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//===-- MSP430RegisterInfo.cpp - MSP430 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 MSP430 implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "MSP430RegisterInfo.h"
#include "MSP430.h"
#include "MSP430MachineFunctionInfo.h"
#include "MSP430TargetMachine.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
#define DEBUG_TYPE "msp430-reg-info"
#define GET_REGINFO_TARGET_DESC
#include "MSP430GenRegisterInfo.inc"
// FIXME: Provide proper call frame setup / destroy opcodes.
MSP430RegisterInfo::MSP430RegisterInfo()
: MSP430GenRegisterInfo(MSP430::PC) {}
const MCPhysReg*
MSP430RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
const MSP430FrameLowering *TFI = getFrameLowering(*MF);
const Function* F = &MF->getFunction();
static const MCPhysReg CalleeSavedRegs[] = {
MSP430::R4, MSP430::R5, MSP430::R6, MSP430::R7,
MSP430::R8, MSP430::R9, MSP430::R10,
0
};
static const MCPhysReg CalleeSavedRegsFP[] = {
MSP430::R5, MSP430::R6, MSP430::R7,
MSP430::R8, MSP430::R9, MSP430::R10,
0
};
static const MCPhysReg CalleeSavedRegsIntr[] = {
MSP430::R4, MSP430::R5, MSP430::R6, MSP430::R7,
MSP430::R8, MSP430::R9, MSP430::R10, MSP430::R11,
MSP430::R12, MSP430::R13, MSP430::R14, MSP430::R15,
0
};
static const MCPhysReg CalleeSavedRegsIntrFP[] = {
MSP430::R5, MSP430::R6, MSP430::R7,
MSP430::R8, MSP430::R9, MSP430::R10, MSP430::R11,
MSP430::R12, MSP430::R13, MSP430::R14, MSP430::R15,
0
};
if (TFI->hasFP(*MF))
return (F->getCallingConv() == CallingConv::MSP430_INTR ?
CalleeSavedRegsIntrFP : CalleeSavedRegsFP);
else
return (F->getCallingConv() == CallingConv::MSP430_INTR ?
CalleeSavedRegsIntr : CalleeSavedRegs);
}
BitVector MSP430RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
const MSP430FrameLowering *TFI = getFrameLowering(MF);
// Mark 4 special registers with subregisters as reserved.
Reserved.set(MSP430::PCB);
Reserved.set(MSP430::SPB);
Reserved.set(MSP430::SRB);
Reserved.set(MSP430::CGB);
Reserved.set(MSP430::PC);
Reserved.set(MSP430::SP);
Reserved.set(MSP430::SR);
Reserved.set(MSP430::CG);
// Mark frame pointer as reserved if needed.
if (TFI->hasFP(MF)) {
Reserved.set(MSP430::R4B);
Reserved.set(MSP430::R4);
}
return Reserved;
}
const TargetRegisterClass *
MSP430RegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind)
const {
return &MSP430::GR16RegClass;
}
bool
MSP430RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const MSP430FrameLowering *TFI = getFrameLowering(MF);
DebugLoc dl = MI.getDebugLoc();
int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
unsigned BasePtr = (TFI->hasFP(MF) ? MSP430::R4 : MSP430::SP);
int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex);
// Skip the saved PC
Offset += 2;
if (!TFI->hasFP(MF))
Offset += MF.getFrameInfo().getStackSize();
else
Offset += 2; // Skip the saved FP
// Fold imm into offset
Offset += MI.getOperand(FIOperandNum + 1).getImm();
if (MI.getOpcode() == MSP430::ADDframe) {
// This is actually "load effective address" of the stack slot
// instruction. We have only two-address instructions, thus we need to
// expand it into mov + add
const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
MI.setDesc(TII.get(MSP430::MOV16rr));
MI.getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
if (Offset == 0)
return false;
// We need to materialize the offset via add instruction.
Register DstReg = MI.getOperand(0).getReg();
if (Offset < 0)
BuildMI(MBB, std::next(II), dl, TII.get(MSP430::SUB16ri), DstReg)
.addReg(DstReg).addImm(-Offset);
else
BuildMI(MBB, std::next(II), dl, TII.get(MSP430::ADD16ri), DstReg)
.addReg(DstReg).addImm(Offset);
return false;
}
MI.getOperand(FIOperandNum).ChangeToRegister(BasePtr, false);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
return false;
}
Register MSP430RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
const MSP430FrameLowering *TFI = getFrameLowering(MF);
return TFI->hasFP(MF) ? MSP430::R4 : MSP430::SP;
}