llvm-6502/lib/CodeGen/TargetInstrInfoImpl.cpp
Dan Gohman 28f02fdd76 Change MachineMemOperand's alignment value to be the alignment of
the base pointer, without the offset. This matches MemSDNode's
new alignment behavior, and holds more interesting information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82473 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-21 19:47:04 +00:00

241 lines
9.0 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/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
// commuteInstruction - The default implementation of this method just exchanges
// the two operands returned by findCommutedOpIndices.
MachineInstr *TargetInstrInfoImpl::commuteInstruction(MachineInstr *MI,
bool NewMI) const {
const TargetInstrDesc &TID = MI->getDesc();
bool HasDef = TID.getNumDefs();
if (HasDef && !MI->getOperand(0).isReg())
// No idea how to commute this instruction. Target should implement its own.
return 0;
unsigned Idx1, Idx2;
if (!findCommutedOpIndices(MI, Idx1, Idx2)) {
std::string msg;
raw_string_ostream Msg(msg);
Msg << "Don't know how to commute: " << *MI;
llvm_report_error(Msg.str());
}
assert(MI->getOperand(Idx1).isReg() && MI->getOperand(Idx2).isReg() &&
"This only knows how to commute register operands so far");
unsigned Reg1 = MI->getOperand(Idx1).getReg();
unsigned Reg2 = MI->getOperand(Idx2).getReg();
bool Reg1IsKill = MI->getOperand(Idx1).isKill();
bool Reg2IsKill = MI->getOperand(Idx2).isKill();
bool ChangeReg0 = false;
if (HasDef && 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 = HasDef
? (ChangeReg0 ? Reg2 : MI->getOperand(0).getReg()) : 0;
bool Reg0IsDead = HasDef ? MI->getOperand(0).isDead() : false;
MachineFunction &MF = *MI->getParent()->getParent();
if (HasDef)
return BuildMI(MF, MI->getDebugLoc(), MI->getDesc())
.addReg(Reg0, RegState::Define | getDeadRegState(Reg0IsDead))
.addReg(Reg2, getKillRegState(Reg2IsKill))
.addReg(Reg1, getKillRegState(Reg2IsKill));
else
return BuildMI(MF, MI->getDebugLoc(), MI->getDesc())
.addReg(Reg2, getKillRegState(Reg2IsKill))
.addReg(Reg1, getKillRegState(Reg2IsKill));
}
if (ChangeReg0)
MI->getOperand(0).setReg(Reg2);
MI->getOperand(Idx2).setReg(Reg1);
MI->getOperand(Idx1).setReg(Reg2);
MI->getOperand(Idx2).setIsKill(Reg1IsKill);
MI->getOperand(Idx1).setIsKill(Reg2IsKill);
return MI;
}
/// findCommutedOpIndices - If specified MI is commutable, return the two
/// operand indices that would swap value. Return true if the instruction
/// is not in a form which this routine understands.
bool TargetInstrInfoImpl::findCommutedOpIndices(MachineInstr *MI,
unsigned &SrcOpIdx1,
unsigned &SrcOpIdx2) const {
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.isCommutable())
return false;
// This assumes v0 = op v1, v2 and commuting would swap v1 and v2. If this
// is not true, then the target must implement this.
SrcOpIdx1 = TID.getNumDefs();
SrcOpIdx2 = SrcOpIdx1 + 1;
if (!MI->getOperand(SrcOpIdx1).isReg() ||
!MI->getOperand(SrcOpIdx2).isReg())
// No idea.
return false;
return true;
}
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,
unsigned SubIdx,
const MachineInstr *Orig) const {
MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
MachineOperand &MO = MI->getOperand(0);
MO.setReg(DestReg);
MO.setSubReg(SubIdx);
MBB.insert(I, MI);
}
bool TargetInstrInfoImpl::isDeadInstruction(const MachineInstr *MI) const {
const TargetInstrDesc &TID = MI->getDesc();
if (TID.mayLoad() || TID.mayStore() || TID.isCall() || TID.isTerminator() ||
TID.isCall() || TID.isBarrier() || TID.isReturn() ||
TID.hasUnmodeledSideEffects())
return false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || !MO.getReg())
continue;
if (MO.isDef() && !MO.isDead())
return false;
if (MO.isUse() && MO.isKill())
// FIXME: We can't remove kill markers or else the scavenger will assert.
// An alternative is to add a ADD pseudo instruction to replace kill
// markers.
return false;
}
return true;
}
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,
/*Offset=*/0,
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;
}