freebsd-dev/lib/CodeGen/TargetInstrInfoImpl.cpp

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2009-06-02 17:52:33 +00:00
//===-- TargetInstrInfoImpl.cpp - Target 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 implements the TargetInstrInfoImpl class, it just provides default
// implementations of various methods.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
using namespace llvm;
// commuteInstruction - The default implementation of this method just exchanges
// operand 1 and 2.
MachineInstr *TargetInstrInfoImpl::commuteInstruction(MachineInstr *MI,
bool NewMI) const {
assert(MI->getOperand(1).isReg() && MI->getOperand(2).isReg() &&
"This only knows how to commute register operands so far");
unsigned Reg1 = MI->getOperand(1).getReg();
unsigned Reg2 = MI->getOperand(2).getReg();
bool Reg1IsKill = MI->getOperand(1).isKill();
bool Reg2IsKill = MI->getOperand(2).isKill();
bool ChangeReg0 = false;
if (MI->getOperand(0).getReg() == Reg1) {
// Must be two address instruction!
assert(MI->getDesc().getOperandConstraint(0, TOI::TIED_TO) &&
"Expecting a two-address instruction!");
Reg2IsKill = false;
ChangeReg0 = true;
}
if (NewMI) {
// Create a new instruction.
unsigned Reg0 = ChangeReg0 ? Reg2 : MI->getOperand(0).getReg();
bool Reg0IsDead = MI->getOperand(0).isDead();
MachineFunction &MF = *MI->getParent()->getParent();
return BuildMI(MF, MI->getDebugLoc(), MI->getDesc())
.addReg(Reg0, RegState::Define | getDeadRegState(Reg0IsDead))
.addReg(Reg2, getKillRegState(Reg2IsKill))
.addReg(Reg1, getKillRegState(Reg2IsKill));
}
if (ChangeReg0)
MI->getOperand(0).setReg(Reg2);
MI->getOperand(2).setReg(Reg1);
MI->getOperand(1).setReg(Reg2);
MI->getOperand(2).setIsKill(Reg1IsKill);
MI->getOperand(1).setIsKill(Reg2IsKill);
return MI;
}
/// CommuteChangesDestination - Return true if commuting the specified
/// instruction will also changes the destination operand. Also return the
/// current operand index of the would be new destination register by
/// reference. This can happen when the commutable instruction is also a
/// two-address instruction.
bool TargetInstrInfoImpl::CommuteChangesDestination(MachineInstr *MI,
unsigned &OpIdx) const{
assert(MI->getOperand(1).isReg() && MI->getOperand(2).isReg() &&
"This only knows how to commute register operands so far");
if (MI->getOperand(0).getReg() == MI->getOperand(1).getReg()) {
// Must be two address instruction!
assert(MI->getDesc().getOperandConstraint(0, TOI::TIED_TO) &&
"Expecting a two-address instruction!");
OpIdx = 2;
return true;
}
return false;
}
bool TargetInstrInfoImpl::PredicateInstruction(MachineInstr *MI,
const SmallVectorImpl<MachineOperand> &Pred) const {
bool MadeChange = false;
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.isPredicable())
return false;
for (unsigned j = 0, i = 0, e = MI->getNumOperands(); i != e; ++i) {
if (TID.OpInfo[i].isPredicate()) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isReg()) {
MO.setReg(Pred[j].getReg());
MadeChange = true;
} else if (MO.isImm()) {
MO.setImm(Pred[j].getImm());
MadeChange = true;
} else if (MO.isMBB()) {
MO.setMBB(Pred[j].getMBB());
MadeChange = true;
}
++j;
}
}
return MadeChange;
}
void TargetInstrInfoImpl::reMaterialize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg,
const MachineInstr *Orig) const {
MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
MI->getOperand(0).setReg(DestReg);
MBB.insert(I, MI);
}
unsigned
TargetInstrInfoImpl::GetFunctionSizeInBytes(const MachineFunction &MF) const {
unsigned FnSize = 0;
for (MachineFunction::const_iterator MBBI = MF.begin(), E = MF.end();
MBBI != E; ++MBBI) {
const MachineBasicBlock &MBB = *MBBI;
for (MachineBasicBlock::const_iterator I = MBB.begin(),E = MBB.end();
I != E; ++I)
FnSize += GetInstSizeInBytes(I);
}
return FnSize;
}
/// foldMemoryOperand - Attempt to fold a load or store of the specified stack
/// slot into the specified machine instruction for the specified operand(s).
/// If this is possible, a new instruction is returned with the specified
/// operand folded, otherwise NULL is returned. The client is responsible for
/// removing the old instruction and adding the new one in the instruction
/// stream.
MachineInstr*
TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
MachineInstr* MI,
const SmallVectorImpl<unsigned> &Ops,
int FrameIndex) const {
unsigned Flags = 0;
for (unsigned i = 0, e = Ops.size(); i != e; ++i)
if (MI->getOperand(Ops[i]).isDef())
Flags |= MachineMemOperand::MOStore;
else
Flags |= MachineMemOperand::MOLoad;
// Ask the target to do the actual folding.
MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, FrameIndex);
if (!NewMI) return 0;
assert((!(Flags & MachineMemOperand::MOStore) ||
NewMI->getDesc().mayStore()) &&
"Folded a def to a non-store!");
assert((!(Flags & MachineMemOperand::MOLoad) ||
NewMI->getDesc().mayLoad()) &&
"Folded a use to a non-load!");
const MachineFrameInfo &MFI = *MF.getFrameInfo();
assert(MFI.getObjectOffset(FrameIndex) != -1);
MachineMemOperand MMO(PseudoSourceValue::getFixedStack(FrameIndex),
Flags,
MFI.getObjectOffset(FrameIndex),
MFI.getObjectSize(FrameIndex),
MFI.getObjectAlignment(FrameIndex));
NewMI->addMemOperand(MF, MMO);
return NewMI;
}
/// foldMemoryOperand - Same as the previous version except it allows folding
/// of any load and store from / to any address, not just from a specific
/// stack slot.
MachineInstr*
TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
MachineInstr* MI,
const SmallVectorImpl<unsigned> &Ops,
MachineInstr* LoadMI) const {
assert(LoadMI->getDesc().canFoldAsLoad() && "LoadMI isn't foldable!");
#ifndef NDEBUG
for (unsigned i = 0, e = Ops.size(); i != e; ++i)
assert(MI->getOperand(Ops[i]).isUse() && "Folding load into def!");
#endif
// Ask the target to do the actual folding.
MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, LoadMI);
if (!NewMI) return 0;
// Copy the memoperands from the load to the folded instruction.
for (std::list<MachineMemOperand>::iterator I = LoadMI->memoperands_begin(),
E = LoadMI->memoperands_end(); I != E; ++I)
NewMI->addMemOperand(MF, *I);
return NewMI;
}