Mips16FrameLowering.cpp [plain text]
#include "Mips16FrameLowering.h"
#include "MCTargetDesc/MipsBaseInfo.h"
#include "Mips16InstrInfo.h"
#include "MipsInstrInfo.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/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
void Mips16FrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Mips16InstrInfo &TII =
*static_cast<const Mips16InstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
uint64_t StackSize = MFI->getStackSize();
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
MachineLocation DstML, SrcML;
TII.makeFrame(Mips::SP, StackSize, MBB, MBBI);
MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
DstML = MachineLocation(MachineLocation::VirtualFP);
SrcML = MachineLocation(MachineLocation::VirtualFP, -StackSize);
Moves.push_back(MachineMove(AdjustSPLabel, DstML, SrcML));
MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
DstML = MachineLocation(MachineLocation::VirtualFP, -8);
SrcML = MachineLocation(Mips::S1);
Moves.push_back(MachineMove(CSLabel, DstML, SrcML));
DstML = MachineLocation(MachineLocation::VirtualFP, -12);
SrcML = MachineLocation(Mips::S0);
Moves.push_back(MachineMove(CSLabel, DstML, SrcML));
DstML = MachineLocation(MachineLocation::VirtualFP, -4);
SrcML = MachineLocation(Mips::RA);
Moves.push_back(MachineMove(CSLabel, DstML, SrcML));
if (hasFP(MF))
BuildMI(MBB, MBBI, dl, TII.get(Mips::MoveR3216), Mips::S0)
.addReg(Mips::SP);
}
void Mips16FrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Mips16InstrInfo &TII =
*static_cast<const Mips16InstrInfo*>(MF.getTarget().getInstrInfo());
DebugLoc dl = MBBI->getDebugLoc();
uint64_t StackSize = MFI->getStackSize();
if (!StackSize)
return;
if (hasFP(MF))
BuildMI(MBB, MBBI, dl, TII.get(Mips::Move32R16), Mips::SP)
.addReg(Mips::S0);
TII.restoreFrame(Mips::SP, StackSize, MBB, MBBI);
}
bool Mips16FrameLowering::
spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
MachineFunction *MF = MBB.getParent();
MachineBasicBlock *EntryBlock = MF->begin();
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
bool IsRAAndRetAddrIsTaken = (Reg == Mips::RA)
&& MF->getFrameInfo()->isReturnAddressTaken();
if (!IsRAAndRetAddrIsTaken)
EntryBlock->addLiveIn(Reg);
}
return true;
}
bool Mips16FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
return true;
}
bool
Mips16FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
return isInt<15>(MFI->getMaxCallFrameSize()) && !MFI->hasVarSizedObjects();
}
void Mips16FrameLowering::
processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS) const {
MF.getRegInfo().setPhysRegUsed(Mips::RA);
MF.getRegInfo().setPhysRegUsed(Mips::S0);
MF.getRegInfo().setPhysRegUsed(Mips::S1);
}
const MipsFrameLowering *
llvm::createMips16FrameLowering(const MipsSubtarget &ST) {
return new Mips16FrameLowering(ST);
}