llvm-6502/lib/CodeGen/TargetInstrInfoImpl.cpp
2008-03-31 20:40:39 +00:00

97 lines
3.5 KiB
C++

//===-- 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/CodeGen/MachineInstr.h"
using namespace llvm;
// commuteInstruction - The default implementation of this method just exchanges
// operand 1 and 2.
MachineInstr *TargetInstrInfoImpl::commuteInstruction(MachineInstr *MI) const {
assert(MI->getOperand(1).isRegister() && MI->getOperand(2).isRegister() &&
"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();
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;
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).isRegister() && MI->getOperand(2).isRegister() &&
"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 std::vector<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 = Orig->clone();
MI->getOperand(0).setReg(DestReg);
MBB.insert(I, MI);
}