lib/Target/ARM/ARMConstantPoolValue.h

//===- ARMConstantPoolValue.h - ARM constantpool value ----------*- 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 ARM specific constantpool value class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TARGET_ARM_CONSTANTPOOLVALUE_H
#define LLVM_TARGET_ARM_CONSTANTPOOLVALUE_H

#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/Support/ErrorHandling.h"
#include <cstddef>

namespace llvm {

class BlockAddress;
class Constant;
class GlobalValue;
class LLVMContext;
class MachineBasicBlock;

namespace ARMCP {
  enum ARMCPKind {
    CPValue,
    CPExtSymbol,
    CPBlockAddress,
    CPLSDA,
    CPMachineBasicBlock
  };

  enum ARMCPModifier {
    no_modifier,
    TLSGD,
    GOT,
    GOTOFF,
    GOTTPOFF,
    TPOFF
  };
}

/// ARMConstantPoolValue - ARM specific constantpool value. This is used to
/// represent PC-relative displacement between the address of the load
/// instruction and the constant being loaded, i.e. (&GV-(LPIC+8)).
class ARMConstantPoolValue : public MachineConstantPoolValue {
  const MachineBasicBlock *MBB; // MachineBasicBlock being loaded.
  const char *S;           // ExtSymbol being loaded.
  unsigned LabelId;        // Label id of the load.
  ARMCP::ARMCPKind Kind;   // Kind of constant.
  unsigned char PCAdjust;  // Extra adjustment if constantpool is pc-relative.
                           // 8 for ARM, 4 for Thumb.
  ARMCP::ARMCPModifier Modifier;   // GV modifier i.e. (&GV(modifier)-(LPIC+8))
  bool AddCurrentAddress;

protected:
  ARMConstantPoolValue(Type *Ty, unsigned id, ARMCP::ARMCPKind Kind,
                       unsigned char PCAdj, ARMCP::ARMCPModifier Modifier,
                       bool AddCurrentAddress);

public:
  ARMConstantPoolValue(LLVMContext &C, const MachineBasicBlock *mbb,unsigned id,
                       ARMCP::ARMCPKind Kind = ARMCP::CPValue,
                       unsigned char PCAdj = 0,
                       ARMCP::ARMCPModifier Modifier = ARMCP::no_modifier,
                       bool AddCurrentAddress = false);
  ARMConstantPoolValue(LLVMContext &C, const char *s, unsigned id,
                       unsigned char PCAdj = 0,
                       ARMCP::ARMCPModifier Modifier = ARMCP::no_modifier,
                       bool AddCurrentAddress = false);
  ~ARMConstantPoolValue();

  const char *getSymbol() const { return S; }
  const MachineBasicBlock *getMBB() const;

  ARMCP::ARMCPModifier getModifier() const { return Modifier; }
  const char *getModifierText() const;
  bool hasModifier() const { return Modifier != ARMCP::no_modifier; }

  bool mustAddCurrentAddress() const { return AddCurrentAddress; }

  unsigned getLabelId() const { return LabelId; }
  unsigned char getPCAdjustment() const { return PCAdjust; }

  bool isGlobalValue() const { return Kind == ARMCP::CPValue; }
  bool isExtSymbol() const { return Kind == ARMCP::CPExtSymbol; }
  bool isBlockAddress() const { return Kind == ARMCP::CPBlockAddress; }
  bool isLSDA() const { return Kind == ARMCP::CPLSDA; }
  bool isMachineBasicBlock() { return Kind == ARMCP::CPMachineBasicBlock; }

  virtual unsigned getRelocationInfo() const { return 2; }

  virtual int getExistingMachineCPValue(MachineConstantPool *CP,
                                        unsigned Alignment);

  virtual void addSelectionDAGCSEId(FoldingSetNodeID &ID);

  /// hasSameValue - Return true if this ARM constpool value can share the same
  /// constantpool entry as another ARM constpool value.
  virtual bool hasSameValue(ARMConstantPoolValue *ACPV);

  virtual void print(raw_ostream &O) const;
  void print(raw_ostream *O) const { if (O) print(*O); }
  void dump() const;

  static bool classof(const ARMConstantPoolValue *) { return true; }
};

inline raw_ostream &operator<<(raw_ostream &O, const ARMConstantPoolValue &V) {
  V.print(O);
  return O;
}

/// ARMConstantPoolConstant - ARM-specific constant pool values for Constants,
/// Functions, and BlockAddresses.
class ARMConstantPoolConstant : public ARMConstantPoolValue {
  const Constant *CVal;         // Constant being loaded.

  ARMConstantPoolConstant(const Constant *C,
                          unsigned ID,
                          ARMCP::ARMCPKind Kind,
                          unsigned char PCAdj,
                          ARMCP::ARMCPModifier Modifier,
                          bool AddCurrentAddress);
  ARMConstantPoolConstant(Type *Ty, const Constant *C,
                          unsigned ID,
                          ARMCP::ARMCPKind Kind,
                          unsigned char PCAdj,
                          ARMCP::ARMCPModifier Modifier,
                          bool AddCurrentAddress);

public:
  static ARMConstantPoolConstant *Create(const Constant *C, unsigned ID);
  static ARMConstantPoolConstant *Create(const GlobalValue *GV,
                                         ARMCP::ARMCPModifier Modifier);
  static ARMConstantPoolConstant *Create(const Constant *C, unsigned ID,
                                         ARMCP::ARMCPKind Kind,
                                         unsigned char PCAdj);
  static ARMConstantPoolConstant *Create(const Constant *C, unsigned ID,
                                         ARMCP::ARMCPKind Kind,
                                         unsigned char PCAdj,
                                         ARMCP::ARMCPModifier Modifier,
                                         bool AddCurrentAddress);

  const GlobalValue *getGV() const;
  const BlockAddress *getBlockAddress() const;

  virtual int getExistingMachineCPValue(MachineConstantPool *CP,
                                        unsigned Alignment);

  /// hasSameValue - Return true if this ARM constpool value can share the same
  /// constantpool entry as another ARM constpool value.
  virtual bool hasSameValue(ARMConstantPoolValue *ACPV);

  virtual void addSelectionDAGCSEId(FoldingSetNodeID &ID);

  virtual void print(raw_ostream &O) const;
  static bool classof(const ARMConstantPoolValue *APV) {
    return APV->isGlobalValue() || APV->isBlockAddress() || APV->isLSDA();
  }
  static bool classof(const ARMConstantPoolConstant *) { return true; }
};

} // End llvm namespace

#endif