X86MCExpr.h

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//=--- X86MCExpr.h - X86 specific MC expression classes ---*- C++ -*-=//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file describes X86-specific MCExprs, i.e, registers used for
// extended variable assignments.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_X86_MCTARGETDESC_X86MCEXPR_H
#define LLVM_LIB_TARGET_X86_MCTARGETDESC_X86MCEXPR_H

#include "InstPrinter/X86ATTInstPrinter.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Support/ErrorHandling.h"

namespace llvm {

class X86MCExpr : public MCTargetExpr {

private:
  const int64_t RegNo; // All

  explicit X86MCExpr(int64_t R) : RegNo(R) {}

public:
  /// @name Construction
  /// @{

  static const X86MCExpr *create(int64_t RegNo, MCContext &Ctx) {
    return new (Ctx) X86MCExpr(RegNo);
  }

  /// @}
  /// @name Accessors
  /// @{

  /// getSubExpr - Get the child of this expression.
  int64_t getRegNo() const { return RegNo; }

  /// @}

  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override {
    if (!MAI || MAI->getAssemblerDialect() == 0)
      OS << '%';
    OS << X86ATTInstPrinter::getRegisterName(RegNo);
  }

  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
                                 const MCFixup *Fixup) const override {
    return false;
  }
  // Register values should be inlined as they are not valid .set expressions.
  bool inlineAssignedExpr() const override { return true; }
  bool isEqualTo(const MCExpr *X) const override {
    if (auto *E = dyn_cast<X86MCExpr>(X))
      return getRegNo() == E->getRegNo();
    return false;
  }
  void visitUsedExpr(MCStreamer &Streamer) const override{};
  MCFragment *findAssociatedFragment() const override { return nullptr; }

  // There are no TLS X86MCExprs at the moment.
  void fixELFSymbolsInTLSFixups(MCAssembler &Asm) const override {}

  static bool classof(const MCExpr *E) {
    return E->getKind() == MCExpr::Target;
  }
};

} // end namespace llvm

#endif