//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "pre-RA-sched"
-#include "llvm/Constants.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
using namespace llvm;
+STATISTIC(NumCommutes, "Number of instructions commuted");
+
+namespace {
+ static cl::opt<bool>
+ SchedLiveInCopies("schedule-livein-copies",
+ cl::desc("Schedule copies of livein registers"),
+ cl::init(false));
+}
+
ScheduleDAG::ScheduleDAG(SelectionDAG &dag, MachineBasicBlock *bb,
const TargetMachine &tm)
- : DAG(dag), BB(bb), TM(tm), RegInfo(BB->getParent()->getRegInfo()) {
- TII = TM.getInstrInfo();
- MF = &DAG.getMachineFunction();
- TRI = TM.getRegisterInfo();
- ConstPool = BB->getParent()->getConstantPool();
+ : DAG(dag), BB(bb), TM(tm), MRI(BB->getParent()->getRegInfo()) {
+ TII = TM.getInstrInfo();
+ MF = &DAG.getMachineFunction();
+ TRI = TM.getRegisterInfo();
+ TLI = &DAG.getTargetLoweringInfo();
+ ConstPool = BB->getParent()->getConstantPool();
}
/// CheckForPhysRegDependency - Check if the dependency between def and use of
II.ImplicitDefs[ResNo - II.getNumDefs()] == Reg) {
PhysReg = Reg;
const TargetRegisterClass *RC =
- TRI->getPhysicalRegisterRegClass(Def->getValueType(ResNo), Reg);
+ TRI->getPhysicalRegisterRegClass(Reg, Def->getValueType(ResNo));
Cost = RC->getCopyCost();
}
}
SUnit *ScheduleDAG::Clone(SUnit *Old) {
SUnit *SU = NewSUnit(Old->Node);
- for (unsigned i = 0, e = SU->FlaggedNodes.size(); i != e; ++i)
- SU->FlaggedNodes.push_back(SU->FlaggedNodes[i]);
- SU->InstanceNo = SUnitMap[Old->Node].size();
+ SU->OrigNode = Old->OrigNode;
+ SU->FlaggedNodes = Old->FlaggedNodes;
SU->Latency = Old->Latency;
SU->isTwoAddress = Old->isTwoAddress;
SU->isCommutable = Old->isCommutable;
SU->hasPhysRegDefs = Old->hasPhysRegDefs;
- SUnitMap[Old->Node].push_back(SU);
return SU;
}
// Reserve entries in the vector for each of the SUnits we are creating. This
// ensure that reallocation of the vector won't happen, so SUnit*'s won't get
// invalidated.
- SUnits.reserve(std::distance(DAG.allnodes_begin(), DAG.allnodes_end()));
+ SUnits.reserve(DAG.allnodes_size());
+ // During scheduling, the NodeId field of SDNode is used to map SDNodes
+ // to their associated SUnits by holding SUnits table indices. A value
+ // of -1 means the SDNode does not yet have an associated SUnit.
+ for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin(),
+ E = DAG.allnodes_end(); NI != E; ++NI)
+ NI->setNodeId(-1);
+
for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin(),
E = DAG.allnodes_end(); NI != E; ++NI) {
if (isPassiveNode(NI)) // Leaf node, e.g. a TargetImmediate.
continue;
// If this node has already been processed, stop now.
- if (SUnitMap[NI].size()) continue;
+ if (NI->getNodeId() != -1) continue;
SUnit *NodeSUnit = NewSUnit(NI);
do {
N = N->getOperand(N->getNumOperands()-1).Val;
NodeSUnit->FlaggedNodes.push_back(N);
- SUnitMap[N].push_back(NodeSUnit);
+ assert(N->getNodeId() == -1 && "Node already inserted!");
+ N->setNodeId(NodeSUnit->NodeNum);
} while (N->getNumOperands() &&
N->getOperand(N->getNumOperands()-1).getValueType()== MVT::Flag);
std::reverse(NodeSUnit->FlaggedNodes.begin(),
bool HasFlagUse = false;
for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end();
UI != E; ++UI)
- if (FlagVal.isOperand(*UI)) {
+ if (FlagVal.isOperandOf(UI->getUser())) {
HasFlagUse = true;
NodeSUnit->FlaggedNodes.push_back(N);
- SUnitMap[N].push_back(NodeSUnit);
- N = *UI;
+ assert(N->getNodeId() == -1 && "Node already inserted!");
+ N->setNodeId(NodeSUnit->NodeNum);
+ N = UI->getUser();
break;
}
if (!HasFlagUse) break;
// Now all flagged nodes are in FlaggedNodes and N is the bottom-most node.
// Update the SUnit
NodeSUnit->Node = N;
- SUnitMap[N].push_back(NodeSUnit);
+ assert(N->getNodeId() == -1 && "Node already inserted!");
+ N->setNodeId(NodeSUnit->NodeNum);
ComputeLatency(NodeSUnit);
}
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
SDNode *OpN = N->getOperand(i).Val;
if (isPassiveNode(OpN)) continue; // Not scheduled.
- SUnit *OpSU = SUnitMap[OpN].front();
+ SUnit *OpSU = &SUnits[OpN->getNodeId()];
assert(OpSU && "Node has no SUnit!");
if (OpSU == SU) continue; // In the same group.
- MVT::ValueType OpVT = N->getOperand(i).getValueType();
+ MVT OpVT = N->getOperand(i).getValueType();
assert(OpVT != MVT::Flag && "Flagged nodes should be in same sunit!");
bool isChain = OpVT == MVT::Other;
// Remove MainNode from FlaggedNodes again.
SU->FlaggedNodes.pop_back();
}
-
- return;
}
void ScheduleDAG::ComputeLatency(SUnit *SU) {
if (SU->Node->isTargetOpcode()) {
unsigned SchedClass =
TII->get(SU->Node->getTargetOpcode()).getSchedClass();
- InstrStage *S = InstrItins.begin(SchedClass);
- InstrStage *E = InstrItins.end(SchedClass);
+ const InstrStage *S = InstrItins.begin(SchedClass);
+ const InstrStage *E = InstrItins.end(SchedClass);
for (; S != E; ++S)
SU->Latency += S->Cycles;
}
SDNode *FNode = SU->FlaggedNodes[i];
if (FNode->isTargetOpcode()) {
unsigned SchedClass =TII->get(FNode->getTargetOpcode()).getSchedClass();
- InstrStage *S = InstrItins.begin(SchedClass);
- InstrStage *E = InstrItins.end(SchedClass);
+ const InstrStage *S = InstrItins.begin(SchedClass);
+ const InstrStage *E = InstrItins.end(SchedClass);
for (; S != E; ++S)
SU->Latency += S->Cycles;
}
}
}
+/// CalculateDepths - compute depths using algorithms for the longest
+/// paths in the DAG
void ScheduleDAG::CalculateDepths() {
- std::vector<std::pair<SUnit*, unsigned> > WorkList;
- for (unsigned i = 0, e = SUnits.size(); i != e; ++i)
- if (SUnits[i].Preds.empty())
- WorkList.push_back(std::make_pair(&SUnits[i], 0U));
+ unsigned DAGSize = SUnits.size();
+ std::vector<unsigned> InDegree(DAGSize);
+ std::vector<SUnit*> WorkList;
+ WorkList.reserve(DAGSize);
+ // Initialize the data structures
+ for (unsigned i = 0, e = DAGSize; i != e; ++i) {
+ SUnit *SU = &SUnits[i];
+ int NodeNum = SU->NodeNum;
+ unsigned Degree = SU->Preds.size();
+ InDegree[NodeNum] = Degree;
+ SU->Depth = 0;
+
+ // Is it a node without dependencies?
+ if (Degree == 0) {
+ assert(SU->Preds.empty() && "SUnit should have no predecessors");
+ // Collect leaf nodes
+ WorkList.push_back(SU);
+ }
+ }
+
+ // Process nodes in the topological order
while (!WorkList.empty()) {
- SUnit *SU = WorkList.back().first;
- unsigned Depth = WorkList.back().second;
+ SUnit *SU = WorkList.back();
WorkList.pop_back();
- if (SU->Depth == 0 || Depth > SU->Depth) {
- SU->Depth = Depth;
- for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
- I != E; ++I)
- WorkList.push_back(std::make_pair(I->Dep, Depth+1));
+ unsigned &SUDepth = SU->Depth;
+
+ // Use dynamic programming:
+ // When current node is being processed, all of its dependencies
+ // are already processed.
+ // So, just iterate over all predecessors and take the longest path
+ for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
+ I != E; ++I) {
+ unsigned PredDepth = I->Dep->Depth;
+ if (PredDepth+1 > SUDepth) {
+ SUDepth = PredDepth + 1;
+ }
+ }
+
+ // Update InDegrees of all nodes depending on current SUnit
+ for (SUnit::const_succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
+ I != E; ++I) {
+ SUnit *SU = I->Dep;
+ if (!--InDegree[SU->NodeNum])
+ // If all dependencies of the node are processed already,
+ // then the longest path for the node can be computed now
+ WorkList.push_back(SU);
}
}
}
+/// CalculateHeights - compute heights using algorithms for the longest
+/// paths in the DAG
void ScheduleDAG::CalculateHeights() {
- std::vector<std::pair<SUnit*, unsigned> > WorkList;
- SUnit *Root = SUnitMap[DAG.getRoot().Val].front();
- WorkList.push_back(std::make_pair(Root, 0U));
+ unsigned DAGSize = SUnits.size();
+ std::vector<unsigned> InDegree(DAGSize);
+ std::vector<SUnit*> WorkList;
+ WorkList.reserve(DAGSize);
+
+ // Initialize the data structures
+ for (unsigned i = 0, e = DAGSize; i != e; ++i) {
+ SUnit *SU = &SUnits[i];
+ int NodeNum = SU->NodeNum;
+ unsigned Degree = SU->Succs.size();
+ InDegree[NodeNum] = Degree;
+ SU->Height = 0;
+
+ // Is it a node without dependencies?
+ if (Degree == 0) {
+ assert(SU->Succs.empty() && "Something wrong");
+ assert(WorkList.empty() && "Should be empty");
+ // Collect leaf nodes
+ WorkList.push_back(SU);
+ }
+ }
+ // Process nodes in the topological order
while (!WorkList.empty()) {
- SUnit *SU = WorkList.back().first;
- unsigned Height = WorkList.back().second;
+ SUnit *SU = WorkList.back();
WorkList.pop_back();
- if (SU->Height == 0 || Height > SU->Height) {
- SU->Height = Height;
- for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
- I != E; ++I)
- WorkList.push_back(std::make_pair(I->Dep, Height+1));
+ unsigned &SUHeight = SU->Height;
+
+ // Use dynamic programming:
+ // When current node is being processed, all of its dependencies
+ // are already processed.
+ // So, just iterate over all successors and take the longest path
+ for (SUnit::const_succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
+ I != E; ++I) {
+ unsigned SuccHeight = I->Dep->Height;
+ if (SuccHeight+1 > SUHeight) {
+ SUHeight = SuccHeight + 1;
+ }
+ }
+
+ // Update InDegrees of all nodes depending on current SUnit
+ for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
+ I != E; ++I) {
+ SUnit *SU = I->Dep;
+ if (!--InDegree[SU->NodeNum])
+ // If all dependencies of the node are processed already,
+ // then the longest path for the node can be computed now
+ WorkList.push_back(SU);
}
}
}
unsigned ScheduleDAG::CountOperands(SDNode *Node) {
unsigned N = ComputeMemOperandsEnd(Node);
while (N && isa<MemOperandSDNode>(Node->getOperand(N - 1).Val))
- --N; // Ignore MemOperand nodes
+ --N; // Ignore MEMOPERAND nodes
return N;
}
}
void ScheduleDAG::EmitCopyFromReg(SDNode *Node, unsigned ResNo,
- unsigned InstanceNo, unsigned SrcReg,
+ bool IsClone, unsigned SrcReg,
DenseMap<SDOperand, unsigned> &VRBaseMap) {
unsigned VRBase = 0;
if (TargetRegisterInfo::isVirtualRegister(SrcReg)) {
// Just use the input register directly!
- if (InstanceNo > 0)
+ if (IsClone)
VRBaseMap.erase(SDOperand(Node, ResNo));
bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,ResNo),SrcReg));
+ isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
return;
}
bool MatchReg = true;
for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
UI != E; ++UI) {
- SDNode *Use = *UI;
+ SDNode *Use = UI->getUser();
bool Match = true;
if (Use->getOpcode() == ISD::CopyToReg &&
Use->getOperand(2).Val == Node &&
SDOperand Op = Use->getOperand(i);
if (Op.Val != Node || Op.ResNo != ResNo)
continue;
- MVT::ValueType VT = Node->getValueType(Op.ResNo);
+ MVT VT = Node->getValueType(Op.ResNo);
if (VT != MVT::Other && VT != MVT::Flag)
Match = false;
}
break;
}
- const TargetRegisterClass *TRC = 0;
+ const TargetRegisterClass *SrcRC = 0, *DstRC = 0;
+ SrcRC = TRI->getPhysicalRegisterRegClass(SrcReg, Node->getValueType(ResNo));
+
// Figure out the register class to create for the destreg.
- if (VRBase)
- TRC = RegInfo.getRegClass(VRBase);
- else
- TRC = TRI->getPhysicalRegisterRegClass(Node->getValueType(ResNo), SrcReg);
+ if (VRBase) {
+ DstRC = MRI.getRegClass(VRBase);
+ } else {
+ DstRC = TLI->getRegClassFor(Node->getValueType(ResNo));
+ }
// If all uses are reading from the src physical register and copying the
// register is either impossible or very expensive, then don't create a copy.
- if (MatchReg && TRC->getCopyCost() < 0) {
+ if (MatchReg && SrcRC->getCopyCost() < 0) {
VRBase = SrcReg;
} else {
// Create the reg, emit the copy.
- VRBase = RegInfo.createVirtualRegister(TRC);
- TII->copyRegToReg(*BB, BB->end(), VRBase, SrcReg, TRC, TRC);
+ VRBase = MRI.createVirtualRegister(DstRC);
+ TII->copyRegToReg(*BB, BB->end(), VRBase, SrcReg, DstRC, SrcRC);
}
- if (InstanceNo > 0)
+ if (IsClone)
VRBaseMap.erase(SDOperand(Node, ResNo));
bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,ResNo), VRBase));
+ isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
}
-void ScheduleDAG::CreateVirtualRegisters(SDNode *Node,
- MachineInstr *MI,
- const TargetInstrDesc &II,
- DenseMap<SDOperand, unsigned> &VRBaseMap) {
+/// getDstOfCopyToRegUse - If the only use of the specified result number of
+/// node is a CopyToReg, return its destination register. Return 0 otherwise.
+unsigned ScheduleDAG::getDstOfOnlyCopyToRegUse(SDNode *Node,
+ unsigned ResNo) const {
+ if (!Node->hasOneUse())
+ return 0;
+
+ SDNode *Use = Node->use_begin()->getUser();
+ if (Use->getOpcode() == ISD::CopyToReg &&
+ Use->getOperand(2).Val == Node &&
+ Use->getOperand(2).ResNo == ResNo) {
+ unsigned Reg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
+ if (TargetRegisterInfo::isVirtualRegister(Reg))
+ return Reg;
+ }
+ return 0;
+}
+
+void ScheduleDAG::CreateVirtualRegisters(SDNode *Node, MachineInstr *MI,
+ const TargetInstrDesc &II,
+ DenseMap<SDOperand, unsigned> &VRBaseMap) {
+ assert(Node->getTargetOpcode() != TargetInstrInfo::IMPLICIT_DEF &&
+ "IMPLICIT_DEF should have been handled as a special case elsewhere!");
+
for (unsigned i = 0; i < II.getNumDefs(); ++i) {
// If the specific node value is only used by a CopyToReg and the dest reg
// is a vreg, use the CopyToReg'd destination register instead of creating
unsigned VRBase = 0;
for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
UI != E; ++UI) {
- SDNode *Use = *UI;
+ SDNode *Use = UI->getUser();
if (Use->getOpcode() == ISD::CopyToReg &&
Use->getOperand(2).Val == Node &&
Use->getOperand(2).ResNo == i) {
if (VRBase == 0) {
const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TII, II, i);
assert(RC && "Isn't a register operand!");
- VRBase = RegInfo.createVirtualRegister(RC);
+ VRBase = MRI.createVirtualRegister(RC);
MI->addOperand(MachineOperand::CreateReg(VRBase, true));
}
bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,i), VRBase));
+ isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
}
}
/// getVR - Return the virtual register corresponding to the specified result
/// of the specified node.
-static unsigned getVR(SDOperand Op, DenseMap<SDOperand, unsigned> &VRBaseMap) {
+unsigned ScheduleDAG::getVR(SDOperand Op,
+ DenseMap<SDOperand, unsigned> &VRBaseMap) {
+ if (Op.isTargetOpcode() &&
+ Op.getTargetOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
+ // Add an IMPLICIT_DEF instruction before every use.
+ unsigned VReg = getDstOfOnlyCopyToRegUse(Op.Val, Op.ResNo);
+ // IMPLICIT_DEF can produce any type of result so its TargetInstrDesc
+ // does not include operand register class info.
+ if (!VReg) {
+ const TargetRegisterClass *RC = TLI->getRegClassFor(Op.getValueType());
+ VReg = MRI.createVirtualRegister(RC);
+ }
+ BuildMI(BB, TII->get(TargetInstrInfo::IMPLICIT_DEF), VReg);
+ return VReg;
+ }
+
DenseMap<SDOperand, unsigned>::iterator I = VRBaseMap.find(Op);
assert(I != VRBaseMap.end() && "Node emitted out of order - late");
return I->second;
assert(Op.getValueType() != MVT::Other &&
Op.getValueType() != MVT::Flag &&
"Chain and flag operands should occur at end of operand list!");
-
// Get/emit the operand.
unsigned VReg = getVR(Op, VRBaseMap);
const TargetInstrDesc &TID = MI->getDesc();
- bool isOptDef = (IIOpNum < TID.getNumOperands())
- ? (TID.OpInfo[IIOpNum].isOptionalDef()) : false;
+ bool isOptDef = IIOpNum < TID.getNumOperands() &&
+ TID.OpInfo[IIOpNum].isOptionalDef();
MI->addOperand(MachineOperand::CreateReg(VReg, isOptDef));
// Verify that it is right.
assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
+#ifndef NDEBUG
if (II) {
+ // There may be no register class for this operand if it is a variadic
+ // argument (RC will be NULL in this case). In this case, we just assume
+ // the regclass is ok.
const TargetRegisterClass *RC =
getInstrOperandRegClass(TRI, TII, *II, IIOpNum);
- assert(RC && "Don't have operand info for this instruction!");
- const TargetRegisterClass *VRC = RegInfo.getRegClass(VReg);
- if (VRC != RC) {
+ assert((RC || II->isVariadic()) && "Expected reg class info!");
+ const TargetRegisterClass *VRC = MRI.getRegClass(VReg);
+ if (RC && VRC != RC) {
cerr << "Register class of operand and regclass of use don't agree!\n";
-#ifndef NDEBUG
cerr << "Operand = " << IIOpNum << "\n";
cerr << "Op->Val = "; Op.Val->dump(&DAG); cerr << "\n";
cerr << "MI = "; MI->print(cerr);
<< ", align = " << VRC->getAlignment() << "\n";
cerr << "Expected RegClass size = " << RC->getSize()
<< ", align = " << RC->getAlignment() << "\n";
-#endif
cerr << "Fatal error, aborting.\n";
abort();
}
}
+#endif
} else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateImm(C->getValue()));
} else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) {
- const Type *FType = MVT::getTypeForValueType(Op.getValueType());
- ConstantFP *CFP = ConstantFP::get(FType, F->getValueAPF());
+ ConstantFP *CFP = ConstantFP::get(F->getValueAPF());
MI->addOperand(MachineOperand::CreateFPImm(CFP));
} else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateReg(R->getReg(), false));
unsigned VReg = getVR(Op, VRBaseMap);
MI->addOperand(MachineOperand::CreateReg(VReg, false));
- // Verify that it is right.
+ // Verify that it is right. Note that the reg class of the physreg and the
+ // vreg don't necessarily need to match, but the target copy insertion has
+ // to be able to handle it. This handles things like copies from ST(0) to
+ // an FP vreg on x86.
assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
- if (II) {
- const TargetRegisterClass *RC =
- getInstrOperandRegClass(TRI, TII, *II, IIOpNum);
- assert(RC && "Don't have operand info for this instruction!");
- assert(RegInfo.getRegClass(VReg) == RC &&
- "Register class of operand and regclass of use don't agree!");
+ if (II && !II->isVariadic()) {
+ assert(getInstrOperandRegClass(TRI, TII, *II, IIOpNum) &&
+ "Don't have operand info for this instruction!");
}
}
}
-void ScheduleDAG::AddMemOperand(MachineInstr *MI, const MemOperand &MO) {
+void ScheduleDAG::AddMemOperand(MachineInstr *MI, const MachineMemOperand &MO) {
MI->addMemOperand(MO);
}
static const TargetRegisterClass *getSuperregRegisterClass(
const TargetRegisterClass *TRC,
unsigned SubIdx,
- MVT::ValueType VT) {
+ MVT VT) {
// Pick the register class of the superegister for this type
for (TargetRegisterInfo::regclass_iterator I = TRC->superregclasses_begin(),
E = TRC->superregclasses_end(); I != E; ++I)
DenseMap<SDOperand, unsigned> &VRBaseMap) {
unsigned VRBase = 0;
unsigned Opc = Node->getTargetOpcode();
- if (Opc == TargetInstrInfo::EXTRACT_SUBREG) {
- // If the node is only used by a CopyToReg and the dest reg is a vreg, use
- // the CopyToReg'd destination register instead of creating a new vreg.
- for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
- UI != E; ++UI) {
- SDNode *Use = *UI;
- if (Use->getOpcode() == ISD::CopyToReg &&
- Use->getOperand(2).Val == Node) {
- unsigned DestReg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
- if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
- VRBase = DestReg;
- break;
- }
+
+ // If the node is only used by a CopyToReg and the dest reg is a vreg, use
+ // the CopyToReg'd destination register instead of creating a new vreg.
+ for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+ UI != E; ++UI) {
+ SDNode *Use = UI->getUser();
+ if (Use->getOpcode() == ISD::CopyToReg &&
+ Use->getOperand(2).Val == Node) {
+ unsigned DestReg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
+ if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
+ VRBase = DestReg;
+ break;
}
}
-
+ }
+
+ if (Opc == TargetInstrInfo::EXTRACT_SUBREG) {
unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getValue();
-
- // TODO: If the node is a use of a CopyFromReg from a physical register
- // fold the extract into the copy now
// Create the extract_subreg machine instruction.
- MachineInstr *MI =
- new MachineInstr(BB, TII->get(TargetInstrInfo::EXTRACT_SUBREG));
+ MachineInstr *MI = BuildMI(TII->get(TargetInstrInfo::EXTRACT_SUBREG));
// Figure out the register class to create for the destreg.
unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
- const TargetRegisterClass *TRC = RegInfo.getRegClass(VReg);
+ const TargetRegisterClass *TRC = MRI.getRegClass(VReg);
const TargetRegisterClass *SRC = getSubRegisterRegClass(TRC, SubIdx);
if (VRBase) {
// Grab the destination register
- const TargetRegisterClass *DRC = 0;
- DRC = RegInfo.getRegClass(VRBase);
+#ifndef NDEBUG
+ const TargetRegisterClass *DRC = MRI.getRegClass(VRBase);
assert(SRC && DRC && SRC == DRC &&
"Source subregister and destination must have the same class");
+#endif
} else {
// Create the reg
assert(SRC && "Couldn't find source register class");
- VRBase = RegInfo.createVirtualRegister(SRC);
+ VRBase = MRI.createVirtualRegister(SRC);
}
// Add def, source, and subreg index
MI->addOperand(MachineOperand::CreateReg(VRBase, true));
AddOperand(MI, Node->getOperand(0), 0, 0, VRBaseMap);
MI->addOperand(MachineOperand::CreateImm(SubIdx));
+ BB->push_back(MI);
+ } else if (Opc == TargetInstrInfo::INSERT_SUBREG ||
+ Opc == TargetInstrInfo::SUBREG_TO_REG) {
+ SDOperand N0 = Node->getOperand(0);
+ SDOperand N1 = Node->getOperand(1);
+ SDOperand N2 = Node->getOperand(2);
+ unsigned SubReg = getVR(N1, VRBaseMap);
+ unsigned SubIdx = cast<ConstantSDNode>(N2)->getValue();
- } else if (Opc == TargetInstrInfo::INSERT_SUBREG) {
- assert((Node->getNumOperands() == 2 || Node->getNumOperands() == 3) &&
- "Malformed insert_subreg node");
- bool isUndefInput = (Node->getNumOperands() == 2);
- unsigned SubReg = 0;
- unsigned SubIdx = 0;
-
- if (isUndefInput) {
- SubReg = getVR(Node->getOperand(0), VRBaseMap);
- SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getValue();
- } else {
- SubReg = getVR(Node->getOperand(1), VRBaseMap);
- SubIdx = cast<ConstantSDNode>(Node->getOperand(2))->getValue();
- }
-
- // TODO: Add tracking info to MachineRegisterInfo of which vregs are subregs
- // to allow coalescing in the allocator
-
- // If the node is only used by a CopyToReg and the dest reg is a vreg, use
- // the CopyToReg'd destination register instead of creating a new vreg.
- // If the CopyToReg'd destination register is physical, then fold the
- // insert into the copy
- for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
- UI != E; ++UI) {
- SDNode *Use = *UI;
- if (Use->getOpcode() == ISD::CopyToReg &&
- Use->getOperand(2).Val == Node) {
- unsigned DestReg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
- if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
- VRBase = DestReg;
- break;
- }
- }
- }
-
- // Create the insert_subreg machine instruction.
- MachineInstr *MI =
- new MachineInstr(BB, TII->get(TargetInstrInfo::INSERT_SUBREG));
// Figure out the register class to create for the destreg.
const TargetRegisterClass *TRC = 0;
if (VRBase) {
- TRC = RegInfo.getRegClass(VRBase);
+ TRC = MRI.getRegClass(VRBase);
} else {
- TRC = getSuperregRegisterClass(RegInfo.getRegClass(SubReg), SubIdx,
+ TRC = getSuperregRegisterClass(MRI.getRegClass(SubReg), SubIdx,
Node->getValueType(0));
assert(TRC && "Couldn't determine register class for insert_subreg");
- VRBase = RegInfo.createVirtualRegister(TRC); // Create the reg
+ VRBase = MRI.createVirtualRegister(TRC); // Create the reg
}
+ // Create the insert_subreg or subreg_to_reg machine instruction.
+ MachineInstr *MI = BuildMI(TII->get(Opc));
MI->addOperand(MachineOperand::CreateReg(VRBase, true));
- AddOperand(MI, Node->getOperand(0), 0, 0, VRBaseMap);
- if (!isUndefInput)
- AddOperand(MI, Node->getOperand(1), 0, 0, VRBaseMap);
+
+ // If creating a subreg_to_reg, then the first input operand
+ // is an implicit value immediate, otherwise it's a register
+ if (Opc == TargetInstrInfo::SUBREG_TO_REG) {
+ const ConstantSDNode *SD = cast<ConstantSDNode>(N0);
+ MI->addOperand(MachineOperand::CreateImm(SD->getValue()));
+ } else
+ AddOperand(MI, N0, 0, 0, VRBaseMap);
+ // Add the subregster being inserted
+ AddOperand(MI, N1, 0, 0, VRBaseMap);
MI->addOperand(MachineOperand::CreateImm(SubIdx));
+ BB->push_back(MI);
} else
- assert(0 && "Node is not a subreg insert or extract");
+ assert(0 && "Node is not insert_subreg, extract_subreg, or subreg_to_reg");
bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,0), VRBase));
+ isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
}
/// EmitNode - Generate machine code for an node and needed dependencies.
///
-void ScheduleDAG::EmitNode(SDNode *Node, unsigned InstanceNo,
+void ScheduleDAG::EmitNode(SDNode *Node, bool IsClone,
DenseMap<SDOperand, unsigned> &VRBaseMap) {
// If machine instruction
if (Node->isTargetOpcode()) {
// Handle subreg insert/extract specially
if (Opc == TargetInstrInfo::EXTRACT_SUBREG ||
- Opc == TargetInstrInfo::INSERT_SUBREG) {
+ Opc == TargetInstrInfo::INSERT_SUBREG ||
+ Opc == TargetInstrInfo::SUBREG_TO_REG) {
EmitSubregNode(Node, VRBaseMap);
return;
}
+
+ if (Opc == TargetInstrInfo::IMPLICIT_DEF)
+ // We want a unique VR for each IMPLICIT_DEF use.
+ return;
const TargetInstrDesc &II = TII->get(Opc);
-
unsigned NumResults = CountResults(Node);
unsigned NodeOperands = CountOperands(Node);
unsigned MemOperandsEnd = ComputeMemOperandsEnd(Node);
- unsigned NumMIOperands = NodeOperands + NumResults;
bool HasPhysRegOuts = (NumResults > II.getNumDefs()) &&
II.getImplicitDefs() != 0;
#ifndef NDEBUG
+ unsigned NumMIOperands = NodeOperands + NumResults;
assert((II.getNumOperands() == NumMIOperands ||
HasPhysRegOuts || II.isVariadic()) &&
"#operands for dag node doesn't match .td file!");
#endif
// Create the new machine instruction.
- MachineInstr *MI = new MachineInstr(II);
+ MachineInstr *MI = BuildMI(II);
// Add result register values for things that are defined by this
// instruction.
delete MI;
MI = NewMI;
}
+ ++NumCommutes;
}
}
if (II.usesCustomDAGSchedInsertionHook())
// Insert this instruction into the basic block using a target
// specific inserter which may returns a new basic block.
- BB = DAG.getTargetLoweringInfo().EmitInstrWithCustomInserter(MI, BB);
+ BB = TLI->EmitInstrWithCustomInserter(MI, BB);
else
BB->push_back(MI);
for (unsigned i = II.getNumDefs(); i < NumResults; ++i) {
unsigned Reg = II.getImplicitDefs()[i - II.getNumDefs()];
if (Node->hasAnyUseOfValue(i))
- EmitCopyFromReg(Node, i, InstanceNo, Reg, VRBaseMap);
+ EmitCopyFromReg(Node, i, IsClone, Reg, VRBaseMap);
}
}
} else {
Node->dump(&DAG);
#endif
assert(0 && "This target-independent node should have been selected!");
- case ISD::EntryToken: // fall thru
- case ISD::TokenFactor:
+ break;
+ case ISD::EntryToken:
+ assert(0 && "EntryToken should have been excluded from the schedule!");
+ break;
+ case ISD::TokenFactor: // fall thru
case ISD::LABEL:
case ISD::DECLARE:
case ISD::SRCVALUE:
break;
case ISD::CopyToReg: {
- unsigned InReg;
- if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Node->getOperand(2)))
- InReg = R->getReg();
+ unsigned SrcReg;
+ SDOperand SrcVal = Node->getOperand(2);
+ if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(SrcVal))
+ SrcReg = R->getReg();
else
- InReg = getVR(Node->getOperand(2), VRBaseMap);
+ SrcReg = getVR(SrcVal, VRBaseMap);
+
unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
- if (InReg != DestReg) {// Coalesced away the copy?
- const TargetRegisterClass *TRC = 0;
- // Get the target register class
- if (TargetRegisterInfo::isVirtualRegister(InReg))
- TRC = RegInfo.getRegClass(InReg);
- else
- TRC =
- TRI->getPhysicalRegisterRegClass(Node->getOperand(2).getValueType(),
- InReg);
- TII->copyRegToReg(*BB, BB->end(), DestReg, InReg, TRC, TRC);
- }
+ if (SrcReg == DestReg) // Coalesced away the copy? Ignore.
+ break;
+
+ const TargetRegisterClass *SrcTRC = 0, *DstTRC = 0;
+ // Get the register classes of the src/dst.
+ if (TargetRegisterInfo::isVirtualRegister(SrcReg))
+ SrcTRC = MRI.getRegClass(SrcReg);
+ else
+ SrcTRC = TRI->getPhysicalRegisterRegClass(SrcReg,SrcVal.getValueType());
+
+ if (TargetRegisterInfo::isVirtualRegister(DestReg))
+ DstTRC = MRI.getRegClass(DestReg);
+ else
+ DstTRC = TRI->getPhysicalRegisterRegClass(DestReg,
+ Node->getOperand(1).getValueType());
+ TII->copyRegToReg(*BB, BB->end(), DestReg, SrcReg, DstTRC, SrcTRC);
break;
}
case ISD::CopyFromReg: {
unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
- EmitCopyFromReg(Node, 0, InstanceNo, SrcReg, VRBaseMap);
+ EmitCopyFromReg(Node, 0, IsClone, SrcReg, VRBaseMap);
break;
}
case ISD::INLINEASM: {
--NumOps; // Ignore the flag operand.
// Create the inline asm machine instruction.
- MachineInstr *MI =
- new MachineInstr(BB, TII->get(TargetInstrInfo::INLINEASM));
+ MachineInstr *MI = BuildMI(TII->get(TargetInstrInfo::INLINEASM));
// Add the asm string as an external symbol operand.
const char *AsmStr =
break;
}
}
+ BB->push_back(MI);
break;
}
}
TII->insertNoop(*BB, BB->end());
}
-void ScheduleDAG::EmitCrossRCCopy(SUnit *SU, DenseMap<SUnit*, unsigned> &VRBaseMap) {
+void ScheduleDAG::EmitCrossRCCopy(SUnit *SU,
+ DenseMap<SUnit*, unsigned> &VRBaseMap) {
for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
I != E; ++I) {
if (I->isCtrl) continue; // ignore chain preds
} else {
// Copy from physical register.
assert(I->Reg && "Unknown physical register!");
- unsigned VRBase = RegInfo.createVirtualRegister(SU->CopyDstRC);
+ unsigned VRBase = MRI.createVirtualRegister(SU->CopyDstRC);
bool isNew = VRBaseMap.insert(std::make_pair(SU, VRBase));
+ isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
TII->copyRegToReg(*BB, BB->end(), VRBase, I->Reg,
SU->CopyDstRC, SU->CopySrcRC);
}
}
+/// EmitLiveInCopy - Emit a copy for a live in physical register. If the
+/// physical register has only a single copy use, then coalesced the copy
+/// if possible.
+void ScheduleDAG::EmitLiveInCopy(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator &InsertPos,
+ unsigned VirtReg, unsigned PhysReg,
+ const TargetRegisterClass *RC,
+ DenseMap<MachineInstr*, unsigned> &CopyRegMap){
+ unsigned NumUses = 0;
+ MachineInstr *UseMI = NULL;
+ for (MachineRegisterInfo::use_iterator UI = MRI.use_begin(VirtReg),
+ UE = MRI.use_end(); UI != UE; ++UI) {
+ UseMI = &*UI;
+ if (++NumUses > 1)
+ break;
+ }
+
+ // If the number of uses is not one, or the use is not a move instruction,
+ // don't coalesce. Also, only coalesce away a virtual register to virtual
+ // register copy.
+ bool Coalesced = false;
+ unsigned SrcReg, DstReg;
+ if (NumUses == 1 &&
+ TII->isMoveInstr(*UseMI, SrcReg, DstReg) &&
+ TargetRegisterInfo::isVirtualRegister(DstReg)) {
+ VirtReg = DstReg;
+ Coalesced = true;
+ }
+
+ // Now find an ideal location to insert the copy.
+ MachineBasicBlock::iterator Pos = InsertPos;
+ while (Pos != MBB->begin()) {
+ MachineInstr *PrevMI = prior(Pos);
+ DenseMap<MachineInstr*, unsigned>::iterator RI = CopyRegMap.find(PrevMI);
+ // copyRegToReg might emit multiple instructions to do a copy.
+ unsigned CopyDstReg = (RI == CopyRegMap.end()) ? 0 : RI->second;
+ if (CopyDstReg && !TRI->regsOverlap(CopyDstReg, PhysReg))
+ // This is what the BB looks like right now:
+ // r1024 = mov r0
+ // ...
+ // r1 = mov r1024
+ //
+ // We want to insert "r1025 = mov r1". Inserting this copy below the
+ // move to r1024 makes it impossible for that move to be coalesced.
+ //
+ // r1025 = mov r1
+ // r1024 = mov r0
+ // ...
+ // r1 = mov 1024
+ // r2 = mov 1025
+ break; // Woot! Found a good location.
+ --Pos;
+ }
+
+ TII->copyRegToReg(*MBB, Pos, VirtReg, PhysReg, RC, RC);
+ CopyRegMap.insert(std::make_pair(prior(Pos), VirtReg));
+ if (Coalesced) {
+ if (&*InsertPos == UseMI) ++InsertPos;
+ MBB->erase(UseMI);
+ }
+}
+
+/// EmitLiveInCopies - If this is the first basic block in the function,
+/// and if it has live ins that need to be copied into vregs, emit the
+/// copies into the top of the block.
+void ScheduleDAG::EmitLiveInCopies(MachineBasicBlock *MBB) {
+ DenseMap<MachineInstr*, unsigned> CopyRegMap;
+ MachineBasicBlock::iterator InsertPos = MBB->begin();
+ for (MachineRegisterInfo::livein_iterator LI = MRI.livein_begin(),
+ E = MRI.livein_end(); LI != E; ++LI)
+ if (LI->second) {
+ const TargetRegisterClass *RC = MRI.getRegClass(LI->second);
+ EmitLiveInCopy(MBB, InsertPos, LI->second, LI->first, RC, CopyRegMap);
+ }
+}
+
/// EmitSchedule - Emit the machine code in scheduled order.
void ScheduleDAG::EmitSchedule() {
- // If this is the first basic block in the function, and if it has live ins
- // that need to be copied into vregs, emit the copies into the top of the
- // block before emitting the code for the block.
- if (&MF->front() == BB) {
- for (MachineRegisterInfo::livein_iterator LI = RegInfo.livein_begin(),
- E = RegInfo.livein_end(); LI != E; ++LI)
+ bool isEntryBB = &MF->front() == BB;
+
+ if (isEntryBB && !SchedLiveInCopies) {
+ // If this is the first basic block in the function, and if it has live ins
+ // that need to be copied into vregs, emit the copies into the top of the
+ // block before emitting the code for the block.
+ for (MachineRegisterInfo::livein_iterator LI = MRI.livein_begin(),
+ E = MRI.livein_end(); LI != E; ++LI)
if (LI->second) {
- const TargetRegisterClass *RC = RegInfo.getRegClass(LI->second);
+ const TargetRegisterClass *RC = MRI.getRegClass(LI->second);
TII->copyRegToReg(*MF->begin(), MF->begin()->end(), LI->second,
LI->first, RC, RC);
}
}
-
-
+
// Finally, emit the code for all of the scheduled instructions.
DenseMap<SDOperand, unsigned> VRBaseMap;
DenseMap<SUnit*, unsigned> CopyVRBaseMap;
for (unsigned i = 0, e = Sequence.size(); i != e; i++) {
- if (SUnit *SU = Sequence[i]) {
- for (unsigned j = 0, ee = SU->FlaggedNodes.size(); j != ee; ++j)
- EmitNode(SU->FlaggedNodes[j], SU->InstanceNo, VRBaseMap);
- if (SU->Node)
- EmitNode(SU->Node, SU->InstanceNo, VRBaseMap);
- else
- EmitCrossRCCopy(SU, CopyVRBaseMap);
- } else {
+ SUnit *SU = Sequence[i];
+ if (!SU) {
// Null SUnit* is a noop.
EmitNoop();
+ continue;
}
+ for (unsigned j = 0, ee = SU->FlaggedNodes.size(); j != ee; ++j)
+ EmitNode(SU->FlaggedNodes[j], SU->OrigNode != SU, VRBaseMap);
+ if (!SU->Node)
+ EmitCrossRCCopy(SU, CopyVRBaseMap);
+ else
+ EmitNode(SU->Node, SU->OrigNode != SU, VRBaseMap);
}
+
+ if (isEntryBB && SchedLiveInCopies)
+ EmitLiveInCopies(MF->begin());
}
/// dump - dump the schedule.
projects / oota-llvm.git / blobdiff