llvm-6502/lib/Target/Sparc/SparcRegisterInfo.cpp
2009-02-23 00:42:30 +00:00

197 lines
6.7 KiB
C++

//===- SparcRegisterInfo.cpp - SPARC 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 SPARC implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "Sparc.h"
#include "SparcRegisterInfo.h"
#include "SparcSubtarget.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Type.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
using namespace llvm;
SparcRegisterInfo::SparcRegisterInfo(SparcSubtarget &st,
const TargetInstrInfo &tii)
: SparcGenRegisterInfo(SP::ADJCALLSTACKDOWN, SP::ADJCALLSTACKUP),
Subtarget(st), TII(tii) {
}
const unsigned* SparcRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF)
const {
static const unsigned CalleeSavedRegs[] = { 0 };
return CalleeSavedRegs;
}
BitVector SparcRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(SP::G2);
Reserved.set(SP::G3);
Reserved.set(SP::G4);
Reserved.set(SP::O6);
Reserved.set(SP::I6);
Reserved.set(SP::I7);
Reserved.set(SP::G0);
Reserved.set(SP::G5);
Reserved.set(SP::G6);
Reserved.set(SP::G7);
return Reserved;
}
const TargetRegisterClass* const*
SparcRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
static const TargetRegisterClass * const CalleeSavedRegClasses[] = { 0 };
return CalleeSavedRegClasses;
}
bool SparcRegisterInfo::hasFP(const MachineFunction &MF) const {
return false;
}
void SparcRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
MachineInstr &MI = *I;
DebugLoc dl = MI.getDebugLoc();
int Size = MI.getOperand(0).getImm();
if (MI.getOpcode() == SP::ADJCALLSTACKDOWN)
Size = -Size;
if (Size)
BuildMI(MBB, I, dl, TII.get(SP::ADDri), SP::O6).addReg(SP::O6).addImm(Size);
MBB.erase(I);
}
void SparcRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
unsigned i = 0;
MachineInstr &MI = *II;
DebugLoc dl = MI.getDebugLoc();
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
int FrameIndex = MI.getOperand(i).getIndex();
// Addressable stack objects are accessed using neg. offsets from %fp
MachineFunction &MF = *MI.getParent()->getParent();
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
MI.getOperand(i+1).getImm();
// Replace frame index with a frame pointer reference.
if (Offset >= -4096 && Offset <= 4095) {
// If the offset is small enough to fit in the immediate field, directly
// encode it.
MI.getOperand(i).ChangeToRegister(SP::I6, false);
MI.getOperand(i+1).ChangeToImmediate(Offset);
} else {
// Otherwise, emit a G1 = SETHI %hi(offset). FIXME: it would be better to
// scavenge a register here instead of reserving G1 all of the time.
unsigned OffHi = (unsigned)Offset >> 10U;
BuildMI(*MI.getParent(), II, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
// Emit G1 = G1 + I6
BuildMI(*MI.getParent(), II, dl, TII.get(SP::ADDrr), SP::G1).addReg(SP::G1)
.addReg(SP::I6);
// Insert: G1+%lo(offset) into the user.
MI.getOperand(i).ChangeToRegister(SP::G1, false);
MI.getOperand(i+1).ChangeToImmediate(Offset & ((1 << 10)-1));
}
}
void SparcRegisterInfo::
processFunctionBeforeFrameFinalized(MachineFunction &MF) const {}
void SparcRegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = (MBBI != MBB.end() ?
MBBI->getDebugLoc() : DebugLoc::getUnknownLoc());
// Get the number of bytes to allocate from the FrameInfo
int NumBytes = (int) MFI->getStackSize();
// Emit the correct save instruction based on the number of bytes in
// the frame. Minimum stack frame size according to V8 ABI is:
// 16 words for register window spill
// 1 word for address of returned aggregate-value
// + 6 words for passing parameters on the stack
// ----------
// 23 words * 4 bytes per word = 92 bytes
NumBytes += 92;
// Round up to next doubleword boundary -- a double-word boundary
// is required by the ABI.
NumBytes = (NumBytes + 7) & ~7;
NumBytes = -NumBytes;
if (NumBytes >= -4096) {
BuildMI(MBB, MBBI, dl, TII.get(SP::SAVEri), SP::O6)
.addReg(SP::O6).addImm(NumBytes);
} else {
// Emit this the hard way. This clobbers G1 which we always know is
// available here.
unsigned OffHi = (unsigned)NumBytes >> 10U;
BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
// Emit G1 = G1 + I6
BuildMI(MBB, MBBI, dl, TII.get(SP::ORri), SP::G1)
.addReg(SP::G1).addImm(NumBytes & ((1 << 10)-1));
BuildMI(MBB, MBBI, dl, TII.get(SP::SAVErr), SP::O6)
.addReg(SP::O6).addReg(SP::G1);
}
}
void SparcRegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = prior(MBB.end());
DebugLoc dl = MBBI->getDebugLoc();
assert(MBBI->getOpcode() == SP::RETL &&
"Can only put epilog before 'retl' instruction!");
BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0)
.addReg(SP::G0);
}
unsigned SparcRegisterInfo::getRARegister() const {
assert(0 && "What is the return address register");
return 0;
}
unsigned SparcRegisterInfo::getFrameRegister(MachineFunction &MF) const {
assert(0 && "What is the frame register");
return SP::G1;
}
unsigned SparcRegisterInfo::getEHExceptionRegister() const {
assert(0 && "What is the exception register");
return 0;
}
unsigned SparcRegisterInfo::getEHHandlerRegister() const {
assert(0 && "What is the exception handler register");
return 0;
}
int SparcRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
assert(0 && "What is the dwarf register number");
return -1;
}
#include "SparcGenRegisterInfo.inc"