llvm-6502/lib/Target/Alpha/AlphaRegisterInfo.cpp
Andrew Lenharth 4907d22a90 ret 0; works, not much else
still lots of uglyness.
Maybe calls will come soon.
Fixing the return value of things will be necessary to make alpha work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23832 91177308-0d34-0410-b5e6-96231b3b80d8
2005-10-20 00:28:31 +00:00

362 lines
12 KiB
C++

//===- AlphaRegisterInfo.cpp - Alpha 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 Alpha implementation of the MRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "reginfo"
#include "Alpha.h"
#include "AlphaRegisterInfo.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/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/STLExtras.h"
#include <cstdlib>
#include <iostream>
using namespace llvm;
namespace llvm {
extern cl::opt<bool> EnableAlphaLSMark;
}
//These describe LDAx
static const int IMM_LOW = -32768;
static const int IMM_HIGH = 32767;
static const int IMM_MULT = 65536;
static long getUpper16(long l)
{
long y = l / IMM_MULT;
if (l % IMM_MULT > IMM_HIGH)
++y;
return y;
}
static long getLower16(long l)
{
long h = getUpper16(l);
return l - h * IMM_MULT;
}
static int getUID()
{
static int id = 0;
return ++id;
}
AlphaRegisterInfo::AlphaRegisterInfo()
: AlphaGenRegisterInfo(Alpha::ADJUSTSTACKDOWN, Alpha::ADJUSTSTACKUP)
{
}
static const TargetRegisterClass *getClass(unsigned SrcReg) {
if (Alpha::FPRCRegisterClass->contains(SrcReg))
return Alpha::FPRCRegisterClass;
assert(Alpha::GPRCRegisterClass->contains(SrcReg) && "Reg not FPR or GPR");
return Alpha::GPRCRegisterClass;
}
void
AlphaRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, int FrameIdx,
const TargetRegisterClass *RC) const {
//std::cerr << "Trying to store " << getPrettyName(SrcReg) << " to " << FrameIdx << "\n";
//BuildMI(MBB, MI, Alpha::WTF, 0).addReg(SrcReg);
if (EnableAlphaLSMark)
BuildMI(MBB, MI, Alpha::MEMLABEL, 4).addImm(4).addImm(0).addImm(1)
.addImm(getUID());
if (getClass(SrcReg) == Alpha::FPRCRegisterClass)
BuildMI(MBB, MI, Alpha::STT, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
else if (getClass(SrcReg) == Alpha::GPRCRegisterClass)
BuildMI(MBB, MI, Alpha::STQ, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
else
abort();
}
void
AlphaRegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC) const {
//std::cerr << "Trying to load " << getPrettyName(DestReg) << " to " << FrameIdx << "\n";
if (EnableAlphaLSMark)
BuildMI(MBB, MI, Alpha::MEMLABEL, 4).addImm(4).addImm(0).addImm(2)
.addImm(getUID());
if (getClass(DestReg) == Alpha::FPRCRegisterClass)
BuildMI(MBB, MI, Alpha::LDT, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
else if (getClass(DestReg) == Alpha::GPRCRegisterClass)
BuildMI(MBB, MI, Alpha::LDQ, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
else
abort();
}
unsigned
AlphaRegisterInfo::isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const
{
switch (MI->getOpcode()) {
case Alpha::LDL:
case Alpha::LDQ:
case Alpha::LDBU:
case Alpha::LDWU:
case Alpha::LDS:
case Alpha::LDT:
if (MI->getOperand(1).isFrameIndex()) {
FrameIndex = MI->getOperand(1).getFrameIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
void AlphaRegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *RC) const {
// std::cerr << "copyRegToReg " << DestReg << " <- " << SrcReg << "\n";
if (RC == Alpha::GPRCRegisterClass) {
BuildMI(MBB, MI, Alpha::BIS, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else if (RC == Alpha::FPRCRegisterClass) {
BuildMI(MBB, MI, Alpha::CPYS, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else {
std::cerr << "Attempt to copy register that is not GPR or FPR";
abort();
}
}
//===----------------------------------------------------------------------===//
// 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) {
MachineFrameInfo *MFI = MF.getFrameInfo();
return MFI->hasVarSizedObjects();
}
void AlphaRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
if (hasFP(MF)) {
// If we have a frame pointer, turn the adjcallstackup instruction into a
// 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP,
// <amt>'
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() == Alpha::ADJUSTSTACKDOWN) {
New=BuildMI(Alpha::LDA, 2, Alpha::R30)
.addImm(-Amount).addReg(Alpha::R30);
} else {
assert(Old->getOpcode() == Alpha::ADJUSTSTACKUP);
New=BuildMI(Alpha::LDA, 2, Alpha::R30)
.addImm(Amount).addReg(Alpha::R30);
}
// Replace the pseudo instruction with a new instruction...
MBB.insert(I, New);
}
}
MBB.erase(I);
}
//Alpha has a slightly funny stack:
//Args
//<- incoming SP
//fixed locals (and spills, callee saved, etc)
//<- FP
//variable locals
//<- SP
void
AlphaRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const {
unsigned i = 0;
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
bool FP = hasFP(MF);
while (!MI.getOperand(i).isFrameIndex()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
int FrameIndex = MI.getOperand(i).getFrameIndex();
// Add the base register of R30 (SP) or R15 (FP).
MI.SetMachineOperandReg(i + 1, FP ? Alpha::R15 : Alpha::R30);
// Now add the frame object offset to the offset from the virtual frame index.
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
DEBUG(std::cerr << "FI: " << FrameIndex << " Offset: " << Offset << "\n");
Offset += MF.getFrameInfo()->getStackSize();
DEBUG(std::cerr << "Corrected Offset " << Offset <<
" for stack size: " << MF.getFrameInfo()->getStackSize() << "\n");
if (Offset > IMM_HIGH || Offset < IMM_LOW) {
//so in this case, we need to use a temporary register, and move the original
//inst off the SP/FP
//fix up the old:
MI.SetMachineOperandReg(i + 1, Alpha::R28);
MI.SetMachineOperandConst(i, MachineOperand::MO_SignExtendedImmed,
getLower16(Offset));
//insert the new
MachineInstr* nMI=BuildMI(Alpha::LDAH, 2, Alpha::R28)
.addImm(getUpper16(Offset)).addReg(FP ? Alpha::R15 : Alpha::R30);
MBB.insert(II, nMI);
} else {
MI.SetMachineOperandConst(i, MachineOperand::MO_SignExtendedImmed, Offset);
}
}
void AlphaRegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
bool FP = hasFP(MF);
static int curgpdist = 0;
//handle GOP offset
BuildMI(MBB, MBBI, Alpha::LDAHg, 3, Alpha::R29)
.addGlobalAddress(const_cast<Function*>(MF.getFunction()))
.addReg(Alpha::R27).addImm(++curgpdist);
BuildMI(MBB, MBBI, Alpha::LDAg, 3, Alpha::R29)
.addGlobalAddress(const_cast<Function*>(MF.getFunction()))
.addReg(Alpha::R29).addImm(curgpdist);
//evil const_cast until MO stuff setup to handle const
BuildMI(MBB, MBBI, Alpha::ALTENT, 1).addGlobalAddress(const_cast<Function*>(MF.getFunction()), true);
// Get the number of bytes to allocate from the FrameInfo
long NumBytes = MFI->getStackSize();
if (MFI->hasCalls() && !FP) {
// 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.
//If there is a frame pointer, then we don't do this
NumBytes += MFI->getMaxCallFrameSize();
DEBUG(std::cerr << "Added " << MFI->getMaxCallFrameSize()
<< " to the stack due to calls\n");
}
if (FP)
NumBytes += 8; //reserve space for the old FP
// Do we need to allocate space on the stack?
if (NumBytes == 0) return;
// Update frame info to pretend that this is part of the stack...
MFI->setStackSize(NumBytes);
// adjust stack pointer: r30 -= numbytes
NumBytes = -NumBytes;
if (NumBytes >= IMM_LOW) {
BuildMI(MBB, MBBI, Alpha::LDA, 2, Alpha::R30).addImm(NumBytes)
.addReg(Alpha::R30);
} else if (getUpper16(NumBytes) >= IMM_LOW) {
BuildMI(MBB, MBBI, Alpha::LDAH, 2, Alpha::R30).addImm(getUpper16(NumBytes))
.addReg(Alpha::R30);
BuildMI(MBB, MBBI, Alpha::LDA, 2, Alpha::R30).addImm(getLower16(NumBytes))
.addReg(Alpha::R30);
} else {
std::cerr << "Too big a stack frame at " << NumBytes << "\n";
abort();
}
//now if we need to, save the old FP and set the new
if (FP)
{
if (EnableAlphaLSMark)
BuildMI(MBB, MBBI, Alpha::MEMLABEL, 4).addImm(4).addImm(0).addImm(1)
.addImm(getUID());
BuildMI(MBB, MBBI, Alpha::STQ, 3).addReg(Alpha::R15).addImm(0).addReg(Alpha::R30);
//this must be the last instr in the prolog
BuildMI(MBB, MBBI, Alpha::BIS, 2, Alpha::R15).addReg(Alpha::R30).addReg(Alpha::R30);
}
}
void AlphaRegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
MachineBasicBlock::iterator MBBI = prior(MBB.end());
assert(((MBBI->getOpcode() == Alpha::RET) || (MBBI->getOpcode() == Alpha::RETDAG))
&& "Can only insert epilog into returning blocks");
bool FP = hasFP(MF);
// Get the number of bytes allocated from the FrameInfo...
long NumBytes = MFI->getStackSize();
//now if we need to, restore the old FP
if (FP)
{
//copy the FP into the SP (discards allocas)
BuildMI(MBB, MBBI, Alpha::BIS, 2, Alpha::R30).addReg(Alpha::R15)
.addReg(Alpha::R15);
//restore the FP
if (EnableAlphaLSMark)
BuildMI(MBB, MBBI, Alpha::MEMLABEL, 4).addImm(4).addImm(0).addImm(2)
.addImm(getUID());
BuildMI(MBB, MBBI, Alpha::LDQ, 2, Alpha::R15).addImm(0).addReg(Alpha::R15);
}
if (NumBytes != 0)
{
if (NumBytes <= IMM_HIGH) {
BuildMI(MBB, MBBI, Alpha::LDA, 2, Alpha::R30).addImm(NumBytes)
.addReg(Alpha::R30);
} else if (getUpper16(NumBytes) <= IMM_HIGH) {
BuildMI(MBB, MBBI, Alpha::LDAH, 2, Alpha::R30)
.addImm(getUpper16(NumBytes)).addReg(Alpha::R30);
BuildMI(MBB, MBBI, Alpha::LDA, 2, Alpha::R30)
.addImm(getLower16(NumBytes)).addReg(Alpha::R30);
} else {
std::cerr << "Too big a stack frame at " << NumBytes << "\n";
abort();
}
}
}
#include "AlphaGenRegisterInfo.inc"
std::string AlphaRegisterInfo::getPrettyName(unsigned reg)
{
std::string s(RegisterDescriptors[reg].Name);
return s;
}