llvm-6502/include/llvm/Target/MInstructionInfo.h
2002-10-25 23:00:40 +00:00

86 lines
3.1 KiB
C++

//===- Target/MInstructionInfo.h - Target Instruction Information -*-C++-*-===//
//
// MInstruction's are completely generic instructions that provide very little
// interpretation upon their arguments and sementics. This file defines an
// interface that should be used to get information about the semantics of the
// actual instructions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MINSTRUCTIONINFO_H
#define LLVM_CODEGEN_MINSTRUCTIONINFO_H
#include <assert.h>
#include <iosfwd>
class MInstruction;
class MRegisterInfo;
/// MInstructionDesc - This record contains all of the information known about a
/// particular instruction. Note that several instructions with the same
/// mnemonic may be represented in the target machine as different instructions.
///
struct MInstructionDesc {
const char *Name; // Assembly language mnemonic for the instruction.
unsigned Flags; // Flags identifying inst properties (defined below)
unsigned TSFlags; // Target Specific Flags
};
/// MIF namespace - This namespace contains flags that pertain to machine
/// instructions
///
namespace MIF {
enum {
// Memory flags...
LOAD = 1 << 0, // This instruction loads from memory
STORE = 1 << 1, // This instruction stores to memory
// Control flow flags...
CALL = 1 << 2, // This instruction calls another function
RET = 1 << 3, // This instruction returns from function
BRANCH = 1 << 4, // This instruction is a branch
};
};
/// MInstructionInfo base class - We assume that the target defines a static
/// array of MInstructionDesc objects that represent all of the machine
/// instructions that the target has. As such, we simply have to track a
/// pointer to this array so that we can turn an instruction opcode into an
/// instruction descriptor.
///
class MInstructionInfo {
const MInstructionDesc *Desc; // Pointer to the descriptor array
unsigned NumInstructions; // Number of entries in the array
protected:
MInstructionInfo(const MInstructionDesc *D, unsigned NI)
: Desc(D), NumInstructions(NI) {}
public:
enum { // Target independant constants
PHIOpcode = 0, /// Opcode for PHI instruction
NoOpOpcode = 1, /// Opcode for noop instruction
};
/// getRegisterInfo - MInstructionInfo is a superset of MRegister info. As
/// such, whenever a client has an instance of instruction info, it should
/// always be able to get register info as well (through this method).
///
virtual const MRegisterInfo &getRegisterInfo() const = 0;
const MInstructionDesc &operator[](unsigned Opcode) const {
assert(Opcode < NumInstructions &&
"Attempting to access record for invalid opcode!");
return Desc[Opcode];
}
/// Provide a get method, equivalent to [], but more useful if we have a
/// pointer to this object.
const MInstructionDesc &get(unsigned Opcode) const {
return operator[](Opcode);
}
virtual void print(const MInstruction *MI, std::ostream &O) const = 0;
};
#endif