llvm-6502/lib/Target/Mips/MipsInstrInfo.cpp
2012-07-10 00:19:06 +00:00

577 lines
19 KiB
C++

//===-- MipsInstrInfo.cpp - Mips 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 Mips implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "MipsAnalyzeImmediate.h"
#include "MipsInstrInfo.h"
#include "MipsTargetMachine.h"
#include "MipsMachineFunction.h"
#include "InstPrinter/MipsInstPrinter.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/ADT/STLExtras.h"
#define GET_INSTRINFO_CTOR
#include "MipsGenInstrInfo.inc"
using namespace llvm;
MipsInstrInfo::MipsInstrInfo(MipsTargetMachine &tm)
: MipsGenInstrInfo(Mips::ADJCALLSTACKDOWN, Mips::ADJCALLSTACKUP),
TM(tm), IsN64(TM.getSubtarget<MipsSubtarget>().isABI_N64()),
RI(*TM.getSubtargetImpl(), *this),
UncondBrOpc(TM.getRelocationModel() == Reloc::PIC_ ? Mips::B : Mips::J) {}
const MipsRegisterInfo &MipsInstrInfo::getRegisterInfo() const {
return RI;
}
static bool isZeroImm(const MachineOperand &op) {
return op.isImm() && op.getImm() == 0;
}
/// isLoadFromStackSlot - If the specified machine instruction is a direct
/// load from a stack slot, return the virtual or physical register number of
/// the destination along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
unsigned MipsInstrInfo::
isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const
{
unsigned Opc = MI->getOpcode();
if ((Opc == Mips::LW) || (Opc == Mips::LW_P8) || (Opc == Mips::LD) ||
(Opc == Mips::LD_P8) || (Opc == Mips::LWC1) || (Opc == Mips::LWC1_P8) ||
(Opc == Mips::LDC1) || (Opc == Mips::LDC164) ||
(Opc == Mips::LDC164_P8)) {
if ((MI->getOperand(1).isFI()) && // is a stack slot
(MI->getOperand(2).isImm()) && // the imm is zero
(isZeroImm(MI->getOperand(2)))) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
/// isStoreToStackSlot - If the specified machine instruction is a direct
/// store to a stack slot, return the virtual or physical register number of
/// the source reg along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
unsigned MipsInstrInfo::
isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const
{
unsigned Opc = MI->getOpcode();
if ((Opc == Mips::SW) || (Opc == Mips::SW_P8) || (Opc == Mips::SD) ||
(Opc == Mips::SD_P8) || (Opc == Mips::SWC1) || (Opc == Mips::SWC1_P8) ||
(Opc == Mips::SDC1) || (Opc == Mips::SDC164) ||
(Opc == Mips::SDC164_P8)) {
if ((MI->getOperand(1).isFI()) && // is a stack slot
(MI->getOperand(2).isImm()) && // the imm is zero
(isZeroImm(MI->getOperand(2)))) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
/// insertNoop - If data hazard condition is found insert the target nop
/// instruction.
void MipsInstrInfo::
insertNoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const
{
DebugLoc DL;
BuildMI(MBB, MI, DL, get(Mips::NOP));
}
void MipsInstrInfo::
copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const {
unsigned Opc = 0, ZeroReg = 0;
if (Mips::CPURegsRegClass.contains(DestReg)) { // Copy to CPU Reg.
if (Mips::CPURegsRegClass.contains(SrcReg))
Opc = Mips::ADDu, ZeroReg = Mips::ZERO;
else if (Mips::CCRRegClass.contains(SrcReg))
Opc = Mips::CFC1;
else if (Mips::FGR32RegClass.contains(SrcReg))
Opc = Mips::MFC1;
else if (SrcReg == Mips::HI)
Opc = Mips::MFHI, SrcReg = 0;
else if (SrcReg == Mips::LO)
Opc = Mips::MFLO, SrcReg = 0;
}
else if (Mips::CPURegsRegClass.contains(SrcReg)) { // Copy from CPU Reg.
if (Mips::CCRRegClass.contains(DestReg))
Opc = Mips::CTC1;
else if (Mips::FGR32RegClass.contains(DestReg))
Opc = Mips::MTC1;
else if (DestReg == Mips::HI)
Opc = Mips::MTHI, DestReg = 0;
else if (DestReg == Mips::LO)
Opc = Mips::MTLO, DestReg = 0;
}
else if (Mips::FGR32RegClass.contains(DestReg, SrcReg))
Opc = Mips::FMOV_S;
else if (Mips::AFGR64RegClass.contains(DestReg, SrcReg))
Opc = Mips::FMOV_D32;
else if (Mips::FGR64RegClass.contains(DestReg, SrcReg))
Opc = Mips::FMOV_D64;
else if (Mips::CCRRegClass.contains(DestReg, SrcReg))
Opc = Mips::MOVCCRToCCR;
else if (Mips::CPU64RegsRegClass.contains(DestReg)) { // Copy to CPU64 Reg.
if (Mips::CPU64RegsRegClass.contains(SrcReg))
Opc = Mips::DADDu, ZeroReg = Mips::ZERO_64;
else if (SrcReg == Mips::HI64)
Opc = Mips::MFHI64, SrcReg = 0;
else if (SrcReg == Mips::LO64)
Opc = Mips::MFLO64, SrcReg = 0;
else if (Mips::FGR64RegClass.contains(SrcReg))
Opc = Mips::DMFC1;
}
else if (Mips::CPU64RegsRegClass.contains(SrcReg)) { // Copy from CPU64 Reg.
if (DestReg == Mips::HI64)
Opc = Mips::MTHI64, DestReg = 0;
else if (DestReg == Mips::LO64)
Opc = Mips::MTLO64, DestReg = 0;
else if (Mips::FGR64RegClass.contains(DestReg))
Opc = Mips::DMTC1;
}
assert(Opc && "Cannot copy registers");
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc));
if (DestReg)
MIB.addReg(DestReg, RegState::Define);
if (ZeroReg)
MIB.addReg(ZeroReg);
if (SrcReg)
MIB.addReg(SrcReg, getKillRegState(KillSrc));
}
static MachineMemOperand* GetMemOperand(MachineBasicBlock &MBB, int FI,
unsigned Flag) {
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
return MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FI), Flag,
MFI.getObjectSize(FI), Align);
}
void MipsInstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOStore);
unsigned Opc = 0;
if (Mips::CPURegsRegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::SW_P8 : Mips::SW;
else if (Mips::CPU64RegsRegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::SD_P8 : Mips::SD;
else if (Mips::FGR32RegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::SWC1_P8 : Mips::SWC1;
else if (Mips::AFGR64RegClass.hasSubClassEq(RC))
Opc = Mips::SDC1;
else if (Mips::FGR64RegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::SDC164_P8 : Mips::SDC164;
assert(Opc && "Register class not handled!");
BuildMI(MBB, I, DL, get(Opc)).addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0).addMemOperand(MMO);
}
void MipsInstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const
{
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineMemOperand *MMO = GetMemOperand(MBB, FI, MachineMemOperand::MOLoad);
unsigned Opc = 0;
if (Mips::CPURegsRegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::LW_P8 : Mips::LW;
else if (Mips::CPU64RegsRegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::LD_P8 : Mips::LD;
else if (Mips::FGR32RegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::LWC1_P8 : Mips::LWC1;
else if (Mips::AFGR64RegClass.hasSubClassEq(RC))
Opc = Mips::LDC1;
else if (Mips::FGR64RegClass.hasSubClassEq(RC))
Opc = IsN64 ? Mips::LDC164_P8 : Mips::LDC164;
assert(Opc && "Register class not handled!");
BuildMI(MBB, I, DL, get(Opc), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
}
void MipsInstrInfo::ExpandRetRA(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned Opc) const {
BuildMI(MBB, I, I->getDebugLoc(), TM.getInstrInfo()->get(Opc))
.addReg(Mips::RA);
}
void MipsInstrInfo::ExpandExtractElementF64(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
const TargetInstrInfo *TII = TM.getInstrInfo();
unsigned DstReg = I->getOperand(0).getReg();
unsigned SrcReg = I->getOperand(1).getReg();
unsigned N = I->getOperand(2).getImm();
const MCInstrDesc& Mfc1Tdd = TII->get(Mips::MFC1);
DebugLoc dl = I->getDebugLoc();
assert(N < 2 && "Invalid immediate");
unsigned SubIdx = N ? Mips::sub_fpodd : Mips::sub_fpeven;
unsigned SubReg = TM.getRegisterInfo()->getSubReg(SrcReg, SubIdx);
BuildMI(MBB, I, dl, Mfc1Tdd, DstReg).addReg(SubReg);
}
void MipsInstrInfo::ExpandBuildPairF64(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
const TargetInstrInfo *TII = TM.getInstrInfo();
unsigned DstReg = I->getOperand(0).getReg();
unsigned LoReg = I->getOperand(1).getReg(), HiReg = I->getOperand(2).getReg();
const MCInstrDesc& Mtc1Tdd = TII->get(Mips::MTC1);
DebugLoc dl = I->getDebugLoc();
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
// mtc1 Lo, $fp
// mtc1 Hi, $fp + 1
BuildMI(MBB, I, dl, Mtc1Tdd, TRI->getSubReg(DstReg, Mips::sub_fpeven))
.addReg(LoReg);
BuildMI(MBB, I, dl, Mtc1Tdd, TRI->getSubReg(DstReg, Mips::sub_fpodd))
.addReg(HiReg);
}
bool MipsInstrInfo::expandPostRAPseudo(MachineBasicBlock::iterator MI) const {
MachineBasicBlock &MBB = *MI->getParent();
switch(MI->getDesc().getOpcode()) {
default:
return false;
case Mips::RetRA:
ExpandRetRA(MBB, MI, Mips::RET);
break;
case Mips::RetRA16:
ExpandRetRA(MBB, MI, Mips::RET16);
break;
case Mips::BuildPairF64:
ExpandBuildPairF64(MBB, MI);
break;
case Mips::ExtractElementF64:
ExpandExtractElementF64(MBB, MI);
break;
}
MBB.erase(MI);
return true;
}
MachineInstr*
MipsInstrInfo::emitFrameIndexDebugValue(MachineFunction &MF, int FrameIx,
uint64_t Offset, const MDNode *MDPtr,
DebugLoc DL) const {
MachineInstrBuilder MIB = BuildMI(MF, DL, get(Mips::DBG_VALUE))
.addFrameIndex(FrameIx).addImm(0).addImm(Offset).addMetadata(MDPtr);
return &*MIB;
}
//===----------------------------------------------------------------------===//
// Branch Analysis
//===----------------------------------------------------------------------===//
static unsigned GetAnalyzableBrOpc(unsigned Opc) {
return (Opc == Mips::BEQ || Opc == Mips::BNE || Opc == Mips::BGTZ ||
Opc == Mips::BGEZ || Opc == Mips::BLTZ || Opc == Mips::BLEZ ||
Opc == Mips::BEQ64 || Opc == Mips::BNE64 || Opc == Mips::BGTZ64 ||
Opc == Mips::BGEZ64 || Opc == Mips::BLTZ64 || Opc == Mips::BLEZ64 ||
Opc == Mips::BC1T || Opc == Mips::BC1F || Opc == Mips::B ||
Opc == Mips::J) ?
Opc : 0;
}
/// GetOppositeBranchOpc - Return the inverse of the specified
/// opcode, e.g. turning BEQ to BNE.
unsigned Mips::GetOppositeBranchOpc(unsigned Opc)
{
switch (Opc) {
default: llvm_unreachable("Illegal opcode!");
case Mips::BEQ: return Mips::BNE;
case Mips::BNE: return Mips::BEQ;
case Mips::BGTZ: return Mips::BLEZ;
case Mips::BGEZ: return Mips::BLTZ;
case Mips::BLTZ: return Mips::BGEZ;
case Mips::BLEZ: return Mips::BGTZ;
case Mips::BEQ64: return Mips::BNE64;
case Mips::BNE64: return Mips::BEQ64;
case Mips::BGTZ64: return Mips::BLEZ64;
case Mips::BGEZ64: return Mips::BLTZ64;
case Mips::BLTZ64: return Mips::BGEZ64;
case Mips::BLEZ64: return Mips::BGTZ64;
case Mips::BC1T: return Mips::BC1F;
case Mips::BC1F: return Mips::BC1T;
}
}
static void AnalyzeCondBr(const MachineInstr *Inst, unsigned Opc,
MachineBasicBlock *&BB,
SmallVectorImpl<MachineOperand> &Cond) {
assert(GetAnalyzableBrOpc(Opc) && "Not an analyzable branch");
int NumOp = Inst->getNumExplicitOperands();
// for both int and fp branches, the last explicit operand is the
// MBB.
BB = Inst->getOperand(NumOp-1).getMBB();
Cond.push_back(MachineOperand::CreateImm(Opc));
for (int i=0; i<NumOp-1; i++)
Cond.push_back(Inst->getOperand(i));
}
bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const
{
MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
// Skip all the debug instructions.
while (I != REnd && I->isDebugValue())
++I;
if (I == REnd || !isUnpredicatedTerminator(&*I)) {
// If this block ends with no branches (it just falls through to its succ)
// just return false, leaving TBB/FBB null.
TBB = FBB = NULL;
return false;
}
MachineInstr *LastInst = &*I;
unsigned LastOpc = LastInst->getOpcode();
// Not an analyzable branch (must be an indirect jump).
if (!GetAnalyzableBrOpc(LastOpc))
return true;
// Get the second to last instruction in the block.
unsigned SecondLastOpc = 0;
MachineInstr *SecondLastInst = NULL;
if (++I != REnd) {
SecondLastInst = &*I;
SecondLastOpc = GetAnalyzableBrOpc(SecondLastInst->getOpcode());
// Not an analyzable branch (must be an indirect jump).
if (isUnpredicatedTerminator(SecondLastInst) && !SecondLastOpc)
return true;
}
// If there is only one terminator instruction, process it.
if (!SecondLastOpc) {
// Unconditional branch
if (LastOpc == UncondBrOpc) {
TBB = LastInst->getOperand(0).getMBB();
return false;
}
// Conditional branch
AnalyzeCondBr(LastInst, LastOpc, TBB, Cond);
return false;
}
// If we reached here, there are two branches.
// If there are three terminators, we don't know what sort of block this is.
if (++I != REnd && isUnpredicatedTerminator(&*I))
return true;
// If second to last instruction is an unconditional branch,
// analyze it and remove the last instruction.
if (SecondLastOpc == UncondBrOpc) {
// Return if the last instruction cannot be removed.
if (!AllowModify)
return true;
TBB = SecondLastInst->getOperand(0).getMBB();
LastInst->eraseFromParent();
return false;
}
// Conditional branch followed by an unconditional branch.
// The last one must be unconditional.
if (LastOpc != UncondBrOpc)
return true;
AnalyzeCondBr(SecondLastInst, SecondLastOpc, TBB, Cond);
FBB = LastInst->getOperand(0).getMBB();
return false;
}
void MipsInstrInfo::BuildCondBr(MachineBasicBlock &MBB,
MachineBasicBlock *TBB, DebugLoc DL,
const SmallVectorImpl<MachineOperand>& Cond)
const {
unsigned Opc = Cond[0].getImm();
const MCInstrDesc &MCID = get(Opc);
MachineInstrBuilder MIB = BuildMI(&MBB, DL, MCID);
for (unsigned i = 1; i < Cond.size(); ++i)
MIB.addReg(Cond[i].getReg());
MIB.addMBB(TBB);
}
unsigned MipsInstrInfo::
InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL) const {
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
// # of condition operands:
// Unconditional branches: 0
// Floating point branches: 1 (opc)
// Int BranchZero: 2 (opc, reg)
// Int Branch: 3 (opc, reg0, reg1)
assert((Cond.size() <= 3) &&
"# of Mips branch conditions must be <= 3!");
// Two-way Conditional branch.
if (FBB) {
BuildCondBr(MBB, TBB, DL, Cond);
BuildMI(&MBB, DL, get(UncondBrOpc)).addMBB(FBB);
return 2;
}
// One way branch.
// Unconditional branch.
if (Cond.empty())
BuildMI(&MBB, DL, get(UncondBrOpc)).addMBB(TBB);
else // Conditional branch.
BuildCondBr(MBB, TBB, DL, Cond);
return 1;
}
unsigned MipsInstrInfo::
RemoveBranch(MachineBasicBlock &MBB) const
{
MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
MachineBasicBlock::reverse_iterator FirstBr;
unsigned removed;
// Skip all the debug instructions.
while (I != REnd && I->isDebugValue())
++I;
FirstBr = I;
// Up to 2 branches are removed.
// Note that indirect branches are not removed.
for(removed = 0; I != REnd && removed < 2; ++I, ++removed)
if (!GetAnalyzableBrOpc(I->getOpcode()))
break;
MBB.erase(I.base(), FirstBr.base());
return removed;
}
/// ReverseBranchCondition - Return the inverse opcode of the
/// specified Branch instruction.
bool MipsInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
{
assert( (Cond.size() && Cond.size() <= 3) &&
"Invalid Mips branch condition!");
Cond[0].setImm(Mips::GetOppositeBranchOpc(Cond[0].getImm()));
return false;
}
/// Return the number of bytes of code the specified instruction may be.
unsigned MipsInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
switch (MI->getOpcode()) {
default:
return MI->getDesc().getSize();
case TargetOpcode::INLINEASM: { // Inline Asm: Variable size.
const MachineFunction *MF = MI->getParent()->getParent();
const char *AsmStr = MI->getOperand(0).getSymbolName();
return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
}
}
}
unsigned
llvm::Mips::loadImmediate(int64_t Imm, bool IsN64, const TargetInstrInfo &TII,
MachineBasicBlock& MBB,
MachineBasicBlock::iterator II, DebugLoc DL,
bool LastInstrIsADDiu,
MipsAnalyzeImmediate::Inst *LastInst) {
MipsAnalyzeImmediate AnalyzeImm;
unsigned Size = IsN64 ? 64 : 32;
unsigned LUi = IsN64 ? Mips::LUi64 : Mips::LUi;
unsigned ZEROReg = IsN64 ? Mips::ZERO_64 : Mips::ZERO;
unsigned ATReg = IsN64 ? Mips::AT_64 : Mips::AT;
const MipsAnalyzeImmediate::InstSeq &Seq =
AnalyzeImm.Analyze(Imm, Size, LastInstrIsADDiu);
MipsAnalyzeImmediate::InstSeq::const_iterator Inst = Seq.begin();
if (LastInst && (Seq.size() == 1)) {
*LastInst = *Inst;
return 0;
}
// The first instruction can be a LUi, which is different from other
// instructions (ADDiu, ORI and SLL) in that it does not have a register
// operand.
if (Inst->Opc == LUi)
BuildMI(MBB, II, DL, TII.get(LUi), ATReg)
.addImm(SignExtend64<16>(Inst->ImmOpnd));
else
BuildMI(MBB, II, DL, TII.get(Inst->Opc), ATReg).addReg(ZEROReg)
.addImm(SignExtend64<16>(Inst->ImmOpnd));
// Build the remaining instructions in Seq. Skip the last instruction if
// LastInst is not 0.
for (++Inst; Inst != Seq.end() - !!LastInst; ++Inst)
BuildMI(MBB, II, DL, TII.get(Inst->Opc), ATReg).addReg(ATReg)
.addImm(SignExtend64<16>(Inst->ImmOpnd));
if (LastInst)
*LastInst = *Inst;
return Seq.size() - !!LastInst;
}