BPFInstPrinter.cpp
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//===-- BPFInstPrinter.cpp - Convert BPF MCInst to asm syntax -------------===//
//
// 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 class prints an BPF MCInst to a .s file.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/BPFInstPrinter.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
using namespace llvm;
#define DEBUG_TYPE "asm-printer"
// Include the auto-generated portion of the assembly writer.
#include "BPFGenAsmWriter.inc"
void BPFInstPrinter::printInst(const MCInst *MI, uint64_t Address,
StringRef Annot, const MCSubtargetInfo &STI,
raw_ostream &O) {
printInstruction(MI, Address, O);
printAnnotation(O, Annot);
}
static void printExpr(const MCExpr *Expr, raw_ostream &O) {
#ifndef NDEBUG
const MCSymbolRefExpr *SRE;
if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr))
SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
else
SRE = dyn_cast<MCSymbolRefExpr>(Expr);
assert(SRE && "Unexpected MCExpr type.");
MCSymbolRefExpr::VariantKind Kind = SRE->getKind();
assert(Kind == MCSymbolRefExpr::VK_None);
#endif
O << *Expr;
}
void BPFInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O, const char *Modifier) {
assert((Modifier == 0 || Modifier[0] == 0) && "No modifiers supported");
const MCOperand &Op = MI->getOperand(OpNo);
if (Op.isReg()) {
O << getRegisterName(Op.getReg());
} else if (Op.isImm()) {
O << formatImm((int32_t)Op.getImm());
} else {
assert(Op.isExpr() && "Expected an expression");
printExpr(Op.getExpr(), O);
}
}
void BPFInstPrinter::printMemOperand(const MCInst *MI, int OpNo, raw_ostream &O,
const char *Modifier) {
const MCOperand &RegOp = MI->getOperand(OpNo);
const MCOperand &OffsetOp = MI->getOperand(OpNo + 1);
// register
assert(RegOp.isReg() && "Register operand not a register");
O << getRegisterName(RegOp.getReg());
// offset
if (OffsetOp.isImm()) {
auto Imm = OffsetOp.getImm();
if (Imm >= 0)
O << " + " << formatImm(Imm);
else
O << " - " << formatImm(-Imm);
} else {
assert(0 && "Expected an immediate");
}
}
void BPFInstPrinter::printImm64Operand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
const MCOperand &Op = MI->getOperand(OpNo);
if (Op.isImm())
O << formatImm(Op.getImm());
else if (Op.isExpr())
printExpr(Op.getExpr(), O);
else
O << Op;
}
void BPFInstPrinter::printBrTargetOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
const MCOperand &Op = MI->getOperand(OpNo);
if (Op.isImm()) {
int16_t Imm = Op.getImm();
O << ((Imm >= 0) ? "+" : "") << formatImm(Imm);
} else if (Op.isExpr()) {
printExpr(Op.getExpr(), O);
} else {
O << Op;
}
}