AsmWriterInst.h

//===- AsmWriterInst.h - Classes encapsulating a printable inst -*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// These classes implement a parser for assembly strings.  The parser splits
// the string into operands, which can be literal strings (the constant bits of
// the string), actual operands (i.e., operands from the MachineInstr), and
// dynamically-generated text, specified by raw C++ code.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_UTILS_TABLEGEN_ASMWRITERINST_H
#define LLVM_UTILS_TABLEGEN_ASMWRITERINST_H

#include <string>
#include <vector>

namespace llvm {
class CodeGenInstruction;

struct AsmWriterOperand {
  enum OpType {
    // Output this text surrounded by quotes to the asm.
    isLiteralTextOperand,
    // This is the name of a routine to call to print the operand.
    isMachineInstrOperand,
    // Output this text verbatim to the asm writer.  It is code that
    // will output some text to the asm.
    isLiteralStatementOperand
  } OperandType;

  /// MiOpNo - For isMachineInstrOperand, this is the operand number of the
  /// machine instruction.
  unsigned MIOpNo = 0;

  /// Str - For isLiteralTextOperand, this IS the literal text.  For
  /// isMachineInstrOperand, this is the PrinterMethodName for the operand..
  /// For isLiteralStatementOperand, this is the code to insert verbatim
  /// into the asm writer.
  std::string Str;

  /// MiModifier - For isMachineInstrOperand, this is the modifier string for
  /// an operand, specified with syntax like ${opname:modifier}.
  std::string MiModifier;

  bool PCRel = false;

  // To make VS STL happy
  AsmWriterOperand(OpType op = isLiteralTextOperand) : OperandType(op) {}

  AsmWriterOperand(const std::string &LitStr, OpType op = isLiteralTextOperand)
      : OperandType(op), Str(LitStr) {}

  AsmWriterOperand(const std::string &Printer, unsigned _MIOpNo,
                   const std::string &Modifier,
                   OpType op = isMachineInstrOperand, bool PCRel = false)
      : OperandType(op), MIOpNo(_MIOpNo), Str(Printer), MiModifier(Modifier),
        PCRel(PCRel) {}

  bool operator!=(const AsmWriterOperand &Other) const {
    if (OperandType != Other.OperandType || Str != Other.Str)
      return true;
    if (OperandType == isMachineInstrOperand)
      return MIOpNo != Other.MIOpNo || MiModifier != Other.MiModifier ||
             PCRel != Other.PCRel;
    return false;
  }
  bool operator==(const AsmWriterOperand &Other) const {
    return !operator!=(Other);
  }

  /// getCode - Return the code that prints this operand.
  std::string getCode(bool PassSubtarget) const;
};

class AsmWriterInst {
public:
  std::vector<AsmWriterOperand> Operands;
  const CodeGenInstruction *CGI;
  unsigned CGIIndex;

  AsmWriterInst(const CodeGenInstruction &CGI, unsigned CGIIndex,
                unsigned Variant);

  /// MatchesAllButOneOp - If this instruction is exactly identical to the
  /// specified instruction except for one differing operand, return the
  /// differing operand number.  Otherwise return ~0.
  unsigned MatchesAllButOneOp(const AsmWriterInst &Other) const;

private:
  void AddLiteralString(const std::string &Str) {
    // If the last operand was already a literal text string, append this to
    // it, otherwise add a new operand.
    if (!Operands.empty() &&
        Operands.back().OperandType == AsmWriterOperand::isLiteralTextOperand)
      Operands.back().Str.append(Str);
    else
      Operands.push_back(AsmWriterOperand(Str));
  }
};
} // namespace llvm

#endif