llvm-project/llvm/lib/Target/PTX/PTXInstrInfo.cpp

411 lines
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C++

//===- PTXInstrInfo.cpp - PTX Instruction Information ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PTX implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "ptx-instrinfo"
#include "PTX.h"
#include "PTXInstrInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#define GET_INSTRINFO_CTOR
#define GET_INSTRINFO_MC_DESC
#include "PTXGenInstrInfo.inc"
using namespace llvm;
PTXInstrInfo::PTXInstrInfo(PTXTargetMachine &_TM)
: PTXGenInstrInfo(),
RI(_TM, *this), TM(_TM) {}
static const struct map_entry {
const TargetRegisterClass *cls;
const int opcode;
} map[] = {
{ &PTX::RegI16RegClass, PTX::MOVU16rr },
{ &PTX::RegI32RegClass, PTX::MOVU32rr },
{ &PTX::RegI64RegClass, PTX::MOVU64rr },
{ &PTX::RegF32RegClass, PTX::MOVF32rr },
{ &PTX::RegF64RegClass, PTX::MOVF64rr },
{ &PTX::RegPredRegClass, PTX::MOVPREDrr }
};
void PTXInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DstReg, unsigned SrcReg,
bool KillSrc) const {
for (int i = 0, e = sizeof(map)/sizeof(map[0]); i != e; ++ i) {
if (map[i].cls->contains(DstReg, SrcReg)) {
const MCInstrDesc &MCID = get(map[i].opcode);
MachineInstr *MI = BuildMI(MBB, I, DL, MCID, DstReg).
addReg(SrcReg, getKillRegState(KillSrc));
AddDefaultPredicate(MI);
return;
}
}
llvm_unreachable("Impossible reg-to-reg copy");
}
bool PTXInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DstReg, unsigned SrcReg,
const TargetRegisterClass *DstRC,
const TargetRegisterClass *SrcRC,
DebugLoc DL) const {
if (DstRC != SrcRC)
return false;
for (int i = 0, e = sizeof(map)/sizeof(map[0]); i != e; ++ i)
if (DstRC == map[i].cls) {
const MCInstrDesc &MCID = get(map[i].opcode);
MachineInstr *MI = BuildMI(MBB, I, DL, MCID, DstReg).addReg(SrcReg);
AddDefaultPredicate(MI);
return true;
}
return false;
}
bool PTXInstrInfo::isMoveInstr(const MachineInstr& MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SrcSubIdx, unsigned &DstSubIdx) const {
switch (MI.getOpcode()) {
default:
return false;
case PTX::MOVU16rr:
case PTX::MOVU32rr:
case PTX::MOVU64rr:
case PTX::MOVF32rr:
case PTX::MOVF64rr:
case PTX::MOVPREDrr:
assert(MI.getNumOperands() >= 2 &&
MI.getOperand(0).isReg() && MI.getOperand(1).isReg() &&
"Invalid register-register move instruction");
SrcSubIdx = DstSubIdx = 0; // No sub-registers
DstReg = MI.getOperand(0).getReg();
SrcReg = MI.getOperand(1).getReg();
return true;
}
}
// predicate support
bool PTXInstrInfo::isPredicated(const MachineInstr *MI) const {
int i = MI->findFirstPredOperandIdx();
return i != -1 && MI->getOperand(i).getReg() != PTX::NoRegister;
}
bool PTXInstrInfo::isUnpredicatedTerminator(const MachineInstr *MI) const {
return !isPredicated(MI) && get(MI->getOpcode()).isTerminator();
}
bool PTXInstrInfo::
PredicateInstruction(MachineInstr *MI,
const SmallVectorImpl<MachineOperand> &Pred) const {
if (Pred.size() < 2)
llvm_unreachable("lesser than 2 predicate operands are provided");
int i = MI->findFirstPredOperandIdx();
if (i == -1)
llvm_unreachable("missing predicate operand");
MI->getOperand(i).setReg(Pred[0].getReg());
MI->getOperand(i+1).setImm(Pred[1].getImm());
return true;
}
bool PTXInstrInfo::
SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1,
const SmallVectorImpl<MachineOperand> &Pred2) const {
const MachineOperand &PredReg1 = Pred1[0];
const MachineOperand &PredReg2 = Pred2[0];
if (PredReg1.getReg() != PredReg2.getReg())
return false;
const MachineOperand &PredOp1 = Pred1[1];
const MachineOperand &PredOp2 = Pred2[1];
if (PredOp1.getImm() != PredOp2.getImm())
return false;
return true;
}
bool PTXInstrInfo::
DefinesPredicate(MachineInstr *MI,
std::vector<MachineOperand> &Pred) const {
// If an instruction sets a predicate register, it defines a predicate.
// TODO supprot 5-operand format of setp instruction
if (MI->getNumOperands() < 1)
return false;
const MachineOperand &MO = MI->getOperand(0);
if (!MO.isReg() || RI.getRegClass(MO.getReg()) != &PTX::RegPredRegClass)
return false;
Pred.push_back(MO);
Pred.push_back(MachineOperand::CreateImm(PTX::PRED_NORMAL));
return true;
}
// branch support
bool PTXInstrInfo::
AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// TODO implement cases when AllowModify is true
if (MBB.empty())
return true;
MachineBasicBlock::const_iterator iter = MBB.end();
const MachineInstr& instLast1 = *--iter;
const MCInstrDesc &desc1 = instLast1.getDesc();
// for special case that MBB has only 1 instruction
const bool IsSizeOne = MBB.size() == 1;
// if IsSizeOne is true, *--iter and instLast2 are invalid
// we put a dummy value in instLast2 and desc2 since they are used
const MachineInstr& instLast2 = IsSizeOne ? instLast1 : *--iter;
const MCInstrDesc &desc2 = IsSizeOne ? desc1 : instLast2.getDesc();
DEBUG(dbgs() << "\n");
DEBUG(dbgs() << "AnalyzeBranch: opcode: " << instLast1.getOpcode() << "\n");
DEBUG(dbgs() << "AnalyzeBranch: MBB: " << MBB.getName().str() << "\n");
DEBUG(dbgs() << "AnalyzeBranch: TBB: " << TBB << "\n");
DEBUG(dbgs() << "AnalyzeBranch: FBB: " << FBB << "\n");
// this block ends with no branches
if (!IsAnyKindOfBranch(instLast1)) {
DEBUG(dbgs() << "AnalyzeBranch: ends with no branch\n");
return false;
}
// this block ends with only an unconditional branch
if (desc1.isUnconditionalBranch() &&
// when IsSizeOne is true, it "absorbs" the evaluation of instLast2
(IsSizeOne || !IsAnyKindOfBranch(instLast2))) {
DEBUG(dbgs() << "AnalyzeBranch: ends with only uncond branch\n");
TBB = GetBranchTarget(instLast1);
return false;
}
// this block ends with a conditional branch and
// it falls through to a successor block
if (desc1.isConditionalBranch() &&
IsAnySuccessorAlsoLayoutSuccessor(MBB)) {
DEBUG(dbgs() << "AnalyzeBranch: ends with cond branch and fall through\n");
TBB = GetBranchTarget(instLast1);
int i = instLast1.findFirstPredOperandIdx();
Cond.push_back(instLast1.getOperand(i));
Cond.push_back(instLast1.getOperand(i+1));
return false;
}
// when IsSizeOne is true, we are done
if (IsSizeOne)
return true;
// this block ends with a conditional branch
// followed by an unconditional branch
if (desc2.isConditionalBranch() &&
desc1.isUnconditionalBranch()) {
DEBUG(dbgs() << "AnalyzeBranch: ends with cond and uncond branch\n");
TBB = GetBranchTarget(instLast2);
FBB = GetBranchTarget(instLast1);
int i = instLast2.findFirstPredOperandIdx();
Cond.push_back(instLast2.getOperand(i));
Cond.push_back(instLast2.getOperand(i+1));
return false;
}
// branch cannot be understood
DEBUG(dbgs() << "AnalyzeBranch: cannot be understood\n");
return true;
}
unsigned PTXInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
unsigned count = 0;
while (!MBB.empty())
if (IsAnyKindOfBranch(MBB.back())) {
MBB.pop_back();
++count;
} else
break;
DEBUG(dbgs() << "RemoveBranch: MBB: " << MBB.getName().str() << "\n");
DEBUG(dbgs() << "RemoveBranch: remove " << count << " branch inst\n");
return count;
}
unsigned PTXInstrInfo::
InsertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL) const {
DEBUG(dbgs() << "InsertBranch: MBB: " << MBB.getName().str() << "\n");
DEBUG(if (TBB) dbgs() << "InsertBranch: TBB: " << TBB->getName().str()
<< "\n";
else dbgs() << "InsertBranch: TBB: (NULL)\n");
DEBUG(if (FBB) dbgs() << "InsertBranch: FBB: " << FBB->getName().str()
<< "\n";
else dbgs() << "InsertBranch: FBB: (NULL)\n");
DEBUG(dbgs() << "InsertBranch: Cond size: " << Cond.size() << "\n");
assert(TBB && "TBB is NULL");
if (FBB) {
BuildMI(&MBB, DL, get(PTX::BRAdp))
.addMBB(TBB).addReg(Cond[0].getReg()).addImm(Cond[1].getImm());
BuildMI(&MBB, DL, get(PTX::BRAd))
.addMBB(FBB).addReg(PTX::NoRegister).addImm(PTX::PRED_NORMAL);
return 2;
} else if (Cond.size()) {
BuildMI(&MBB, DL, get(PTX::BRAdp))
.addMBB(TBB).addReg(Cond[0].getReg()).addImm(Cond[1].getImm());
return 1;
} else {
BuildMI(&MBB, DL, get(PTX::BRAd))
.addMBB(TBB).addReg(PTX::NoRegister).addImm(PTX::PRED_NORMAL);
return 1;
}
}
// Memory operand folding for spills
void PTXInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MII,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
MachineInstr& MI = *MII;
DebugLoc DL = MI.getDebugLoc();
DEBUG(dbgs() << "storeRegToStackSlot: " << MI);
int OpCode;
// Select the appropriate opcode based on the register class
if (RC == PTX::RegI16RegisterClass) {
OpCode = PTX::STACKSTOREI16;
} else if (RC == PTX::RegI32RegisterClass) {
OpCode = PTX::STACKSTOREI32;
} else if (RC == PTX::RegI64RegisterClass) {
OpCode = PTX::STACKSTOREI32;
} else if (RC == PTX::RegF32RegisterClass) {
OpCode = PTX::STACKSTOREF32;
} else if (RC == PTX::RegF64RegisterClass) {
OpCode = PTX::STACKSTOREF64;
} else {
llvm_unreachable("Unknown PTX register class!");
}
// Build the store instruction (really a mov)
MachineInstrBuilder MIB = BuildMI(MBB, MII, DL, get(OpCode));
MIB.addFrameIndex(FrameIdx);
MIB.addReg(SrcReg);
AddDefaultPredicate(MIB);
}
void PTXInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MII,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
MachineInstr& MI = *MII;
DebugLoc DL = MI.getDebugLoc();
DEBUG(dbgs() << "loadRegToStackSlot: " << MI);
int OpCode;
// Select the appropriate opcode based on the register class
if (RC == PTX::RegI16RegisterClass) {
OpCode = PTX::STACKLOADI16;
} else if (RC == PTX::RegI32RegisterClass) {
OpCode = PTX::STACKLOADI32;
} else if (RC == PTX::RegI64RegisterClass) {
OpCode = PTX::STACKLOADI32;
} else if (RC == PTX::RegF32RegisterClass) {
OpCode = PTX::STACKLOADF32;
} else if (RC == PTX::RegF64RegisterClass) {
OpCode = PTX::STACKLOADF64;
} else {
llvm_unreachable("Unknown PTX register class!");
}
// Build the load instruction (really a mov)
MachineInstrBuilder MIB = BuildMI(MBB, MII, DL, get(OpCode));
MIB.addReg(DestReg);
MIB.addFrameIndex(FrameIdx);
AddDefaultPredicate(MIB);
}
// static helper routines
MachineSDNode *PTXInstrInfo::
GetPTXMachineNode(SelectionDAG *DAG, unsigned Opcode,
DebugLoc dl, EVT VT, SDValue Op1) {
SDValue predReg = DAG->getRegister(PTX::NoRegister, MVT::i1);
SDValue predOp = DAG->getTargetConstant(PTX::PRED_NORMAL, MVT::i32);
SDValue ops[] = { Op1, predReg, predOp };
return DAG->getMachineNode(Opcode, dl, VT, ops, array_lengthof(ops));
}
MachineSDNode *PTXInstrInfo::
GetPTXMachineNode(SelectionDAG *DAG, unsigned Opcode,
DebugLoc dl, EVT VT, SDValue Op1, SDValue Op2) {
SDValue predReg = DAG->getRegister(PTX::NoRegister, MVT::i1);
SDValue predOp = DAG->getTargetConstant(PTX::PRED_NORMAL, MVT::i32);
SDValue ops[] = { Op1, Op2, predReg, predOp };
return DAG->getMachineNode(Opcode, dl, VT, ops, array_lengthof(ops));
}
void PTXInstrInfo::AddDefaultPredicate(MachineInstr *MI) {
if (MI->findFirstPredOperandIdx() == -1) {
MI->addOperand(MachineOperand::CreateReg(PTX::NoRegister, /*IsDef=*/false));
MI->addOperand(MachineOperand::CreateImm(PTX::PRED_NORMAL));
}
}
bool PTXInstrInfo::IsAnyKindOfBranch(const MachineInstr& inst) {
const MCInstrDesc &desc = inst.getDesc();
return desc.isTerminator() || desc.isBranch() || desc.isIndirectBranch();
}
bool PTXInstrInfo::
IsAnySuccessorAlsoLayoutSuccessor(const MachineBasicBlock& MBB) {
for (MachineBasicBlock::const_succ_iterator
i = MBB.succ_begin(), e = MBB.succ_end(); i != e; ++i)
if (MBB.isLayoutSuccessor((const MachineBasicBlock*) &*i))
return true;
return false;
}
MachineBasicBlock *PTXInstrInfo::GetBranchTarget(const MachineInstr& inst) {
// FIXME So far all branch instructions put destination in 1st operand
const MachineOperand& target = inst.getOperand(0);
assert(target.isMBB() && "FIXME: detect branch target operand");
return target.getMBB();
}