llvm-project/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp

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3.6 KiB
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// WebAssemblyMCInstLower.cpp - Convert WebAssembly MachineInstr to an MCInst //
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file contains code to lower WebAssembly MachineInstrs to their
/// corresponding MCInst records.
///
//===----------------------------------------------------------------------===//
#include "WebAssemblyMCInstLower.h"
#include "WebAssemblyMachineFunctionInfo.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/IR/Constants.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;
MCSymbol *
WebAssemblyMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const {
return Printer.getSymbol(MO.getGlobal());
}
MCSymbol *WebAssemblyMCInstLower::GetExternalSymbolSymbol(
const MachineOperand &MO) const {
return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
}
MCOperand WebAssemblyMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
MCSymbol *Sym) const {
assert(MO.getTargetFlags() == 0 && "WebAssembly does not use target flags");
const MCExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
int64_t Offset = MO.getOffset();
if (Offset != 0) {
assert(!MO.isJTI() && "Unexpected offset with jump table index");
Expr =
MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(Offset, Ctx), Ctx);
}
return MCOperand::createExpr(Expr);
}
void WebAssemblyMCInstLower::Lower(const MachineInstr *MI,
MCInst &OutMI) const {
OutMI.setOpcode(MI->getOpcode());
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
MCOperand MCOp;
switch (MO.getType()) {
default:
MI->dump();
llvm_unreachable("unknown operand type");
case MachineOperand::MO_Register: {
// Ignore all implicit register operands.
if (MO.isImplicit())
continue;
const WebAssemblyFunctionInfo &MFI =
*MI->getParent()->getParent()->getInfo<WebAssemblyFunctionInfo>();
unsigned WAReg = MFI.getWAReg(MO.getReg());
MCOp = MCOperand::createReg(WAReg);
break;
}
case MachineOperand::MO_Immediate:
MCOp = MCOperand::createImm(MO.getImm());
break;
case MachineOperand::MO_FPImmediate: {
// TODO: MC converts all floating point immediate operands to double.
// This is fine for numeric values, but may cause NaNs to change bits.
const ConstantFP *Imm = MO.getFPImm();
if (Imm->getType()->isFloatTy())
MCOp = MCOperand::createFPImm(Imm->getValueAPF().convertToFloat());
else if (Imm->getType()->isDoubleTy())
MCOp = MCOperand::createFPImm(Imm->getValueAPF().convertToDouble());
else
llvm_unreachable("unknown floating point immediate type");
break;
}
case MachineOperand::MO_MachineBasicBlock:
MCOp = MCOperand::createExpr(
MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), Ctx));
break;
case MachineOperand::MO_GlobalAddress:
MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
break;
case MachineOperand::MO_ExternalSymbol:
MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
break;
}
OutMI.addOperand(MCOp);
}
}