llvm-6502/include/llvm/CodeGen/MachineMemOperand.h
2010-09-21 18:51:21 +00:00

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6.0 KiB
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//==- llvm/CodeGen/MachineMemOperand.h - MachineMemOperand class -*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the MachineMemOperand class, which is a
// description of a memory reference. It is used to help track dependencies
// in the backend.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINEMEMOPERAND_H
#define LLVM_CODEGEN_MACHINEMEMOPERAND_H
#include "llvm/System/DataTypes.h"
namespace llvm {
class Value;
class FoldingSetNodeID;
class raw_ostream;
/// MachinePointerInfo - This class contains a discriminated union of
/// information about pointers in memory operands, relating them back to LLVM IR
/// or to virtual locations (such as frame indices) that are exposed during
/// codegen.
struct MachinePointerInfo {
/// V - This is the IR pointer value for the access, or it is null if unknown.
/// If this is null, then the access is to a pointer in the default address
/// space.
const Value *V;
/// Offset - This is an offset from the base Value*.
int64_t Offset;
explicit MachinePointerInfo(const Value *v = 0, int64_t offset = 0)
: V(v), Offset(offset) {}
MachinePointerInfo getWithOffset(int64_t O) const {
if (V == 0) return MachinePointerInfo(0, 0);
return MachinePointerInfo(V, Offset+O);
}
/// getAddrSpace - Return the LLVM IR address space number that this pointer
/// points into.
unsigned getAddrSpace() const;
/// getConstantPool - Return a MachinePointerInfo record that refers to the
/// constant pool.
static MachinePointerInfo getConstantPool();
/// getFixedStack - Return a MachinePointerInfo record that refers to the
/// the specified FrameIndex.
static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0);
/// getJumpTable - Return a MachinePointerInfo record that refers to a
/// jump table entry.
static MachinePointerInfo getJumpTable();
/// getGOT - Return a MachinePointerInfo record that refers to a
/// GOT entry.
static MachinePointerInfo getGOT();
/// getStack - stack pointer relative access.
static MachinePointerInfo getStack(int64_t Offset);
};
//===----------------------------------------------------------------------===//
/// MachineMemOperand - A description of a memory reference used in the backend.
/// Instead of holding a StoreInst or LoadInst, this class holds the address
/// Value of the reference along with a byte size and offset. This allows it
/// to describe lowered loads and stores. Also, the special PseudoSourceValue
/// objects can be used to represent loads and stores to memory locations
/// that aren't explicit in the regular LLVM IR.
///
class MachineMemOperand {
MachinePointerInfo PtrInfo;
uint64_t Size;
unsigned Flags;
public:
/// Flags values. These may be or'd together.
enum MemOperandFlags {
/// The memory access reads data.
MOLoad = 1,
/// The memory access writes data.
MOStore = 2,
/// The memory access is volatile.
MOVolatile = 4,
/// The memory access is non-temporal.
MONonTemporal = 8,
// This is the number of bits we need to represent flags.
MOMaxBits = 4
};
/// MachineMemOperand - Construct an MachineMemOperand object with the
/// specified PtrInfo, flags, size, and base alignment.
MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s,
unsigned base_alignment);
const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
/// getValue - Return the base address of the memory access. This may either
/// be a normal LLVM IR Value, or one of the special values used in CodeGen.
/// Special values are those obtained via
/// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and
/// other PseudoSourceValue member functions which return objects which stand
/// for frame/stack pointer relative references and other special references
/// which are not representable in the high-level IR.
const Value *getValue() const { return PtrInfo.V; }
/// getFlags - Return the raw flags of the source value, \see MemOperandFlags.
unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); }
/// getOffset - For normal values, this is a byte offset added to the base
/// address. For PseudoSourceValue::FPRel values, this is the FrameIndex
/// number.
int64_t getOffset() const { return PtrInfo.Offset; }
/// getSize - Return the size in bytes of the memory reference.
uint64_t getSize() const { return Size; }
/// getAlignment - Return the minimum known alignment in bytes of the
/// actual memory reference.
uint64_t getAlignment() const;
/// getBaseAlignment - Return the minimum known alignment in bytes of the
/// base address, without the offset.
uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; }
bool isLoad() const { return Flags & MOLoad; }
bool isStore() const { return Flags & MOStore; }
bool isVolatile() const { return Flags & MOVolatile; }
bool isNonTemporal() const { return Flags & MONonTemporal; }
/// refineAlignment - Update this MachineMemOperand to reflect the alignment
/// of MMO, if it has a greater alignment. This must only be used when the
/// new alignment applies to all users of this MachineMemOperand.
void refineAlignment(const MachineMemOperand *MMO);
/// setValue - Change the SourceValue for this MachineMemOperand. This
/// should only be used when an object is being relocated and all references
/// to it are being updated.
void setValue(const Value *NewSV) { PtrInfo.V = NewSV; }
void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; }
/// Profile - Gather unique data for the object.
///
void Profile(FoldingSetNodeID &ID) const;
};
raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO);
} // End llvm namespace
#endif