[Alignment][NFC] Support compile time constants
[llvm-core.git] / include / llvm / MC / MCInstrDesc.h
blobe75a27614a22d599a20e769c795fae5dea748584
1 //===-- llvm/MC/MCInstrDesc.h - Instruction Descriptors -*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the MCOperandInfo and MCInstrDesc classes, which
10 // are used to describe target instructions and their operands.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_MC_MCINSTRDESC_H
15 #define LLVM_MC_MCINSTRDESC_H
17 #include "llvm/MC/MCRegisterInfo.h"
18 #include "llvm/Support/DataTypes.h"
19 #include <string>
21 namespace llvm {
22 class MCInst;
23 class MCSubtargetInfo;
24 class FeatureBitset;
26 //===----------------------------------------------------------------------===//
27 // Machine Operand Flags and Description
28 //===----------------------------------------------------------------------===//
30 namespace MCOI {
31 // Operand constraints
32 enum OperandConstraint {
33 TIED_TO = 0, // Must be allocated the same register as.
34 EARLY_CLOBBER // Operand is an early clobber register operand
37 /// These are flags set on operands, but should be considered
38 /// private, all access should go through the MCOperandInfo accessors.
39 /// See the accessors for a description of what these are.
40 enum OperandFlags { LookupPtrRegClass = 0, Predicate, OptionalDef };
42 /// Operands are tagged with one of the values of this enum.
43 enum OperandType {
44 OPERAND_UNKNOWN = 0,
45 OPERAND_IMMEDIATE = 1,
46 OPERAND_REGISTER = 2,
47 OPERAND_MEMORY = 3,
48 OPERAND_PCREL = 4,
50 OPERAND_FIRST_GENERIC = 6,
51 OPERAND_GENERIC_0 = 6,
52 OPERAND_GENERIC_1 = 7,
53 OPERAND_GENERIC_2 = 8,
54 OPERAND_GENERIC_3 = 9,
55 OPERAND_GENERIC_4 = 10,
56 OPERAND_GENERIC_5 = 11,
57 OPERAND_LAST_GENERIC = 11,
59 OPERAND_FIRST_GENERIC_IMM = 12,
60 OPERAND_GENERIC_IMM_0 = 12,
61 OPERAND_LAST_GENERIC_IMM = 12,
63 OPERAND_FIRST_TARGET = 13,
68 /// This holds information about one operand of a machine instruction,
69 /// indicating the register class for register operands, etc.
70 class MCOperandInfo {
71 public:
72 /// This specifies the register class enumeration of the operand
73 /// if the operand is a register. If isLookupPtrRegClass is set, then this is
74 /// an index that is passed to TargetRegisterInfo::getPointerRegClass(x) to
75 /// get a dynamic register class.
76 int16_t RegClass;
78 /// These are flags from the MCOI::OperandFlags enum.
79 uint8_t Flags;
81 /// Information about the type of the operand.
82 uint8_t OperandType;
83 /// The lower 16 bits are used to specify which constraints are set.
84 /// The higher 16 bits are used to specify the value of constraints (4 bits
85 /// each).
86 uint32_t Constraints;
88 /// Set if this operand is a pointer value and it requires a callback
89 /// to look up its register class.
90 bool isLookupPtrRegClass() const {
91 return Flags & (1 << MCOI::LookupPtrRegClass);
94 /// Set if this is one of the operands that made up of the predicate
95 /// operand that controls an isPredicable() instruction.
96 bool isPredicate() const { return Flags & (1 << MCOI::Predicate); }
98 /// Set if this operand is a optional def.
99 bool isOptionalDef() const { return Flags & (1 << MCOI::OptionalDef); }
101 bool isGenericType() const {
102 return OperandType >= MCOI::OPERAND_FIRST_GENERIC &&
103 OperandType <= MCOI::OPERAND_LAST_GENERIC;
106 unsigned getGenericTypeIndex() const {
107 assert(isGenericType() && "non-generic types don't have an index");
108 return OperandType - MCOI::OPERAND_FIRST_GENERIC;
111 bool isGenericImm() const {
112 return OperandType >= MCOI::OPERAND_FIRST_GENERIC_IMM &&
113 OperandType <= MCOI::OPERAND_LAST_GENERIC_IMM;
116 unsigned getGenericImmIndex() const {
117 assert(isGenericImm() && "non-generic immediates don't have an index");
118 return OperandType - MCOI::OPERAND_FIRST_GENERIC_IMM;
122 //===----------------------------------------------------------------------===//
123 // Machine Instruction Flags and Description
124 //===----------------------------------------------------------------------===//
126 namespace MCID {
127 /// These should be considered private to the implementation of the
128 /// MCInstrDesc class. Clients should use the predicate methods on MCInstrDesc,
129 /// not use these directly. These all correspond to bitfields in the
130 /// MCInstrDesc::Flags field.
131 enum Flag {
132 PreISelOpcode = 0,
133 Variadic,
134 HasOptionalDef,
135 Pseudo,
136 Return,
137 EHScopeReturn,
138 Call,
139 Barrier,
140 Terminator,
141 Branch,
142 IndirectBranch,
143 Compare,
144 MoveImm,
145 MoveReg,
146 Bitcast,
147 Select,
148 DelaySlot,
149 FoldableAsLoad,
150 MayLoad,
151 MayStore,
152 MayRaiseFPException,
153 Predicable,
154 NotDuplicable,
155 UnmodeledSideEffects,
156 Commutable,
157 ConvertibleTo3Addr,
158 UsesCustomInserter,
159 HasPostISelHook,
160 Rematerializable,
161 CheapAsAMove,
162 ExtraSrcRegAllocReq,
163 ExtraDefRegAllocReq,
164 RegSequence,
165 ExtractSubreg,
166 InsertSubreg,
167 Convergent,
168 Add,
169 Trap,
170 VariadicOpsAreDefs,
174 /// Describe properties that are true of each instruction in the target
175 /// description file. This captures information about side effects, register
176 /// use and many other things. There is one instance of this struct for each
177 /// target instruction class, and the MachineInstr class points to this struct
178 /// directly to describe itself.
179 class MCInstrDesc {
180 public:
181 unsigned short Opcode; // The opcode number
182 unsigned short NumOperands; // Num of args (may be more if variable_ops)
183 unsigned char NumDefs; // Num of args that are definitions
184 unsigned char Size; // Number of bytes in encoding.
185 unsigned short SchedClass; // enum identifying instr sched class
186 uint64_t Flags; // Flags identifying machine instr class
187 uint64_t TSFlags; // Target Specific Flag values
188 const MCPhysReg *ImplicitUses; // Registers implicitly read by this instr
189 const MCPhysReg *ImplicitDefs; // Registers implicitly defined by this instr
190 const MCOperandInfo *OpInfo; // 'NumOperands' entries about operands
191 // Subtarget feature that this is deprecated on, if any
192 // -1 implies this is not deprecated by any single feature. It may still be
193 // deprecated due to a "complex" reason, below.
194 int64_t DeprecatedFeature;
196 // A complex method to determine if a certain instruction is deprecated or
197 // not, and return the reason for deprecation.
198 bool (*ComplexDeprecationInfo)(MCInst &, const MCSubtargetInfo &,
199 std::string &);
201 /// Returns the value of the specific constraint if
202 /// it is set. Returns -1 if it is not set.
203 int getOperandConstraint(unsigned OpNum,
204 MCOI::OperandConstraint Constraint) const {
205 if (OpNum < NumOperands &&
206 (OpInfo[OpNum].Constraints & (1 << Constraint))) {
207 unsigned Pos = 16 + Constraint * 4;
208 return (int)(OpInfo[OpNum].Constraints >> Pos) & 0xf;
210 return -1;
213 /// Returns true if a certain instruction is deprecated and if so
214 /// returns the reason in \p Info.
215 bool getDeprecatedInfo(MCInst &MI, const MCSubtargetInfo &STI,
216 std::string &Info) const;
218 /// Return the opcode number for this descriptor.
219 unsigned getOpcode() const { return Opcode; }
221 /// Return the number of declared MachineOperands for this
222 /// MachineInstruction. Note that variadic (isVariadic() returns true)
223 /// instructions may have additional operands at the end of the list, and note
224 /// that the machine instruction may include implicit register def/uses as
225 /// well.
226 unsigned getNumOperands() const { return NumOperands; }
228 using const_opInfo_iterator = const MCOperandInfo *;
230 const_opInfo_iterator opInfo_begin() const { return OpInfo; }
231 const_opInfo_iterator opInfo_end() const { return OpInfo + NumOperands; }
233 iterator_range<const_opInfo_iterator> operands() const {
234 return make_range(opInfo_begin(), opInfo_end());
237 /// Return the number of MachineOperands that are register
238 /// definitions. Register definitions always occur at the start of the
239 /// machine operand list. This is the number of "outs" in the .td file,
240 /// and does not include implicit defs.
241 unsigned getNumDefs() const { return NumDefs; }
243 /// Return flags of this instruction.
244 uint64_t getFlags() const { return Flags; }
246 /// \returns true if this instruction is emitted before instruction selection
247 /// and should be legalized/regbankselected/selected.
248 bool isPreISelOpcode() const { return Flags & (1ULL << MCID::PreISelOpcode); }
250 /// Return true if this instruction can have a variable number of
251 /// operands. In this case, the variable operands will be after the normal
252 /// operands but before the implicit definitions and uses (if any are
253 /// present).
254 bool isVariadic() const { return Flags & (1ULL << MCID::Variadic); }
256 /// Set if this instruction has an optional definition, e.g.
257 /// ARM instructions which can set condition code if 's' bit is set.
258 bool hasOptionalDef() const { return Flags & (1ULL << MCID::HasOptionalDef); }
260 /// Return true if this is a pseudo instruction that doesn't
261 /// correspond to a real machine instruction.
262 bool isPseudo() const { return Flags & (1ULL << MCID::Pseudo); }
264 /// Return true if the instruction is a return.
265 bool isReturn() const { return Flags & (1ULL << MCID::Return); }
267 /// Return true if the instruction is an add instruction.
268 bool isAdd() const { return Flags & (1ULL << MCID::Add); }
270 /// Return true if this instruction is a trap.
271 bool isTrap() const { return Flags & (1ULL << MCID::Trap); }
273 /// Return true if the instruction is a register to register move.
274 bool isMoveReg() const { return Flags & (1ULL << MCID::MoveReg); }
276 /// Return true if the instruction is a call.
277 bool isCall() const { return Flags & (1ULL << MCID::Call); }
279 /// Returns true if the specified instruction stops control flow
280 /// from executing the instruction immediately following it. Examples include
281 /// unconditional branches and return instructions.
282 bool isBarrier() const { return Flags & (1ULL << MCID::Barrier); }
284 /// Returns true if this instruction part of the terminator for
285 /// a basic block. Typically this is things like return and branch
286 /// instructions.
288 /// Various passes use this to insert code into the bottom of a basic block,
289 /// but before control flow occurs.
290 bool isTerminator() const { return Flags & (1ULL << MCID::Terminator); }
292 /// Returns true if this is a conditional, unconditional, or
293 /// indirect branch. Predicates below can be used to discriminate between
294 /// these cases, and the TargetInstrInfo::AnalyzeBranch method can be used to
295 /// get more information.
296 bool isBranch() const { return Flags & (1ULL << MCID::Branch); }
298 /// Return true if this is an indirect branch, such as a
299 /// branch through a register.
300 bool isIndirectBranch() const { return Flags & (1ULL << MCID::IndirectBranch); }
302 /// Return true if this is a branch which may fall
303 /// through to the next instruction or may transfer control flow to some other
304 /// block. The TargetInstrInfo::AnalyzeBranch method can be used to get more
305 /// information about this branch.
306 bool isConditionalBranch() const {
307 return isBranch() & !isBarrier() & !isIndirectBranch();
310 /// Return true if this is a branch which always
311 /// transfers control flow to some other block. The
312 /// TargetInstrInfo::AnalyzeBranch method can be used to get more information
313 /// about this branch.
314 bool isUnconditionalBranch() const {
315 return isBranch() & isBarrier() & !isIndirectBranch();
318 /// Return true if this is a branch or an instruction which directly
319 /// writes to the program counter. Considered 'may' affect rather than
320 /// 'does' affect as things like predication are not taken into account.
321 bool mayAffectControlFlow(const MCInst &MI, const MCRegisterInfo &RI) const;
323 /// Return true if this instruction has a predicate operand
324 /// that controls execution. It may be set to 'always', or may be set to other
325 /// values. There are various methods in TargetInstrInfo that can be used to
326 /// control and modify the predicate in this instruction.
327 bool isPredicable() const { return Flags & (1ULL << MCID::Predicable); }
329 /// Return true if this instruction is a comparison.
330 bool isCompare() const { return Flags & (1ULL << MCID::Compare); }
332 /// Return true if this instruction is a move immediate
333 /// (including conditional moves) instruction.
334 bool isMoveImmediate() const { return Flags & (1ULL << MCID::MoveImm); }
336 /// Return true if this instruction is a bitcast instruction.
337 bool isBitcast() const { return Flags & (1ULL << MCID::Bitcast); }
339 /// Return true if this is a select instruction.
340 bool isSelect() const { return Flags & (1ULL << MCID::Select); }
342 /// Return true if this instruction cannot be safely
343 /// duplicated. For example, if the instruction has a unique labels attached
344 /// to it, duplicating it would cause multiple definition errors.
345 bool isNotDuplicable() const { return Flags & (1ULL << MCID::NotDuplicable); }
347 /// Returns true if the specified instruction has a delay slot which
348 /// must be filled by the code generator.
349 bool hasDelaySlot() const { return Flags & (1ULL << MCID::DelaySlot); }
351 /// Return true for instructions that can be folded as memory operands
352 /// in other instructions. The most common use for this is instructions that
353 /// are simple loads from memory that don't modify the loaded value in any
354 /// way, but it can also be used for instructions that can be expressed as
355 /// constant-pool loads, such as V_SETALLONES on x86, to allow them to be
356 /// folded when it is beneficial. This should only be set on instructions
357 /// that return a value in their only virtual register definition.
358 bool canFoldAsLoad() const { return Flags & (1ULL << MCID::FoldableAsLoad); }
360 /// Return true if this instruction behaves
361 /// the same way as the generic REG_SEQUENCE instructions.
362 /// E.g., on ARM,
363 /// dX VMOVDRR rY, rZ
364 /// is equivalent to
365 /// dX = REG_SEQUENCE rY, ssub_0, rZ, ssub_1.
367 /// Note that for the optimizers to be able to take advantage of
368 /// this property, TargetInstrInfo::getRegSequenceLikeInputs has to be
369 /// override accordingly.
370 bool isRegSequenceLike() const { return Flags & (1ULL << MCID::RegSequence); }
372 /// Return true if this instruction behaves
373 /// the same way as the generic EXTRACT_SUBREG instructions.
374 /// E.g., on ARM,
375 /// rX, rY VMOVRRD dZ
376 /// is equivalent to two EXTRACT_SUBREG:
377 /// rX = EXTRACT_SUBREG dZ, ssub_0
378 /// rY = EXTRACT_SUBREG dZ, ssub_1
380 /// Note that for the optimizers to be able to take advantage of
381 /// this property, TargetInstrInfo::getExtractSubregLikeInputs has to be
382 /// override accordingly.
383 bool isExtractSubregLike() const {
384 return Flags & (1ULL << MCID::ExtractSubreg);
387 /// Return true if this instruction behaves
388 /// the same way as the generic INSERT_SUBREG instructions.
389 /// E.g., on ARM,
390 /// dX = VSETLNi32 dY, rZ, Imm
391 /// is equivalent to a INSERT_SUBREG:
392 /// dX = INSERT_SUBREG dY, rZ, translateImmToSubIdx(Imm)
394 /// Note that for the optimizers to be able to take advantage of
395 /// this property, TargetInstrInfo::getInsertSubregLikeInputs has to be
396 /// override accordingly.
397 bool isInsertSubregLike() const { return Flags & (1ULL << MCID::InsertSubreg); }
400 /// Return true if this instruction is convergent.
402 /// Convergent instructions may not be made control-dependent on any
403 /// additional values.
404 bool isConvergent() const { return Flags & (1ULL << MCID::Convergent); }
406 /// Return true if variadic operands of this instruction are definitions.
407 bool variadicOpsAreDefs() const {
408 return Flags & (1ULL << MCID::VariadicOpsAreDefs);
411 //===--------------------------------------------------------------------===//
412 // Side Effect Analysis
413 //===--------------------------------------------------------------------===//
415 /// Return true if this instruction could possibly read memory.
416 /// Instructions with this flag set are not necessarily simple load
417 /// instructions, they may load a value and modify it, for example.
418 bool mayLoad() const { return Flags & (1ULL << MCID::MayLoad); }
420 /// Return true if this instruction could possibly modify memory.
421 /// Instructions with this flag set are not necessarily simple store
422 /// instructions, they may store a modified value based on their operands, or
423 /// may not actually modify anything, for example.
424 bool mayStore() const { return Flags & (1ULL << MCID::MayStore); }
426 /// Return true if this instruction may raise a floating-point exception.
427 bool mayRaiseFPException() const {
428 return Flags & (1ULL << MCID::MayRaiseFPException);
431 /// Return true if this instruction has side
432 /// effects that are not modeled by other flags. This does not return true
433 /// for instructions whose effects are captured by:
435 /// 1. Their operand list and implicit definition/use list. Register use/def
436 /// info is explicit for instructions.
437 /// 2. Memory accesses. Use mayLoad/mayStore.
438 /// 3. Calling, branching, returning: use isCall/isReturn/isBranch.
440 /// Examples of side effects would be modifying 'invisible' machine state like
441 /// a control register, flushing a cache, modifying a register invisible to
442 /// LLVM, etc.
443 bool hasUnmodeledSideEffects() const {
444 return Flags & (1ULL << MCID::UnmodeledSideEffects);
447 //===--------------------------------------------------------------------===//
448 // Flags that indicate whether an instruction can be modified by a method.
449 //===--------------------------------------------------------------------===//
451 /// Return true if this may be a 2- or 3-address instruction (of the
452 /// form "X = op Y, Z, ..."), which produces the same result if Y and Z are
453 /// exchanged. If this flag is set, then the
454 /// TargetInstrInfo::commuteInstruction method may be used to hack on the
455 /// instruction.
457 /// Note that this flag may be set on instructions that are only commutable
458 /// sometimes. In these cases, the call to commuteInstruction will fail.
459 /// Also note that some instructions require non-trivial modification to
460 /// commute them.
461 bool isCommutable() const { return Flags & (1ULL << MCID::Commutable); }
463 /// Return true if this is a 2-address instruction which can be changed
464 /// into a 3-address instruction if needed. Doing this transformation can be
465 /// profitable in the register allocator, because it means that the
466 /// instruction can use a 2-address form if possible, but degrade into a less
467 /// efficient form if the source and dest register cannot be assigned to the
468 /// same register. For example, this allows the x86 backend to turn a "shl
469 /// reg, 3" instruction into an LEA instruction, which is the same speed as
470 /// the shift but has bigger code size.
472 /// If this returns true, then the target must implement the
473 /// TargetInstrInfo::convertToThreeAddress method for this instruction, which
474 /// is allowed to fail if the transformation isn't valid for this specific
475 /// instruction (e.g. shl reg, 4 on x86).
477 bool isConvertibleTo3Addr() const {
478 return Flags & (1ULL << MCID::ConvertibleTo3Addr);
481 /// Return true if this instruction requires custom insertion support
482 /// when the DAG scheduler is inserting it into a machine basic block. If
483 /// this is true for the instruction, it basically means that it is a pseudo
484 /// instruction used at SelectionDAG time that is expanded out into magic code
485 /// by the target when MachineInstrs are formed.
487 /// If this is true, the TargetLoweringInfo::InsertAtEndOfBasicBlock method
488 /// is used to insert this into the MachineBasicBlock.
489 bool usesCustomInsertionHook() const {
490 return Flags & (1ULL << MCID::UsesCustomInserter);
493 /// Return true if this instruction requires *adjustment* after
494 /// instruction selection by calling a target hook. For example, this can be
495 /// used to fill in ARM 's' optional operand depending on whether the
496 /// conditional flag register is used.
497 bool hasPostISelHook() const { return Flags & (1ULL << MCID::HasPostISelHook); }
499 /// Returns true if this instruction is a candidate for remat. This
500 /// flag is only used in TargetInstrInfo method isTriviallyRematerializable.
502 /// If this flag is set, the isReallyTriviallyReMaterializable()
503 /// or isReallyTriviallyReMaterializableGeneric methods are called to verify
504 /// the instruction is really rematable.
505 bool isRematerializable() const {
506 return Flags & (1ULL << MCID::Rematerializable);
509 /// Returns true if this instruction has the same cost (or less) than a
510 /// move instruction. This is useful during certain types of optimizations
511 /// (e.g., remat during two-address conversion or machine licm) where we would
512 /// like to remat or hoist the instruction, but not if it costs more than
513 /// moving the instruction into the appropriate register. Note, we are not
514 /// marking copies from and to the same register class with this flag.
516 /// This method could be called by interface TargetInstrInfo::isAsCheapAsAMove
517 /// for different subtargets.
518 bool isAsCheapAsAMove() const { return Flags & (1ULL << MCID::CheapAsAMove); }
520 /// Returns true if this instruction source operands have special
521 /// register allocation requirements that are not captured by the operand
522 /// register classes. e.g. ARM::STRD's two source registers must be an even /
523 /// odd pair, ARM::STM registers have to be in ascending order. Post-register
524 /// allocation passes should not attempt to change allocations for sources of
525 /// instructions with this flag.
526 bool hasExtraSrcRegAllocReq() const {
527 return Flags & (1ULL << MCID::ExtraSrcRegAllocReq);
530 /// Returns true if this instruction def operands have special register
531 /// allocation requirements that are not captured by the operand register
532 /// classes. e.g. ARM::LDRD's two def registers must be an even / odd pair,
533 /// ARM::LDM registers have to be in ascending order. Post-register
534 /// allocation passes should not attempt to change allocations for definitions
535 /// of instructions with this flag.
536 bool hasExtraDefRegAllocReq() const {
537 return Flags & (1ULL << MCID::ExtraDefRegAllocReq);
540 /// Return a list of registers that are potentially read by any
541 /// instance of this machine instruction. For example, on X86, the "adc"
542 /// instruction adds two register operands and adds the carry bit in from the
543 /// flags register. In this case, the instruction is marked as implicitly
544 /// reading the flags. Likewise, the variable shift instruction on X86 is
545 /// marked as implicitly reading the 'CL' register, which it always does.
547 /// This method returns null if the instruction has no implicit uses.
548 const MCPhysReg *getImplicitUses() const { return ImplicitUses; }
550 /// Return the number of implicit uses this instruction has.
551 unsigned getNumImplicitUses() const {
552 if (!ImplicitUses)
553 return 0;
554 unsigned i = 0;
555 for (; ImplicitUses[i]; ++i) /*empty*/
557 return i;
560 /// Return a list of registers that are potentially written by any
561 /// instance of this machine instruction. For example, on X86, many
562 /// instructions implicitly set the flags register. In this case, they are
563 /// marked as setting the FLAGS. Likewise, many instructions always deposit
564 /// their result in a physical register. For example, the X86 divide
565 /// instruction always deposits the quotient and remainder in the EAX/EDX
566 /// registers. For that instruction, this will return a list containing the
567 /// EAX/EDX/EFLAGS registers.
569 /// This method returns null if the instruction has no implicit defs.
570 const MCPhysReg *getImplicitDefs() const { return ImplicitDefs; }
572 /// Return the number of implicit defs this instruct has.
573 unsigned getNumImplicitDefs() const {
574 if (!ImplicitDefs)
575 return 0;
576 unsigned i = 0;
577 for (; ImplicitDefs[i]; ++i) /*empty*/
579 return i;
582 /// Return true if this instruction implicitly
583 /// uses the specified physical register.
584 bool hasImplicitUseOfPhysReg(unsigned Reg) const {
585 if (const MCPhysReg *ImpUses = ImplicitUses)
586 for (; *ImpUses; ++ImpUses)
587 if (*ImpUses == Reg)
588 return true;
589 return false;
592 /// Return true if this instruction implicitly
593 /// defines the specified physical register.
594 bool hasImplicitDefOfPhysReg(unsigned Reg,
595 const MCRegisterInfo *MRI = nullptr) const;
597 /// Return the scheduling class for this instruction. The
598 /// scheduling class is an index into the InstrItineraryData table. This
599 /// returns zero if there is no known scheduling information for the
600 /// instruction.
601 unsigned getSchedClass() const { return SchedClass; }
603 /// Return the number of bytes in the encoding of this instruction,
604 /// or zero if the encoding size cannot be known from the opcode.
605 unsigned getSize() const { return Size; }
607 /// Find the index of the first operand in the
608 /// operand list that is used to represent the predicate. It returns -1 if
609 /// none is found.
610 int findFirstPredOperandIdx() const {
611 if (isPredicable()) {
612 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
613 if (OpInfo[i].isPredicate())
614 return i;
616 return -1;
619 /// Return true if this instruction defines the specified physical
620 /// register, either explicitly or implicitly.
621 bool hasDefOfPhysReg(const MCInst &MI, unsigned Reg,
622 const MCRegisterInfo &RI) const;
625 } // end namespace llvm
627 #endif