llvm-6502/lib/Target/X86/X86InstrInfo.h
2007-12-08 23:58:46 +00:00

291 lines
11 KiB
C++

//===- X86InstrInfo.h - X86 Instruction Information ------------*- C++ -*- ===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the X86 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef X86INSTRUCTIONINFO_H
#define X86INSTRUCTIONINFO_H
#include "llvm/Target/TargetInstrInfo.h"
#include "X86RegisterInfo.h"
namespace llvm {
class X86RegisterInfo;
class X86TargetMachine;
namespace X86 {
// X86 specific condition code. These correspond to X86_*_COND in
// X86InstrInfo.td. They must be kept in synch.
enum CondCode {
COND_A = 0,
COND_AE = 1,
COND_B = 2,
COND_BE = 3,
COND_E = 4,
COND_G = 5,
COND_GE = 6,
COND_L = 7,
COND_LE = 8,
COND_NE = 9,
COND_NO = 10,
COND_NP = 11,
COND_NS = 12,
COND_O = 13,
COND_P = 14,
COND_S = 15,
COND_INVALID
};
// Turn condition code into conditional branch opcode.
unsigned GetCondBranchFromCond(CondCode CC);
/// GetOppositeBranchCondition - Return the inverse of the specified cond,
/// e.g. turning COND_E to COND_NE.
CondCode GetOppositeBranchCondition(X86::CondCode CC);
}
/// 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,
/// MRM[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...
MRM0r = 16, MRM1r = 17, MRM2r = 18, MRM3r = 19, // Format /0 /1 /2 /3
MRM4r = 20, MRM5r = 21, MRM6r = 22, MRM7r = 23, // Format /4 /5 /6 /7
// Next, instructions that operate on a memory r/m operand...
MRM0m = 24, MRM1m = 25, MRM2m = 26, MRM3m = 27, // Format /0 /1 /2 /3
MRM4m = 28, MRM5m = 29, MRM6m = 30, MRM7m = 31, // Format /4 /5 /6 /7
// MRMInitReg - This form is used for instructions whose source and
// destinations are the same register.
MRMInitReg = 32,
FormMask = 63,
//===------------------------------------------------------------------===//
// 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 << 6,
// AsSize - Set if this instruction requires an operand size prefix (0x67),
// which most often indicates that the instruction address 16 bit address
// instead of 32 bit address (or 32 bit address in 64 bit mode).
AdSize = 1 << 7,
//===------------------------------------------------------------------===//
// Op0Mask - There are several prefix bytes that are used to form two byte
// opcodes. These are currently 0x0F, 0xF3, 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 = 8,
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,
// REP - The 0xF3 prefix byte indicating repetition of the following
// instruction.
REP = 2 << Op0Shift,
// D8-DF - These escape opcodes are used by the floating point unit. These
// values must remain sequential.
D8 = 3 << Op0Shift, D9 = 4 << Op0Shift,
DA = 5 << Op0Shift, DB = 6 << Op0Shift,
DC = 7 << Op0Shift, DD = 8 << Op0Shift,
DE = 9 << Op0Shift, DF = 10 << Op0Shift,
// XS, XD - These prefix codes are for single and double precision scalar
// floating point operations performed in the SSE registers.
XD = 11 << Op0Shift, XS = 12 << Op0Shift,
// T8, TA - Prefix after the 0x0F prefix.
T8 = 13 << Op0Shift, TA = 14 << Op0Shift,
//===------------------------------------------------------------------===//
// REX_W - REX prefixes are instruction prefixes used in 64-bit mode.
// They are used to specify GPRs and SSE registers, 64-bit operand size,
// etc. We only cares about REX.W and REX.R bits and only the former is
// statically determined.
//
REXShift = 12,
REX_W = 1 << REXShift,
//===------------------------------------------------------------------===//
// This three-bit field describes the size of an immediate operand. Zero is
// unused so that we can tell if we forgot to set a value.
ImmShift = 13,
ImmMask = 7 << ImmShift,
Imm8 = 1 << ImmShift,
Imm16 = 2 << ImmShift,
Imm32 = 3 << ImmShift,
Imm64 = 4 << ImmShift,
//===------------------------------------------------------------------===//
// FP Instruction Classification... Zero is non-fp instruction.
// FPTypeMask - Mask for all of the FP types...
FPTypeShift = 16,
FPTypeMask = 7 << FPTypeShift,
// NotFP - The default, set for instructions that do not use FP registers.
NotFP = 0 << 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,
// CompareFP - 2 arg FP instructions which implicitly read ST(0) and an
// explicit argument, but have no destination. Example: fucom, fucomi, ...
CompareFP = 5 << FPTypeShift,
// CondMovFP - "2 operand" floating point conditional move instructions.
CondMovFP = 6 << FPTypeShift,
// SpecialFP - Special instruction forms. Dispatch by opcode explicitly.
SpecialFP = 7 << FPTypeShift,
// Bits 19 -> 23 are unused
OpcodeShift = 24,
OpcodeMask = 0xFF << OpcodeShift
};
}
class X86InstrInfo : public TargetInstrInfo {
X86TargetMachine &TM;
const X86RegisterInfo RI;
public:
X86InstrInfo(X86TargetMachine &tm);
/// 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; }
// Return true if the instruction is a register to register move and
// leave the source and dest operands in the passed parameters.
//
bool isMoveInstr(const MachineInstr& MI, unsigned& sourceReg,
unsigned& destReg) const;
unsigned isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const;
unsigned isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const;
bool isReallyTriviallyReMaterializable(MachineInstr *MI) const;
/// convertToThreeAddress - This method must be implemented by targets that
/// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
/// may be able to convert a two-address instruction into a true
/// three-address instruction on demand. This allows the X86 target (for
/// example) to convert ADD and SHL instructions into LEA instructions if they
/// would require register copies due to two-addressness.
///
/// This method returns a null pointer if the transformation cannot be
/// performed, otherwise it returns the new instruction.
///
virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables &LV) const;
/// commuteInstruction - We have a few instructions that must be hacked on to
/// commute them.
///
virtual MachineInstr *commuteInstruction(MachineInstr *MI) const;
// Branch analysis.
virtual bool isUnpredicatedTerminator(const MachineInstr* MI) const;
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
std::vector<MachineOperand> &Cond) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const std::vector<MachineOperand> &Cond) const;
virtual bool BlockHasNoFallThrough(MachineBasicBlock &MBB) const;
virtual bool ReverseBranchCondition(std::vector<MachineOperand> &Cond) const;
const TargetRegisterClass *getPointerRegClass() const;
// getBaseOpcodeFor - This function returns the "base" X86 opcode for the
// specified machine instruction.
//
unsigned char getBaseOpcodeFor(const TargetInstrDescriptor *TID) const {
return TID->TSFlags >> X86II::OpcodeShift;
}
unsigned char getBaseOpcodeFor(MachineOpCode Opcode) const {
return getBaseOpcodeFor(&get(Opcode));
}
};
} // End llvm namespace
#endif