llvm-6502/lib/Target/Mips/MipsRegisterInfo.cpp
2011-07-07 19:13:09 +00:00

280 lines
9.9 KiB
C++

//===- MipsRegisterInfo.cpp - MIPS 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 MIPS implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mips-reg-info"
#include "Mips.h"
#include "MipsSubtarget.h"
#include "MipsRegisterInfo.h"
#include "MipsMachineFunction.h"
#include "llvm/Constants.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/CodeGen/MachineLocation.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"
#include "llvm/Analysis/DebugInfo.h"
#define GET_REGINFO_MC_DESC
#define GET_REGINFO_TARGET_DESC
#include "MipsGenRegisterInfo.inc"
using namespace llvm;
MipsRegisterInfo::MipsRegisterInfo(const MipsSubtarget &ST,
const TargetInstrInfo &tii)
: MipsGenRegisterInfo(), Subtarget(ST), TII(tii) {}
/// getRegisterNumbering - Given the enum value for some register, e.g.
/// Mips::RA, return the number that it corresponds to (e.g. 31).
unsigned MipsRegisterInfo::
getRegisterNumbering(unsigned RegEnum)
{
switch (RegEnum) {
case Mips::ZERO : case Mips::F0 : case Mips::D0 : return 0;
case Mips::AT : case Mips::F1 : return 1;
case Mips::V0 : case Mips::F2 : case Mips::D1 : return 2;
case Mips::V1 : case Mips::F3 : return 3;
case Mips::A0 : case Mips::F4 : case Mips::D2 : return 4;
case Mips::A1 : case Mips::F5 : return 5;
case Mips::A2 : case Mips::F6 : case Mips::D3 : return 6;
case Mips::A3 : case Mips::F7 : return 7;
case Mips::T0 : case Mips::F8 : case Mips::D4 : return 8;
case Mips::T1 : case Mips::F9 : return 9;
case Mips::T2 : case Mips::F10: case Mips::D5: return 10;
case Mips::T3 : case Mips::F11: return 11;
case Mips::T4 : case Mips::F12: case Mips::D6: return 12;
case Mips::T5 : case Mips::F13: return 13;
case Mips::T6 : case Mips::F14: case Mips::D7: return 14;
case Mips::T7 : case Mips::F15: return 15;
case Mips::S0 : case Mips::F16: case Mips::D8: return 16;
case Mips::S1 : case Mips::F17: return 17;
case Mips::S2 : case Mips::F18: case Mips::D9: return 18;
case Mips::S3 : case Mips::F19: return 19;
case Mips::S4 : case Mips::F20: case Mips::D10: return 20;
case Mips::S5 : case Mips::F21: return 21;
case Mips::S6 : case Mips::F22: case Mips::D11: return 22;
case Mips::S7 : case Mips::F23: return 23;
case Mips::T8 : case Mips::F24: case Mips::D12: return 24;
case Mips::T9 : case Mips::F25: return 25;
case Mips::K0 : case Mips::F26: case Mips::D13: return 26;
case Mips::K1 : case Mips::F27: return 27;
case Mips::GP : case Mips::F28: case Mips::D14: return 28;
case Mips::SP : case Mips::F29: return 29;
case Mips::FP : case Mips::F30: case Mips::D15: return 30;
case Mips::RA : case Mips::F31: return 31;
default: llvm_unreachable("Unknown register number!");
}
return 0; // Not reached
}
unsigned MipsRegisterInfo::getPICCallReg() { return Mips::T9; }
//===----------------------------------------------------------------------===//
// Callee Saved Registers methods
//===----------------------------------------------------------------------===//
/// Mips Callee Saved Registers
const unsigned* MipsRegisterInfo::
getCalleeSavedRegs(const MachineFunction *MF) const
{
// Mips callee-save register range is $16-$23, $f20-$f30
static const unsigned SingleFloatOnlyCalleeSavedRegs[] = {
Mips::F30, Mips::F29, Mips::F28, Mips::F27, Mips::F26,
Mips::F25, Mips::F24, Mips::F23, Mips::F22, Mips::F21, Mips::F20,
Mips::RA, Mips::FP, Mips::S7, Mips::S6, Mips::S5, Mips::S4,
Mips::S3, Mips::S2, Mips::S1, Mips::S0, 0
};
static const unsigned Mips32CalleeSavedRegs[] = {
Mips::D15, Mips::D14, Mips::D13, Mips::D12, Mips::D11, Mips::D10,
Mips::RA, Mips::FP, Mips::S7, Mips::S6, Mips::S5, Mips::S4,
Mips::S3, Mips::S2, Mips::S1, Mips::S0, 0
};
if (Subtarget.isSingleFloat())
return SingleFloatOnlyCalleeSavedRegs;
else
return Mips32CalleeSavedRegs;
}
BitVector MipsRegisterInfo::
getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(Mips::ZERO);
Reserved.set(Mips::AT);
Reserved.set(Mips::K0);
Reserved.set(Mips::K1);
Reserved.set(Mips::GP);
Reserved.set(Mips::SP);
Reserved.set(Mips::FP);
Reserved.set(Mips::RA);
Reserved.set(Mips::F31);
Reserved.set(Mips::D15);
// SRV4 requires that odd register can't be used.
if (!Subtarget.isSingleFloat() && !Subtarget.isMips32())
for (unsigned FReg=(Mips::F0)+1; FReg < Mips::F30; FReg+=2)
Reserved.set(FReg);
return Reserved;
}
// 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();
int stackSize = MF.getFrameInfo()->getStackSize();
int 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 = 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.
int Offset;
if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isGPFI(FrameIndex) ||
MipsFI->isDynAllocFI(FrameIndex))
Offset = spOffset;
else
Offset = spOffset + 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() && (Offset >= 0x8000 || Offset < -0x8000)) {
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = II->getDebugLoc();
int ImmHi = (((unsigned)Offset & 0xffff0000) >> 16) +
((Offset & 0x8000) != 0);
// FIXME: change this when mips goes MC".
BuildMI(MBB, II, DL, TII.get(Mips::NOAT));
BuildMI(MBB, II, DL, TII.get(Mips::LUi), Mips::AT).addImm(ImmHi);
BuildMI(MBB, II, DL, TII.get(Mips::ADDu), Mips::AT).addReg(FrameReg)
.addReg(Mips::AT);
FrameReg = Mips::AT;
Offset = (short)(Offset & 0xffff);
BuildMI(MBB, ++II, MI.getDebugLoc(), TII.get(Mips::ATMACRO));
}
MI.getOperand(i).ChangeToRegister(FrameReg, false);
MI.getOperand(i+1).ChangeToImmediate(Offset);
}
unsigned MipsRegisterInfo::
getRARegister() const {
return Mips::RA;
}
unsigned MipsRegisterInfo::
getFrameRegister(const MachineFunction &MF) const {
const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
return TFI->hasFP(MF) ? Mips::FP : Mips::SP;
}
unsigned MipsRegisterInfo::
getEHExceptionRegister() const {
llvm_unreachable("What is the exception register");
return 0;
}
unsigned MipsRegisterInfo::
getEHHandlerRegister() const {
llvm_unreachable("What is the exception handler register");
return 0;
}
int MipsRegisterInfo::
getDwarfRegNum(unsigned RegNum, bool isEH) const {
return MipsGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
}
int MipsRegisterInfo::getLLVMRegNum(unsigned DwarfRegNo, bool isEH) const {
return MipsGenRegisterInfo::getLLVMRegNumFull(DwarfRegNo,0);
}