llvm-6502/lib/Target/Mips/MipsSEFrameLowering.cpp
Bill Wendling 99cb622041 Use pointers to the MCAsmInfo and MCRegInfo.
Someone may want to do something crazy, like replace these objects if they
change or something.

No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 07:20:20 +00:00

543 lines
19 KiB
C++

//===-- MipsSEFrameLowering.cpp - Mips32/64 Frame 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 Mips32/64 implementation of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//
#include "MipsSEFrameLowering.h"
#include "MCTargetDesc/MipsBaseInfo.h"
#include "MipsAnalyzeImmediate.h"
#include "MipsMachineFunction.h"
#include "MipsSEInstrInfo.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
namespace {
typedef MachineBasicBlock::iterator Iter;
/// Helper class to expand pseudos.
class ExpandPseudo {
public:
ExpandPseudo(MachineFunction &MF);
bool expand();
private:
bool expandInstr(MachineBasicBlock &MBB, Iter I);
void expandLoadCCond(MachineBasicBlock &MBB, Iter I);
void expandStoreCCond(MachineBasicBlock &MBB, Iter I);
void expandLoadACC(MachineBasicBlock &MBB, Iter I, unsigned RegSize);
void expandStoreACC(MachineBasicBlock &MBB, Iter I, unsigned RegSize);
bool expandCopy(MachineBasicBlock &MBB, Iter I);
bool expandCopyACC(MachineBasicBlock &MBB, Iter I, unsigned Dst,
unsigned Src, unsigned RegSize);
MachineFunction &MF;
MachineRegisterInfo &MRI;
};
}
ExpandPseudo::ExpandPseudo(MachineFunction &MF_)
: MF(MF_), MRI(MF.getRegInfo()) {}
bool ExpandPseudo::expand() {
bool Expanded = false;
for (MachineFunction::iterator BB = MF.begin(), BBEnd = MF.end();
BB != BBEnd; ++BB)
for (Iter I = BB->begin(), End = BB->end(); I != End;)
Expanded |= expandInstr(*BB, I++);
return Expanded;
}
bool ExpandPseudo::expandInstr(MachineBasicBlock &MBB, Iter I) {
switch(I->getOpcode()) {
case Mips::LOAD_CCOND_DSP:
case Mips::LOAD_CCOND_DSP_P8:
expandLoadCCond(MBB, I);
break;
case Mips::STORE_CCOND_DSP:
case Mips::STORE_CCOND_DSP_P8:
expandStoreCCond(MBB, I);
break;
case Mips::LOAD_AC64:
case Mips::LOAD_AC64_P8:
case Mips::LOAD_AC_DSP:
case Mips::LOAD_AC_DSP_P8:
expandLoadACC(MBB, I, 4);
break;
case Mips::LOAD_AC128:
case Mips::LOAD_AC128_P8:
expandLoadACC(MBB, I, 8);
break;
case Mips::STORE_AC64:
case Mips::STORE_AC64_P8:
case Mips::STORE_AC_DSP:
case Mips::STORE_AC_DSP_P8:
expandStoreACC(MBB, I, 4);
break;
case Mips::STORE_AC128:
case Mips::STORE_AC128_P8:
expandStoreACC(MBB, I, 8);
break;
case TargetOpcode::COPY:
if (!expandCopy(MBB, I))
return false;
break;
default:
return false;
}
MBB.erase(I);
return true;
}
void ExpandPseudo::expandLoadCCond(MachineBasicBlock &MBB, Iter I) {
// load $vr, FI
// copy ccond, $vr
assert(I->getOperand(0).isReg() && I->getOperand(1).isFI());
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const TargetRegisterClass *RC = RegInfo.intRegClass(4);
unsigned VR = MRI.createVirtualRegister(RC);
unsigned Dst = I->getOperand(0).getReg(), FI = I->getOperand(1).getIndex();
TII.loadRegFromStack(MBB, I, VR, FI, RC, &RegInfo, 0);
BuildMI(MBB, I, I->getDebugLoc(), TII.get(TargetOpcode::COPY), Dst)
.addReg(VR, RegState::Kill);
}
void ExpandPseudo::expandStoreCCond(MachineBasicBlock &MBB, Iter I) {
// copy $vr, ccond
// store $vr, FI
assert(I->getOperand(0).isReg() && I->getOperand(1).isFI());
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const TargetRegisterClass *RC = RegInfo.intRegClass(4);
unsigned VR = MRI.createVirtualRegister(RC);
unsigned Src = I->getOperand(0).getReg(), FI = I->getOperand(1).getIndex();
BuildMI(MBB, I, I->getDebugLoc(), TII.get(TargetOpcode::COPY), VR)
.addReg(Src, getKillRegState(I->getOperand(0).isKill()));
TII.storeRegToStack(MBB, I, VR, true, FI, RC, &RegInfo, 0);
}
void ExpandPseudo::expandLoadACC(MachineBasicBlock &MBB, Iter I,
unsigned RegSize) {
// load $vr0, FI
// copy lo, $vr0
// load $vr1, FI + 4
// copy hi, $vr1
assert(I->getOperand(0).isReg() && I->getOperand(1).isFI());
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const TargetRegisterClass *RC = RegInfo.intRegClass(RegSize);
unsigned VR0 = MRI.createVirtualRegister(RC);
unsigned VR1 = MRI.createVirtualRegister(RC);
unsigned Dst = I->getOperand(0).getReg(), FI = I->getOperand(1).getIndex();
unsigned Lo = RegInfo.getSubReg(Dst, Mips::sub_lo);
unsigned Hi = RegInfo.getSubReg(Dst, Mips::sub_hi);
DebugLoc DL = I->getDebugLoc();
const MCInstrDesc &Desc = TII.get(TargetOpcode::COPY);
TII.loadRegFromStack(MBB, I, VR0, FI, RC, &RegInfo, 0);
BuildMI(MBB, I, DL, Desc, Lo).addReg(VR0, RegState::Kill);
TII.loadRegFromStack(MBB, I, VR1, FI, RC, &RegInfo, RegSize);
BuildMI(MBB, I, DL, Desc, Hi).addReg(VR1, RegState::Kill);
}
void ExpandPseudo::expandStoreACC(MachineBasicBlock &MBB, Iter I,
unsigned RegSize) {
// copy $vr0, lo
// store $vr0, FI
// copy $vr1, hi
// store $vr1, FI + 4
assert(I->getOperand(0).isReg() && I->getOperand(1).isFI());
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const TargetRegisterClass *RC = RegInfo.intRegClass(RegSize);
unsigned VR0 = MRI.createVirtualRegister(RC);
unsigned VR1 = MRI.createVirtualRegister(RC);
unsigned Src = I->getOperand(0).getReg(), FI = I->getOperand(1).getIndex();
unsigned SrcKill = getKillRegState(I->getOperand(0).isKill());
unsigned Lo = RegInfo.getSubReg(Src, Mips::sub_lo);
unsigned Hi = RegInfo.getSubReg(Src, Mips::sub_hi);
DebugLoc DL = I->getDebugLoc();
BuildMI(MBB, I, DL, TII.get(TargetOpcode::COPY), VR0).addReg(Lo, SrcKill);
TII.storeRegToStack(MBB, I, VR0, true, FI, RC, &RegInfo, 0);
BuildMI(MBB, I, DL, TII.get(TargetOpcode::COPY), VR1).addReg(Hi, SrcKill);
TII.storeRegToStack(MBB, I, VR1, true, FI, RC, &RegInfo, RegSize);
}
bool ExpandPseudo::expandCopy(MachineBasicBlock &MBB, Iter I) {
unsigned Dst = I->getOperand(0).getReg(), Src = I->getOperand(1).getReg();
if (Mips::ACRegsDSPRegClass.contains(Dst, Src))
return expandCopyACC(MBB, I, Dst, Src, 4);
if (Mips::ACRegs128RegClass.contains(Dst, Src))
return expandCopyACC(MBB, I, Dst, Src, 8);
return false;
}
bool ExpandPseudo::expandCopyACC(MachineBasicBlock &MBB, Iter I, unsigned Dst,
unsigned Src, unsigned RegSize) {
// copy $vr0, src_lo
// copy dst_lo, $vr0
// copy $vr1, src_hi
// copy dst_hi, $vr1
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const TargetRegisterClass *RC = RegInfo.intRegClass(RegSize);
unsigned VR0 = MRI.createVirtualRegister(RC);
unsigned VR1 = MRI.createVirtualRegister(RC);
unsigned SrcKill = getKillRegState(I->getOperand(1).isKill());
unsigned DstLo = RegInfo.getSubReg(Dst, Mips::sub_lo);
unsigned DstHi = RegInfo.getSubReg(Dst, Mips::sub_hi);
unsigned SrcLo = RegInfo.getSubReg(Src, Mips::sub_lo);
unsigned SrcHi = RegInfo.getSubReg(Src, Mips::sub_hi);
DebugLoc DL = I->getDebugLoc();
BuildMI(MBB, I, DL, TII.get(TargetOpcode::COPY), VR0).addReg(SrcLo, SrcKill);
BuildMI(MBB, I, DL, TII.get(TargetOpcode::COPY), DstLo)
.addReg(VR0, RegState::Kill);
BuildMI(MBB, I, DL, TII.get(TargetOpcode::COPY), VR1).addReg(SrcHi, SrcKill);
BuildMI(MBB, I, DL, TII.get(TargetOpcode::COPY), DstHi)
.addReg(VR1, RegState::Kill);
return true;
}
unsigned MipsSEFrameLowering::ehDataReg(unsigned I) const {
static const unsigned EhDataReg[] = {
Mips::A0, Mips::A1, Mips::A2, Mips::A3
};
static const unsigned EhDataReg64[] = {
Mips::A0_64, Mips::A1_64, Mips::A2_64, Mips::A3_64
};
return STI.isABI_N64() ? EhDataReg64[I] : EhDataReg[I];
}
void MipsSEFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
// First, compute final stack size.
uint64_t StackSize = MFI->getStackSize();
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MachineLocation DstML, SrcML;
// Adjust stack.
TII.adjustStackPtr(SP, -StackSize, MBB, MBBI);
// emit ".cfi_def_cfa_offset StackSize"
MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(AdjustSPLabel, -StackSize));
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
// Find the instruction past the last instruction that saves a callee-saved
// register to the stack.
for (unsigned i = 0; i < CSI.size(); ++i)
++MBBI;
// Iterate over list of callee-saved registers and emit .cfi_offset
// directives.
MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = I->getReg();
// If Reg is a double precision register, emit two cfa_offsets,
// one for each of the paired single precision registers.
if (Mips::AFGR64RegClass.contains(Reg)) {
unsigned Reg0 =
MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_fpeven), true);
unsigned Reg1 =
MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_fpodd), true);
if (!STI.isLittle())
std::swap(Reg0, Reg1);
MMI.addFrameInst(
MCCFIInstruction::createOffset(CSLabel, Reg0, Offset));
MMI.addFrameInst(
MCCFIInstruction::createOffset(CSLabel, Reg1, Offset + 4));
} else {
// Reg is either in CPURegs or FGR32.
MMI.addFrameInst(MCCFIInstruction::createOffset(
CSLabel, MRI->getDwarfRegNum(Reg, 1), Offset));
}
}
}
if (MipsFI->callsEhReturn()) {
const TargetRegisterClass *RC = STI.isABI_N64() ?
&Mips::CPU64RegsRegClass : &Mips::CPURegsRegClass;
// Insert instructions that spill eh data registers.
for (int I = 0; I < 4; ++I) {
if (!MBB.isLiveIn(ehDataReg(I)))
MBB.addLiveIn(ehDataReg(I));
TII.storeRegToStackSlot(MBB, MBBI, ehDataReg(I), false,
MipsFI->getEhDataRegFI(I), RC, &RegInfo);
}
// Emit .cfi_offset directives for eh data registers.
MCSymbol *CSLabel2 = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel2);
for (int I = 0; I < 4; ++I) {
int64_t Offset = MFI->getObjectOffset(MipsFI->getEhDataRegFI(I));
unsigned Reg = MRI->getDwarfRegNum(ehDataReg(I), true);
MMI.addFrameInst(MCCFIInstruction::createOffset(CSLabel2, Reg, Offset));
}
}
// if framepointer enabled, set it to point to the stack pointer.
if (hasFP(MF)) {
// Insert instruction "move $fp, $sp" at this location.
BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);
// emit ".cfi_def_cfa_register $fp"
MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
SetFPLabel, MRI->getDwarfRegNum(FP, true)));
}
}
void MipsSEFrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
DebugLoc dl = MBBI->getDebugLoc();
unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
// if framepointer enabled, restore the stack pointer.
if (hasFP(MF)) {
// Find the first instruction that restores a callee-saved register.
MachineBasicBlock::iterator I = MBBI;
for (unsigned i = 0; i < MFI->getCalleeSavedInfo().size(); ++i)
--I;
// Insert instruction "move $sp, $fp" at this location.
BuildMI(MBB, I, dl, TII.get(ADDu), SP).addReg(FP).addReg(ZERO);
}
if (MipsFI->callsEhReturn()) {
const TargetRegisterClass *RC = STI.isABI_N64() ?
&Mips::CPU64RegsRegClass : &Mips::CPURegsRegClass;
// Find first instruction that restores a callee-saved register.
MachineBasicBlock::iterator I = MBBI;
for (unsigned i = 0; i < MFI->getCalleeSavedInfo().size(); ++i)
--I;
// Insert instructions that restore eh data registers.
for (int J = 0; J < 4; ++J) {
TII.loadRegFromStackSlot(MBB, I, ehDataReg(J), MipsFI->getEhDataRegFI(J),
RC, &RegInfo);
}
}
// Get the number of bytes from FrameInfo
uint64_t StackSize = MFI->getStackSize();
if (!StackSize)
return;
// Adjust stack.
TII.adjustStackPtr(SP, StackSize, MBB, MBBI);
}
bool MipsSEFrameLowering::
spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
MachineFunction *MF = MBB.getParent();
MachineBasicBlock *EntryBlock = MF->begin();
const TargetInstrInfo &TII = *MF->getTarget().getInstrInfo();
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
// Add the callee-saved register as live-in. Do not add if the register is
// RA and return address is taken, because it has already been added in
// method MipsTargetLowering::LowerRETURNADDR.
// It's killed at the spill, unless the register is RA and return address
// is taken.
unsigned Reg = CSI[i].getReg();
bool IsRAAndRetAddrIsTaken = (Reg == Mips::RA || Reg == Mips::RA_64)
&& MF->getFrameInfo()->isReturnAddressTaken();
if (!IsRAAndRetAddrIsTaken)
EntryBlock->addLiveIn(Reg);
// Insert the spill to the stack frame.
bool IsKill = !IsRAAndRetAddrIsTaken;
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
TII.storeRegToStackSlot(*EntryBlock, MI, Reg, IsKill,
CSI[i].getFrameIdx(), RC, TRI);
}
return true;
}
bool
MipsSEFrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
// Reserve call frame if the size of the maximum call frame fits into 16-bit
// immediate field and there are no variable sized objects on the stack.
// Make sure the second register scavenger spill slot can be accessed with one
// instruction.
return isInt<16>(MFI->getMaxCallFrameSize() + getStackAlignment()) &&
!MFI->hasVarSizedObjects();
}
// Eliminate ADJCALLSTACKDOWN, ADJCALLSTACKUP pseudo instructions
void MipsSEFrameLowering::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo*>(MF.getTarget().getInstrInfo());
if (!hasReservedCallFrame(MF)) {
int64_t Amount = I->getOperand(0).getImm();
if (I->getOpcode() == Mips::ADJCALLSTACKDOWN)
Amount = -Amount;
unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
TII.adjustStackPtr(SP, Amount, MBB, I);
}
MBB.erase(I);
}
void MipsSEFrameLowering::
processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS) const {
MachineRegisterInfo &MRI = MF.getRegInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
// Mark $fp as used if function has dedicated frame pointer.
if (hasFP(MF))
MRI.setPhysRegUsed(FP);
// Create spill slots for eh data registers if function calls eh_return.
if (MipsFI->callsEhReturn())
MipsFI->createEhDataRegsFI();
// Expand pseudo instructions which load, store or copy accumulators.
// Add an emergency spill slot if a pseudo was expanded.
if (ExpandPseudo(MF).expand()) {
// The spill slot should be half the size of the accumulator. If target is
// mips64, it should be 64-bit, otherwise it should be 32-bt.
const TargetRegisterClass *RC = STI.hasMips64() ?
&Mips::CPU64RegsRegClass : &Mips::CPURegsRegClass;
int FI = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
RC->getAlignment(), false);
RS->addScavengingFrameIndex(FI);
}
// Set scavenging frame index if necessary.
uint64_t MaxSPOffset = MF.getInfo<MipsFunctionInfo>()->getIncomingArgSize() +
estimateStackSize(MF);
if (isInt<16>(MaxSPOffset))
return;
const TargetRegisterClass *RC = STI.isABI_N64() ?
&Mips::CPU64RegsRegClass : &Mips::CPURegsRegClass;
int FI = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
RC->getAlignment(), false);
RS->addScavengingFrameIndex(FI);
}
const MipsFrameLowering *
llvm::createMipsSEFrameLowering(const MipsSubtarget &ST) {
return new MipsSEFrameLowering(ST);
}