llvm-6502/lib/Target/PowerPC/PowerPCRegisterInfo.cpp
2004-08-10 22:47:03 +00:00

279 lines
9.8 KiB
C++

//===- PowerPCRegisterInfo.cpp - PowerPC Register Information ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the MRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "reginfo"
#include "PowerPC.h"
#include "PowerPCRegisterInfo.h"
#include "PowerPCInstrBuilder.h"
#include "llvm/Constants.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "Support/CommandLine.h"
#include "Support/Debug.h"
#include "Support/STLExtras.h"
#include <iostream>
using namespace llvm;
PowerPCRegisterInfo::PowerPCRegisterInfo()
: PowerPCGenRegisterInfo(PPC::ADJCALLSTACKDOWN,
PPC::ADJCALLSTACKUP) {}
static unsigned getIdx(const TargetRegisterClass *RC) {
if (RC == PowerPC::GPRCRegisterClass) {
switch (RC->getSize()) {
default: assert(0 && "Invalid data size!");
case 1: return 0;
case 2: return 1;
case 4: return 2;
}
} else if (RC == PowerPC::FPRCRegisterClass) {
switch (RC->getSize()) {
default: assert(0 && "Invalid data size!");
case 4: return 3;
case 8: return 4;
}
}
std::cerr << "Invalid register class to getIdx()!\n";
abort();
}
int
PowerPCRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, int FrameIdx,
const TargetRegisterClass *RC) const {
static const unsigned Opcode[] = {
PPC::STB, PPC::STH, PPC::STW, PPC::STFS, PPC::STFD
};
unsigned OC = Opcode[getIdx(RC)];
if (SrcReg == PPC::LR) {
MBB.insert(MI, BuildMI(PPC::MFLR, 0, PPC::R0));
MBB.insert(MI, addFrameReference(BuildMI(OC,3).addReg(PPC::R0),FrameIdx));
return 2;
} else {
MBB.insert(MI, addFrameReference(BuildMI(OC, 3).addReg(SrcReg),FrameIdx));
return 1;
}
}
int
PowerPCRegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC) const {
static const unsigned Opcode[] = {
PPC::LBZ, PPC::LHZ, PPC::LWZ, PPC::LFS, PPC::LFD
};
unsigned OC = Opcode[getIdx(RC)];
if (DestReg == PPC::LR) {
MBB.insert(MI, addFrameReference(BuildMI(OC, 2, PPC::R0), FrameIdx));
MBB.insert(MI, BuildMI(PPC::MTLR, 1).addReg(PPC::R0));
return 2;
} else {
MBB.insert(MI, addFrameReference(BuildMI(OC, 2, DestReg), FrameIdx));
return 1;
}
}
int PowerPCRegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *RC) const {
MachineInstr *I;
if (RC == PowerPC::GPRCRegisterClass) {
I = BuildMI(PPC::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else if (RC == PowerPC::FPRCRegisterClass) {
I = BuildMI(PPC::FMR, 1, DestReg).addReg(SrcReg);
} else {
std::cerr << "Attempt to copy register that is not GPR or FPR";
abort();
}
MBB.insert(MI, I);
return 1;
}
//===----------------------------------------------------------------------===//
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
// hasFP - Return true if the specified function should have a dedicated frame
// pointer register. This is true if the function has variable sized allocas or
// if frame pointer elimination is disabled.
//
static bool hasFP(MachineFunction &MF) {
return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
}
void PowerPCRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
if (hasFP(MF)) {
// If we have a frame pointer, convert as follows:
// ADJCALLSTACKDOWN -> addi, r1, r1, -amount
// ADJCALLSTACKUP -> addi, r1, r1, amount
MachineInstr *Old = I;
unsigned Amount = Old->getOperand(0).getImmedValue();
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;
MachineInstr *New;
if (Old->getOpcode() == PPC::ADJCALLSTACKDOWN) {
New = BuildMI(PPC::ADDI, 2, PPC::R1).addReg(PPC::R1)
.addSImm(-Amount);
} else {
assert(Old->getOpcode() == PPC::ADJCALLSTACKUP);
New = BuildMI(PPC::ADDI, 2, PPC::R1).addReg(PPC::R1)
.addSImm(Amount);
}
// Replace the pseudo instruction with a new instruction...
MBB.insert(I, New);
}
}
MBB.erase(I);
}
void
PowerPCRegisterInfo::eliminateFrameIndex(MachineFunction &MF,
MachineBasicBlock::iterator II) const {
unsigned i = 0;
MachineInstr &MI = *II;
while (!MI.getOperand(i).isFrameIndex()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
int FrameIndex = MI.getOperand(i).getFrameIndex();
// Replace the FrameIndex with base register with GPR1.
MI.SetMachineOperandReg(i, PPC::R1);
// Take into account whether it's an add or mem instruction
unsigned OffIdx = (i == 2) ? 1 : 2;
// Now add the frame object offset to the offset from r1.
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
MI.getOperand(OffIdx).getImmedValue();
// Fixed offsets have a negative frame index. Fixed negative offests denote
// spilled callee save regs. Fixed positive offset is the va_start offset,
// and needs to be added to the amount we decremented the stack pointer.
// Positive frame indices are regular offsets from the stack pointer, and
// also need the stack size added.
if (FrameIndex >= 0 || (FrameIndex < 0 && Offset >= 24))
Offset += MF.getFrameInfo()->getStackSize();
MI.SetMachineOperandConst(OffIdx,MachineOperand::MO_SignExtendedImmed,Offset);
}
void PowerPCRegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineInstr *MI;
// Get the number of bytes to allocate from the FrameInfo
unsigned NumBytes = MFI->getStackSize();
// If we have calls, we cannot use the red zone to store callee save registers
// and we must set up a stack frame, so calculate the necessary size here.
if (MFI->hasCalls()) {
// We reserve argument space for call sites in the function immediately on
// entry to the current function. This eliminates the need for add/sub
// brackets around call sites.
NumBytes += MFI->getMaxCallFrameSize();
}
// Do we need to allocate space on the stack?
if (NumBytes == 0) return;
// Add the size of R1 to NumBytes size for the store of R1 to the bottom
// of the stack and round the size to a multiple of the alignment.
unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned Size = getRegClass(PPC::R1)->getSize();
NumBytes = (NumBytes+Size+Align-1)/Align*Align;
// Update frame info to pretend that this is part of the stack...
MFI->setStackSize(NumBytes);
// adjust stack pointer: r1 -= numbytes
if (NumBytes <= 32768) {
MI = BuildMI(PPC::STWU, 3).addReg(PPC::R1).addSImm(-NumBytes)
.addReg(PPC::R1);
MBB.insert(MBBI, MI);
} else {
int NegNumbytes = -NumBytes;
MI = BuildMI(PPC::LIS, 1, PPC::R0).addSImm(NegNumbytes >> 16);
MBB.insert(MBBI, MI);
MI = BuildMI(PPC::ORI, 2, PPC::R0).addReg(PPC::R0)
.addImm(NegNumbytes & 0xFFFF);
MBB.insert(MBBI, MI);
MI = BuildMI(PPC::STWUX, 3).addReg(PPC::R1).addReg(PPC::R1)
.addReg(PPC::R0);
MBB.insert(MBBI, MI);
}
}
void PowerPCRegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
MachineBasicBlock::iterator MBBI = prior(MBB.end());
MachineInstr *MI;
assert(MBBI->getOpcode() == PPC::BLR &&
"Can only insert epilog into returning blocks");
// Get the number of bytes allocated from the FrameInfo...
unsigned NumBytes = MFI->getStackSize();
if (NumBytes != 0) {
MI = BuildMI(PPC::LWZ, 2, PPC::R1).addSImm(0).addReg(PPC::R1);
MBB.insert(MBBI, MI);
}
}
#include "PowerPCGenRegisterInfo.inc"
const TargetRegisterClass*
PowerPCRegisterInfo::getRegClassForType(const Type* Ty) const {
switch (Ty->getTypeID()) {
case Type::LongTyID:
case Type::ULongTyID: assert(0 && "Long values can't fit in registers!");
default: assert(0 && "Invalid type to getClass!");
case Type::BoolTyID:
case Type::SByteTyID:
case Type::UByteTyID:
case Type::ShortTyID:
case Type::UShortTyID:
case Type::IntTyID:
case Type::UIntTyID:
case Type::PointerTyID: return &GPRCInstance;
case Type::FloatTyID:
case Type::DoubleTyID: return &FPRCInstance;
}
}