llvm-6502/lib/Target/Alpha/AlphaInstrInfo.cpp
2010-04-02 20:16:16 +00:00

468 lines
16 KiB
C++

//===- AlphaInstrInfo.cpp - Alpha Instruction Information -------*- C++ -*-===//
//
// 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 Alpha implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "Alpha.h"
#include "AlphaInstrInfo.h"
#include "AlphaMachineFunctionInfo.h"
#include "AlphaGenInstrInfo.inc"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
AlphaInstrInfo::AlphaInstrInfo()
: TargetInstrInfoImpl(AlphaInsts, array_lengthof(AlphaInsts)),
RI(*this) { }
bool AlphaInstrInfo::isMoveInstr(const MachineInstr& MI,
unsigned& sourceReg, unsigned& destReg,
unsigned& SrcSR, unsigned& DstSR) const {
unsigned oc = MI.getOpcode();
if (oc == Alpha::BISr ||
oc == Alpha::CPYSS ||
oc == Alpha::CPYST ||
oc == Alpha::CPYSSt ||
oc == Alpha::CPYSTs) {
// or r1, r2, r2
// cpys(s|t) r1 r2 r2
assert(MI.getNumOperands() >= 3 &&
MI.getOperand(0).isReg() &&
MI.getOperand(1).isReg() &&
MI.getOperand(2).isReg() &&
"invalid Alpha BIS instruction!");
if (MI.getOperand(1).getReg() == MI.getOperand(2).getReg()) {
sourceReg = MI.getOperand(1).getReg();
destReg = MI.getOperand(0).getReg();
SrcSR = DstSR = 0;
return true;
}
}
return false;
}
unsigned
AlphaInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
case Alpha::LDL:
case Alpha::LDQ:
case Alpha::LDBU:
case Alpha::LDWU:
case Alpha::LDS:
case Alpha::LDT:
if (MI->getOperand(1).isFI()) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
unsigned
AlphaInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
case Alpha::STL:
case Alpha::STQ:
case Alpha::STB:
case Alpha::STW:
case Alpha::STS:
case Alpha::STT:
if (MI->getOperand(1).isFI()) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
static bool isAlphaIntCondCode(unsigned Opcode) {
switch (Opcode) {
case Alpha::BEQ:
case Alpha::BNE:
case Alpha::BGE:
case Alpha::BGT:
case Alpha::BLE:
case Alpha::BLT:
case Alpha::BLBC:
case Alpha::BLBS:
return true;
default:
return false;
}
}
unsigned AlphaInstrInfo::InsertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond) const {
// FIXME this should probably have a DebugLoc argument
DebugLoc dl;
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"Alpha branch conditions have two components!");
// One-way branch.
if (FBB == 0) {
if (Cond.empty()) // Unconditional branch
BuildMI(&MBB, dl, get(Alpha::BR)).addMBB(TBB);
else // Conditional branch
if (isAlphaIntCondCode(Cond[0].getImm()))
BuildMI(&MBB, dl, get(Alpha::COND_BRANCH_I))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
else
BuildMI(&MBB, dl, get(Alpha::COND_BRANCH_F))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
return 1;
}
// Two-way Conditional Branch.
if (isAlphaIntCondCode(Cond[0].getImm()))
BuildMI(&MBB, dl, get(Alpha::COND_BRANCH_I))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
else
BuildMI(&MBB, dl, get(Alpha::COND_BRANCH_F))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
BuildMI(&MBB, dl, get(Alpha::BR)).addMBB(FBB);
return 2;
}
bool AlphaInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *DestRC,
const TargetRegisterClass *SrcRC) const {
//cerr << "copyRegToReg " << DestReg << " <- " << SrcReg << "\n";
if (DestRC != SrcRC) {
// Not yet supported!
return false;
}
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
if (DestRC == Alpha::GPRCRegisterClass) {
BuildMI(MBB, MI, DL, get(Alpha::BISr), DestReg)
.addReg(SrcReg)
.addReg(SrcReg);
} else if (DestRC == Alpha::F4RCRegisterClass) {
BuildMI(MBB, MI, DL, get(Alpha::CPYSS), DestReg)
.addReg(SrcReg)
.addReg(SrcReg);
} else if (DestRC == Alpha::F8RCRegisterClass) {
BuildMI(MBB, MI, DL, get(Alpha::CPYST), DestReg)
.addReg(SrcReg)
.addReg(SrcReg);
} else {
// Attempt to copy register that is not GPR or FPR
return false;
}
return true;
}
void
AlphaInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC) const {
//cerr << "Trying to store " << getPrettyName(SrcReg) << " to "
// << FrameIdx << "\n";
//BuildMI(MBB, MI, Alpha::WTF, 0).addReg(SrcReg);
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
if (RC == Alpha::F4RCRegisterClass)
BuildMI(MBB, MI, DL, get(Alpha::STS))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FrameIdx).addReg(Alpha::F31);
else if (RC == Alpha::F8RCRegisterClass)
BuildMI(MBB, MI, DL, get(Alpha::STT))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FrameIdx).addReg(Alpha::F31);
else if (RC == Alpha::GPRCRegisterClass)
BuildMI(MBB, MI, DL, get(Alpha::STQ))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FrameIdx).addReg(Alpha::F31);
else
llvm_unreachable("Unhandled register class");
}
void
AlphaInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC) const {
//cerr << "Trying to load " << getPrettyName(DestReg) << " to "
// << FrameIdx << "\n";
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
if (RC == Alpha::F4RCRegisterClass)
BuildMI(MBB, MI, DL, get(Alpha::LDS), DestReg)
.addFrameIndex(FrameIdx).addReg(Alpha::F31);
else if (RC == Alpha::F8RCRegisterClass)
BuildMI(MBB, MI, DL, get(Alpha::LDT), DestReg)
.addFrameIndex(FrameIdx).addReg(Alpha::F31);
else if (RC == Alpha::GPRCRegisterClass)
BuildMI(MBB, MI, DL, get(Alpha::LDQ), DestReg)
.addFrameIndex(FrameIdx).addReg(Alpha::F31);
else
llvm_unreachable("Unhandled register class");
}
MachineInstr *AlphaInstrInfo::foldMemoryOperandImpl(MachineFunction &MF,
MachineInstr *MI,
const SmallVectorImpl<unsigned> &Ops,
int FrameIndex) const {
if (Ops.size() != 1) return NULL;
// Make sure this is a reg-reg copy.
unsigned Opc = MI->getOpcode();
MachineInstr *NewMI = NULL;
switch(Opc) {
default:
break;
case Alpha::BISr:
case Alpha::CPYSS:
case Alpha::CPYST:
if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
if (Ops[0] == 0) { // move -> store
unsigned InReg = MI->getOperand(1).getReg();
bool isKill = MI->getOperand(1).isKill();
bool isUndef = MI->getOperand(1).isUndef();
Opc = (Opc == Alpha::BISr) ? Alpha::STQ :
((Opc == Alpha::CPYSS) ? Alpha::STS : Alpha::STT);
NewMI = BuildMI(MF, MI->getDebugLoc(), get(Opc))
.addReg(InReg, getKillRegState(isKill) | getUndefRegState(isUndef))
.addFrameIndex(FrameIndex)
.addReg(Alpha::F31);
} else { // load -> move
unsigned OutReg = MI->getOperand(0).getReg();
bool isDead = MI->getOperand(0).isDead();
bool isUndef = MI->getOperand(0).isUndef();
Opc = (Opc == Alpha::BISr) ? Alpha::LDQ :
((Opc == Alpha::CPYSS) ? Alpha::LDS : Alpha::LDT);
NewMI = BuildMI(MF, MI->getDebugLoc(), get(Opc))
.addReg(OutReg, RegState::Define | getDeadRegState(isDead) |
getUndefRegState(isUndef))
.addFrameIndex(FrameIndex)
.addReg(Alpha::F31);
}
}
break;
}
return NewMI;
}
static unsigned AlphaRevCondCode(unsigned Opcode) {
switch (Opcode) {
case Alpha::BEQ: return Alpha::BNE;
case Alpha::BNE: return Alpha::BEQ;
case Alpha::BGE: return Alpha::BLT;
case Alpha::BGT: return Alpha::BLE;
case Alpha::BLE: return Alpha::BGT;
case Alpha::BLT: return Alpha::BGE;
case Alpha::BLBC: return Alpha::BLBS;
case Alpha::BLBS: return Alpha::BLBC;
case Alpha::FBEQ: return Alpha::FBNE;
case Alpha::FBNE: return Alpha::FBEQ;
case Alpha::FBGE: return Alpha::FBLT;
case Alpha::FBGT: return Alpha::FBLE;
case Alpha::FBLE: return Alpha::FBGT;
case Alpha::FBLT: return Alpha::FBGE;
default:
llvm_unreachable("Unknown opcode");
}
return 0; // Not reached
}
// Branch analysis.
bool AlphaInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin())
return false;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return false;
--I;
}
if (!isUnpredicatedTerminator(I))
return false;
// Get the last instruction in the block.
MachineInstr *LastInst = I;
// If there is only one terminator instruction, process it.
if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
if (LastInst->getOpcode() == Alpha::BR) {
TBB = LastInst->getOperand(0).getMBB();
return false;
} else if (LastInst->getOpcode() == Alpha::COND_BRANCH_I ||
LastInst->getOpcode() == Alpha::COND_BRANCH_F) {
// Block ends with fall-through condbranch.
TBB = LastInst->getOperand(2).getMBB();
Cond.push_back(LastInst->getOperand(0));
Cond.push_back(LastInst->getOperand(1));
return false;
}
// Otherwise, don't know what this is.
return true;
}
// Get the instruction before it if it's a terminator.
MachineInstr *SecondLastInst = I;
// If there are three terminators, we don't know what sort of block this is.
if (SecondLastInst && I != MBB.begin() &&
isUnpredicatedTerminator(--I))
return true;
// If the block ends with Alpha::BR and Alpha::COND_BRANCH_*, handle it.
if ((SecondLastInst->getOpcode() == Alpha::COND_BRANCH_I ||
SecondLastInst->getOpcode() == Alpha::COND_BRANCH_F) &&
LastInst->getOpcode() == Alpha::BR) {
TBB = SecondLastInst->getOperand(2).getMBB();
Cond.push_back(SecondLastInst->getOperand(0));
Cond.push_back(SecondLastInst->getOperand(1));
FBB = LastInst->getOperand(0).getMBB();
return false;
}
// If the block ends with two Alpha::BRs, handle it. The second one is not
// executed, so remove it.
if (SecondLastInst->getOpcode() == Alpha::BR &&
LastInst->getOpcode() == Alpha::BR) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// Otherwise, can't handle this.
return true;
}
unsigned AlphaInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin()) return 0;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return 0;
--I;
}
if (I->getOpcode() != Alpha::BR &&
I->getOpcode() != Alpha::COND_BRANCH_I &&
I->getOpcode() != Alpha::COND_BRANCH_F)
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (I->getOpcode() != Alpha::COND_BRANCH_I &&
I->getOpcode() != Alpha::COND_BRANCH_F)
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
void AlphaInstrInfo::insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const {
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
BuildMI(MBB, MI, DL, get(Alpha::BISr), Alpha::R31)
.addReg(Alpha::R31)
.addReg(Alpha::R31);
}
bool AlphaInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
assert(Cond.size() == 2 && "Invalid Alpha branch opcode!");
Cond[0].setImm(AlphaRevCondCode(Cond[0].getImm()));
return false;
}
/// getGlobalBaseReg - Return a virtual register initialized with the
/// the global base register value. Output instructions required to
/// initialize the register in the function entry block, if necessary.
///
unsigned AlphaInstrInfo::getGlobalBaseReg(MachineFunction *MF) const {
AlphaMachineFunctionInfo *AlphaFI = MF->getInfo<AlphaMachineFunctionInfo>();
unsigned GlobalBaseReg = AlphaFI->getGlobalBaseReg();
if (GlobalBaseReg != 0)
return GlobalBaseReg;
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
MachineRegisterInfo &RegInfo = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
GlobalBaseReg = RegInfo.createVirtualRegister(&Alpha::GPRCRegClass);
bool Ok = TII->copyRegToReg(FirstMBB, MBBI, GlobalBaseReg, Alpha::R29,
&Alpha::GPRCRegClass, &Alpha::GPRCRegClass);
assert(Ok && "Couldn't assign to global base register!");
Ok = Ok; // Silence warning when assertions are turned off.
RegInfo.addLiveIn(Alpha::R29);
AlphaFI->setGlobalBaseReg(GlobalBaseReg);
return GlobalBaseReg;
}
/// getGlobalRetAddr - Return a virtual register initialized with the
/// the global base register value. Output instructions required to
/// initialize the register in the function entry block, if necessary.
///
unsigned AlphaInstrInfo::getGlobalRetAddr(MachineFunction *MF) const {
AlphaMachineFunctionInfo *AlphaFI = MF->getInfo<AlphaMachineFunctionInfo>();
unsigned GlobalRetAddr = AlphaFI->getGlobalRetAddr();
if (GlobalRetAddr != 0)
return GlobalRetAddr;
// Insert the set of GlobalRetAddr into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
MachineRegisterInfo &RegInfo = MF->getRegInfo();
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
GlobalRetAddr = RegInfo.createVirtualRegister(&Alpha::GPRCRegClass);
bool Ok = TII->copyRegToReg(FirstMBB, MBBI, GlobalRetAddr, Alpha::R26,
&Alpha::GPRCRegClass, &Alpha::GPRCRegClass);
assert(Ok && "Couldn't assign to global return address register!");
Ok = Ok; // Silence warning when assertions are turned off.
RegInfo.addLiveIn(Alpha::R26);
AlphaFI->setGlobalRetAddr(GlobalRetAddr);
return GlobalRetAddr;
}