1//===-- llvm/Operator.h - Operator utility subclass -------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines various classes for working with Instructions and
11// ConstantExprs.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_IR_OPERATOR_H
16#define LLVM_IR_OPERATOR_H
17
18#include "llvm/ADT/None.h"
19#include "llvm/ADT/Optional.h"
20#include "llvm/IR/Constants.h"
21#include "llvm/IR/Instruction.h"
22#include "llvm/IR/Type.h"
23#include "llvm/IR/Value.h"
24#include "llvm/Support/Casting.h"
25#include <cstddef>
26
27namespace llvm {
28
29/// This is a utility class that provides an abstraction for the common
30/// functionality between Instructions and ConstantExprs.
31class Operator : public User {
32public:
33 // The Operator class is intended to be used as a utility, and is never itself
34 // instantiated.
35 Operator() = delete;
36 ~Operator() = delete;
37
38 void *operator new(size_t s) = delete;
39
40 /// Return the opcode for this Instruction or ConstantExpr.
41 unsigned getOpcode() const {
42 if (const Instruction *I = dyn_cast<Instruction>(this))
43 return I->getOpcode();
44 return cast<ConstantExpr>(this)->getOpcode();
45 }
46
47 /// If V is an Instruction or ConstantExpr, return its opcode.
48 /// Otherwise return UserOp1.
49 static unsigned getOpcode(const Value *V) {
50 if (const Instruction *I = dyn_cast<Instruction>(V))
51 return I->getOpcode();
52 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
53 return CE->getOpcode();
54 return Instruction::UserOp1;
55 }
56
57 static bool classof(const Instruction *) { return true; }
58 static bool classof(const ConstantExpr *) { return true; }
59 static bool classof(const Value *V) {
60 return isa<Instruction>(V) || isa<ConstantExpr>(V);
61 }
62};
63
64/// Utility class for integer operators which may exhibit overflow - Add, Sub,
65/// Mul, and Shl. It does not include SDiv, despite that operator having the
66/// potential for overflow.
67class OverflowingBinaryOperator : public Operator {
68public:
69 enum {
70 NoUnsignedWrap = (1 << 0),
71 NoSignedWrap = (1 << 1)
72 };
73
74private:
75 friend class Instruction;
76 friend class ConstantExpr;
77
78 void setHasNoUnsignedWrap(bool B) {
79 SubclassOptionalData =
80 (SubclassOptionalData & ~NoUnsignedWrap) | (B * NoUnsignedWrap);
81 }
82 void setHasNoSignedWrap(bool B) {
83 SubclassOptionalData =
84 (SubclassOptionalData & ~NoSignedWrap) | (B * NoSignedWrap);
85 }
86
87public:
88 /// Test whether this operation is known to never
89 /// undergo unsigned overflow, aka the nuw property.
90 bool hasNoUnsignedWrap() const {
91 return SubclassOptionalData & NoUnsignedWrap;
92 }
93
94 /// Test whether this operation is known to never
95 /// undergo signed overflow, aka the nsw property.
96 bool hasNoSignedWrap() const {
97 return (SubclassOptionalData & NoSignedWrap) != 0;
98 }
99
100 static bool classof(const Instruction *I) {
101 return I->getOpcode() == Instruction::Add ||
102 I->getOpcode() == Instruction::Sub ||
103 I->getOpcode() == Instruction::Mul ||
104 I->getOpcode() == Instruction::Shl;
105 }
106 static bool classof(const ConstantExpr *CE) {
107 return CE->getOpcode() == Instruction::Add ||
108 CE->getOpcode() == Instruction::Sub ||
109 CE->getOpcode() == Instruction::Mul ||
110 CE->getOpcode() == Instruction::Shl;
111 }
112 static bool classof(const Value *V) {
113 return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
114 (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
115 }
116};
117
118/// A udiv or sdiv instruction, which can be marked as "exact",
119/// indicating that no bits are destroyed.
120class PossiblyExactOperator : public Operator {
121public:
122 enum {
123 IsExact = (1 << 0)
124 };
125
126private:
127 friend class Instruction;
128 friend class ConstantExpr;
129
130 void setIsExact(bool B) {
131 SubclassOptionalData = (SubclassOptionalData & ~IsExact) | (B * IsExact);
132 }
133
134public:
135 /// Test whether this division is known to be exact, with zero remainder.
136 bool isExact() const {
137 return SubclassOptionalData & IsExact;
138 }
139
140 static bool isPossiblyExactOpcode(unsigned OpC) {
141 return OpC == Instruction::SDiv ||
142 OpC == Instruction::UDiv ||
143 OpC == Instruction::AShr ||
144 OpC == Instruction::LShr;
145 }
146
147 static bool classof(const ConstantExpr *CE) {
148 return isPossiblyExactOpcode(CE->getOpcode());
149 }
150 static bool classof(const Instruction *I) {
151 return isPossiblyExactOpcode(I->getOpcode());
152 }
153 static bool classof(const Value *V) {
154 return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
155 (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
156 }
157};
158
159/// Convenience struct for specifying and reasoning about fast-math flags.
160class FastMathFlags {
161private:
162 friend class FPMathOperator;
163
164 unsigned Flags = 0;
165
166 FastMathFlags(unsigned F) {
167 // If all 7 bits are set, turn this into -1. If the number of bits grows,
168 // this must be updated. This is intended to provide some forward binary
169 // compatibility insurance for the meaning of 'fast' in case bits are added.
170 if (F == 0x7F) Flags = ~0U;
171 else Flags = F;
172 }
173
174public:
175 // This is how the bits are used in Value::SubclassOptionalData so they
176 // should fit there too.
177 // WARNING: We're out of space. SubclassOptionalData only has 7 bits. New
178 // functionality will require a change in how this information is stored.
179 enum {
180 AllowReassoc = (1 << 0),
181 NoNaNs = (1 << 1),
182 NoInfs = (1 << 2),
183 NoSignedZeros = (1 << 3),
184 AllowReciprocal = (1 << 4),
185 AllowContract = (1 << 5),
186 ApproxFunc = (1 << 6)
187 };
188
189 FastMathFlags() = default;
190
191 bool any() const { return Flags != 0; }
192 bool none() const { return Flags == 0; }
193 bool all() const { return Flags == ~0U; }
194
195 void clear() { Flags = 0; }
196 void set() { Flags = ~0U; }
197
198 /// Flag queries
199 bool allowReassoc() const { return 0 != (Flags & AllowReassoc); }
200 bool noNaNs() const { return 0 != (Flags & NoNaNs); }
201 bool noInfs() const { return 0 != (Flags & NoInfs); }
202 bool noSignedZeros() const { return 0 != (Flags & NoSignedZeros); }
203 bool allowReciprocal() const { return 0 != (Flags & AllowReciprocal); }
204 bool allowContract() const { return 0 != (Flags & AllowContract); }
205 bool approxFunc() const { return 0 != (Flags & ApproxFunc); }
206 /// 'Fast' means all bits are set.
207 bool isFast() const { return all(); }
208
209 /// Flag setters
210 void setAllowReassoc(bool B = true) {
211 Flags = (Flags & ~AllowReassoc) | B * AllowReassoc;
212 }
213 void setNoNaNs(bool B = true) {
214 Flags = (Flags & ~NoNaNs) | B * NoNaNs;
215 }
216 void setNoInfs(bool B = true) {
217 Flags = (Flags & ~NoInfs) | B * NoInfs;
218 }
219 void setNoSignedZeros(bool B = true) {
220 Flags = (Flags & ~NoSignedZeros) | B * NoSignedZeros;
221 }
222 void setAllowReciprocal(bool B = true) {
223 Flags = (Flags & ~AllowReciprocal) | B * AllowReciprocal;
224 }
225 void setAllowContract(bool B = true) {
226 Flags = (Flags & ~AllowContract) | B * AllowContract;
227 }
228 void setApproxFunc(bool B = true) {
229 Flags = (Flags & ~ApproxFunc) | B * ApproxFunc;
230 }
231 void setFast(bool B = true) { B ? set() : clear(); }
232
233 void operator&=(const FastMathFlags &OtherFlags) {
234 Flags &= OtherFlags.Flags;
235 }
236};
237
238/// Utility class for floating point operations which can have
239/// information about relaxed accuracy requirements attached to them.
240class FPMathOperator : public Operator {
241private:
242 friend class Instruction;
243
244 /// 'Fast' means all bits are set.
245 void setFast(bool B) {
246 setHasAllowReassoc(B);
247 setHasNoNaNs(B);
248 setHasNoInfs(B);
249 setHasNoSignedZeros(B);
250 setHasAllowReciprocal(B);
251 setHasAllowContract(B);
252 setHasApproxFunc(B);
253 }
254
255 void setHasAllowReassoc(bool B) {
256 SubclassOptionalData =
257 (SubclassOptionalData & ~FastMathFlags::AllowReassoc) |
258 (B * FastMathFlags::AllowReassoc);
259 }
260
261 void setHasNoNaNs(bool B) {
262 SubclassOptionalData =
263 (SubclassOptionalData & ~FastMathFlags::NoNaNs) |
264 (B * FastMathFlags::NoNaNs);
265 }
266
267 void setHasNoInfs(bool B) {
268 SubclassOptionalData =
269 (SubclassOptionalData & ~FastMathFlags::NoInfs) |
270 (B * FastMathFlags::NoInfs);
271 }
272
273 void setHasNoSignedZeros(bool B) {
274 SubclassOptionalData =
275 (SubclassOptionalData & ~FastMathFlags::NoSignedZeros) |
276 (B * FastMathFlags::NoSignedZeros);
277 }
278
279 void setHasAllowReciprocal(bool B) {
280 SubclassOptionalData =
281 (SubclassOptionalData & ~FastMathFlags::AllowReciprocal) |
282 (B * FastMathFlags::AllowReciprocal);
283 }
284
285 void setHasAllowContract(bool B) {
286 SubclassOptionalData =
287 (SubclassOptionalData & ~FastMathFlags::AllowContract) |
288 (B * FastMathFlags::AllowContract);
289 }
290
291 void setHasApproxFunc(bool B) {
292 SubclassOptionalData =
293 (SubclassOptionalData & ~FastMathFlags::ApproxFunc) |
294 (B * FastMathFlags::ApproxFunc);
295 }
296
297 /// Convenience function for setting multiple fast-math flags.
298 /// FMF is a mask of the bits to set.
299 void setFastMathFlags(FastMathFlags FMF) {
300 SubclassOptionalData |= FMF.Flags;
301 }
302
303 /// Convenience function for copying all fast-math flags.
304 /// All values in FMF are transferred to this operator.
305 void copyFastMathFlags(FastMathFlags FMF) {
306 SubclassOptionalData = FMF.Flags;
307 }
308
309public:
310 /// Test if this operation allows all non-strict floating-point transforms.
311 bool isFast() const {
312 return ((SubclassOptionalData & FastMathFlags::AllowReassoc) != 0 &&
313 (SubclassOptionalData & FastMathFlags::NoNaNs) != 0 &&
314 (SubclassOptionalData & FastMathFlags::NoInfs) != 0 &&
315 (SubclassOptionalData & FastMathFlags::NoSignedZeros) != 0 &&
316 (SubclassOptionalData & FastMathFlags::AllowReciprocal) != 0 &&
317 (SubclassOptionalData & FastMathFlags::AllowContract) != 0 &&
318 (SubclassOptionalData & FastMathFlags::ApproxFunc) != 0);
319 }
320
321 /// Test if this operation may be simplified with reassociative transforms.
322 bool hasAllowReassoc() const {
323 return (SubclassOptionalData & FastMathFlags::AllowReassoc) != 0;
324 }
325
326 /// Test if this operation's arguments and results are assumed not-NaN.
327 bool hasNoNaNs() const {
328 return (SubclassOptionalData & FastMathFlags::NoNaNs) != 0;
329 }
330
331 /// Test if this operation's arguments and results are assumed not-infinite.
332 bool hasNoInfs() const {
333 return (SubclassOptionalData & FastMathFlags::NoInfs) != 0;
334 }
335
336 /// Test if this operation can ignore the sign of zero.
337 bool hasNoSignedZeros() const {
338 return (SubclassOptionalData & FastMathFlags::NoSignedZeros) != 0;
339 }
340
341 /// Test if this operation can use reciprocal multiply instead of division.
342 bool hasAllowReciprocal() const {
343 return (SubclassOptionalData & FastMathFlags::AllowReciprocal) != 0;
344 }
345
346 /// Test if this operation can be floating-point contracted (FMA).
347 bool hasAllowContract() const {
348 return (SubclassOptionalData & FastMathFlags::AllowContract) != 0;
349 }
350
351 /// Test if this operation allows approximations of math library functions or
352 /// intrinsics.
353 bool hasApproxFunc() const {
354 return (SubclassOptionalData & FastMathFlags::ApproxFunc) != 0;
355 }
356
357 /// Convenience function for getting all the fast-math flags
358 FastMathFlags getFastMathFlags() const {
359 return FastMathFlags(SubclassOptionalData);
360 }
361
362 /// Get the maximum error permitted by this operation in ULPs. An accuracy of
363 /// 0.0 means that the operation should be performed with the default
364 /// precision.
365 float getFPAccuracy() const;
366
367 static bool classof(const Value *V) {
368 unsigned Opcode;
369 if (auto *I = dyn_cast<Instruction>(V))
370 Opcode = I->getOpcode();
371 else if (auto *CE = dyn_cast<ConstantExpr>(V))
372 Opcode = CE->getOpcode();
373 else
374 return false;
375
376 switch (Opcode) {
377 case Instruction::FCmp:
378 return true;
379 // non math FP Operators (no FMF)
380 case Instruction::ExtractElement:
381 case Instruction::ShuffleVector:
382 case Instruction::InsertElement:
383 return false;
384 default:
385 return V->getType()->isFPOrFPVectorTy();
386 }
387 }
388};
389
390/// A helper template for defining operators for individual opcodes.
391template<typename SuperClass, unsigned Opc>
392class ConcreteOperator : public SuperClass {
393public:
394 static bool classof(const Instruction *I) {
395 return I->getOpcode() == Opc;
396 }
397 static bool classof(const ConstantExpr *CE) {
398 return CE->getOpcode() == Opc;
399 }
400 static bool classof(const Value *V) {
401 return (isa<Instruction>(V) && classof(cast<Instruction>(V))) ||
402 (isa<ConstantExpr>(V) && classof(cast<ConstantExpr>(V)));
403 }
404};
405
406class AddOperator
407 : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Add> {
408};
409class SubOperator
410 : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Sub> {
411};
412class MulOperator
413 : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Mul> {
414};
415class ShlOperator
416 : public ConcreteOperator<OverflowingBinaryOperator, Instruction::Shl> {
417};
418
419class SDivOperator
420 : public ConcreteOperator<PossiblyExactOperator, Instruction::SDiv> {
421};
422class UDivOperator
423 : public ConcreteOperator<PossiblyExactOperator, Instruction::UDiv> {
424};
425class AShrOperator
426 : public ConcreteOperator<PossiblyExactOperator, Instruction::AShr> {
427};
428class LShrOperator
429 : public ConcreteOperator<PossiblyExactOperator, Instruction::LShr> {
430};
431
432class ZExtOperator : public ConcreteOperator<Operator, Instruction::ZExt> {};
433
434class GEPOperator
435 : public ConcreteOperator<Operator, Instruction::GetElementPtr> {
436 friend class GetElementPtrInst;
437 friend class ConstantExpr;
438
439 enum {
440 IsInBounds = (1 << 0),
441 // InRangeIndex: bits 1-6
442 };
443
444 void setIsInBounds(bool B) {
445 SubclassOptionalData =
446 (SubclassOptionalData & ~IsInBounds) | (B * IsInBounds);
447 }
448
449public:
450 /// Test whether this is an inbounds GEP, as defined by LangRef.html.
451 bool isInBounds() const {
452 return SubclassOptionalData & IsInBounds;
453 }
454
455 /// Returns the offset of the index with an inrange attachment, or None if
456 /// none.
457 Optional<unsigned> getInRangeIndex() const {
458 if (SubclassOptionalData >> 1 == 0) return None;
459 return (SubclassOptionalData >> 1) - 1;
460 }
461
462 inline op_iterator idx_begin() { return op_begin()+1; }
463 inline const_op_iterator idx_begin() const { return op_begin()+1; }
464 inline op_iterator idx_end() { return op_end(); }
465 inline const_op_iterator idx_end() const { return op_end(); }
466
467 Value *getPointerOperand() {
468 return getOperand(0);
469 }
470 const Value *getPointerOperand() const {
471 return getOperand(0);
472 }
473 static unsigned getPointerOperandIndex() {
474 return 0U; // get index for modifying correct operand
475 }
476
477 /// Method to return the pointer operand as a PointerType.
478 Type *getPointerOperandType() const {
479 return getPointerOperand()->getType();
480 }
481
482 Type *getSourceElementType() const;
483 Type *getResultElementType() const;
484
485 /// Method to return the address space of the pointer operand.
486 unsigned getPointerAddressSpace() const {
487 return getPointerOperandType()->getPointerAddressSpace();
488 }
489
490 unsigned getNumIndices() const { // Note: always non-negative
491 return getNumOperands() - 1;
492 }
493
494 bool hasIndices() const {
495 return getNumOperands() > 1;
496 }
497
498 /// Return true if all of the indices of this GEP are zeros.
499 /// If so, the result pointer and the first operand have the same
500 /// value, just potentially different types.
501 bool hasAllZeroIndices() const {
502 for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
503 if (ConstantInt *C = dyn_cast<ConstantInt>(I))
504 if (C->isZero())
505 continue;
506 return false;
507 }
508 return true;
509 }
510
511 /// Return true if all of the indices of this GEP are constant integers.
512 /// If so, the result pointer and the first operand have
513 /// a constant offset between them.
514 bool hasAllConstantIndices() const {
515 for (const_op_iterator I = idx_begin(), E = idx_end(); I != E; ++I) {
516 if (!isa<ConstantInt>(I))
517 return false;
518 }
519 return true;
520 }
521
522 unsigned countNonConstantIndices() const {
523 return count_if(make_range(idx_begin(), idx_end()), [](const Use& use) {
524 return !isa<ConstantInt>(*use);
525 });
526 }
527
528 /// Accumulate the constant address offset of this GEP if possible.
529 ///
530 /// This routine accepts an APInt into which it will accumulate the constant
531 /// offset of this GEP if the GEP is in fact constant. If the GEP is not
532 /// all-constant, it returns false and the value of the offset APInt is
533 /// undefined (it is *not* preserved!). The APInt passed into this routine
534 /// must be at exactly as wide as the IntPtr type for the address space of the
535 /// base GEP pointer.
536 bool accumulateConstantOffset(const DataLayout &DL, APInt &Offset) const;
537};
538
539class PtrToIntOperator
540 : public ConcreteOperator<Operator, Instruction::PtrToInt> {
541 friend class PtrToInt;
542 friend class ConstantExpr;
543
544public:
545 Value *getPointerOperand() {
546 return getOperand(0);
547 }
548 const Value *getPointerOperand() const {
549 return getOperand(0);
550 }
551
552 static unsigned getPointerOperandIndex() {
553 return 0U; // get index for modifying correct operand
554 }
555
556 /// Method to return the pointer operand as a PointerType.
557 Type *getPointerOperandType() const {
558 return getPointerOperand()->getType();
559 }
560
561 /// Method to return the address space of the pointer operand.
562 unsigned getPointerAddressSpace() const {
563 return cast<PointerType>(getPointerOperandType())->getAddressSpace();
564 }
565};
566
567class BitCastOperator
568 : public ConcreteOperator<Operator, Instruction::BitCast> {
569 friend class BitCastInst;
570 friend class ConstantExpr;
571
572public:
573 Type *getSrcTy() const {
574 return getOperand(0)->getType();
575 }
576
577 Type *getDestTy() const {
578 return getType();
579 }
580};
581
582} // end namespace llvm
583
584#endif // LLVM_IR_OPERATOR_H
585