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//===-- SparcRegisterInfo.cpp - SPARC Register Information ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the SPARC implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "SparcRegisterInfo.h"
#include "Sparc.h"
#include "SparcMachineFunctionInfo.h"
#include "SparcSubtarget.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
#define GET_REGINFO_TARGET_DESC
#include "SparcGenRegisterInfo.inc"
static cl::opt<bool>
ReserveAppRegisters("sparc-reserve-app-registers", cl::Hidden, cl::init(false),
cl::desc("Reserve application registers (%g2-%g4)"));
SparcRegisterInfo::SparcRegisterInfo() : SparcGenRegisterInfo(SP::O7) {}
const MCPhysReg*
SparcRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
return CSR_SaveList;
}
const uint32_t *
SparcRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
CallingConv::ID CC) const {
return CSR_RegMask;
}
const uint32_t*
SparcRegisterInfo::getRTCallPreservedMask(CallingConv::ID CC) const {
return RTCSR_RegMask;
}
BitVector SparcRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
const SparcSubtarget &Subtarget = MF.getSubtarget<SparcSubtarget>();
// FIXME: G1 reserved for now for large imm generation by frame code.
Reserved.set(SP::G1);
// G1-G4 can be used in applications.
if (ReserveAppRegisters) {
Reserved.set(SP::G2);
Reserved.set(SP::G3);
Reserved.set(SP::G4);
}
// G5 is not reserved in 64 bit mode.
if (!Subtarget.is64Bit())
Reserved.set(SP::G5);
Reserved.set(SP::O6);
Reserved.set(SP::I6);
Reserved.set(SP::I7);
Reserved.set(SP::G0);
Reserved.set(SP::G6);
Reserved.set(SP::G7);
// Also reserve the register pair aliases covering the above
// registers, with the same conditions.
Reserved.set(SP::G0_G1);
if (ReserveAppRegisters)
Reserved.set(SP::G2_G3);
if (ReserveAppRegisters || !Subtarget.is64Bit())
Reserved.set(SP::G4_G5);
Reserved.set(SP::O6_O7);
Reserved.set(SP::I6_I7);
Reserved.set(SP::G6_G7);
// Unaliased double registers are not available in non-V9 targets.
if (!Subtarget.isV9()) {
for (unsigned n = 0; n != 16; ++n) {
for (MCRegAliasIterator AI(SP::D16 + n, this, true); AI.isValid(); ++AI)
Reserved.set(*AI);
}
}
// Reserve ASR1-ASR31
for (unsigned n = 0; n < 31; n++)
Reserved.set(SP::ASR1 + n);
return Reserved;
}
const TargetRegisterClass*
SparcRegisterInfo::getPointerRegClass(const MachineFunction &MF,
unsigned Kind) const {
const SparcSubtarget &Subtarget = MF.getSubtarget<SparcSubtarget>();
return Subtarget.is64Bit() ? &SP::I64RegsRegClass : &SP::IntRegsRegClass;
}
static void replaceFI(MachineFunction &MF, MachineBasicBlock::iterator II,
MachineInstr &MI, const DebugLoc &dl,
unsigned FIOperandNum, int Offset, unsigned FramePtr) {
// 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(FIOperandNum).ChangeToRegister(FramePtr, false);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
return;
}
const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
// FIXME: it would be better to scavenge a register here instead of
// reserving G1 all of the time.
if (Offset >= 0) {
// Emit nonnegaive immediates with sethi + or.
// sethi %hi(Offset), %g1
// add %g1, %fp, %g1
// Insert G1+%lo(offset) into the user.
BuildMI(*MI.getParent(), II, dl, TII.get(SP::SETHIi), SP::G1)
.addImm(HI22(Offset));
// Emit G1 = G1 + I6
BuildMI(*MI.getParent(), II, dl, TII.get(SP::ADDrr), SP::G1).addReg(SP::G1)
.addReg(FramePtr);
// Insert: G1+%lo(offset) into the user.
MI.getOperand(FIOperandNum).ChangeToRegister(SP::G1, false);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(LO10(Offset));
return;
}
// Emit Negative numbers with sethi + xor
// sethi %hix(Offset), %g1
// xor %g1, %lox(offset), %g1
// add %g1, %fp, %g1
// Insert: G1 + 0 into the user.
BuildMI(*MI.getParent(), II, dl, TII.get(SP::SETHIi), SP::G1)
.addImm(HIX22(Offset));
BuildMI(*MI.getParent(), II, dl, TII.get(SP::XORri), SP::G1)
.addReg(SP::G1).addImm(LOX10(Offset));
BuildMI(*MI.getParent(), II, dl, TII.get(SP::ADDrr), SP::G1).addReg(SP::G1)
.addReg(FramePtr);
// Insert: G1+%lo(offset) into the user.
MI.getOperand(FIOperandNum).ChangeToRegister(SP::G1, false);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(0);
}
bool
SparcRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
MachineInstr &MI = *II;
DebugLoc dl = MI.getDebugLoc();
int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
MachineFunction &MF = *MI.getParent()->getParent();
const SparcSubtarget &Subtarget = MF.getSubtarget<SparcSubtarget>();
const SparcFrameLowering *TFI = getFrameLowering(MF);
Register FrameReg;
int Offset;
Offset = TFI->getFrameIndexReference(MF, FrameIndex, FrameReg).getFixed();
Offset += MI.getOperand(FIOperandNum + 1).getImm();
if (!Subtarget.isV9() || !Subtarget.hasHardQuad()) {
if (MI.getOpcode() == SP::STQFri) {
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
Register SrcReg = MI.getOperand(2).getReg();
Register SrcEvenReg = getSubReg(SrcReg, SP::sub_even64);
Register SrcOddReg = getSubReg(SrcReg, SP::sub_odd64);
MachineInstr *StMI =
BuildMI(*MI.getParent(), II, dl, TII.get(SP::STDFri))
.addReg(FrameReg).addImm(0).addReg(SrcEvenReg);
replaceFI(MF, *StMI, *StMI, dl, 0, Offset, FrameReg);
MI.setDesc(TII.get(SP::STDFri));
MI.getOperand(2).setReg(SrcOddReg);
Offset += 8;
} else if (MI.getOpcode() == SP::LDQFri) {
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
Register DestReg = MI.getOperand(0).getReg();
Register DestEvenReg = getSubReg(DestReg, SP::sub_even64);
Register DestOddReg = getSubReg(DestReg, SP::sub_odd64);
MachineInstr *LdMI =
BuildMI(*MI.getParent(), II, dl, TII.get(SP::LDDFri), DestEvenReg)
.addReg(FrameReg).addImm(0);
replaceFI(MF, *LdMI, *LdMI, dl, 1, Offset, FrameReg);
MI.setDesc(TII.get(SP::LDDFri));
MI.getOperand(0).setReg(DestOddReg);
Offset += 8;
}
}
replaceFI(MF, II, MI, dl, FIOperandNum, Offset, FrameReg);
// replaceFI never removes II
return false;
}
Register SparcRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
return SP::I6;
}
// Sparc has no architectural need for stack realignment support,
// except that LLVM unfortunately currently implements overaligned
// stack objects by depending upon stack realignment support.
// If that ever changes, this can probably be deleted.
bool SparcRegisterInfo::canRealignStack(const MachineFunction &MF) const {
if (!TargetRegisterInfo::canRealignStack(MF))
return false;
// Sparc always has a fixed frame pointer register, so don't need to
// worry about needing to reserve it. [even if we don't have a frame
// pointer for our frame, it still cannot be used for other things,
// or register window traps will be SADNESS.]
// If there's a reserved call frame, we can use SP to access locals.
if (getFrameLowering(MF)->hasReservedCallFrame(MF))
return true;
// Otherwise, we'd need a base pointer, but those aren't implemented
// for SPARC at the moment.
return false;
}