llvm/lib/Target/X86/X86InstrInfo.h
2003-08-06 15:32:20 +00:00

178 lines
6.7 KiB
C++

//===- X86InstructionInfo.h - X86 Instruction Information ---------*-C++-*-===//
//
// This file contains the X86 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef X86INSTRUCTIONINFO_H
#define X86INSTRUCTIONINFO_H
#include "llvm/Target/TargetInstrInfo.h"
#include "X86RegisterInfo.h"
/// X86II - This namespace holds all of the target specific flags that
/// instruction info tracks.
///
namespace X86II {
enum {
//===------------------------------------------------------------------===//
// Instruction types. These are the standard/most common forms for X86
// instructions.
//
// PseudoFrm - This represents an instruction that is a pseudo instruction
// or one that has not been implemented yet. It is illegal to code generate
// it, but tolerated for intermediate implementation stages.
Pseudo = 0,
/// Raw - This form is for instructions that don't have any operands, so
/// they are just a fixed opcode value, like 'leave'.
RawFrm = 1,
/// AddRegFrm - This form is used for instructions like 'push r32' that have
/// their one register operand added to their opcode.
AddRegFrm = 2,
/// MRMDestReg - This form is used for instructions that use the Mod/RM byte
/// to specify a destination, which in this case is a register.
///
MRMDestReg = 3,
/// MRMDestMem - This form is used for instructions that use the Mod/RM byte
/// to specify a destination, which in this case is memory.
///
MRMDestMem = 4,
/// MRMSrcReg - This form is used for instructions that use the Mod/RM byte
/// to specify a source, which in this case is a register.
///
MRMSrcReg = 5,
/// MRMSrcMem - This form is used for instructions that use the Mod/RM byte
/// to specify a source, which in this case is memory.
///
MRMSrcMem = 6,
/// MRMS[0-7][rm] - These forms are used to represent instructions that use
/// a Mod/RM byte, and use the middle field to hold extended opcode
/// information. In the intel manual these are represented as /0, /1, ...
///
// First, instructions that operate on a register r/m operand...
MRMS0r = 16, MRMS1r = 17, MRMS2r = 18, MRMS3r = 19, // Format /0 /1 /2 /3
MRMS4r = 20, MRMS5r = 21, MRMS6r = 22, MRMS7r = 23, // Format /4 /5 /6 /7
// Next, instructions that operate on a memory r/m operand...
MRMS0m = 24, MRMS1m = 25, MRMS2m = 26, MRMS3m = 27, // Format /0 /1 /2 /3
MRMS4m = 28, MRMS5m = 29, MRMS6m = 30, MRMS7m = 31, // Format /4 /5 /6 /7
FormMask = 31,
//===------------------------------------------------------------------===//
// Actual flags...
// OpSize - Set if this instruction requires an operand size prefix (0x66),
// which most often indicates that the instruction operates on 16 bit data
// instead of 32 bit data.
OpSize = 1 << 5,
// Op0Mask - There are several prefix bytes that are used to form two byte
// opcodes. These are currently 0x0F, and 0xD8-0xDF. This mask is used to
// obtain the setting of this field. If no bits in this field is set, there
// is no prefix byte for obtaining a multibyte opcode.
//
Op0Shift = 6,
Op0Mask = 0xF << Op0Shift,
// TB - TwoByte - Set if this instruction has a two byte opcode, which
// starts with a 0x0F byte before the real opcode.
TB = 1 << Op0Shift,
// D8-DF - These escape opcodes are used by the floating point unit. These
// values must remain sequential.
D8 = 2 << Op0Shift, D9 = 3 << Op0Shift,
DA = 4 << Op0Shift, DB = 5 << Op0Shift,
DC = 6 << Op0Shift, DD = 7 << Op0Shift,
DE = 8 << Op0Shift, DF = 9 << Op0Shift,
//===------------------------------------------------------------------===//
// This three-bit field describes the size of a memory operand. Zero is
// unused so that we can tell if we forgot to set a value.
ArgShift = 10,
ArgMask = 7 << ArgShift,
Arg8 = 1 << ArgShift,
Arg16 = 2 << ArgShift,
Arg32 = 3 << ArgShift,
Arg64 = 4 << ArgShift, // 64 bit int argument for FILD64
ArgF32 = 5 << ArgShift,
ArgF64 = 6 << ArgShift,
ArgF80 = 7 << ArgShift,
//===------------------------------------------------------------------===//
// FP Instruction Classification... Zero is non-fp instruction.
// FPTypeMask - Mask for all of the FP types...
FPTypeShift = 13,
FPTypeMask = 7 << FPTypeShift,
// ZeroArgFP - 0 arg FP instruction which implicitly pushes ST(0), f.e. fld0
ZeroArgFP = 1 << FPTypeShift,
// OneArgFP - 1 arg FP instructions which implicitly read ST(0), such as fst
OneArgFP = 2 << FPTypeShift,
// OneArgFPRW - 1 arg FP instruction which implicitly read ST(0) and write a
// result back to ST(0). For example, fcos, fsqrt, etc.
//
OneArgFPRW = 3 << FPTypeShift,
// TwoArgFP - 2 arg FP instructions which implicitly read ST(0), and an
// explicit argument, storing the result to either ST(0) or the implicit
// argument. For example: fadd, fsub, fmul, etc...
TwoArgFP = 4 << FPTypeShift,
// SpecialFP - Special instruction forms. Dispatch by opcode explicitly.
SpecialFP = 5 << FPTypeShift,
// PrintImplUses - Print out implicit uses in the assembly output.
PrintImplUses = 1 << 16,
OpcodeShift = 17,
OpcodeMask = 0xFF << OpcodeShift,
// Bits 25 -> 31 are unused
};
}
class X86InstrInfo : public TargetInstrInfo {
const X86RegisterInfo RI;
public:
X86InstrInfo();
/// getRegisterInfo - TargetInstrInfo 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 { return RI; }
/// createNOPinstr - returns the target's implementation of NOP, which is
/// usually a pseudo-instruction, implemented by a degenerate version of
/// another instruction, e.g. X86: `xchg ax, ax'; SparcV9: `sethi r0, r0, r0'
///
MachineInstr* createNOPinstr() const;
/// isNOPinstr - not having a special NOP opcode, we need to know if a given
/// instruction is interpreted as an `official' NOP instr, i.e., there may be
/// more than one way to `do nothing' but only one canonical way to slack off.
///
bool isNOPinstr(const MachineInstr &MI) const;
// getBaseOpcodeFor - This function returns the "base" X86 opcode for the
// specified opcode number.
//
unsigned char getBaseOpcodeFor(unsigned Opcode) const {
return get(Opcode).TSFlags >> X86II::OpcodeShift;
}
};
#endif