEF should have been handled as a special case elsewhere!");
@@ -167,20 +170,22 @@
// is a vreg, use the CopyToReg'd destination register instead of creating
// a new vreg.
unsigned VRBase = 0;
- for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
- UI != E; ++UI) {
- SDNode *User = *UI;
- if (User->getOpcode() == ISD::CopyToReg &&
- User->getOperand(2).getNode() == Node &&
- User->getOperand(2).getResNo() == i) {
- unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
- if (TargetRegisterInfo::isVirtualRegister(Reg)) {
- VRBase = Reg;
- MI->addOperand(MachineOperand::CreateReg(Reg, true));
- break;
+
+ if (!IsClone && !IsCloned)
+ for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+ UI != E; ++UI) {
+ SDNode *User = *UI;
+ if (User->getOpcode() == ISD::CopyToReg &&
+ User->getOperand(2).getNode() == Node &&
+ User->getOperand(2).getResNo() == i) {
+ unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
+ if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+ VRBase = Reg;
+ MI->addOperand(MachineOperand::CreateReg(Reg, true));
+ break;
+ }
}
}
- }
// Create the result registers for this node and add the result regs to
// the machine instruction.
@@ -452,7 +457,7 @@
/// EmitNode - Generate machine code for an node and needed dependencies.
///
-void ScheduleDAGSDNodes::EmitNode(SDNode *Node, bool IsClone,
+void ScheduleDAGSDNodes::EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
DenseMap<SDValue, unsigned> &VRBaseMap) {
// If machine instruction
if (Node->isMachineOpcode()) {
@@ -489,7 +494,7 @@
// Add result register values for things that are defined by this
// instruction.
if (NumResults)
- CreateVirtualRegisters(Node, MI, II, IsClone, VRBaseMap);
+ CreateVirtualRegisters(Node, MI, II, IsClone, IsCloned, VRBaseMap);
// Emit all of the actual operands of this instruction, adding them to the
// instruction as appropriate.
@@ -512,7 +517,7 @@
for (unsigned i = II.getNumDefs(); i < NumResults; ++i) {
unsigned Reg = II.getImplicitDefs()[i - II.getNumDefs()];
if (Node->hasAnyUseOfValue(i))
- EmitCopyFromReg(Node, i, IsClone, Reg, VRBaseMap);
+ EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
}
}
return;
@@ -559,7 +564,7 @@
}
case ISD::CopyFromReg: {
unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
- EmitCopyFromReg(Node, 0, IsClone, SrcReg, VRBaseMap);
+ EmitCopyFromReg(Node, 0, IsClone, IsCloned, SrcReg, VRBaseMap);
break;
}
case ISD::INLINEASM: {
@@ -636,13 +641,14 @@
}
SmallVector<SDNode *, 4> FlaggedNodes;
- for (SDNode *N = SU->getNode()->getFlaggedNode(); N; N = N->getFlaggedNode())
+ for (SDNode *N = SU->getNode()->getFlaggedNode(); N;
+ N = N->getFlaggedNode())
FlaggedNodes.push_back(N);
while (!FlaggedNodes.empty()) {
- EmitNode(FlaggedNodes.back(), SU->OrigNode != SU, VRBaseMap);
+ EmitNode(FlaggedNodes.back(), SU->OrigNode != SU, SU->isCloned,VRBaseMap);
FlaggedNodes.pop_back();
}
- EmitNode(SU->getNode(), SU->OrigNode != SU, VRBaseMap);
+ EmitNode(SU->getNode(), SU->OrigNode != SU, SU->isCloned, VRBaseMap);
}
return BB;