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llvm-6502/lib/Target/XCore/XCoreRegisterInfo.cpp
Bill Wendling 587daedce2 Change MachineInstrBuilder::addReg() to take a flag instead of a list of 
booleans. This gives a better indication of what the "addReg()" is
doing. Remembering what all of those booleans mean isn't easy, especially if you
aren't spending all of your time in that code.

I took Jakob's suggestion and made it illegal to pass in "true" for the
flag. This should hopefully prevent any unintended misuse of this (by reverting
to the old way of using addReg()).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71722 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-13 21:33:08 +00:00

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//===- XCoreRegisterInfo.cpp - XCore Register 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 XCore implementation of the MRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "XCoreRegisterInfo.h"
#include "XCoreMachineFunctionInfo.h"
#include "XCore.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Type.h"
#include "llvm/Function.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
XCoreRegisterInfo::XCoreRegisterInfo(const TargetInstrInfo &tii)
: XCoreGenRegisterInfo(XCore::ADJCALLSTACKDOWN, XCore::ADJCALLSTACKUP),
TII(tii) {
}
// helper functions
static inline bool isImmUs(unsigned val) {
return val <= 11;
}
static inline bool isImmU6(unsigned val) {
return val < (1 << 6);
}
static inline bool isImmU16(unsigned val) {
return val < (1 << 16);
}
static const unsigned XCore_ArgRegs[] = {
XCore::R0, XCore::R1, XCore::R2, XCore::R3
};
const unsigned * XCoreRegisterInfo::getArgRegs(const MachineFunction *MF)
{
return XCore_ArgRegs;
}
unsigned XCoreRegisterInfo::getNumArgRegs(const MachineFunction *MF)
{
return array_lengthof(XCore_ArgRegs);
}
bool XCoreRegisterInfo::needsFrameMoves(const MachineFunction &MF)
{
const MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
return (MMI && MMI->hasDebugInfo()) ||
!MF.getFunction()->doesNotThrow() ||
UnwindTablesMandatory;
}
const unsigned* XCoreRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF)
const {
static const unsigned CalleeSavedRegs[] = {
XCore::R4, XCore::R5, XCore::R6, XCore::R7,
XCore::R8, XCore::R9, XCore::R10, XCore::LR,
0
};
return CalleeSavedRegs;
}
const TargetRegisterClass* const*
XCoreRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
static const TargetRegisterClass * const CalleeSavedRegClasses[] = {
XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass,
XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass,
XCore::GRRegsRegisterClass, XCore::GRRegsRegisterClass,
XCore::GRRegsRegisterClass, XCore::RRegsRegisterClass,
0
};
return CalleeSavedRegClasses;
}
BitVector XCoreRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(XCore::CP);
Reserved.set(XCore::DP);
Reserved.set(XCore::SP);
Reserved.set(XCore::LR);
if (hasFP(MF)) {
Reserved.set(XCore::R10);
}
return Reserved;
}
bool
XCoreRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
// TODO can we estimate stack size?
return hasFP(MF);
}
bool XCoreRegisterInfo::hasFP(const MachineFunction &MF) const {
return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
}
// This function eliminates ADJCALLSTACKDOWN,
// ADJCALLSTACKUP pseudo instructions
void XCoreRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
if (!hasReservedCallFrame(MF)) {
// Turn the adjcallstackdown instruction into 'extsp <amt>' and the
// adjcallstackup instruction into 'ldaw sp, sp[<amt>]'
MachineInstr *Old = I;
uint64_t Amount = Old->getOperand(0).getImm();
if (Amount != 0) {
// We need to keep the stack aligned properly. To do this, we round the
// amount of space needed for the outgoing arguments up to the next
// alignment boundary.
unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
Amount = (Amount+Align-1)/Align*Align;
assert(Amount%4 == 0);
Amount /= 4;
bool isU6 = isImmU6(Amount);
if (!isU6 && !isImmU16(Amount)) {
// FIX could emit multiple instructions in this case.
cerr << "eliminateCallFramePseudoInstr size too big: "
<< Amount << "\n";
abort();
}
MachineInstr *New;
if (Old->getOpcode() == XCore::ADJCALLSTACKDOWN) {
int Opcode = isU6 ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
New=BuildMI(MF, Old->getDebugLoc(), TII.get(Opcode))
.addImm(Amount);
} else {
assert(Old->getOpcode() == XCore::ADJCALLSTACKUP);
int Opcode = isU6 ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs;
New=BuildMI(MF, Old->getDebugLoc(), TII.get(Opcode), XCore::SP)
.addImm(Amount);
}
// Replace the pseudo instruction with a new instruction...
MBB.insert(I, New);
}
}
MBB.erase(I);
}
void XCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
MachineInstr &MI = *II;
DebugLoc dl = MI.getDebugLoc();
unsigned i = 0;
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
MachineOperand &FrameOp = MI.getOperand(i);
int FrameIndex = FrameOp.getIndex();
MachineFunction &MF = *MI.getParent()->getParent();
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
int StackSize = MF.getFrameInfo()->getStackSize();
#ifndef NDEBUG
DOUT << "\nFunction : " << MF.getFunction()->getName() << "\n";
DOUT << "<--------->\n";
MI.print(DOUT);
DOUT << "FrameIndex : " << FrameIndex << "\n";
DOUT << "FrameOffset : " << Offset << "\n";
DOUT << "StackSize : " << StackSize << "\n";
#endif
Offset += StackSize;
// fold constant into offset.
Offset += MI.getOperand(i + 1).getImm();
MI.getOperand(i + 1).ChangeToImmediate(0);
assert(Offset%4 == 0 && "Misaligned stack offset");
#ifndef NDEBUG
DOUT << "Offset : " << Offset << "\n";
DOUT << "<--------->\n";
#endif
Offset/=4;
bool FP = hasFP(MF);
unsigned Reg = MI.getOperand(0).getReg();
bool isKill = MI.getOpcode() == XCore::STWFI && MI.getOperand(0).isKill();
assert(XCore::GRRegsRegisterClass->contains(Reg) &&
"Unexpected register operand");
MachineBasicBlock &MBB = *MI.getParent();
if (FP) {
bool isUs = isImmUs(Offset);
unsigned FramePtr = XCore::R10;
MachineInstr *New = 0;
if (!isUs) {
if (!RS) {
cerr << "eliminateFrameIndex Frame size too big: " << Offset << "\n";
abort();
}
unsigned ScratchReg = RS->scavengeRegister(XCore::GRRegsRegisterClass, II,
SPAdj);
loadConstant(MBB, II, ScratchReg, Offset, dl);
switch (MI.getOpcode()) {
case XCore::LDWFI:
New = BuildMI(MBB, II, dl, TII.get(XCore::LDW_3r), Reg)
.addReg(FramePtr)
.addReg(ScratchReg, RegState::Kill);
break;
case XCore::STWFI:
New = BuildMI(MBB, II, dl, TII.get(XCore::STW_3r))
.addReg(Reg, getKillRegState(isKill))
.addReg(FramePtr)
.addReg(ScratchReg, RegState::Kill);
break;
case XCore::LDAWFI:
New = BuildMI(MBB, II, dl, TII.get(XCore::LDAWF_l3r), Reg)
.addReg(FramePtr)
.addReg(ScratchReg, RegState::Kill);
break;
default:
assert(0 && "Unexpected Opcode\n");
}
} else {
switch (MI.getOpcode()) {
case XCore::LDWFI:
New = BuildMI(MBB, II, dl, TII.get(XCore::LDW_2rus), Reg)
.addReg(FramePtr)
.addImm(Offset);
break;
case XCore::STWFI:
New = BuildMI(MBB, II, dl, TII.get(XCore::STW_2rus))
.addReg(Reg, getKillRegState(isKill))
.addReg(FramePtr)
.addImm(Offset);
break;
case XCore::LDAWFI:
New = BuildMI(MBB, II, dl, TII.get(XCore::LDAWF_l2rus), Reg)
.addReg(FramePtr)
.addImm(Offset);
break;
default:
assert(0 && "Unexpected Opcode\n");
}
}
} else {
bool isU6 = isImmU6(Offset);
if (!isU6 && !isImmU16(Offset)) {
// FIXME could make this work for LDWSP, LDAWSP.
cerr << "eliminateFrameIndex Frame size too big: " << Offset << "\n";
abort();
}
switch (MI.getOpcode()) {
int NewOpcode;
case XCore::LDWFI:
NewOpcode = (isU6) ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
BuildMI(MBB, II, dl, TII.get(NewOpcode), Reg)
.addImm(Offset);
break;
case XCore::STWFI:
NewOpcode = (isU6) ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
BuildMI(MBB, II, dl, TII.get(NewOpcode))
.addReg(Reg, getKillRegState(isKill))
.addImm(Offset);
break;
case XCore::LDAWFI:
NewOpcode = (isU6) ? XCore::LDAWSP_ru6 : XCore::LDAWSP_lru6;
BuildMI(MBB, II, dl, TII.get(NewOpcode), Reg)
.addImm(Offset);
break;
default:
assert(0 && "Unexpected Opcode\n");
}
}
// Erase old instruction.
MBB.erase(II);
}
void
XCoreRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
bool LRUsed = MF.getRegInfo().isPhysRegUsed(XCore::LR);
const TargetRegisterClass *RC = XCore::GRRegsRegisterClass;
XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
if (LRUsed) {
MF.getRegInfo().setPhysRegUnused(XCore::LR);
bool isVarArg = MF.getFunction()->isVarArg();
int FrameIdx;
if (! isVarArg) {
// A fixed offset of 0 allows us to save / restore LR using entsp / retsp.
FrameIdx = MFI->CreateFixedObject(RC->getSize(), 0);
} else {
FrameIdx = MFI->CreateStackObject(RC->getSize(), RC->getAlignment());
}
XFI->setUsesLR(FrameIdx);
XFI->setLRSpillSlot(FrameIdx);
}
if (requiresRegisterScavenging(MF)) {
// Reserve a slot close to SP or frame pointer.
RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
RC->getAlignment()));
}
if (hasFP(MF)) {
// A callee save register is used to hold the FP.
// This needs saving / restoring in the epilogue / prologue.
XFI->setFPSpillSlot(MFI->CreateStackObject(RC->getSize(),
RC->getAlignment()));
}
}
void XCoreRegisterInfo::
processFunctionBeforeFrameFinalized(MachineFunction &MF) const {
}
void XCoreRegisterInfo::
loadConstant(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DstReg, int64_t Value, DebugLoc dl) const {
// TODO use mkmsk if possible.
if (!isImmU16(Value)) {
// TODO use constant pool.
cerr << "loadConstant value too big " << Value << "\n";
abort();
}
int Opcode = isImmU6(Value) ? XCore::LDC_ru6 : XCore::LDC_lru6;
BuildMI(MBB, I, dl, TII.get(Opcode), DstReg).addImm(Value);
}
void XCoreRegisterInfo::
storeToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, int Offset, DebugLoc dl) const {
assert(Offset%4 == 0 && "Misaligned stack offset");
Offset/=4;
bool isU6 = isImmU6(Offset);
if (!isU6 && !isImmU16(Offset)) {
cerr << "storeToStack offset too big " << Offset << "\n";
abort();
}
int Opcode = isU6 ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
BuildMI(MBB, I, dl, TII.get(Opcode))
.addReg(SrcReg)
.addImm(Offset);
}
void XCoreRegisterInfo::
loadFromStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DstReg, int Offset, DebugLoc dl) const {
assert(Offset%4 == 0 && "Misaligned stack offset");
Offset/=4;
bool isU6 = isImmU6(Offset);
if (!isU6 && !isImmU16(Offset)) {
cerr << "loadFromStack offset too big " << Offset << "\n";
abort();
}
int Opcode = isU6 ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
BuildMI(MBB, I, dl, TII.get(Opcode), DstReg)
.addImm(Offset);
}
void XCoreRegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
DebugLoc dl = (MBBI != MBB.end() ?
MBBI->getDebugLoc() : DebugLoc::getUnknownLoc());
bool FP = hasFP(MF);
// Work out frame sizes.
int FrameSize = MFI->getStackSize();
assert(FrameSize%4 == 0 && "Misaligned frame size");
FrameSize/=4;
bool isU6 = isImmU6(FrameSize);
if (!isU6 && !isImmU16(FrameSize)) {
// FIXME could emit multiple instructions.
cerr << "emitPrologue Frame size too big: " << FrameSize << "\n";
abort();
}
bool emitFrameMoves = needsFrameMoves(MF);
// Do we need to allocate space on the stack?
if (FrameSize) {
bool saveLR = XFI->getUsesLR();
bool LRSavedOnEntry = false;
int Opcode;
if (saveLR && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0)) {
Opcode = (isU6) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
MBB.addLiveIn(XCore::LR);
saveLR = false;
LRSavedOnEntry = true;
} else {
Opcode = (isU6) ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
}
BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);
if (emitFrameMoves) {
std::vector<MachineMove> &Moves = MMI->getFrameMoves();
// Show update of SP.
unsigned FrameLabelId = MMI->NextLabelID();
BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(FrameLabelId);
MachineLocation SPDst(MachineLocation::VirtualFP);
MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize * 4);
Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
if (LRSavedOnEntry) {
MachineLocation CSDst(MachineLocation::VirtualFP, 0);
MachineLocation CSSrc(XCore::LR);
Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc));
}
}
if (saveLR) {
int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
storeToStack(MBB, MBBI, XCore::LR, LRSpillOffset + FrameSize*4, dl);
MBB.addLiveIn(XCore::LR);
if (emitFrameMoves) {
unsigned SaveLRLabelId = MMI->NextLabelID();
BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(SaveLRLabelId);
MachineLocation CSDst(MachineLocation::VirtualFP, LRSpillOffset);
MachineLocation CSSrc(XCore::LR);
MMI->getFrameMoves().push_back(MachineMove(SaveLRLabelId,
CSDst, CSSrc));
}
}
}
if (FP) {
// Save R10 to the stack.
int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
storeToStack(MBB, MBBI, XCore::R10, FPSpillOffset + FrameSize*4, dl);
// R10 is live-in. It is killed at the spill.
MBB.addLiveIn(XCore::R10);
if (emitFrameMoves) {
unsigned SaveR10LabelId = MMI->NextLabelID();
BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(SaveR10LabelId);
MachineLocation CSDst(MachineLocation::VirtualFP, FPSpillOffset);
MachineLocation CSSrc(XCore::R10);
MMI->getFrameMoves().push_back(MachineMove(SaveR10LabelId,
CSDst, CSSrc));
}
// Set the FP from the SP.
unsigned FramePtr = XCore::R10;
BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr)
.addImm(0);
if (emitFrameMoves) {
// Show FP is now valid.
unsigned FrameLabelId = MMI->NextLabelID();
BuildMI(MBB, MBBI, dl, TII.get(XCore::DBG_LABEL)).addImm(FrameLabelId);
MachineLocation SPDst(FramePtr);
MachineLocation SPSrc(MachineLocation::VirtualFP);
MMI->getFrameMoves().push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
}
}
if (emitFrameMoves) {
// Frame moves for callee saved.
std::vector<MachineMove> &Moves = MMI->getFrameMoves();
std::vector<std::pair<unsigned, CalleeSavedInfo> >&SpillLabels =
XFI->getSpillLabels();
for (unsigned I = 0, E = SpillLabels.size(); I != E; ++I) {
unsigned SpillLabel = SpillLabels[I].first;
CalleeSavedInfo &CSI = SpillLabels[I].second;
int Offset = MFI->getObjectOffset(CSI.getFrameIdx());
unsigned Reg = CSI.getReg();
MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
MachineLocation CSSrc(Reg);
Moves.push_back(MachineMove(SpillLabel, CSDst, CSSrc));
}
}
}
void XCoreRegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineBasicBlock::iterator MBBI = prior(MBB.end());
DebugLoc dl = MBBI->getDebugLoc();
bool FP = hasFP(MF);
if (FP) {
// Restore the stack pointer.
unsigned FramePtr = XCore::R10;
BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r))
.addReg(FramePtr);
}
// Work out frame sizes.
int FrameSize = MFI->getStackSize();
assert(FrameSize%4 == 0 && "Misaligned frame size");
FrameSize/=4;
bool isU6 = isImmU6(FrameSize);
if (!isU6 && !isImmU16(FrameSize)) {
// FIXME could emit multiple instructions.
cerr << "emitEpilogue Frame size too big: " << FrameSize << "\n";
abort();
}
if (FrameSize) {
XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
if (FP) {
// Restore R10
int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
FPSpillOffset += FrameSize*4;
loadFromStack(MBB, MBBI, XCore::R10, FPSpillOffset, dl);
}
bool restoreLR = XFI->getUsesLR();
if (restoreLR && MFI->getObjectOffset(XFI->getLRSpillSlot()) != 0) {
int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
LRSpillOffset += FrameSize*4;
loadFromStack(MBB, MBBI, XCore::LR, LRSpillOffset, dl);
restoreLR = false;
}
if (restoreLR) {
// Fold prologue into return instruction
assert(MBBI->getOpcode() == XCore::RETSP_u6
|| MBBI->getOpcode() == XCore::RETSP_lu6);
int Opcode = (isU6) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);
MBB.erase(MBBI);
} else {
int Opcode = (isU6) ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs;
BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(FrameSize);
}
}
}
int XCoreRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
return XCoreGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
}
unsigned XCoreRegisterInfo::getFrameRegister(MachineFunction &MF) const {
bool FP = hasFP(MF);
return FP ? XCore::R10 : XCore::SP;
}
unsigned XCoreRegisterInfo::getRARegister() const {
return XCore::LR;
}
void XCoreRegisterInfo::getInitialFrameState(std::vector<MachineMove> &Moves)
const {
// Initial state of the frame pointer is SP.
MachineLocation Dst(MachineLocation::VirtualFP);
MachineLocation Src(XCore::SP, 0);
Moves.push_back(MachineMove(0, Dst, Src));
}
#include "XCoreGenRegisterInfo.inc"
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