lib/CodeGen/PseudoSourceValue.cpp

//===-- llvm/CodeGen/PseudoSourceValue.cpp ----------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the PseudoSourceValue class.
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ManagedStatic.h"
#include <map>

namespace llvm {
  static ManagedStatic<PseudoSourceValue[4]> PSVs;

  const PseudoSourceValue *PseudoSourceValue::getStack()
  { return &(*PSVs)[0]; }
  const PseudoSourceValue *PseudoSourceValue::getGOT()
  { return &(*PSVs)[1]; }
  const PseudoSourceValue *PseudoSourceValue::getJumpTable()
  { return &(*PSVs)[2]; }
  const PseudoSourceValue *PseudoSourceValue::getConstantPool()
  { return &(*PSVs)[3]; }

  static const char *const PSVNames[] = {
    "Stack",
    "GOT",
    "JumpTable",
    "ConstantPool"
  };

  PseudoSourceValue::PseudoSourceValue() :
    Value(PointerType::getUnqual(Type::Int8Ty), PseudoSourceValueVal) {}

  void PseudoSourceValue::print(std::ostream &OS) const {
    OS << PSVNames[this - *PSVs];
  }

  /// FixedStackPseudoSourceValue - A specialized PseudoSourceValue
  /// for holding FixedStack values, which must include a frame
  /// index.
  class VISIBILITY_HIDDEN FixedStackPseudoSourceValue
    : public PseudoSourceValue {
    const int FI;
  public:
    explicit FixedStackPseudoSourceValue(int fi) : FI(fi) {}

    virtual bool isConstant(const MachineFrameInfo *MFI) const;

    virtual void print(std::ostream &OS) const {
      OS << "FixedStack" << FI;
    }
  };

  static ManagedStatic<std::map<int, const PseudoSourceValue *> > FSValues;

  const PseudoSourceValue *PseudoSourceValue::getFixedStack(int FI) {
    const PseudoSourceValue *&V = (*FSValues)[FI];
    if (!V)
      V = new FixedStackPseudoSourceValue(FI);
    return V;
  }

  bool PseudoSourceValue::isConstant(const MachineFrameInfo *) const {
    if (this == getStack())
      return false;
    if (this == getGOT() ||
        this == getConstantPool() ||
        this == getJumpTable())
      return true;
    assert(0 && "Unknown PseudoSourceValue!");
    return false;
  }

  bool
  FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const {
    return MFI && MFI->isImmutableObjectIndex(FI);
  }
}