1 //===- X86InstrInfo.h - X86 Instruction Information ------------*- C++ -*- ===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the X86 implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #ifndef X86INSTRUCTIONINFO_H
15 #define X86INSTRUCTIONINFO_H
17 #include "llvm/Target/TargetInstrInfo.h"
18 #include "X86RegisterInfo.h"
19 #include "llvm/ADT/IndexedMap.h"
20 #include "llvm/Target/MRegisterInfo.h"
23 class X86RegisterInfo;
24 class X86TargetMachine;
27 // X86 specific condition code. These correspond to X86_*_COND in
28 // X86InstrInfo.td. They must be kept in synch.
49 // Turn condition code into conditional branch opcode.
50 unsigned GetCondBranchFromCond(CondCode CC);
52 /// GetOppositeBranchCondition - Return the inverse of the specified cond,
53 /// e.g. turning COND_E to COND_NE.
54 CondCode GetOppositeBranchCondition(X86::CondCode CC);
58 /// X86II - This namespace holds all of the target specific flags that
59 /// instruction info tracks.
63 //===------------------------------------------------------------------===//
64 // Instruction types. These are the standard/most common forms for X86
68 // PseudoFrm - This represents an instruction that is a pseudo instruction
69 // or one that has not been implemented yet. It is illegal to code generate
70 // it, but tolerated for intermediate implementation stages.
73 /// Raw - This form is for instructions that don't have any operands, so
74 /// they are just a fixed opcode value, like 'leave'.
77 /// AddRegFrm - This form is used for instructions like 'push r32' that have
78 /// their one register operand added to their opcode.
81 /// MRMDestReg - This form is used for instructions that use the Mod/RM byte
82 /// to specify a destination, which in this case is a register.
86 /// MRMDestMem - This form is used for instructions that use the Mod/RM byte
87 /// to specify a destination, which in this case is memory.
91 /// MRMSrcReg - This form is used for instructions that use the Mod/RM byte
92 /// to specify a source, which in this case is a register.
96 /// MRMSrcMem - This form is used for instructions that use the Mod/RM byte
97 /// to specify a source, which in this case is memory.
101 /// MRM[0-7][rm] - These forms are used to represent instructions that use
102 /// a Mod/RM byte, and use the middle field to hold extended opcode
103 /// information. In the intel manual these are represented as /0, /1, ...
106 // First, instructions that operate on a register r/m operand...
107 MRM0r = 16, MRM1r = 17, MRM2r = 18, MRM3r = 19, // Format /0 /1 /2 /3
108 MRM4r = 20, MRM5r = 21, MRM6r = 22, MRM7r = 23, // Format /4 /5 /6 /7
110 // Next, instructions that operate on a memory r/m operand...
111 MRM0m = 24, MRM1m = 25, MRM2m = 26, MRM3m = 27, // Format /0 /1 /2 /3
112 MRM4m = 28, MRM5m = 29, MRM6m = 30, MRM7m = 31, // Format /4 /5 /6 /7
114 // MRMInitReg - This form is used for instructions whose source and
115 // destinations are the same register.
120 //===------------------------------------------------------------------===//
123 // OpSize - Set if this instruction requires an operand size prefix (0x66),
124 // which most often indicates that the instruction operates on 16 bit data
125 // instead of 32 bit data.
128 // AsSize - Set if this instruction requires an operand size prefix (0x67),
129 // which most often indicates that the instruction address 16 bit address
130 // instead of 32 bit address (or 32 bit address in 64 bit mode).
133 //===------------------------------------------------------------------===//
134 // Op0Mask - There are several prefix bytes that are used to form two byte
135 // opcodes. These are currently 0x0F, 0xF3, and 0xD8-0xDF. This mask is
136 // used to obtain the setting of this field. If no bits in this field is
137 // set, there is no prefix byte for obtaining a multibyte opcode.
140 Op0Mask = 0xF << Op0Shift,
142 // TB - TwoByte - Set if this instruction has a two byte opcode, which
143 // starts with a 0x0F byte before the real opcode.
146 // REP - The 0xF3 prefix byte indicating repetition of the following
150 // D8-DF - These escape opcodes are used by the floating point unit. These
151 // values must remain sequential.
152 D8 = 3 << Op0Shift, D9 = 4 << Op0Shift,
153 DA = 5 << Op0Shift, DB = 6 << Op0Shift,
154 DC = 7 << Op0Shift, DD = 8 << Op0Shift,
155 DE = 9 << Op0Shift, DF = 10 << Op0Shift,
157 // XS, XD - These prefix codes are for single and double precision scalar
158 // floating point operations performed in the SSE registers.
159 XD = 11 << Op0Shift, XS = 12 << Op0Shift,
161 // T8, TA - Prefix after the 0x0F prefix.
162 T8 = 13 << Op0Shift, TA = 14 << Op0Shift,
164 //===------------------------------------------------------------------===//
165 // REX_W - REX prefixes are instruction prefixes used in 64-bit mode.
166 // They are used to specify GPRs and SSE registers, 64-bit operand size,
167 // etc. We only cares about REX.W and REX.R bits and only the former is
168 // statically determined.
171 REX_W = 1 << REXShift,
173 //===------------------------------------------------------------------===//
174 // This three-bit field describes the size of an immediate operand. Zero is
175 // unused so that we can tell if we forgot to set a value.
177 ImmMask = 7 << ImmShift,
178 Imm8 = 1 << ImmShift,
179 Imm16 = 2 << ImmShift,
180 Imm32 = 3 << ImmShift,
181 Imm64 = 4 << ImmShift,
183 //===------------------------------------------------------------------===//
184 // FP Instruction Classification... Zero is non-fp instruction.
186 // FPTypeMask - Mask for all of the FP types...
188 FPTypeMask = 7 << FPTypeShift,
190 // NotFP - The default, set for instructions that do not use FP registers.
191 NotFP = 0 << FPTypeShift,
193 // ZeroArgFP - 0 arg FP instruction which implicitly pushes ST(0), f.e. fld0
194 ZeroArgFP = 1 << FPTypeShift,
196 // OneArgFP - 1 arg FP instructions which implicitly read ST(0), such as fst
197 OneArgFP = 2 << FPTypeShift,
199 // OneArgFPRW - 1 arg FP instruction which implicitly read ST(0) and write a
200 // result back to ST(0). For example, fcos, fsqrt, etc.
202 OneArgFPRW = 3 << FPTypeShift,
204 // TwoArgFP - 2 arg FP instructions which implicitly read ST(0), and an
205 // explicit argument, storing the result to either ST(0) or the implicit
206 // argument. For example: fadd, fsub, fmul, etc...
207 TwoArgFP = 4 << FPTypeShift,
209 // CompareFP - 2 arg FP instructions which implicitly read ST(0) and an
210 // explicit argument, but have no destination. Example: fucom, fucomi, ...
211 CompareFP = 5 << FPTypeShift,
213 // CondMovFP - "2 operand" floating point conditional move instructions.
214 CondMovFP = 6 << FPTypeShift,
216 // SpecialFP - Special instruction forms. Dispatch by opcode explicitly.
217 SpecialFP = 7 << FPTypeShift,
219 // Bits 19 -> 23 are unused
221 OpcodeMask = 0xFF << OpcodeShift
225 class X86InstrInfo : public TargetInstrInfo {
226 X86TargetMachine &TM;
227 const X86RegisterInfo RI;
228 mutable IndexedMap<const MachineInstr*, VirtReg2IndexFunctor> MachineInstrMap;
230 /// isDefinedInEntryBlock - Goes through the entry block to see if the given
231 /// virtual register is indeed defined in the entry block.
233 bool isDefinedInEntryBlock(const MachineBasicBlock &Entry,
234 unsigned VReg) const;
236 X86InstrInfo(X86TargetMachine &tm);
238 /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
239 /// such, whenever a client has an instance of instruction info, it should
240 /// always be able to get register info as well (through this method).
242 virtual const MRegisterInfo &getRegisterInfo() const { return RI; }
244 // Return true if the instruction is a register to register move and
245 // leave the source and dest operands in the passed parameters.
247 bool isMoveInstr(const MachineInstr& MI, unsigned& sourceReg,
248 unsigned& destReg) const;
249 unsigned isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const;
250 unsigned isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const;
251 bool isReallyTriviallyReMaterializable(MachineInstr *MI) const;
252 bool isReallySideEffectFree(MachineInstr *MI) const;
254 /// convertToThreeAddress - This method must be implemented by targets that
255 /// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
256 /// may be able to convert a two-address instruction into a true
257 /// three-address instruction on demand. This allows the X86 target (for
258 /// example) to convert ADD and SHL instructions into LEA instructions if they
259 /// would require register copies due to two-addressness.
261 /// This method returns a null pointer if the transformation cannot be
262 /// performed, otherwise it returns the new instruction.
264 virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
265 MachineBasicBlock::iterator &MBBI,
266 LiveVariables &LV) const;
268 /// commuteInstruction - We have a few instructions that must be hacked on to
271 virtual MachineInstr *commuteInstruction(MachineInstr *MI) const;
274 virtual bool isUnpredicatedTerminator(const MachineInstr* MI) const;
275 virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
276 MachineBasicBlock *&FBB,
277 std::vector<MachineOperand> &Cond) const;
278 virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
279 virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
280 MachineBasicBlock *FBB,
281 const std::vector<MachineOperand> &Cond) const;
282 virtual void copyRegToReg(MachineBasicBlock &MBB,
283 MachineBasicBlock::iterator MI,
284 unsigned DestReg, unsigned SrcReg,
285 const TargetRegisterClass *DestRC,
286 const TargetRegisterClass *SrcRC) const;
287 virtual bool BlockHasNoFallThrough(MachineBasicBlock &MBB) const;
288 virtual bool ReverseBranchCondition(std::vector<MachineOperand> &Cond) const;
290 const TargetRegisterClass *getPointerRegClass() const;
292 // getBaseOpcodeFor - This function returns the "base" X86 opcode for the
293 // specified machine instruction.
295 unsigned char getBaseOpcodeFor(const TargetInstrDescriptor *TID) const {
296 return TID->TSFlags >> X86II::OpcodeShift;
298 unsigned char getBaseOpcodeFor(MachineOpCode Opcode) const {
299 return getBaseOpcodeFor(&get(Opcode));
303 } // End llvm namespace