llvm-6502/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodesEmit.cpp
Evan Cheng 4784f1fc73 Add a bit IsUndef to MachineOperand. This indicates the def / use register operand is defined by an implicit_def. That means it can def / use any register and passes (e.g. register scavenger) can feel free to ignore them.
The register allocator, when it allocates a register to a virtual register defined by an implicit_def, can allocate any physical register without worrying about overlapping live ranges. It should mark all of operands of the said virtual register so later passes will do the right thing.

This is not the best solution. But it should be a lot less fragile to having the scavenger try to track what is defined by implicit_def.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74518 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-30 08:49:04 +00:00

672 lines
26 KiB
C++

//===---- ScheduleDAGEmit.cpp - Emit routines for the ScheduleDAG class ---===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements the Emit routines for the ScheduleDAG class, which creates
// MachineInstrs according to the computed schedule.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "pre-RA-sched"
#include "ScheduleDAGSDNodes.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;
/// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
/// implicit physical register output.
void ScheduleDAGSDNodes::
EmitCopyFromReg(SDNode *Node, unsigned ResNo, bool IsClone, bool IsCloned,
unsigned SrcReg, DenseMap<SDValue, unsigned> &VRBaseMap) {
unsigned VRBase = 0;
if (TargetRegisterInfo::isVirtualRegister(SrcReg)) {
// Just use the input register directly!
SDValue Op(Node, ResNo);
if (IsClone)
VRBaseMap.erase(Op);
bool isNew = VRBaseMap.insert(std::make_pair(Op, SrcReg)).second;
isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
return;
}
// 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.
bool MatchReg = true;
const TargetRegisterClass *UseRC = NULL;
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, II, i+II.getNumDefs());
if (!UseRC)
UseRC = RC;
else if (RC) {
if (UseRC->hasSuperClass(RC))
UseRC = RC;
else
assert((UseRC == RC || RC->hasSuperClass(UseRC)) &&
"Multiple uses expecting different register classes!");
}
}
}
}
MatchReg &= Match;
if (VRBase)
break;
}
MVT VT = Node->getValueType(ResNo);
const TargetRegisterClass *SrcRC = 0, *DstRC = 0;
SrcRC = TRI->getPhysicalRegisterRegClass(SrcReg, VT);
// Figure out the register class to create for the destreg.
if (VRBase) {
DstRC = MRI.getRegClass(VRBase);
} else if (UseRC) {
assert(UseRC->hasType(VT) && "Incompatible phys register def and uses!");
DstRC = UseRC;
} else {
DstRC = TLI->getRegClassFor(VT);
}
// 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 && SrcRC->getCopyCost() < 0) {
VRBase = SrcReg;
} else {
// Create the reg, emit the copy.
VRBase = MRI.createVirtualRegister(DstRC);
bool Emitted = TII->copyRegToReg(*BB, InsertPos, VRBase, SrcReg,
DstRC, SrcRC);
assert(Emitted && "Unable to issue a copy instruction!\n");
(void) Emitted;
}
SDValue Op(Node, ResNo);
if (IsClone)
VRBaseMap.erase(Op);
bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
}
/// getDstOfCopyToRegUse - If the only use of the specified result number of
/// node is a CopyToReg, return its destination register. Return 0 otherwise.
unsigned ScheduleDAGSDNodes::getDstOfOnlyCopyToRegUse(SDNode *Node,
unsigned ResNo) const {
if (!Node->hasOneUse())
return 0;
SDNode *User = *Node->use_begin();
if (User->getOpcode() == ISD::CopyToReg &&
User->getOperand(2).getNode() == Node &&
User->getOperand(2).getResNo() == ResNo) {
unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
if (TargetRegisterInfo::isVirtualRegister(Reg))
return Reg;
}
return 0;
}
void ScheduleDAGSDNodes::CreateVirtualRegisters(SDNode *Node, MachineInstr *MI,
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!");
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 in the same register class, use the CopyToReg'd destination
// register instead of creating a new vreg.
unsigned VRBase = 0;
const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, II, i);
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)) {
const TargetRegisterClass *RegRC = MRI.getRegClass(Reg);
if (RegRC == RC) {
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.
if (VRBase == 0) {
assert(RC && "Isn't a register operand!");
VRBase = MRI.createVirtualRegister(RC);
MI->addOperand(MachineOperand::CreateReg(VRBase, true));
}
SDValue Op(Node, i);
if (IsClone)
VRBaseMap.erase(Op);
bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
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.
unsigned ScheduleDAGSDNodes::getVR(SDValue Op,
DenseMap<SDValue, unsigned> &VRBaseMap) {
if (Op.isMachineOpcode() &&
Op.getMachineOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
// Add an IMPLICIT_DEF instruction before every use.
unsigned VReg = getDstOfOnlyCopyToRegUse(Op.getNode(), Op.getResNo());
// 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, Op.getDebugLoc(), TII->get(TargetInstrInfo::IMPLICIT_DEF),VReg);
return VReg;
}
DenseMap<SDValue, unsigned>::iterator I = VRBaseMap.find(Op);
assert(I != VRBaseMap.end() && "Node emitted out of order - late");
return I->second;
}
/// AddRegisterOperand - Add the specified register as an operand to the
/// specified machine instr. Insert register copies if the register is
/// not in the required register class.
void
ScheduleDAGSDNodes::AddRegisterOperand(MachineInstr *MI, SDValue Op,
unsigned IIOpNum,
const TargetInstrDesc *II,
DenseMap<SDValue, unsigned> &VRBaseMap) {
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);
assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
const TargetInstrDesc &TID = MI->getDesc();
bool isOptDef = IIOpNum < TID.getNumOperands() &&
TID.OpInfo[IIOpNum].isOptionalDef();
// If the instruction requires a register in a different class, create
// a new virtual register and copy the value into it.
if (II) {
const TargetRegisterClass *SrcRC =
MRI.getRegClass(VReg);
const TargetRegisterClass *DstRC =
getInstrOperandRegClass(TRI, *II, IIOpNum);
assert((DstRC || (TID.isVariadic() && IIOpNum >= TID.getNumOperands())) &&
"Don't have operand info for this instruction!");
if (DstRC && SrcRC != DstRC && !SrcRC->hasSuperClass(DstRC)) {
unsigned NewVReg = MRI.createVirtualRegister(DstRC);
bool Emitted = TII->copyRegToReg(*BB, InsertPos, NewVReg, VReg,
DstRC, SrcRC);
assert(Emitted && "Unable to issue a copy instruction!\n");
(void) Emitted;
VReg = NewVReg;
}
}
MI->addOperand(MachineOperand::CreateReg(VReg, isOptDef));
}
/// AddOperand - Add the specified operand to the specified machine instr. II
/// specifies the instruction information for the node, and IIOpNum is the
/// operand number (in the II) that we are adding. IIOpNum and II are used for
/// assertions only.
void ScheduleDAGSDNodes::AddOperand(MachineInstr *MI, SDValue Op,
unsigned IIOpNum,
const TargetInstrDesc *II,
DenseMap<SDValue, unsigned> &VRBaseMap) {
if (Op.isMachineOpcode()) {
AddRegisterOperand(MI, Op, IIOpNum, II, VRBaseMap);
} else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateImm(C->getZExtValue()));
} else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) {
const ConstantFP *CFP = F->getConstantFPValue();
MI->addOperand(MachineOperand::CreateFPImm(CFP));
} else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateReg(R->getReg(), false));
} else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateGA(TGA->getGlobal(), TGA->getOffset(),
TGA->getTargetFlags()));
} else if (BasicBlockSDNode *BBNode = dyn_cast<BasicBlockSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateMBB(BBNode->getBasicBlock()));
} else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateFI(FI->getIndex()));
} else if (JumpTableSDNode *JT = dyn_cast<JumpTableSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateJTI(JT->getIndex(),
JT->getTargetFlags()));
} else if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Op)) {
int Offset = CP->getOffset();
unsigned Align = CP->getAlignment();
const Type *Type = CP->getType();
// MachineConstantPool wants an explicit alignment.
if (Align == 0) {
Align = TM.getTargetData()->getPrefTypeAlignment(Type);
if (Align == 0) {
// Alignment of vector types. FIXME!
Align = TM.getTargetData()->getTypeAllocSize(Type);
}
}
unsigned Idx;
if (CP->isMachineConstantPoolEntry())
Idx = ConstPool->getConstantPoolIndex(CP->getMachineCPVal(), Align);
else
Idx = ConstPool->getConstantPoolIndex(CP->getConstVal(), Align);
MI->addOperand(MachineOperand::CreateCPI(Idx, Offset,
CP->getTargetFlags()));
} else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) {
MI->addOperand(MachineOperand::CreateES(ES->getSymbol(), 0,
ES->getTargetFlags()));
} else {
assert(Op.getValueType() != MVT::Other &&
Op.getValueType() != MVT::Flag &&
"Chain and flag operands should occur at end of operand list!");
AddRegisterOperand(MI, Op, IIOpNum, II, VRBaseMap);
}
}
/// getSuperRegisterRegClass - Returns the register class of a superreg A whose
/// "SubIdx"'th sub-register class is the specified register class and whose
/// type matches the specified type.
static const TargetRegisterClass*
getSuperRegisterRegClass(const TargetRegisterClass *TRC,
unsigned SubIdx, 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)
if ((*I)->hasType(VT) && (*I)->getSubRegisterRegClass(SubIdx) == TRC)
return *I;
assert(false && "Couldn't find the register class");
return 0;
}
/// EmitSubregNode - Generate machine code for subreg nodes.
///
void ScheduleDAGSDNodes::EmitSubregNode(SDNode *Node,
DenseMap<SDValue, unsigned> &VRBaseMap){
unsigned VRBase = 0;
unsigned Opc = Node->getMachineOpcode();
// 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 *User = *UI;
if (User->getOpcode() == ISD::CopyToReg &&
User->getOperand(2).getNode() == Node) {
unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
VRBase = DestReg;
break;
}
}
}
if (Opc == TargetInstrInfo::EXTRACT_SUBREG) {
unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
// Create the extract_subreg machine instruction.
MachineInstr *MI = BuildMI(MF, Node->getDebugLoc(),
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 = MRI.getRegClass(VReg);
const TargetRegisterClass *SRC = TRC->getSubRegisterRegClass(SubIdx);
assert(SRC && "Invalid subregister index in EXTRACT_SUBREG");
// Figure out the register class to create for the destreg.
// Note that if we're going to directly use an existing register,
// it must be precisely the required class, and not a subclass
// thereof.
if (VRBase == 0 || SRC != MRI.getRegClass(VRBase)) {
// Create the reg
assert(SRC && "Couldn't find source register class");
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->insert(InsertPos, MI);
} else if (Opc == TargetInstrInfo::INSERT_SUBREG ||
Opc == TargetInstrInfo::SUBREG_TO_REG) {
SDValue N0 = Node->getOperand(0);
SDValue N1 = Node->getOperand(1);
SDValue N2 = Node->getOperand(2);
unsigned SubReg = getVR(N1, VRBaseMap);
unsigned SubIdx = cast<ConstantSDNode>(N2)->getZExtValue();
const TargetRegisterClass *TRC = MRI.getRegClass(SubReg);
const TargetRegisterClass *SRC =
getSuperRegisterRegClass(TRC, SubIdx,
Node->getValueType(0));
// Figure out the register class to create for the destreg.
// Note that if we're going to directly use an existing register,
// it must be precisely the required class, and not a subclass
// thereof.
if (VRBase == 0 || SRC != MRI.getRegClass(VRBase)) {
// Create the reg
assert(SRC && "Couldn't find source register class");
VRBase = MRI.createVirtualRegister(SRC);
}
// Create the insert_subreg or subreg_to_reg machine instruction.
MachineInstr *MI = BuildMI(MF, Node->getDebugLoc(), TII->get(Opc));
MI->addOperand(MachineOperand::CreateReg(VRBase, true));
// 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->getZExtValue()));
} else
AddOperand(MI, N0, 0, 0, VRBaseMap);
// Add the subregster being inserted
AddOperand(MI, N1, 0, 0, VRBaseMap);
MI->addOperand(MachineOperand::CreateImm(SubIdx));
BB->insert(InsertPos, MI);
} else
assert(0 && "Node is not insert_subreg, extract_subreg, or subreg_to_reg");
SDValue Op(Node, 0);
bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
}
/// EmitCopyToRegClassNode - Generate machine code for COPY_TO_REGCLASS nodes.
/// COPY_TO_REGCLASS is just a normal copy, except that the destination
/// register is constrained to be in a particular register class.
///
void
ScheduleDAGSDNodes::EmitCopyToRegClassNode(SDNode *Node,
DenseMap<SDValue, unsigned> &VRBaseMap) {
unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
const TargetRegisterClass *SrcRC = MRI.getRegClass(VReg);
unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
const TargetRegisterClass *DstRC = TRI->getRegClass(DstRCIdx);
// Create the new VReg in the destination class and emit a copy.
unsigned NewVReg = MRI.createVirtualRegister(DstRC);
bool Emitted = TII->copyRegToReg(*BB, InsertPos, NewVReg, VReg,
DstRC, SrcRC);
assert(Emitted &&
"Unable to issue a copy instruction for a COPY_TO_REGCLASS node!\n");
(void) Emitted;
SDValue Op(Node, 0);
bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
isNew = isNew; // Silence compiler warning.
assert(isNew && "Node emitted out of order - early");
}
/// EmitNode - Generate machine code for an node and needed dependencies.
///
void ScheduleDAGSDNodes::EmitNode(SDNode *Node, bool IsClone, bool IsCloned,
DenseMap<SDValue, unsigned> &VRBaseMap) {
// If machine instruction
if (Node->isMachineOpcode()) {
unsigned Opc = Node->getMachineOpcode();
// Handle subreg insert/extract specially
if (Opc == TargetInstrInfo::EXTRACT_SUBREG ||
Opc == TargetInstrInfo::INSERT_SUBREG ||
Opc == TargetInstrInfo::SUBREG_TO_REG) {
EmitSubregNode(Node, VRBaseMap);
return;
}
// Handle COPY_TO_REGCLASS specially.
if (Opc == TargetInstrInfo::COPY_TO_REGCLASS) {
EmitCopyToRegClassNode(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);
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 = BuildMI(MF, Node->getDebugLoc(), II);
// Add result register values for things that are defined by this
// instruction.
if (NumResults)
CreateVirtualRegisters(Node, MI, II, IsClone, IsCloned, VRBaseMap);
// Emit all of the actual operands of this instruction, adding them to the
// instruction as appropriate.
for (unsigned i = 0; i != NodeOperands; ++i)
AddOperand(MI, Node->getOperand(i), i+II.getNumDefs(), &II, VRBaseMap);
// Emit all of the memory operands of this instruction
for (unsigned i = NodeOperands; i != MemOperandsEnd; ++i)
AddMemOperand(MI, cast<MemOperandSDNode>(Node->getOperand(i))->MO);
if (II.usesCustomDAGSchedInsertionHook()) {
// Insert this instruction into the basic block using a target
// specific inserter which may returns a new basic block.
BB = TLI->EmitInstrWithCustomInserter(MI, BB);
InsertPos = BB->end();
} else {
BB->insert(InsertPos, MI);
}
// Additional results must be an physical register def.
if (HasPhysRegOuts) {
for (unsigned i = II.getNumDefs(); i < NumResults; ++i) {
unsigned Reg = II.getImplicitDefs()[i - II.getNumDefs()];
if (Node->hasAnyUseOfValue(i))
EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
}
}
return;
}
switch (Node->getOpcode()) {
default:
#ifndef NDEBUG
Node->dump(DAG);
#endif
assert(0 && "This target-independent node should have been selected!");
break;
case ISD::EntryToken:
assert(0 && "EntryToken should have been excluded from the schedule!");
break;
case ISD::TokenFactor: // fall thru
break;
case ISD::CopyToReg: {
unsigned SrcReg;
SDValue SrcVal = Node->getOperand(2);
if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(SrcVal))
SrcReg = R->getReg();
else
SrcReg = getVR(SrcVal, VRBaseMap);
unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
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());
bool Emitted = TII->copyRegToReg(*BB, InsertPos, DestReg, SrcReg,
DstTRC, SrcTRC);
assert(Emitted && "Unable to issue a copy instruction!\n");
(void) Emitted;
break;
}
case ISD::CopyFromReg: {
unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
EmitCopyFromReg(Node, 0, IsClone, IsCloned, SrcReg, VRBaseMap);
break;
}
case ISD::INLINEASM: {
unsigned NumOps = Node->getNumOperands();
if (Node->getOperand(NumOps-1).getValueType() == MVT::Flag)
--NumOps; // Ignore the flag operand.
// Create the inline asm machine instruction.
MachineInstr *MI = BuildMI(MF, Node->getDebugLoc(),
TII->get(TargetInstrInfo::INLINEASM));
// Add the asm string as an external symbol operand.
const char *AsmStr =
cast<ExternalSymbolSDNode>(Node->getOperand(1))->getSymbol();
MI->addOperand(MachineOperand::CreateES(AsmStr));
// Add all of the operand registers to the instruction.
for (unsigned i = 2; i != NumOps;) {
unsigned Flags =
cast<ConstantSDNode>(Node->getOperand(i))->getZExtValue();
unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
MI->addOperand(MachineOperand::CreateImm(Flags));
++i; // Skip the ID value.
switch (Flags & 7) {
default: assert(0 && "Bad flags!");
case 2: // Def of register.
for (; NumVals; --NumVals, ++i) {
unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
MI->addOperand(MachineOperand::CreateReg(Reg, true));
}
break;
case 6: // Def of earlyclobber register.
for (; NumVals; --NumVals, ++i) {
unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
MI->addOperand(MachineOperand::CreateReg(Reg, true, false, false,
false, false, true));
}
break;
case 1: // Use of register.
case 3: // Immediate.
case 4: // Addressing mode.
// The addressing mode has been selected, just add all of the
// operands to the machine instruction.
for (; NumVals; --NumVals, ++i)
AddOperand(MI, Node->getOperand(i), 0, 0, VRBaseMap);
break;
}
}
BB->insert(InsertPos, MI);
break;
}
}
}
/// EmitSchedule - Emit the machine code in scheduled order.
MachineBasicBlock *ScheduleDAGSDNodes::EmitSchedule() {
DenseMap<SDValue, unsigned> VRBaseMap;
DenseMap<SUnit*, unsigned> CopyVRBaseMap;
for (unsigned i = 0, e = Sequence.size(); i != e; i++) {
SUnit *SU = Sequence[i];
if (!SU) {
// Null SUnit* is a noop.
EmitNoop();
continue;
}
// For pre-regalloc scheduling, create instructions corresponding to the
// SDNode and any flagged SDNodes and append them to the block.
if (!SU->getNode()) {
// Emit a copy.
EmitPhysRegCopy(SU, CopyVRBaseMap);
continue;
}
SmallVector<SDNode *, 4> FlaggedNodes;
for (SDNode *N = SU->getNode()->getFlaggedNode(); N;
N = N->getFlaggedNode())
FlaggedNodes.push_back(N);
while (!FlaggedNodes.empty()) {
EmitNode(FlaggedNodes.back(), SU->OrigNode != SU, SU->isCloned,VRBaseMap);
FlaggedNodes.pop_back();
}
EmitNode(SU->getNode(), SU->OrigNode != SU, SU->isCloned, VRBaseMap);
}
return BB;
}