blob: 3ed1dec434ceef7b036cf1e47df292f0e6671a65 [file] [log] [blame]
//===-- RISCVRegisterInfo.cpp - RISCV 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 RISCV implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "RISCVRegisterInfo.h"
#include "RISCV.h"
#include "RISCVSubtarget.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/Support/ErrorHandling.h"
#define GET_REGINFO_TARGET_DESC
#include "RISCVGenRegisterInfo.inc"
using namespace llvm;
RISCVRegisterInfo::RISCVRegisterInfo(unsigned HwMode)
: RISCVGenRegisterInfo(RISCV::X1, /*DwarfFlavour*/0, /*EHFlavor*/0,
/*PC*/0, HwMode) {}
const MCPhysReg *
RISCVRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
if (MF->getFunction().hasFnAttribute("interrupt")) {
if (MF->getSubtarget<RISCVSubtarget>().hasStdExtD())
return CSR_XLEN_F64_Interrupt_SaveList;
if (MF->getSubtarget<RISCVSubtarget>().hasStdExtF())
return CSR_XLEN_F32_Interrupt_SaveList;
return CSR_Interrupt_SaveList;
}
return CSR_SaveList;
}
BitVector RISCVRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
// Use markSuperRegs to ensure any register aliases are also reserved
markSuperRegs(Reserved, RISCV::X0); // zero
markSuperRegs(Reserved, RISCV::X1); // ra
markSuperRegs(Reserved, RISCV::X2); // sp
markSuperRegs(Reserved, RISCV::X3); // gp
markSuperRegs(Reserved, RISCV::X4); // tp
markSuperRegs(Reserved, RISCV::X8); // fp
assert(checkAllSuperRegsMarked(Reserved));
return Reserved;
}
bool RISCVRegisterInfo::isConstantPhysReg(unsigned PhysReg) const {
return PhysReg == RISCV::X0;
}
const uint32_t *RISCVRegisterInfo::getNoPreservedMask() const {
return CSR_NoRegs_RegMask;
}
void RISCVRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected non-zero SPAdj value");
MachineInstr &MI = *II;
MachineFunction &MF = *MI.getParent()->getParent();
MachineRegisterInfo &MRI = MF.getRegInfo();
const RISCVInstrInfo *TII = MF.getSubtarget<RISCVSubtarget>().getInstrInfo();
DebugLoc DL = MI.getDebugLoc();
int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
unsigned FrameReg;
int Offset =
getFrameLowering(MF)->getFrameIndexReference(MF, FrameIndex, FrameReg) +
MI.getOperand(FIOperandNum + 1).getImm();
if (!isInt<32>(Offset)) {
report_fatal_error(
"Frame offsets outside of the signed 32-bit range not supported");
}
MachineBasicBlock &MBB = *MI.getParent();
bool FrameRegIsKill = false;
if (!isInt<12>(Offset)) {
assert(isInt<32>(Offset) && "Int32 expected");
// The offset won't fit in an immediate, so use a scratch register instead
// Modify Offset and FrameReg appropriately
unsigned ScratchReg = MRI.createVirtualRegister(&RISCV::GPRRegClass);
TII->movImm32(MBB, II, DL, ScratchReg, Offset);
BuildMI(MBB, II, DL, TII->get(RISCV::ADD), ScratchReg)
.addReg(FrameReg)
.addReg(ScratchReg, RegState::Kill);
Offset = 0;
FrameReg = ScratchReg;
FrameRegIsKill = true;
}
MI.getOperand(FIOperandNum)
.ChangeToRegister(FrameReg, false, false, FrameRegIsKill);
MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
}
unsigned RISCVRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
const TargetFrameLowering *TFI = getFrameLowering(MF);
return TFI->hasFP(MF) ? RISCV::X8 : RISCV::X2;
}
const uint32_t *
RISCVRegisterInfo::getCallPreservedMask(const MachineFunction & MF,
CallingConv::ID /*CC*/) const {
if (MF.getFunction().hasFnAttribute("interrupt")) {
if (MF.getSubtarget<RISCVSubtarget>().hasStdExtD())
return CSR_XLEN_F64_Interrupt_RegMask;
if (MF.getSubtarget<RISCVSubtarget>().hasStdExtF())
return CSR_XLEN_F32_Interrupt_RegMask;
return CSR_Interrupt_RegMask;
}
return CSR_RegMask;
}