llvm-6502/lib/Target/MSP430/MSP430InstrInfo.cpp
Dan Gohman 864e2efce2 Remove the target hook TargetInstrInfo::BlockHasNoFallThrough in favor of
MachineBasicBlock::canFallThrough(), which is target-independent and more
thorough.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90634 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-05 00:44:40 +00:00

347 lines
11 KiB
C++

//===- MSP430InstrInfo.cpp - MSP430 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 MSP430 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "MSP430.h"
#include "MSP430InstrInfo.h"
#include "MSP430MachineFunctionInfo.h"
#include "MSP430TargetMachine.h"
#include "MSP430GenInstrInfo.inc"
#include "llvm/Function.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
MSP430InstrInfo::MSP430InstrInfo(MSP430TargetMachine &tm)
: TargetInstrInfoImpl(MSP430Insts, array_lengthof(MSP430Insts)),
RI(tm, *this), TM(tm) {}
void MSP430InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC) const {
DebugLoc DL = DebugLoc::getUnknownLoc();
if (MI != MBB.end()) DL = MI->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
MachineMemOperand *MMO =
MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FrameIdx),
MachineMemOperand::MOStore, 0,
MFI.getObjectSize(FrameIdx),
MFI.getObjectAlignment(FrameIdx));
if (RC == &MSP430::GR16RegClass)
BuildMI(MBB, MI, DL, get(MSP430::MOV16mr))
.addFrameIndex(FrameIdx).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else if (RC == &MSP430::GR8RegClass)
BuildMI(MBB, MI, DL, get(MSP430::MOV8mr))
.addFrameIndex(FrameIdx).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else
llvm_unreachable("Cannot store this register to stack slot!");
}
void MSP430InstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC) const{
DebugLoc DL = DebugLoc::getUnknownLoc();
if (MI != MBB.end()) DL = MI->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
MachineMemOperand *MMO =
MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FrameIdx),
MachineMemOperand::MOLoad, 0,
MFI.getObjectSize(FrameIdx),
MFI.getObjectAlignment(FrameIdx));
if (RC == &MSP430::GR16RegClass)
BuildMI(MBB, MI, DL, get(MSP430::MOV16rm))
.addReg(DestReg).addFrameIndex(FrameIdx).addImm(0).addMemOperand(MMO);
else if (RC == &MSP430::GR8RegClass)
BuildMI(MBB, MI, DL, get(MSP430::MOV8rm))
.addReg(DestReg).addFrameIndex(FrameIdx).addImm(0).addMemOperand(MMO);
else
llvm_unreachable("Cannot store this register to stack slot!");
}
bool MSP430InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *DestRC,
const TargetRegisterClass *SrcRC) const {
DebugLoc DL = DebugLoc::getUnknownLoc();
if (I != MBB.end()) DL = I->getDebugLoc();
if (DestRC == SrcRC) {
unsigned Opc;
if (DestRC == &MSP430::GR16RegClass) {
Opc = MSP430::MOV16rr;
} else if (DestRC == &MSP430::GR8RegClass) {
Opc = MSP430::MOV8rr;
} else {
return false;
}
BuildMI(MBB, I, DL, get(Opc), DestReg).addReg(SrcReg);
return true;
}
return false;
}
bool
MSP430InstrInfo::isMoveInstr(const MachineInstr& MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SrcSubIdx, unsigned &DstSubIdx) const {
SrcSubIdx = DstSubIdx = 0; // No sub-registers yet.
switch (MI.getOpcode()) {
default:
return false;
case MSP430::MOV8rr:
case MSP430::MOV16rr:
assert(MI.getNumOperands() >= 2 &&
MI.getOperand(0).isReg() &&
MI.getOperand(1).isReg() &&
"invalid register-register move instruction");
SrcReg = MI.getOperand(1).getReg();
DstReg = MI.getOperand(0).getReg();
return true;
}
}
bool
MSP430InstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const {
if (CSI.empty())
return false;
DebugLoc DL = DebugLoc::getUnknownLoc();
if (MI != MBB.end()) DL = MI->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MSP430MachineFunctionInfo *MFI = MF.getInfo<MSP430MachineFunctionInfo>();
MFI->setCalleeSavedFrameSize(CSI.size() * 2);
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
// Add the callee-saved register as live-in. It's killed at the spill.
MBB.addLiveIn(Reg);
BuildMI(MBB, MI, DL, get(MSP430::PUSH16r))
.addReg(Reg, RegState::Kill);
}
return true;
}
bool
MSP430InstrInfo::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const {
if (CSI.empty())
return false;
DebugLoc DL = DebugLoc::getUnknownLoc();
if (MI != MBB.end()) DL = MI->getDebugLoc();
for (unsigned i = 0, e = CSI.size(); i != e; ++i)
BuildMI(MBB, MI, DL, get(MSP430::POP16r), CSI[i].getReg());
return true;
}
unsigned MSP430InstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.end();
unsigned Count = 0;
while (I != MBB.begin()) {
--I;
if (I->getOpcode() != MSP430::JMP &&
I->getOpcode() != MSP430::JCC)
break;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
++Count;
}
return Count;
}
bool MSP430InstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
assert(Cond.size() == 1 && "Invalid Xbranch condition!");
MSP430CC::CondCodes CC = static_cast<MSP430CC::CondCodes>(Cond[0].getImm());
switch (CC) {
default:
assert(0 && "Invalid branch condition!");
break;
case MSP430CC::COND_E:
CC = MSP430CC::COND_NE;
break;
case MSP430CC::COND_NE:
CC = MSP430CC::COND_E;
break;
case MSP430CC::COND_L:
CC = MSP430CC::COND_GE;
break;
case MSP430CC::COND_GE:
CC = MSP430CC::COND_L;
break;
case MSP430CC::COND_HS:
CC = MSP430CC::COND_LO;
break;
case MSP430CC::COND_LO:
CC = MSP430CC::COND_HS;
break;
}
Cond[0].setImm(CC);
return false;
}
bool MSP430InstrInfo::isUnpredicatedTerminator(const MachineInstr *MI) const {
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.isTerminator()) return false;
// Conditional branch is a special case.
if (TID.isBranch() && !TID.isBarrier())
return true;
if (!TID.isPredicable())
return true;
return !isPredicated(MI);
}
bool MSP430InstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// Start from the bottom of the block and work up, examining the
// terminator instructions.
MachineBasicBlock::iterator I = MBB.end();
while (I != MBB.begin()) {
--I;
// Working from the bottom, when we see a non-terminator
// instruction, we're done.
if (!isUnpredicatedTerminator(I))
break;
// A terminator that isn't a branch can't easily be handled
// by this analysis.
if (!I->getDesc().isBranch())
return true;
// Handle unconditional branches.
if (I->getOpcode() == MSP430::JMP) {
if (!AllowModify) {
TBB = I->getOperand(0).getMBB();
continue;
}
// If the block has any instructions after a JMP, delete them.
while (llvm::next(I) != MBB.end())
llvm::next(I)->eraseFromParent();
Cond.clear();
FBB = 0;
// Delete the JMP if it's equivalent to a fall-through.
if (MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
TBB = 0;
I->eraseFromParent();
I = MBB.end();
continue;
}
// TBB is used to indicate the unconditinal destination.
TBB = I->getOperand(0).getMBB();
continue;
}
// Handle conditional branches.
assert(I->getOpcode() == MSP430::JCC && "Invalid conditional branch");
MSP430CC::CondCodes BranchCode =
static_cast<MSP430CC::CondCodes>(I->getOperand(1).getImm());
if (BranchCode == MSP430CC::COND_INVALID)
return true; // Can't handle weird stuff.
// Working from the bottom, handle the first conditional branch.
if (Cond.empty()) {
FBB = TBB;
TBB = I->getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(BranchCode));
continue;
}
// Handle subsequent conditional branches. Only handle the case where all
// conditional branches branch to the same destination.
assert(Cond.size() == 1);
assert(TBB);
// Only handle the case where all conditional branches branch to
// the same destination.
if (TBB != I->getOperand(0).getMBB())
return true;
MSP430CC::CondCodes OldBranchCode = (MSP430CC::CondCodes)Cond[0].getImm();
// If the conditions are the same, we can leave them alone.
if (OldBranchCode == BranchCode)
continue;
return true;
}
return false;
}
unsigned
MSP430InstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond) const {
// FIXME this should probably have a DebugLoc operand
DebugLoc dl = DebugLoc::getUnknownLoc();
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 1 || Cond.size() == 0) &&
"MSP430 branch conditions have one component!");
if (Cond.empty()) {
// Unconditional branch?
assert(!FBB && "Unconditional branch with multiple successors!");
BuildMI(&MBB, dl, get(MSP430::JMP)).addMBB(TBB);
return 1;
}
// Conditional branch.
unsigned Count = 0;
BuildMI(&MBB, dl, get(MSP430::JCC)).addMBB(TBB).addImm(Cond[0].getImm());
++Count;
if (FBB) {
// Two-way Conditional branch. Insert the second branch.
BuildMI(&MBB, dl, get(MSP430::JMP)).addMBB(FBB);
++Count;
}
return Count;
}