llvm-project/llvm/lib/Target/RISCV/RISCVMCInstLower.cpp

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8.0 KiB
C++

//===-- RISCVMCInstLower.cpp - Convert RISCV MachineInstr to an MCInst ------=//
//
// 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 code to lower RISCV MachineInstrs to their corresponding
// MCInst records.
//
//===----------------------------------------------------------------------===//
#include "RISCV.h"
#include "RISCVSubtarget.h"
#include "MCTargetDesc/RISCVMCExpr.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
static MCOperand lowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym,
const AsmPrinter &AP) {
MCContext &Ctx = AP.OutContext;
RISCVMCExpr::VariantKind Kind;
switch (MO.getTargetFlags()) {
default:
llvm_unreachable("Unknown target flag on GV operand");
case RISCVII::MO_None:
Kind = RISCVMCExpr::VK_RISCV_None;
break;
case RISCVII::MO_CALL:
Kind = RISCVMCExpr::VK_RISCV_CALL;
break;
case RISCVII::MO_PLT:
Kind = RISCVMCExpr::VK_RISCV_CALL_PLT;
break;
case RISCVII::MO_LO:
Kind = RISCVMCExpr::VK_RISCV_LO;
break;
case RISCVII::MO_HI:
Kind = RISCVMCExpr::VK_RISCV_HI;
break;
case RISCVII::MO_PCREL_LO:
Kind = RISCVMCExpr::VK_RISCV_PCREL_LO;
break;
case RISCVII::MO_PCREL_HI:
Kind = RISCVMCExpr::VK_RISCV_PCREL_HI;
break;
case RISCVII::MO_GOT_HI:
Kind = RISCVMCExpr::VK_RISCV_GOT_HI;
break;
case RISCVII::MO_TPREL_LO:
Kind = RISCVMCExpr::VK_RISCV_TPREL_LO;
break;
case RISCVII::MO_TPREL_HI:
Kind = RISCVMCExpr::VK_RISCV_TPREL_HI;
break;
case RISCVII::MO_TPREL_ADD:
Kind = RISCVMCExpr::VK_RISCV_TPREL_ADD;
break;
case RISCVII::MO_TLS_GOT_HI:
Kind = RISCVMCExpr::VK_RISCV_TLS_GOT_HI;
break;
case RISCVII::MO_TLS_GD_HI:
Kind = RISCVMCExpr::VK_RISCV_TLS_GD_HI;
break;
}
const MCExpr *ME =
MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, Ctx);
if (!MO.isJTI() && !MO.isMBB() && MO.getOffset())
ME = MCBinaryExpr::createAdd(
ME, MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
if (Kind != RISCVMCExpr::VK_RISCV_None)
ME = RISCVMCExpr::create(ME, Kind, Ctx);
return MCOperand::createExpr(ME);
}
bool llvm::LowerRISCVMachineOperandToMCOperand(const MachineOperand &MO,
MCOperand &MCOp,
const AsmPrinter &AP) {
switch (MO.getType()) {
default:
report_fatal_error("LowerRISCVMachineInstrToMCInst: unknown operand type");
case MachineOperand::MO_Register:
// Ignore all implicit register operands.
if (MO.isImplicit())
return false;
MCOp = MCOperand::createReg(MO.getReg());
break;
case MachineOperand::MO_RegisterMask:
// Regmasks are like implicit defs.
return false;
case MachineOperand::MO_Immediate:
MCOp = MCOperand::createImm(MO.getImm());
break;
case MachineOperand::MO_MachineBasicBlock:
MCOp = lowerSymbolOperand(MO, MO.getMBB()->getSymbol(), AP);
break;
case MachineOperand::MO_GlobalAddress:
MCOp = lowerSymbolOperand(MO, AP.getSymbolPreferLocal(*MO.getGlobal()), AP);
break;
case MachineOperand::MO_BlockAddress:
MCOp = lowerSymbolOperand(
MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()), AP);
break;
case MachineOperand::MO_ExternalSymbol:
MCOp = lowerSymbolOperand(
MO, AP.GetExternalSymbolSymbol(MO.getSymbolName()), AP);
break;
case MachineOperand::MO_ConstantPoolIndex:
MCOp = lowerSymbolOperand(MO, AP.GetCPISymbol(MO.getIndex()), AP);
break;
case MachineOperand::MO_JumpTableIndex:
MCOp = lowerSymbolOperand(MO, AP.GetJTISymbol(MO.getIndex()), AP);
break;
}
return true;
}
static bool lowerRISCVVMachineInstrToMCInst(const MachineInstr *MI,
MCInst &OutMI) {
const RISCVVPseudosTable::PseudoInfo *RVV =
RISCVVPseudosTable::getPseudoInfo(MI->getOpcode());
if (!RVV)
return false;
OutMI.setOpcode(RVV->BaseInstr);
const MachineBasicBlock *MBB = MI->getParent();
assert(MBB && "MI expected to be in a basic block");
const MachineFunction *MF = MBB->getParent();
assert(MF && "MBB expected to be in a machine function");
const TargetRegisterInfo *TRI =
MF->getSubtarget<RISCVSubtarget>().getRegisterInfo();
assert(TRI && "TargetRegisterInfo expected");
uint64_t TSFlags = MI->getDesc().TSFlags;
int NumOps = MI->getNumExplicitOperands();
for (const MachineOperand &MO : MI->explicit_operands()) {
int OpNo = (int)MI->getOperandNo(&MO);
assert(OpNo >= 0 && "Operand number doesn't fit in an 'int' type");
// Skip VL and SEW operands which are the last two operands if present.
if (RISCVII::hasVLOp(TSFlags) && OpNo == (NumOps - 2))
continue;
if (RISCVII::hasSEWOp(TSFlags) && OpNo == (NumOps - 1))
continue;
// Skip merge op. It should be the first operand after the result.
if (RISCVII::hasMergeOp(TSFlags) && OpNo == 1) {
assert(MI->getNumExplicitDefs() == 1);
continue;
}
MCOperand MCOp;
switch (MO.getType()) {
default:
llvm_unreachable("Unknown operand type");
case MachineOperand::MO_Register: {
unsigned Reg = MO.getReg();
if (RISCV::VRM2RegClass.contains(Reg) ||
RISCV::VRM4RegClass.contains(Reg) ||
RISCV::VRM8RegClass.contains(Reg)) {
Reg = TRI->getSubReg(Reg, RISCV::sub_vrm1_0);
assert(Reg && "Subregister does not exist");
} else if (RISCV::FPR16RegClass.contains(Reg)) {
Reg = TRI->getMatchingSuperReg(Reg, RISCV::sub_16, &RISCV::FPR32RegClass);
assert(Reg && "Subregister does not exist");
} else if (RISCV::FPR64RegClass.contains(Reg)) {
Reg = TRI->getSubReg(Reg, RISCV::sub_32);
assert(Reg && "Superregister does not exist");
}
MCOp = MCOperand::createReg(Reg);
break;
}
case MachineOperand::MO_Immediate:
MCOp = MCOperand::createImm(MO.getImm());
break;
}
OutMI.addOperand(MCOp);
}
// Unmasked pseudo instructions need to append dummy mask operand to
// V instructions. All V instructions are modeled as the masked version.
if (RISCVII::hasDummyMaskOp(TSFlags))
OutMI.addOperand(MCOperand::createReg(RISCV::NoRegister));
return true;
}
bool llvm::lowerRISCVMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
AsmPrinter &AP) {
if (lowerRISCVVMachineInstrToMCInst(MI, OutMI))
return false;
OutMI.setOpcode(MI->getOpcode());
for (const MachineOperand &MO : MI->operands()) {
MCOperand MCOp;
if (LowerRISCVMachineOperandToMCOperand(MO, MCOp, AP))
OutMI.addOperand(MCOp);
}
switch (OutMI.getOpcode()) {
case TargetOpcode::PATCHABLE_FUNCTION_ENTER: {
const Function &F = MI->getParent()->getParent()->getFunction();
if (F.hasFnAttribute("patchable-function-entry")) {
unsigned Num;
if (F.getFnAttribute("patchable-function-entry")
.getValueAsString()
.getAsInteger(10, Num))
return false;
AP.emitNops(Num);
return true;
}
break;
}
case RISCV::PseudoReadVLENB:
OutMI.setOpcode(RISCV::CSRRS);
OutMI.addOperand(MCOperand::createImm(
RISCVSysReg::lookupSysRegByName("VLENB")->Encoding));
OutMI.addOperand(MCOperand::createReg(RISCV::X0));
break;
case RISCV::PseudoReadVL:
OutMI.setOpcode(RISCV::CSRRS);
OutMI.addOperand(
MCOperand::createImm(RISCVSysReg::lookupSysRegByName("VL")->Encoding));
OutMI.addOperand(MCOperand::createReg(RISCV::X0));
break;
}
return false;
}