llvm-6502/lib/Target/Mips/MipsRegisterInfo.cpp
2012-07-10 00:19:06 +00:00

267 lines
8.6 KiB
C++

//===-- MipsRegisterInfo.cpp - MIPS Register 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 MIPS implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mips-reg-info"
#include "MipsRegisterInfo.h"
#include "Mips.h"
#include "MipsAnalyzeImmediate.h"
#include "MipsInstrInfo.h"
#include "MipsSubtarget.h"
#include "MipsMachineFunction.h"
#include "llvm/Constants.h"
#include "llvm/DebugInfo.h"
#include "llvm/Type.h"
#include "llvm/Function.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#define GET_REGINFO_TARGET_DESC
#include "MipsGenRegisterInfo.inc"
using namespace llvm;
MipsRegisterInfo::MipsRegisterInfo(const MipsSubtarget &ST,
const TargetInstrInfo &tii)
: MipsGenRegisterInfo(Mips::RA), Subtarget(ST), TII(tii) {}
unsigned MipsRegisterInfo::getPICCallReg() { return Mips::T9; }
//===----------------------------------------------------------------------===//
// Callee Saved Registers methods
//===----------------------------------------------------------------------===//
/// Mips Callee Saved Registers
const uint16_t* MipsRegisterInfo::
getCalleeSavedRegs(const MachineFunction *MF) const {
if (Subtarget.isSingleFloat())
return CSR_SingleFloatOnly_SaveList;
else if (!Subtarget.hasMips64())
return CSR_O32_SaveList;
else if (Subtarget.isABI_N32())
return CSR_N32_SaveList;
assert(Subtarget.isABI_N64());
return CSR_N64_SaveList;
}
const uint32_t*
MipsRegisterInfo::getCallPreservedMask(CallingConv::ID) const {
if (Subtarget.isSingleFloat())
return CSR_SingleFloatOnly_RegMask;
else if (!Subtarget.hasMips64())
return CSR_O32_RegMask;
else if (Subtarget.isABI_N32())
return CSR_N32_RegMask;
assert(Subtarget.isABI_N64());
return CSR_N64_RegMask;
}
BitVector MipsRegisterInfo::
getReservedRegs(const MachineFunction &MF) const {
static const uint16_t ReservedCPURegs[] = {
Mips::ZERO, Mips::AT, Mips::K0, Mips::K1, Mips::SP
};
static const uint16_t ReservedCPU64Regs[] = {
Mips::ZERO_64, Mips::AT_64, Mips::K0_64, Mips::K1_64, Mips::SP_64
};
BitVector Reserved(getNumRegs());
typedef TargetRegisterClass::const_iterator RegIter;
for (unsigned I = 0; I < array_lengthof(ReservedCPURegs); ++I)
Reserved.set(ReservedCPURegs[I]);
if (Subtarget.hasMips64()) {
for (unsigned I = 0; I < array_lengthof(ReservedCPU64Regs); ++I)
Reserved.set(ReservedCPU64Regs[I]);
// Reserve all registers in AFGR64.
for (RegIter Reg = Mips::AFGR64RegClass.begin(),
EReg = Mips::AFGR64RegClass.end(); Reg != EReg; ++Reg)
Reserved.set(*Reg);
} else {
// Reserve all registers in CPU64Regs & FGR64.
for (RegIter Reg = Mips::CPU64RegsRegClass.begin(),
EReg = Mips::CPU64RegsRegClass.end(); Reg != EReg; ++Reg)
Reserved.set(*Reg);
for (RegIter Reg = Mips::FGR64RegClass.begin(),
EReg = Mips::FGR64RegClass.end(); Reg != EReg; ++Reg)
Reserved.set(*Reg);
}
// Reserve FP if this function should have a dedicated frame pointer register.
if (MF.getTarget().getFrameLowering()->hasFP(MF)) {
Reserved.set(Mips::FP);
Reserved.set(Mips::FP_64);
}
// Reserve hardware registers.
Reserved.set(Mips::HWR29);
Reserved.set(Mips::HWR29_64);
// Reserve RA if in mips16 mode.
if (Subtarget.inMips16Mode()) {
Reserved.set(Mips::RA);
Reserved.set(Mips::RA_64);
}
return Reserved;
}
bool
MipsRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
return true;
}
bool
MipsRegisterInfo::trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
return true;
}
// This function eliminate ADJCALLSTACKDOWN,
// ADJCALLSTACKUP pseudo instructions
void MipsRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
// Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
MBB.erase(I);
}
// FrameIndex represent objects inside a abstract stack.
// We must replace FrameIndex with an stack/frame pointer
// direct reference.
void MipsRegisterInfo::
eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
RegScavenger *RS) const {
MachineInstr &MI = *II;
MachineFunction &MF = *MI.getParent()->getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
unsigned i = 0;
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() &&
"Instr doesn't have FrameIndex operand!");
}
DEBUG(errs() << "\nFunction : " << MF.getFunction()->getName() << "\n";
errs() << "<--------->\n" << MI);
int FrameIndex = MI.getOperand(i).getIndex();
uint64_t stackSize = MF.getFrameInfo()->getStackSize();
int64_t spOffset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
DEBUG(errs() << "FrameIndex : " << FrameIndex << "\n"
<< "spOffset : " << spOffset << "\n"
<< "stackSize : " << stackSize << "\n");
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
int MinCSFI = 0;
int MaxCSFI = -1;
if (CSI.size()) {
MinCSFI = CSI[0].getFrameIdx();
MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
}
// The following stack frame objects are always referenced relative to $sp:
// 1. Outgoing arguments.
// 2. Pointer to dynamically allocated stack space.
// 3. Locations for callee-saved registers.
// Everything else is referenced relative to whatever register
// getFrameRegister() returns.
unsigned FrameReg;
if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isDynAllocFI(FrameIndex) ||
(FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI))
FrameReg = Subtarget.isABI_N64() ? Mips::SP_64 : Mips::SP;
else
FrameReg = getFrameRegister(MF);
// Calculate final offset.
// - There is no need to change the offset if the frame object is one of the
// following: an outgoing argument, pointer to a dynamically allocated
// stack space or a $gp restore location,
// - If the frame object is any of the following, its offset must be adjusted
// by adding the size of the stack:
// incoming argument, callee-saved register location or local variable.
int64_t Offset;
if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isDynAllocFI(FrameIndex) ||
MipsFI->isGlobalRegFI(FrameIndex))
Offset = spOffset;
else
Offset = spOffset + (int64_t)stackSize;
Offset += MI.getOperand(i+1).getImm();
DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n");
// If MI is not a debug value, make sure Offset fits in the 16-bit immediate
// field.
if (!MI.isDebugValue() && !isInt<16>(Offset)) {
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = II->getDebugLoc();
unsigned ADDu = Subtarget.isABI_N64() ? Mips::DADDu : Mips::ADDu;
unsigned ATReg = Subtarget.isABI_N64() ? Mips::AT_64 : Mips::AT;
MipsAnalyzeImmediate::Inst LastInst(0, 0);
MipsFI->setEmitNOAT();
Mips::loadImmediate(Offset, Subtarget.isABI_N64(), TII, MBB, II, DL, true,
&LastInst);
BuildMI(MBB, II, DL, TII.get(ADDu), ATReg).addReg(FrameReg).addReg(ATReg);
FrameReg = ATReg;
Offset = SignExtend64<16>(LastInst.ImmOpnd);
}
MI.getOperand(i).ChangeToRegister(FrameReg, false);
MI.getOperand(i+1).ChangeToImmediate(Offset);
}
unsigned MipsRegisterInfo::
getFrameRegister(const MachineFunction &MF) const {
const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
bool IsN64 = Subtarget.isABI_N64();
return TFI->hasFP(MF) ? (IsN64 ? Mips::FP_64 : Mips::FP) :
(IsN64 ? Mips::SP_64 : Mips::SP);
}
unsigned MipsRegisterInfo::
getEHExceptionRegister() const {
llvm_unreachable("What is the exception register");
}
unsigned MipsRegisterInfo::
getEHHandlerRegister() const {
llvm_unreachable("What is the exception handler register");
}