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| //===- ARCRegisterInfo.cpp - ARC Register Information -----------*- C++ -*-===//
//
// 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 ARC implementation of the MRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARCRegisterInfo.h"
#include "ARC.h"
#include "ARCInstrInfo.h"
#include "ARCMachineFunctionInfo.h"
#include "ARCSubtarget.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/Debug.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
#define DEBUG_TYPE "arc-reg-info"
#define GET_REGINFO_TARGET_DESC
#include "ARCGenRegisterInfo.inc"
static void ReplaceFrameIndex(MachineBasicBlock::iterator II,
const ARCInstrInfo &TII, unsigned Reg,
unsigned FrameReg, int Offset, int StackSize,
int ObjSize, RegScavenger *RS, int SPAdj) {
assert(RS && "Need register scavenger.");
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc dl = MI.getDebugLoc();
unsigned BaseReg = FrameReg;
unsigned KillState = 0;
if (MI.getOpcode() == ARC::LD_rs9 && (Offset >= 256 || Offset < -256)) {
// Loads can always be reached with LD_rlimm.
BuildMI(MBB, II, dl, TII.get(ARC::LD_rlimm), Reg)
.addReg(BaseReg)
.addImm(Offset)
.addMemOperand(*MI.memoperands_begin());
MBB.erase(II);
return;
}
if (MI.getOpcode() != ARC::GETFI && (Offset >= 256 || Offset < -256)) {
// We need to use a scratch register to reach the far-away frame indexes.
BaseReg = RS->FindUnusedReg(&ARC::GPR32RegClass);
if (!BaseReg) {
// We can be sure that the scavenged-register slot is within the range
// of the load offset.
const TargetRegisterInfo *TRI =
MBB.getParent()->getSubtarget().getRegisterInfo();
BaseReg = RS->scavengeRegister(&ARC::GPR32RegClass, II, SPAdj);
assert(BaseReg && "Register scavenging failed.");
LLVM_DEBUG(dbgs() << "Scavenged register " << printReg(BaseReg, TRI)
<< " for FrameReg=" << printReg(FrameReg, TRI)
<< "+Offset=" << Offset << "\n");
(void)TRI;
RS->setRegUsed(BaseReg);
}
unsigned AddOpc = isUInt<6>(Offset) ? ARC::ADD_rru6 : ARC::ADD_rrlimm;
BuildMI(MBB, II, dl, TII.get(AddOpc))
.addReg(BaseReg, RegState::Define)
.addReg(FrameReg)
.addImm(Offset);
Offset = 0;
KillState = RegState::Kill;
}
switch (MI.getOpcode()) {
case ARC::LD_rs9:
assert((Offset % 4 == 0) && "LD needs 4 byte alignment.");
LLVM_FALLTHROUGH;
case ARC::LDH_rs9:
case ARC::LDH_X_rs9:
assert((Offset % 2 == 0) && "LDH needs 2 byte alignment.");
LLVM_FALLTHROUGH;
case ARC::LDB_rs9:
case ARC::LDB_X_rs9:
LLVM_DEBUG(dbgs() << "Building LDFI\n");
BuildMI(MBB, II, dl, TII.get(MI.getOpcode()), Reg)
.addReg(BaseReg, KillState)
.addImm(Offset)
.addMemOperand(*MI.memoperands_begin());
break;
case ARC::ST_rs9:
assert((Offset % 4 == 0) && "ST needs 4 byte alignment.");
LLVM_FALLTHROUGH;
case ARC::STH_rs9:
assert((Offset % 2 == 0) && "STH needs 2 byte alignment.");
LLVM_FALLTHROUGH;
case ARC::STB_rs9:
LLVM_DEBUG(dbgs() << "Building STFI\n");
BuildMI(MBB, II, dl, TII.get(MI.getOpcode()))
.addReg(Reg, getKillRegState(MI.getOperand(0).isKill()))
.addReg(BaseReg, KillState)
.addImm(Offset)
.addMemOperand(*MI.memoperands_begin());
break;
case ARC::GETFI:
LLVM_DEBUG(dbgs() << "Building GETFI\n");
BuildMI(MBB, II, dl,
TII.get(isUInt<6>(Offset) ? ARC::ADD_rru6 : ARC::ADD_rrlimm))
.addReg(Reg, RegState::Define)
.addReg(FrameReg)
.addImm(Offset);
break;
default:
llvm_unreachable("Unhandled opcode.");
}
// Erase old instruction.
MBB.erase(II);
}
ARCRegisterInfo::ARCRegisterInfo() : ARCGenRegisterInfo(ARC::BLINK) {}
bool ARCRegisterInfo::needsFrameMoves(const MachineFunction &MF) {
return MF.getMMI().hasDebugInfo() || MF.getFunction().needsUnwindTableEntry();
}
const MCPhysReg *
ARCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
return CSR_ARC_SaveList;
}
BitVector ARCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(ARC::ILINK);
Reserved.set(ARC::SP);
Reserved.set(ARC::GP);
Reserved.set(ARC::R25);
Reserved.set(ARC::BLINK);
Reserved.set(ARC::FP);
return Reserved;
}
bool ARCRegisterInfo::requiresRegisterScavenging(
const MachineFunction &MF) const {
return true;
}
bool ARCRegisterInfo::trackLivenessAfterRegAlloc(
const MachineFunction &MF) const {
return true;
}
bool ARCRegisterInfo::useFPForScavengingIndex(const MachineFunction &MF) const {
return true;
}
void ARCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
MachineInstr &MI = *II;
MachineOperand &FrameOp = MI.getOperand(FIOperandNum);
int FrameIndex = FrameOp.getIndex();
MachineFunction &MF = *MI.getParent()->getParent();
const ARCInstrInfo &TII = *MF.getSubtarget<ARCSubtarget>().getInstrInfo();
const ARCFrameLowering *TFI = getFrameLowering(MF);
int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex);
int ObjSize = MF.getFrameInfo().getObjectSize(FrameIndex);
int StackSize = MF.getFrameInfo().getStackSize();
int LocalFrameSize = MF.getFrameInfo().getLocalFrameSize();
LLVM_DEBUG(dbgs() << "\nFunction : " << MF.getName() << "\n");
LLVM_DEBUG(dbgs() << "<--------->\n");
LLVM_DEBUG(dbgs() << MI << "\n");
LLVM_DEBUG(dbgs() << "FrameIndex : " << FrameIndex << "\n");
LLVM_DEBUG(dbgs() << "ObjSize : " << ObjSize << "\n");
LLVM_DEBUG(dbgs() << "FrameOffset : " << Offset << "\n");
LLVM_DEBUG(dbgs() << "StackSize : " << StackSize << "\n");
LLVM_DEBUG(dbgs() << "LocalFrameSize : " << LocalFrameSize << "\n");
(void)LocalFrameSize;
// Special handling of DBG_VALUE instructions.
if (MI.isDebugValue()) {
Register FrameReg = getFrameRegister(MF);
MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false /*isDef*/);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
return;
}
// fold constant into offset.
Offset += MI.getOperand(FIOperandNum + 1).getImm();
// TODO: assert based on the load type:
// ldb needs no alignment,
// ldh needs 2 byte alignment
// ld needs 4 byte alignment
LLVM_DEBUG(dbgs() << "Offset : " << Offset << "\n"
<< "<--------->\n");
Register Reg = MI.getOperand(0).getReg();
assert(ARC::GPR32RegClass.contains(Reg) && "Unexpected register operand");
if (!TFI->hasFP(MF)) {
Offset = StackSize + Offset;
if (FrameIndex >= 0)
assert((Offset >= 0 && Offset < StackSize) && "SP Offset not in bounds.");
} else {
if (FrameIndex >= 0) {
assert((Offset < 0 && -Offset <= StackSize) &&
"FP Offset not in bounds.");
}
}
ReplaceFrameIndex(II, TII, Reg, getFrameRegister(MF), Offset, StackSize,
ObjSize, RS, SPAdj);
}
Register ARCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
const ARCFrameLowering *TFI = getFrameLowering(MF);
return TFI->hasFP(MF) ? ARC::FP : ARC::SP;
}
const uint32_t *
ARCRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
CallingConv::ID CC) const {
return CSR_ARC_RegMask;
}
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