LLVM  13.0.0git
InstCombineAddSub.cpp
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1 //===- InstCombineAddSub.cpp ------------------------------------*- 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 implements the visit functions for add, fadd, sub, and fsub.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "InstCombineInternal.h"
14 #include "llvm/ADT/APFloat.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/IR/Constant.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/InstrTypes.h"
23 #include "llvm/IR/Instruction.h"
24 #include "llvm/IR/Instructions.h"
25 #include "llvm/IR/Operator.h"
26 #include "llvm/IR/PatternMatch.h"
27 #include "llvm/IR/Type.h"
28 #include "llvm/IR/Value.h"
29 #include "llvm/Support/AlignOf.h"
30 #include "llvm/Support/Casting.h"
31 #include "llvm/Support/KnownBits.h"
33 #include <cassert>
34 #include <utility>
35 
36 using namespace llvm;
37 using namespace PatternMatch;
38 
39 #define DEBUG_TYPE "instcombine"
40 
41 namespace {
42 
43  /// Class representing coefficient of floating-point addend.
44  /// This class needs to be highly efficient, which is especially true for
45  /// the constructor. As of I write this comment, the cost of the default
46  /// constructor is merely 4-byte-store-zero (Assuming compiler is able to
47  /// perform write-merging).
48  ///
49  class FAddendCoef {
50  public:
51  // The constructor has to initialize a APFloat, which is unnecessary for
52  // most addends which have coefficient either 1 or -1. So, the constructor
53  // is expensive. In order to avoid the cost of the constructor, we should
54  // reuse some instances whenever possible. The pre-created instances
55  // FAddCombine::Add[0-5] embodies this idea.
56  FAddendCoef() = default;
57  ~FAddendCoef();
58 
59  // If possible, don't define operator+/operator- etc because these
60  // operators inevitably call FAddendCoef's constructor which is not cheap.
61  void operator=(const FAddendCoef &A);
62  void operator+=(const FAddendCoef &A);
63  void operator*=(const FAddendCoef &S);
64 
65  void set(short C) {
66  assert(!insaneIntVal(C) && "Insane coefficient");
67  IsFp = false; IntVal = C;
68  }
69 
70  void set(const APFloat& C);
71 
72  void negate();
73 
74  bool isZero() const { return isInt() ? !IntVal : getFpVal().isZero(); }
75  Value *getValue(Type *) const;
76 
77  bool isOne() const { return isInt() && IntVal == 1; }
78  bool isTwo() const { return isInt() && IntVal == 2; }
79  bool isMinusOne() const { return isInt() && IntVal == -1; }
80  bool isMinusTwo() const { return isInt() && IntVal == -2; }
81 
82  private:
83  bool insaneIntVal(int V) { return V > 4 || V < -4; }
84 
85  APFloat *getFpValPtr() { return reinterpret_cast<APFloat *>(&FpValBuf); }
86 
87  const APFloat *getFpValPtr() const {
88  return reinterpret_cast<const APFloat *>(&FpValBuf);
89  }
90 
91  const APFloat &getFpVal() const {
92  assert(IsFp && BufHasFpVal && "Incorret state");
93  return *getFpValPtr();
94  }
95 
96  APFloat &getFpVal() {
97  assert(IsFp && BufHasFpVal && "Incorret state");
98  return *getFpValPtr();
99  }
100 
101  bool isInt() const { return !IsFp; }
102 
103  // If the coefficient is represented by an integer, promote it to a
104  // floating point.
105  void convertToFpType(const fltSemantics &Sem);
106 
107  // Construct an APFloat from a signed integer.
108  // TODO: We should get rid of this function when APFloat can be constructed
109  // from an *SIGNED* integer.
110  APFloat createAPFloatFromInt(const fltSemantics &Sem, int Val);
111 
112  bool IsFp = false;
113 
114  // True iff FpValBuf contains an instance of APFloat.
115  bool BufHasFpVal = false;
116 
117  // The integer coefficient of an individual addend is either 1 or -1,
118  // and we try to simplify at most 4 addends from neighboring at most
119  // two instructions. So the range of <IntVal> falls in [-4, 4]. APInt
120  // is overkill of this end.
121  short IntVal = 0;
122 
124  };
125 
126  /// FAddend is used to represent floating-point addend. An addend is
127  /// represented as <C, V>, where the V is a symbolic value, and C is a
128  /// constant coefficient. A constant addend is represented as <C, 0>.
129  class FAddend {
130  public:
131  FAddend() = default;
132 
133  void operator+=(const FAddend &T) {
134  assert((Val == T.Val) && "Symbolic-values disagree");
135  Coeff += T.Coeff;
136  }
137 
138  Value *getSymVal() const { return Val; }
139  const FAddendCoef &getCoef() const { return Coeff; }
140 
141  bool isConstant() const { return Val == nullptr; }
142  bool isZero() const { return Coeff.isZero(); }
143 
144  void set(short Coefficient, Value *V) {
145  Coeff.set(Coefficient);
146  Val = V;
147  }
148  void set(const APFloat &Coefficient, Value *V) {
149  Coeff.set(Coefficient);
150  Val = V;
151  }
152  void set(const ConstantFP *Coefficient, Value *V) {
153  Coeff.set(Coefficient->getValueAPF());
154  Val = V;
155  }
156 
157  void negate() { Coeff.negate(); }
158 
159  /// Drill down the U-D chain one step to find the definition of V, and
160  /// try to break the definition into one or two addends.
161  static unsigned drillValueDownOneStep(Value* V, FAddend &A0, FAddend &A1);
162 
163  /// Similar to FAddend::drillDownOneStep() except that the value being
164  /// splitted is the addend itself.
165  unsigned drillAddendDownOneStep(FAddend &Addend0, FAddend &Addend1) const;
166 
167  private:
168  void Scale(const FAddendCoef& ScaleAmt) { Coeff *= ScaleAmt; }
169 
170  // This addend has the value of "Coeff * Val".
171  Value *Val = nullptr;
172  FAddendCoef Coeff;
173  };
174 
175  /// FAddCombine is the class for optimizing an unsafe fadd/fsub along
176  /// with its neighboring at most two instructions.
177  ///
178  class FAddCombine {
179  public:
180  FAddCombine(InstCombiner::BuilderTy &B) : Builder(B) {}
181 
183 
184  private:
185  using AddendVect = SmallVector<const FAddend *, 4>;
186 
187  Value *simplifyFAdd(AddendVect& V, unsigned InstrQuota);
188 
189  /// Convert given addend to a Value
190  Value *createAddendVal(const FAddend &A, bool& NeedNeg);
191 
192  /// Return the number of instructions needed to emit the N-ary addition.
193  unsigned calcInstrNumber(const AddendVect& Vect);
194 
195  Value *createFSub(Value *Opnd0, Value *Opnd1);
196  Value *createFAdd(Value *Opnd0, Value *Opnd1);
197  Value *createFMul(Value *Opnd0, Value *Opnd1);
198  Value *createFNeg(Value *V);
199  Value *createNaryFAdd(const AddendVect& Opnds, unsigned InstrQuota);
200  void createInstPostProc(Instruction *NewInst, bool NoNumber = false);
201 
202  // Debugging stuff are clustered here.
203  #ifndef NDEBUG
204  unsigned CreateInstrNum;
205  void initCreateInstNum() { CreateInstrNum = 0; }
206  void incCreateInstNum() { CreateInstrNum++; }
207  #else
208  void initCreateInstNum() {}
209  void incCreateInstNum() {}
210  #endif
211 
213  Instruction *Instr = nullptr;
214  };
215 
216 } // end anonymous namespace
217 
218 //===----------------------------------------------------------------------===//
219 //
220 // Implementation of
221 // {FAddendCoef, FAddend, FAddition, FAddCombine}.
222 //
223 //===----------------------------------------------------------------------===//
224 FAddendCoef::~FAddendCoef() {
225  if (BufHasFpVal)
226  getFpValPtr()->~APFloat();
227 }
228 
229 void FAddendCoef::set(const APFloat& C) {
230  APFloat *P = getFpValPtr();
231 
232  if (isInt()) {
233  // As the buffer is meanless byte stream, we cannot call
234  // APFloat::operator=().
235  new(P) APFloat(C);
236  } else
237  *P = C;
238 
239  IsFp = BufHasFpVal = true;
240 }
241 
242 void FAddendCoef::convertToFpType(const fltSemantics &Sem) {
243  if (!isInt())
244  return;
245 
246  APFloat *P = getFpValPtr();
247  if (IntVal > 0)
248  new(P) APFloat(Sem, IntVal);
249  else {
250  new(P) APFloat(Sem, 0 - IntVal);
251  P->changeSign();
252  }
253  IsFp = BufHasFpVal = true;
254 }
255 
256 APFloat FAddendCoef::createAPFloatFromInt(const fltSemantics &Sem, int Val) {
257  if (Val >= 0)
258  return APFloat(Sem, Val);
259 
260  APFloat T(Sem, 0 - Val);
261  T.changeSign();
262 
263  return T;
264 }
265 
266 void FAddendCoef::operator=(const FAddendCoef &That) {
267  if (That.isInt())
268  set(That.IntVal);
269  else
270  set(That.getFpVal());
271 }
272 
273 void FAddendCoef::operator+=(const FAddendCoef &That) {
275  if (isInt() == That.isInt()) {
276  if (isInt())
277  IntVal += That.IntVal;
278  else
279  getFpVal().add(That.getFpVal(), RndMode);
280  return;
281  }
282 
283  if (isInt()) {
284  const APFloat &T = That.getFpVal();
285  convertToFpType(T.getSemantics());
286  getFpVal().add(T, RndMode);
287  return;
288  }
289 
290  APFloat &T = getFpVal();
291  T.add(createAPFloatFromInt(T.getSemantics(), That.IntVal), RndMode);
292 }
293 
294 void FAddendCoef::operator*=(const FAddendCoef &That) {
295  if (That.isOne())
296  return;
297 
298  if (That.isMinusOne()) {
299  negate();
300  return;
301  }
302 
303  if (isInt() && That.isInt()) {
304  int Res = IntVal * (int)That.IntVal;
305  assert(!insaneIntVal(Res) && "Insane int value");
306  IntVal = Res;
307  return;
308  }
309 
310  const fltSemantics &Semantic =
311  isInt() ? That.getFpVal().getSemantics() : getFpVal().getSemantics();
312 
313  if (isInt())
314  convertToFpType(Semantic);
315  APFloat &F0 = getFpVal();
316 
317  if (That.isInt())
318  F0.multiply(createAPFloatFromInt(Semantic, That.IntVal),
320  else
321  F0.multiply(That.getFpVal(), APFloat::rmNearestTiesToEven);
322 }
323 
324 void FAddendCoef::negate() {
325  if (isInt())
326  IntVal = 0 - IntVal;
327  else
328  getFpVal().changeSign();
329 }
330 
331 Value *FAddendCoef::getValue(Type *Ty) const {
332  return isInt() ?
333  ConstantFP::get(Ty, float(IntVal)) :
334  ConstantFP::get(Ty->getContext(), getFpVal());
335 }
336 
337 // The definition of <Val> Addends
338 // =========================================
339 // A + B <1, A>, <1,B>
340 // A - B <1, A>, <1,B>
341 // 0 - B <-1, B>
342 // C * A, <C, A>
343 // A + C <1, A> <C, NULL>
344 // 0 +/- 0 <0, NULL> (corner case)
345 //
346 // Legend: A and B are not constant, C is constant
347 unsigned FAddend::drillValueDownOneStep
348  (Value *Val, FAddend &Addend0, FAddend &Addend1) {
349  Instruction *I = nullptr;
350  if (!Val || !(I = dyn_cast<Instruction>(Val)))
351  return 0;
352 
353  unsigned Opcode = I->getOpcode();
354 
355  if (Opcode == Instruction::FAdd || Opcode == Instruction::FSub) {
356  ConstantFP *C0, *C1;
357  Value *Opnd0 = I->getOperand(0);
358  Value *Opnd1 = I->getOperand(1);
359  if ((C0 = dyn_cast<ConstantFP>(Opnd0)) && C0->isZero())
360  Opnd0 = nullptr;
361 
362  if ((C1 = dyn_cast<ConstantFP>(Opnd1)) && C1->isZero())
363  Opnd1 = nullptr;
364 
365  if (Opnd0) {
366  if (!C0)
367  Addend0.set(1, Opnd0);
368  else
369  Addend0.set(C0, nullptr);
370  }
371 
372  if (Opnd1) {
373  FAddend &Addend = Opnd0 ? Addend1 : Addend0;
374  if (!C1)
375  Addend.set(1, Opnd1);
376  else
377  Addend.set(C1, nullptr);
378  if (Opcode == Instruction::FSub)
379  Addend.negate();
380  }
381 
382  if (Opnd0 || Opnd1)
383  return Opnd0 && Opnd1 ? 2 : 1;
384 
385  // Both operands are zero. Weird!
386  Addend0.set(APFloat(C0->getValueAPF().getSemantics()), nullptr);
387  return 1;
388  }
389 
390  if (I->getOpcode() == Instruction::FMul) {
391  Value *V0 = I->getOperand(0);
392  Value *V1 = I->getOperand(1);
393  if (ConstantFP *C = dyn_cast<ConstantFP>(V0)) {
394  Addend0.set(C, V1);
395  return 1;
396  }
397 
398  if (ConstantFP *C = dyn_cast<ConstantFP>(V1)) {
399  Addend0.set(C, V0);
400  return 1;
401  }
402  }
403 
404  return 0;
405 }
406 
407 // Try to break *this* addend into two addends. e.g. Suppose this addend is
408 // <2.3, V>, and V = X + Y, by calling this function, we obtain two addends,
409 // i.e. <2.3, X> and <2.3, Y>.
410 unsigned FAddend::drillAddendDownOneStep
411  (FAddend &Addend0, FAddend &Addend1) const {
412  if (isConstant())
413  return 0;
414 
415  unsigned BreakNum = FAddend::drillValueDownOneStep(Val, Addend0, Addend1);
416  if (!BreakNum || Coeff.isOne())
417  return BreakNum;
418 
419  Addend0.Scale(Coeff);
420 
421  if (BreakNum == 2)
422  Addend1.Scale(Coeff);
423 
424  return BreakNum;
425 }
426 
428  assert(I->hasAllowReassoc() && I->hasNoSignedZeros() &&
429  "Expected 'reassoc'+'nsz' instruction");
430 
431  // Currently we are not able to handle vector type.
432  if (I->getType()->isVectorTy())
433  return nullptr;
434 
435  assert((I->getOpcode() == Instruction::FAdd ||
436  I->getOpcode() == Instruction::FSub) && "Expect add/sub");
437 
438  // Save the instruction before calling other member-functions.
439  Instr = I;
440 
441  FAddend Opnd0, Opnd1, Opnd0_0, Opnd0_1, Opnd1_0, Opnd1_1;
442 
443  unsigned OpndNum = FAddend::drillValueDownOneStep(I, Opnd0, Opnd1);
444 
445  // Step 1: Expand the 1st addend into Opnd0_0 and Opnd0_1.
446  unsigned Opnd0_ExpNum = 0;
447  unsigned Opnd1_ExpNum = 0;
448 
449  if (!Opnd0.isConstant())
450  Opnd0_ExpNum = Opnd0.drillAddendDownOneStep(Opnd0_0, Opnd0_1);
451 
452  // Step 2: Expand the 2nd addend into Opnd1_0 and Opnd1_1.
453  if (OpndNum == 2 && !Opnd1.isConstant())
454  Opnd1_ExpNum = Opnd1.drillAddendDownOneStep(Opnd1_0, Opnd1_1);
455 
456  // Step 3: Try to optimize Opnd0_0 + Opnd0_1 + Opnd1_0 + Opnd1_1
457  if (Opnd0_ExpNum && Opnd1_ExpNum) {
458  AddendVect AllOpnds;
459  AllOpnds.push_back(&Opnd0_0);
460  AllOpnds.push_back(&Opnd1_0);
461  if (Opnd0_ExpNum == 2)
462  AllOpnds.push_back(&Opnd0_1);
463  if (Opnd1_ExpNum == 2)
464  AllOpnds.push_back(&Opnd1_1);
465 
466  // Compute instruction quota. We should save at least one instruction.
467  unsigned InstQuota = 0;
468 
469  Value *V0 = I->getOperand(0);
470  Value *V1 = I->getOperand(1);
471  InstQuota = ((!isa<Constant>(V0) && V0->hasOneUse()) &&
472  (!isa<Constant>(V1) && V1->hasOneUse())) ? 2 : 1;
473 
474  if (Value *R = simplifyFAdd(AllOpnds, InstQuota))
475  return R;
476  }
477 
478  if (OpndNum != 2) {
479  // The input instruction is : "I=0.0 +/- V". If the "V" were able to be
480  // splitted into two addends, say "V = X - Y", the instruction would have
481  // been optimized into "I = Y - X" in the previous steps.
482  //
483  const FAddendCoef &CE = Opnd0.getCoef();
484  return CE.isOne() ? Opnd0.getSymVal() : nullptr;
485  }
486 
487  // step 4: Try to optimize Opnd0 + Opnd1_0 [+ Opnd1_1]
488  if (Opnd1_ExpNum) {
489  AddendVect AllOpnds;
490  AllOpnds.push_back(&Opnd0);
491  AllOpnds.push_back(&Opnd1_0);
492  if (Opnd1_ExpNum == 2)
493  AllOpnds.push_back(&Opnd1_1);
494 
495  if (Value *R = simplifyFAdd(AllOpnds, 1))
496  return R;
497  }
498 
499  // step 5: Try to optimize Opnd1 + Opnd0_0 [+ Opnd0_1]
500  if (Opnd0_ExpNum) {
501  AddendVect AllOpnds;
502  AllOpnds.push_back(&Opnd1);
503  AllOpnds.push_back(&Opnd0_0);
504  if (Opnd0_ExpNum == 2)
505  AllOpnds.push_back(&Opnd0_1);
506 
507  if (Value *R = simplifyFAdd(AllOpnds, 1))
508  return R;
509  }
510 
511  return nullptr;
512 }
513 
514 Value *FAddCombine::simplifyFAdd(AddendVect& Addends, unsigned InstrQuota) {
515  unsigned AddendNum = Addends.size();
516  assert(AddendNum <= 4 && "Too many addends");
517 
518  // For saving intermediate results;
519  unsigned NextTmpIdx = 0;
520  FAddend TmpResult[3];
521 
522  // Points to the constant addend of the resulting simplified expression.
523  // If the resulting expr has constant-addend, this constant-addend is
524  // desirable to reside at the top of the resulting expression tree. Placing
525  // constant close to supper-expr(s) will potentially reveal some optimization
526  // opportunities in super-expr(s).
527  const FAddend *ConstAdd = nullptr;
528 
529  // Simplified addends are placed <SimpVect>.
530  AddendVect SimpVect;
531 
532  // The outer loop works on one symbolic-value at a time. Suppose the input
533  // addends are : <a1, x>, <b1, y>, <a2, x>, <c1, z>, <b2, y>, ...
534  // The symbolic-values will be processed in this order: x, y, z.
535  for (unsigned SymIdx = 0; SymIdx < AddendNum; SymIdx++) {
536 
537  const FAddend *ThisAddend = Addends[SymIdx];
538  if (!ThisAddend) {
539  // This addend was processed before.
540  continue;
541  }
542 
543  Value *Val = ThisAddend->getSymVal();
544  unsigned StartIdx = SimpVect.size();
545  SimpVect.push_back(ThisAddend);
546 
547  // The inner loop collects addends sharing same symbolic-value, and these
548  // addends will be later on folded into a single addend. Following above
549  // example, if the symbolic value "y" is being processed, the inner loop
550  // will collect two addends "<b1,y>" and "<b2,Y>". These two addends will
551  // be later on folded into "<b1+b2, y>".
552  for (unsigned SameSymIdx = SymIdx + 1;
553  SameSymIdx < AddendNum; SameSymIdx++) {
554  const FAddend *T = Addends[SameSymIdx];
555  if (T && T->getSymVal() == Val) {
556  // Set null such that next iteration of the outer loop will not process
557  // this addend again.
558  Addends[SameSymIdx] = nullptr;
559  SimpVect.push_back(T);
560  }
561  }
562 
563  // If multiple addends share same symbolic value, fold them together.
564  if (StartIdx + 1 != SimpVect.size()) {
565  FAddend &R = TmpResult[NextTmpIdx ++];
566  R = *SimpVect[StartIdx];
567  for (unsigned Idx = StartIdx + 1; Idx < SimpVect.size(); Idx++)
568  R += *SimpVect[Idx];
569 
570  // Pop all addends being folded and push the resulting folded addend.
571  SimpVect.resize(StartIdx);
572  if (Val) {
573  if (!R.isZero()) {
574  SimpVect.push_back(&R);
575  }
576  } else {
577  // Don't push constant addend at this time. It will be the last element
578  // of <SimpVect>.
579  ConstAdd = &R;
580  }
581  }
582  }
583 
584  assert((NextTmpIdx <= array_lengthof(TmpResult) + 1) &&
585  "out-of-bound access");
586 
587  if (ConstAdd)
588  SimpVect.push_back(ConstAdd);
589 
590  Value *Result;
591  if (!SimpVect.empty())
592  Result = createNaryFAdd(SimpVect, InstrQuota);
593  else {
594  // The addition is folded to 0.0.
595  Result = ConstantFP::get(Instr->getType(), 0.0);
596  }
597 
598  return Result;
599 }
600 
601 Value *FAddCombine::createNaryFAdd
602  (const AddendVect &Opnds, unsigned InstrQuota) {
603  assert(!Opnds.empty() && "Expect at least one addend");
604 
605  // Step 1: Check if the # of instructions needed exceeds the quota.
606 
607  unsigned InstrNeeded = calcInstrNumber(Opnds);
608  if (InstrNeeded > InstrQuota)
609  return nullptr;
610 
611  initCreateInstNum();
612 
613  // step 2: Emit the N-ary addition.
614  // Note that at most three instructions are involved in Fadd-InstCombine: the
615  // addition in question, and at most two neighboring instructions.
616  // The resulting optimized addition should have at least one less instruction
617  // than the original addition expression tree. This implies that the resulting
618  // N-ary addition has at most two instructions, and we don't need to worry
619  // about tree-height when constructing the N-ary addition.
620 
621  Value *LastVal = nullptr;
622  bool LastValNeedNeg = false;
623 
624  // Iterate the addends, creating fadd/fsub using adjacent two addends.
625  for (const FAddend *Opnd : Opnds) {
626  bool NeedNeg;
627  Value *V = createAddendVal(*Opnd, NeedNeg);
628  if (!LastVal) {
629  LastVal = V;
630  LastValNeedNeg = NeedNeg;
631  continue;
632  }
633 
634  if (LastValNeedNeg == NeedNeg) {
635  LastVal = createFAdd(LastVal, V);
636  continue;
637  }
638 
639  if (LastValNeedNeg)
640  LastVal = createFSub(V, LastVal);
641  else
642  LastVal = createFSub(LastVal, V);
643 
644  LastValNeedNeg = false;
645  }
646 
647  if (LastValNeedNeg) {
648  LastVal = createFNeg(LastVal);
649  }
650 
651 #ifndef NDEBUG
652  assert(CreateInstrNum == InstrNeeded &&
653  "Inconsistent in instruction numbers");
654 #endif
655 
656  return LastVal;
657 }
658 
659 Value *FAddCombine::createFSub(Value *Opnd0, Value *Opnd1) {
660  Value *V = Builder.CreateFSub(Opnd0, Opnd1);
661  if (Instruction *I = dyn_cast<Instruction>(V))
662  createInstPostProc(I);
663  return V;
664 }
665 
666 Value *FAddCombine::createFNeg(Value *V) {
667  Value *NewV = Builder.CreateFNeg(V);
668  if (Instruction *I = dyn_cast<Instruction>(NewV))
669  createInstPostProc(I, true); // fneg's don't receive instruction numbers.
670  return NewV;
671 }
672 
673 Value *FAddCombine::createFAdd(Value *Opnd0, Value *Opnd1) {
674  Value *V = Builder.CreateFAdd(Opnd0, Opnd1);
675  if (Instruction *I = dyn_cast<Instruction>(V))
676  createInstPostProc(I);
677  return V;
678 }
679 
680 Value *FAddCombine::createFMul(Value *Opnd0, Value *Opnd1) {
681  Value *V = Builder.CreateFMul(Opnd0, Opnd1);
682  if (Instruction *I = dyn_cast<Instruction>(V))
683  createInstPostProc(I);
684  return V;
685 }
686 
687 void FAddCombine::createInstPostProc(Instruction *NewInstr, bool NoNumber) {
688  NewInstr->setDebugLoc(Instr->getDebugLoc());
689 
690  // Keep track of the number of instruction created.
691  if (!NoNumber)
692  incCreateInstNum();
693 
694  // Propagate fast-math flags
695  NewInstr->setFastMathFlags(Instr->getFastMathFlags());
696 }
697 
698 // Return the number of instruction needed to emit the N-ary addition.
699 // NOTE: Keep this function in sync with createAddendVal().
700 unsigned FAddCombine::calcInstrNumber(const AddendVect &Opnds) {
701  unsigned OpndNum = Opnds.size();
702  unsigned InstrNeeded = OpndNum - 1;
703 
704  // The number of addends in the form of "(-1)*x".
705  unsigned NegOpndNum = 0;
706 
707  // Adjust the number of instructions needed to emit the N-ary add.
708  for (const FAddend *Opnd : Opnds) {
709  if (Opnd->isConstant())
710  continue;
711 
712  // The constant check above is really for a few special constant
713  // coefficients.
714  if (isa<UndefValue>(Opnd->getSymVal()))
715  continue;
716 
717  const FAddendCoef &CE = Opnd->getCoef();
718  if (CE.isMinusOne() || CE.isMinusTwo())
719  NegOpndNum++;
720 
721  // Let the addend be "c * x". If "c == +/-1", the value of the addend
722  // is immediately available; otherwise, it needs exactly one instruction
723  // to evaluate the value.
724  if (!CE.isMinusOne() && !CE.isOne())
725  InstrNeeded++;
726  }
727  return InstrNeeded;
728 }
729 
730 // Input Addend Value NeedNeg(output)
731 // ================================================================
732 // Constant C C false
733 // <+/-1, V> V coefficient is -1
734 // <2/-2, V> "fadd V, V" coefficient is -2
735 // <C, V> "fmul V, C" false
736 //
737 // NOTE: Keep this function in sync with FAddCombine::calcInstrNumber.
738 Value *FAddCombine::createAddendVal(const FAddend &Opnd, bool &NeedNeg) {
739  const FAddendCoef &Coeff = Opnd.getCoef();
740 
741  if (Opnd.isConstant()) {
742  NeedNeg = false;
743  return Coeff.getValue(Instr->getType());
744  }
745 
746  Value *OpndVal = Opnd.getSymVal();
747 
748  if (Coeff.isMinusOne() || Coeff.isOne()) {
749  NeedNeg = Coeff.isMinusOne();
750  return OpndVal;
751  }
752 
753  if (Coeff.isTwo() || Coeff.isMinusTwo()) {
754  NeedNeg = Coeff.isMinusTwo();
755  return createFAdd(OpndVal, OpndVal);
756  }
757 
758  NeedNeg = false;
759  return createFMul(OpndVal, Coeff.getValue(Instr->getType()));
760 }
761 
762 // Checks if any operand is negative and we can convert add to sub.
763 // This function checks for following negative patterns
764 // ADD(XOR(OR(Z, NOT(C)), C)), 1) == NEG(AND(Z, C))
765 // ADD(XOR(AND(Z, C), C), 1) == NEG(OR(Z, ~C))
766 // XOR(AND(Z, C), (C + 1)) == NEG(OR(Z, ~C)) if C is even
769  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
770 
771  // This function creates 2 instructions to replace ADD, we need at least one
772  // of LHS or RHS to have one use to ensure benefit in transform.
773  if (!LHS->hasOneUse() && !RHS->hasOneUse())
774  return nullptr;
775 
776  Value *X = nullptr, *Y = nullptr, *Z = nullptr;
777  const APInt *C1 = nullptr, *C2 = nullptr;
778 
779  // if ONE is on other side, swap
780  if (match(RHS, m_Add(m_Value(X), m_One())))
781  std::swap(LHS, RHS);
782 
783  if (match(LHS, m_Add(m_Value(X), m_One()))) {
784  // if XOR on other side, swap
785  if (match(RHS, m_Xor(m_Value(Y), m_APInt(C1))))
786  std::swap(X, RHS);
787 
788  if (match(X, m_Xor(m_Value(Y), m_APInt(C1)))) {
789  // X = XOR(Y, C1), Y = OR(Z, C2), C2 = NOT(C1) ==> X == NOT(AND(Z, C1))
790  // ADD(ADD(X, 1), RHS) == ADD(X, ADD(RHS, 1)) == SUB(RHS, AND(Z, C1))
791  if (match(Y, m_Or(m_Value(Z), m_APInt(C2))) && (*C2 == ~(*C1))) {
792  Value *NewAnd = Builder.CreateAnd(Z, *C1);
793  return Builder.CreateSub(RHS, NewAnd, "sub");
794  } else if (match(Y, m_And(m_Value(Z), m_APInt(C2))) && (*C1 == *C2)) {
795  // X = XOR(Y, C1), Y = AND(Z, C2), C2 == C1 ==> X == NOT(OR(Z, ~C1))
796  // ADD(ADD(X, 1), RHS) == ADD(X, ADD(RHS, 1)) == SUB(RHS, OR(Z, ~C1))
797  Value *NewOr = Builder.CreateOr(Z, ~(*C1));
798  return Builder.CreateSub(RHS, NewOr, "sub");
799  }
800  }
801  }
802 
803  // Restore LHS and RHS
804  LHS = I.getOperand(0);
805  RHS = I.getOperand(1);
806 
807  // if XOR is on other side, swap
808  if (match(RHS, m_Xor(m_Value(Y), m_APInt(C1))))
809  std::swap(LHS, RHS);
810 
811  // C2 is ODD
812  // LHS = XOR(Y, C1), Y = AND(Z, C2), C1 == (C2 + 1) => LHS == NEG(OR(Z, ~C2))
813  // ADD(LHS, RHS) == SUB(RHS, OR(Z, ~C2))
814  if (match(LHS, m_Xor(m_Value(Y), m_APInt(C1))))
815  if (C1->countTrailingZeros() == 0)
816  if (match(Y, m_And(m_Value(Z), m_APInt(C2))) && *C1 == (*C2 + 1)) {
817  Value *NewOr = Builder.CreateOr(Z, ~(*C2));
818  return Builder.CreateSub(RHS, NewOr, "sub");
819  }
820  return nullptr;
821 }
822 
823 /// Wrapping flags may allow combining constants separated by an extend.
826  Value *Op0 = Add.getOperand(0), *Op1 = Add.getOperand(1);
827  Type *Ty = Add.getType();
828  Constant *Op1C;
829  if (!match(Op1, m_Constant(Op1C)))
830  return nullptr;
831 
832  // Try this match first because it results in an add in the narrow type.
833  // (zext (X +nuw C2)) + C1 --> zext (X + (C2 + trunc(C1)))
834  Value *X;
835  const APInt *C1, *C2;
836  if (match(Op1, m_APInt(C1)) &&
837  match(Op0, m_OneUse(m_ZExt(m_NUWAdd(m_Value(X), m_APInt(C2))))) &&
838  C1->isNegative() && C1->sge(-C2->sext(C1->getBitWidth()))) {
839  Constant *NewC =
840  ConstantInt::get(X->getType(), *C2 + C1->trunc(C2->getBitWidth()));
841  return new ZExtInst(Builder.CreateNUWAdd(X, NewC), Ty);
842  }
843 
844  // More general combining of constants in the wide type.
845  // (sext (X +nsw NarrowC)) + C --> (sext X) + (sext(NarrowC) + C)
846  Constant *NarrowC;
847  if (match(Op0, m_OneUse(m_SExt(m_NSWAdd(m_Value(X), m_Constant(NarrowC)))))) {
848  Constant *WideC = ConstantExpr::getSExt(NarrowC, Ty);
849  Constant *NewC = ConstantExpr::getAdd(WideC, Op1C);
850  Value *WideX = Builder.CreateSExt(X, Ty);
851  return BinaryOperator::CreateAdd(WideX, NewC);
852  }
853  // (zext (X +nuw NarrowC)) + C --> (zext X) + (zext(NarrowC) + C)
854  if (match(Op0, m_OneUse(m_ZExt(m_NUWAdd(m_Value(X), m_Constant(NarrowC)))))) {
855  Constant *WideC = ConstantExpr::getZExt(NarrowC, Ty);
856  Constant *NewC = ConstantExpr::getAdd(WideC, Op1C);
857  Value *WideX = Builder.CreateZExt(X, Ty);
858  return BinaryOperator::CreateAdd(WideX, NewC);
859  }
860 
861  return nullptr;
862 }
863 
865  Value *Op0 = Add.getOperand(0), *Op1 = Add.getOperand(1);
866  Constant *Op1C;
867  if (!match(Op1, m_ImmConstant(Op1C)))
868  return nullptr;
869 
870  if (Instruction *NV = foldBinOpIntoSelectOrPhi(Add))
871  return NV;
872 
873  Value *X;
874  Constant *Op00C;
875 
876  // add (sub C1, X), C2 --> sub (add C1, C2), X
877  if (match(Op0, m_Sub(m_Constant(Op00C), m_Value(X))))
878  return BinaryOperator::CreateSub(ConstantExpr::getAdd(Op00C, Op1C), X);
879 
880  Value *Y;
881 
882  // add (sub X, Y), -1 --> add (not Y), X
883  if (match(Op0, m_OneUse(m_Sub(m_Value(X), m_Value(Y)))) &&
884  match(Op1, m_AllOnes()))
885  return BinaryOperator::CreateAdd(Builder.CreateNot(Y), X);
886 
887  // zext(bool) + C -> bool ? C + 1 : C
888  if (match(Op0, m_ZExt(m_Value(X))) &&
889  X->getType()->getScalarSizeInBits() == 1)
890  return SelectInst::Create(X, InstCombiner::AddOne(Op1C), Op1);
891  // sext(bool) + C -> bool ? C - 1 : C
892  if (match(Op0, m_SExt(m_Value(X))) &&
893  X->getType()->getScalarSizeInBits() == 1)
894  return SelectInst::Create(X, InstCombiner::SubOne(Op1C), Op1);
895 
896  // ~X + C --> (C-1) - X
897  if (match(Op0, m_Not(m_Value(X))))
898  return BinaryOperator::CreateSub(InstCombiner::SubOne(Op1C), X);
899 
900  const APInt *C;
901  if (!match(Op1, m_APInt(C)))
902  return nullptr;
903 
904  // (X | Op01C) + Op1C --> X + (Op01C + Op1C) iff the `or` is actually an `add`
905  Constant *Op01C;
906  if (match(Op0, m_Or(m_Value(X), m_ImmConstant(Op01C))) &&
907  haveNoCommonBitsSet(X, Op01C, DL, &AC, &Add, &DT))
908  return BinaryOperator::CreateAdd(X, ConstantExpr::getAdd(Op01C, Op1C));
909 
910  // (X | C2) + C --> (X | C2) ^ C2 iff (C2 == -C)
911  const APInt *C2;
912  if (match(Op0, m_Or(m_Value(), m_APInt(C2))) && *C2 == -*C)
913  return BinaryOperator::CreateXor(Op0, ConstantInt::get(Add.getType(), *C2));
914 
915  if (C->isSignMask()) {
916  // If wrapping is not allowed, then the addition must set the sign bit:
917  // X + (signmask) --> X | signmask
918  if (Add.hasNoSignedWrap() || Add.hasNoUnsignedWrap())
919  return BinaryOperator::CreateOr(Op0, Op1);
920 
921  // If wrapping is allowed, then the addition flips the sign bit of LHS:
922  // X + (signmask) --> X ^ signmask
923  return BinaryOperator::CreateXor(Op0, Op1);
924  }
925 
926  // Is this add the last step in a convoluted sext?
927  // add(zext(xor i16 X, -32768), -32768) --> sext X
928  Type *Ty = Add.getType();
929  if (match(Op0, m_ZExt(m_Xor(m_Value(X), m_APInt(C2)))) &&
930  C2->isMinSignedValue() && C2->sext(Ty->getScalarSizeInBits()) == *C)
931  return CastInst::Create(Instruction::SExt, X, Ty);
932 
933  if (match(Op0, m_Xor(m_Value(X), m_APInt(C2)))) {
934  // (X ^ signmask) + C --> (X + (signmask ^ C))
935  if (C2->isSignMask())
936  return BinaryOperator::CreateAdd(X, ConstantInt::get(Ty, *C2 ^ *C));
937 
938  // If X has no high-bits set above an xor mask:
939  // add (xor X, LowMaskC), C --> sub (LowMaskC + C), X
940  if (C2->isMask()) {
941  KnownBits LHSKnown = computeKnownBits(X, 0, &Add);
942  if ((*C2 | LHSKnown.Zero).isAllOnesValue())
943  return BinaryOperator::CreateSub(ConstantInt::get(Ty, *C2 + *C), X);
944  }
945 
946  // Look for a math+logic pattern that corresponds to sext-in-register of a
947  // value with cleared high bits. Convert that into a pair of shifts:
948  // add (xor X, 0x80), 0xF..F80 --> (X << ShAmtC) >>s ShAmtC
949  // add (xor X, 0xF..F80), 0x80 --> (X << ShAmtC) >>s ShAmtC
950  if (Op0->hasOneUse() && *C2 == -(*C)) {
951  unsigned BitWidth = Ty->getScalarSizeInBits();
952  unsigned ShAmt = 0;
953  if (C->isPowerOf2())
954  ShAmt = BitWidth - C->logBase2() - 1;
955  else if (C2->isPowerOf2())
956  ShAmt = BitWidth - C2->logBase2() - 1;
957  if (ShAmt && MaskedValueIsZero(X, APInt::getHighBitsSet(BitWidth, ShAmt),
958  0, &Add)) {
959  Constant *ShAmtC = ConstantInt::get(Ty, ShAmt);
960  Value *NewShl = Builder.CreateShl(X, ShAmtC, "sext");
961  return BinaryOperator::CreateAShr(NewShl, ShAmtC);
962  }
963  }
964  }
965 
966  if (C->isOneValue() && Op0->hasOneUse()) {
967  // add (sext i1 X), 1 --> zext (not X)
968  // TODO: The smallest IR representation is (select X, 0, 1), and that would
969  // not require the one-use check. But we need to remove a transform in
970  // visitSelect and make sure that IR value tracking for select is equal or
971  // better than for these ops.
972  if (match(Op0, m_SExt(m_Value(X))) &&
973  X->getType()->getScalarSizeInBits() == 1)
974  return new ZExtInst(Builder.CreateNot(X), Ty);
975 
976  // Shifts and add used to flip and mask off the low bit:
977  // add (ashr (shl i32 X, 31), 31), 1 --> and (not X), 1
978  const APInt *C3;
979  if (match(Op0, m_AShr(m_Shl(m_Value(X), m_APInt(C2)), m_APInt(C3))) &&
980  C2 == C3 && *C2 == Ty->getScalarSizeInBits() - 1) {
981  Value *NotX = Builder.CreateNot(X);
982  return BinaryOperator::CreateAnd(NotX, ConstantInt::get(Ty, 1));
983  }
984  }
985 
986  // If all bits affected by the add are included in a high-bit-mask, do the
987  // add before the mask op:
988  // (X & 0xFF00) + xx00 --> (X + xx00) & 0xFF00
989  if (match(Op0, m_OneUse(m_And(m_Value(X), m_APInt(C2)))) &&
990  C2->isNegative() && C2->isShiftedMask() && *C == (*C & *C2)) {
991  Value *NewAdd = Builder.CreateAdd(X, ConstantInt::get(Ty, *C));
992  return BinaryOperator::CreateAnd(NewAdd, ConstantInt::get(Ty, *C2));
993  }
994 
995  return nullptr;
996 }
997 
998 // Matches multiplication expression Op * C where C is a constant. Returns the
999 // constant value in C and the other operand in Op. Returns true if such a
1000 // match is found.
1001 static bool MatchMul(Value *E, Value *&Op, APInt &C) {
1002  const APInt *AI;
1003  if (match(E, m_Mul(m_Value(Op), m_APInt(AI)))) {
1004  C = *AI;
1005  return true;
1006  }
1007  if (match(E, m_Shl(m_Value(Op), m_APInt(AI)))) {
1008  C = APInt(AI->getBitWidth(), 1);
1009  C <<= *AI;
1010  return true;
1011  }
1012  return false;
1013 }
1014 
1015 // Matches remainder expression Op % C where C is a constant. Returns the
1016 // constant value in C and the other operand in Op. Returns the signedness of
1017 // the remainder operation in IsSigned. Returns true if such a match is
1018 // found.
1019 static bool MatchRem(Value *E, Value *&Op, APInt &C, bool &IsSigned) {
1020  const APInt *AI;
1021  IsSigned = false;
1022  if (match(E, m_SRem(m_Value(Op), m_APInt(AI)))) {
1023  IsSigned = true;
1024  C = *AI;
1025  return true;
1026  }
1027  if (match(E, m_URem(m_Value(Op), m_APInt(AI)))) {
1028  C = *AI;
1029  return true;
1030  }
1031  if (match(E, m_And(m_Value(Op), m_APInt(AI))) && (*AI + 1).isPowerOf2()) {
1032  C = *AI + 1;
1033  return true;
1034  }
1035  return false;
1036 }
1037 
1038 // Matches division expression Op / C with the given signedness as indicated
1039 // by IsSigned, where C is a constant. Returns the constant value in C and the
1040 // other operand in Op. Returns true if such a match is found.
1041 static bool MatchDiv(Value *E, Value *&Op, APInt &C, bool IsSigned) {
1042  const APInt *AI;
1043  if (IsSigned && match(E, m_SDiv(m_Value(Op), m_APInt(AI)))) {
1044  C = *AI;
1045  return true;
1046  }
1047  if (!IsSigned) {
1048  if (match(E, m_UDiv(m_Value(Op), m_APInt(AI)))) {
1049  C = *AI;
1050  return true;
1051  }
1052  if (match(E, m_LShr(m_Value(Op), m_APInt(AI)))) {
1053  C = APInt(AI->getBitWidth(), 1);
1054  C <<= *AI;
1055  return true;
1056  }
1057  }
1058  return false;
1059 }
1060 
1061 // Returns whether C0 * C1 with the given signedness overflows.
1062 static bool MulWillOverflow(APInt &C0, APInt &C1, bool IsSigned) {
1063  bool overflow;
1064  if (IsSigned)
1065  (void)C0.smul_ov(C1, overflow);
1066  else
1067  (void)C0.umul_ov(C1, overflow);
1068  return overflow;
1069 }
1070 
1071 // Simplifies X % C0 + (( X / C0 ) % C1) * C0 to X % (C0 * C1), where (C0 * C1)
1072 // does not overflow.
1074  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
1075  Value *X, *MulOpV;
1076  APInt C0, MulOpC;
1077  bool IsSigned;
1078  // Match I = X % C0 + MulOpV * C0
1079  if (((MatchRem(LHS, X, C0, IsSigned) && MatchMul(RHS, MulOpV, MulOpC)) ||
1080  (MatchRem(RHS, X, C0, IsSigned) && MatchMul(LHS, MulOpV, MulOpC))) &&
1081  C0 == MulOpC) {
1082  Value *RemOpV;
1083  APInt C1;
1084  bool Rem2IsSigned;
1085  // Match MulOpC = RemOpV % C1
1086  if (MatchRem(MulOpV, RemOpV, C1, Rem2IsSigned) &&
1087  IsSigned == Rem2IsSigned) {
1088  Value *DivOpV;
1089  APInt DivOpC;
1090  // Match RemOpV = X / C0
1091  if (MatchDiv(RemOpV, DivOpV, DivOpC, IsSigned) && X == DivOpV &&
1092  C0 == DivOpC && !MulWillOverflow(C0, C1, IsSigned)) {
1093  Value *NewDivisor = ConstantInt::get(X->getType(), C0 * C1);
1094  return IsSigned ? Builder.CreateSRem(X, NewDivisor, "srem")
1095  : Builder.CreateURem(X, NewDivisor, "urem");
1096  }
1097  }
1098  }
1099 
1100  return nullptr;
1101 }
1102 
1103 /// Fold
1104 /// (1 << NBits) - 1
1105 /// Into:
1106 /// ~(-(1 << NBits))
1107 /// Because a 'not' is better for bit-tracking analysis and other transforms
1108 /// than an 'add'. The new shl is always nsw, and is nuw if old `and` was.
1111  Value *NBits;
1112  if (!match(&I, m_Add(m_OneUse(m_Shl(m_One(), m_Value(NBits))), m_AllOnes())))
1113  return nullptr;
1114 
1115  Constant *MinusOne = Constant::getAllOnesValue(NBits->getType());
1116  Value *NotMask = Builder.CreateShl(MinusOne, NBits, "notmask");
1117  // Be wary of constant folding.
1118  if (auto *BOp = dyn_cast<BinaryOperator>(NotMask)) {
1119  // Always NSW. But NUW propagates from `add`.
1120  BOp->setHasNoSignedWrap();
1121  BOp->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
1122  }
1123 
1124  return BinaryOperator::CreateNot(NotMask, I.getName());
1125 }
1126 
1128  assert(I.getOpcode() == Instruction::Add && "Expecting add instruction");
1129  Type *Ty = I.getType();
1130  auto getUAddSat = [&]() {
1131  return Intrinsic::getDeclaration(I.getModule(), Intrinsic::uadd_sat, Ty);
1132  };
1133 
1134  // add (umin X, ~Y), Y --> uaddsat X, Y
1135  Value *X, *Y;
1136  if (match(&I, m_c_Add(m_c_UMin(m_Value(X), m_Not(m_Value(Y))),
1137  m_Deferred(Y))))
1138  return CallInst::Create(getUAddSat(), { X, Y });
1139 
1140  // add (umin X, ~C), C --> uaddsat X, C
1141  const APInt *C, *NotC;
1142  if (match(&I, m_Add(m_UMin(m_Value(X), m_APInt(NotC)), m_APInt(C))) &&
1143  *C == ~*NotC)
1144  return CallInst::Create(getUAddSat(), { X, ConstantInt::get(Ty, *C) });
1145 
1146  return nullptr;
1147 }
1148 
1151  BinaryOperator &I) {
1152  assert((I.getOpcode() == Instruction::Add ||
1153  I.getOpcode() == Instruction::Or ||
1154  I.getOpcode() == Instruction::Sub) &&
1155  "Expecting add/or/sub instruction");
1156 
1157  // We have a subtraction/addition between a (potentially truncated) *logical*
1158  // right-shift of X and a "select".
1159  Value *X, *Select;
1160  Instruction *LowBitsToSkip, *Extract;
1162  m_LShr(m_Value(X), m_Instruction(LowBitsToSkip)),
1163  m_Instruction(Extract))),
1164  m_Value(Select))))
1165  return nullptr;
1166 
1167  // `add`/`or` is commutative; but for `sub`, "select" *must* be on RHS.
1168  if (I.getOpcode() == Instruction::Sub && I.getOperand(1) != Select)
1169  return nullptr;
1170 
1171  Type *XTy = X->getType();
1172  bool HadTrunc = I.getType() != XTy;
1173 
1174  // If there was a truncation of extracted value, then we'll need to produce
1175  // one extra instruction, so we need to ensure one instruction will go away.
1176  if (HadTrunc && !match(&I, m_c_BinOp(m_OneUse(m_Value()), m_Value())))
1177  return nullptr;
1178 
1179  // Extraction should extract high NBits bits, with shift amount calculated as:
1180  // low bits to skip = shift bitwidth - high bits to extract
1181  // The shift amount itself may be extended, and we need to look past zero-ext
1182  // when matching NBits, that will matter for matching later.
1183  Constant *C;
1184  Value *NBits;
1185  if (!match(
1186  LowBitsToSkip,
1188  !match(C, m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_EQ,
1189  APInt(C->getType()->getScalarSizeInBits(),
1190  X->getType()->getScalarSizeInBits()))))
1191  return nullptr;
1192 
1193  // Sign-extending value can be zero-extended if we `sub`tract it,
1194  // or sign-extended otherwise.
1195  auto SkipExtInMagic = [&I](Value *&V) {
1196  if (I.getOpcode() == Instruction::Sub)
1197  match(V, m_ZExtOrSelf(m_Value(V)));
1198  else
1199  match(V, m_SExtOrSelf(m_Value(V)));
1200  };
1201 
1202  // Now, finally validate the sign-extending magic.
1203  // `select` itself may be appropriately extended, look past that.
1204  SkipExtInMagic(Select);
1205 
1206  ICmpInst::Predicate Pred;
1207  const APInt *Thr;
1208  Value *SignExtendingValue, *Zero;
1209  bool ShouldSignext;
1210  // It must be a select between two values we will later establish to be a
1211  // sign-extending value and a zero constant. The condition guarding the
1212  // sign-extension must be based on a sign bit of the same X we had in `lshr`.
1213  if (!match(Select, m_Select(m_ICmp(Pred, m_Specific(X), m_APInt(Thr)),
1214  m_Value(SignExtendingValue), m_Value(Zero))) ||
1215  !isSignBitCheck(Pred, *Thr, ShouldSignext))
1216  return nullptr;
1217 
1218  // icmp-select pair is commutative.
1219  if (!ShouldSignext)
1220  std::swap(SignExtendingValue, Zero);
1221 
1222  // If we should not perform sign-extension then we must add/or/subtract zero.
1223  if (!match(Zero, m_Zero()))
1224  return nullptr;
1225  // Otherwise, it should be some constant, left-shifted by the same NBits we
1226  // had in `lshr`. Said left-shift can also be appropriately extended.
1227  // Again, we must look past zero-ext when looking for NBits.
1228  SkipExtInMagic(SignExtendingValue);
1229  Constant *SignExtendingValueBaseConstant;
1230  if (!match(SignExtendingValue,
1231  m_Shl(m_Constant(SignExtendingValueBaseConstant),
1232  m_ZExtOrSelf(m_Specific(NBits)))))
1233  return nullptr;
1234  // If we `sub`, then the constant should be one, else it should be all-ones.
1235  if (I.getOpcode() == Instruction::Sub
1236  ? !match(SignExtendingValueBaseConstant, m_One())
1237  : !match(SignExtendingValueBaseConstant, m_AllOnes()))
1238  return nullptr;
1239 
1240  auto *NewAShr = BinaryOperator::CreateAShr(X, LowBitsToSkip,
1241  Extract->getName() + ".sext");
1242  NewAShr->copyIRFlags(Extract); // Preserve `exact`-ness.
1243  if (!HadTrunc)
1244  return NewAShr;
1245 
1246  Builder.Insert(NewAShr);
1247  return TruncInst::CreateTruncOrBitCast(NewAShr, I.getType());
1248 }
1249 
1250 /// This is a specialization of a more general transform from
1251 /// SimplifyUsingDistributiveLaws. If that code can be made to work optimally
1252 /// for multi-use cases or propagating nsw/nuw, then we would not need this.
1255  // TODO: Also handle mul by doubling the shift amount?
1256  assert((I.getOpcode() == Instruction::Add ||
1257  I.getOpcode() == Instruction::Sub) &&
1258  "Expected add/sub");
1259  auto *Op0 = dyn_cast<BinaryOperator>(I.getOperand(0));
1260  auto *Op1 = dyn_cast<BinaryOperator>(I.getOperand(1));
1261  if (!Op0 || !Op1 || !(Op0->hasOneUse() || Op1->hasOneUse()))
1262  return nullptr;
1263 
1264  Value *X, *Y, *ShAmt;
1265  if (!match(Op0, m_Shl(m_Value(X), m_Value(ShAmt))) ||
1266  !match(Op1, m_Shl(m_Value(Y), m_Specific(ShAmt))))
1267  return nullptr;
1268 
1269  // No-wrap propagates only when all ops have no-wrap.
1270  bool HasNSW = I.hasNoSignedWrap() && Op0->hasNoSignedWrap() &&
1271  Op1->hasNoSignedWrap();
1272  bool HasNUW = I.hasNoUnsignedWrap() && Op0->hasNoUnsignedWrap() &&
1273  Op1->hasNoUnsignedWrap();
1274 
1275  // add/sub (X << ShAmt), (Y << ShAmt) --> (add/sub X, Y) << ShAmt
1276  Value *NewMath = Builder.CreateBinOp(I.getOpcode(), X, Y);
1277  if (auto *NewI = dyn_cast<BinaryOperator>(NewMath)) {
1278  NewI->setHasNoSignedWrap(HasNSW);
1279  NewI->setHasNoUnsignedWrap(HasNUW);
1280  }
1281  auto *NewShl = BinaryOperator::CreateShl(NewMath, ShAmt);
1282  NewShl->setHasNoSignedWrap(HasNSW);
1283  NewShl->setHasNoUnsignedWrap(HasNUW);
1284  return NewShl;
1285 }
1286 
1288  if (Value *V = SimplifyAddInst(I.getOperand(0), I.getOperand(1),
1289  I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
1290  SQ.getWithInstruction(&I)))
1291  return replaceInstUsesWith(I, V);
1292 
1293  if (SimplifyAssociativeOrCommutative(I))
1294  return &I;
1295 
1296  if (Instruction *X = foldVectorBinop(I))
1297  return X;
1298 
1299  // (A*B)+(A*C) -> A*(B+C) etc
1300  if (Value *V = SimplifyUsingDistributiveLaws(I))
1301  return replaceInstUsesWith(I, V);
1302 
1304  return R;
1305 
1306  if (Instruction *X = foldAddWithConstant(I))
1307  return X;
1308 
1309  if (Instruction *X = foldNoWrapAdd(I, Builder))
1310  return X;
1311 
1312  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
1313  Type *Ty = I.getType();
1314  if (Ty->isIntOrIntVectorTy(1))
1315  return BinaryOperator::CreateXor(LHS, RHS);
1316 
1317  // X + X --> X << 1
1318  if (LHS == RHS) {
1319  auto *Shl = BinaryOperator::CreateShl(LHS, ConstantInt::get(Ty, 1));
1320  Shl->setHasNoSignedWrap(I.hasNoSignedWrap());
1321  Shl->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
1322  return Shl;
1323  }
1324 
1325  Value *A, *B;
1326  if (match(LHS, m_Neg(m_Value(A)))) {
1327  // -A + -B --> -(A + B)
1328  if (match(RHS, m_Neg(m_Value(B))))
1329  return BinaryOperator::CreateNeg(Builder.CreateAdd(A, B));
1330 
1331  // -A + B --> B - A
1332  return BinaryOperator::CreateSub(RHS, A);
1333  }
1334 
1335  // A + -B --> A - B
1336  if (match(RHS, m_Neg(m_Value(B))))
1337  return BinaryOperator::CreateSub(LHS, B);
1338 
1340  return replaceInstUsesWith(I, V);
1341 
1342  // (A + 1) + ~B --> A - B
1343  // ~B + (A + 1) --> A - B
1344  // (~B + A) + 1 --> A - B
1345  // (A + ~B) + 1 --> A - B
1346  if (match(&I, m_c_BinOp(m_Add(m_Value(A), m_One()), m_Not(m_Value(B)))) ||
1347  match(&I, m_BinOp(m_c_Add(m_Not(m_Value(B)), m_Value(A)), m_One())))
1348  return BinaryOperator::CreateSub(A, B);
1349 
1350  // (A + RHS) + RHS --> A + (RHS << 1)
1351  if (match(LHS, m_OneUse(m_c_Add(m_Value(A), m_Specific(RHS)))))
1352  return BinaryOperator::CreateAdd(A, Builder.CreateShl(RHS, 1, "reass.add"));
1353 
1354  // LHS + (A + LHS) --> A + (LHS << 1)
1355  if (match(RHS, m_OneUse(m_c_Add(m_Value(A), m_Specific(LHS)))))
1356  return BinaryOperator::CreateAdd(A, Builder.CreateShl(LHS, 1, "reass.add"));
1357 
1358  // X % C0 + (( X / C0 ) % C1) * C0 => X % (C0 * C1)
1359  if (Value *V = SimplifyAddWithRemainder(I)) return replaceInstUsesWith(I, V);
1360 
1361  // ((X s/ C1) << C2) + X => X s% -C1 where -C1 is 1 << C2
1362  const APInt *C1, *C2;
1363  if (match(LHS, m_Shl(m_SDiv(m_Specific(RHS), m_APInt(C1)), m_APInt(C2)))) {
1364  APInt one(C2->getBitWidth(), 1);
1365  APInt minusC1 = -(*C1);
1366  if (minusC1 == (one << *C2)) {
1367  Constant *NewRHS = ConstantInt::get(RHS->getType(), minusC1);
1368  return BinaryOperator::CreateSRem(RHS, NewRHS);
1369  }
1370  }
1371 
1372  // A+B --> A|B iff A and B have no bits set in common.
1373  if (haveNoCommonBitsSet(LHS, RHS, DL, &AC, &I, &DT))
1374  return BinaryOperator::CreateOr(LHS, RHS);
1375 
1376  // add (select X 0 (sub n A)) A --> select X A n
1377  {
1378  SelectInst *SI = dyn_cast<SelectInst>(LHS);
1379  Value *A = RHS;
1380  if (!SI) {
1381  SI = dyn_cast<SelectInst>(RHS);
1382  A = LHS;
1383  }
1384  if (SI && SI->hasOneUse()) {
1385  Value *TV = SI->getTrueValue();
1386  Value *FV = SI->getFalseValue();
1387  Value *N;
1388 
1389  // Can we fold the add into the argument of the select?
1390  // We check both true and false select arguments for a matching subtract.
1391  if (match(FV, m_Zero()) && match(TV, m_Sub(m_Value(N), m_Specific(A))))
1392  // Fold the add into the true select value.
1393  return SelectInst::Create(SI->getCondition(), N, A);
1394 
1395  if (match(TV, m_Zero()) && match(FV, m_Sub(m_Value(N), m_Specific(A))))
1396  // Fold the add into the false select value.
1397  return SelectInst::Create(SI->getCondition(), A, N);
1398  }
1399  }
1400 
1401  if (Instruction *Ext = narrowMathIfNoOverflow(I))
1402  return Ext;
1403 
1404  // (add (xor A, B) (and A, B)) --> (or A, B)
1405  // (add (and A, B) (xor A, B)) --> (or A, B)
1406  if (match(&I, m_c_BinOp(m_Xor(m_Value(A), m_Value(B)),
1407  m_c_And(m_Deferred(A), m_Deferred(B)))))
1408  return BinaryOperator::CreateOr(A, B);
1409 
1410  // (add (or A, B) (and A, B)) --> (add A, B)
1411  // (add (and A, B) (or A, B)) --> (add A, B)
1412  if (match(&I, m_c_BinOp(m_Or(m_Value(A), m_Value(B)),
1413  m_c_And(m_Deferred(A), m_Deferred(B))))) {
1414  // Replacing operands in-place to preserve nuw/nsw flags.
1415  replaceOperand(I, 0, A);
1416  replaceOperand(I, 1, B);
1417  return &I;
1418  }
1419 
1420  // TODO(jingyue): Consider willNotOverflowSignedAdd and
1421  // willNotOverflowUnsignedAdd to reduce the number of invocations of
1422  // computeKnownBits.
1423  bool Changed = false;
1424  if (!I.hasNoSignedWrap() && willNotOverflowSignedAdd(LHS, RHS, I)) {
1425  Changed = true;
1426  I.setHasNoSignedWrap(true);
1427  }
1428  if (!I.hasNoUnsignedWrap() && willNotOverflowUnsignedAdd(LHS, RHS, I)) {
1429  Changed = true;
1430  I.setHasNoUnsignedWrap(true);
1431  }
1432 
1434  return V;
1435 
1436  if (Instruction *V =
1437  canonicalizeCondSignextOfHighBitExtractToSignextHighBitExtract(I))
1438  return V;
1439 
1440  if (Instruction *SatAdd = foldToUnsignedSaturatedAdd(I))
1441  return SatAdd;
1442 
1443  // usub.sat(A, B) + B => umax(A, B)
1444  if (match(&I, m_c_BinOp(
1445  m_OneUse(m_Intrinsic<Intrinsic::usub_sat>(m_Value(A), m_Value(B))),
1446  m_Deferred(B)))) {
1447  return replaceInstUsesWith(I,
1448  Builder.CreateIntrinsic(Intrinsic::umax, {I.getType()}, {A, B}));
1449  }
1450 
1451  return Changed ? &I : nullptr;
1452 }
1453 
1454 /// Eliminate an op from a linear interpolation (lerp) pattern.
1457  Value *X, *Y, *Z;
1460  m_Value(Z))))),
1462  return nullptr;
1463 
1464  // (Y * (1.0 - Z)) + (X * Z) --> Y + Z * (X - Y) [8 commuted variants]
1465  Value *XY = Builder.CreateFSubFMF(X, Y, &I);
1466  Value *MulZ = Builder.CreateFMulFMF(Z, XY, &I);
1467  return BinaryOperator::CreateFAddFMF(Y, MulZ, &I);
1468 }
1469 
1470 /// Factor a common operand out of fadd/fsub of fmul/fdiv.
1473  assert((I.getOpcode() == Instruction::FAdd ||
1474  I.getOpcode() == Instruction::FSub) && "Expecting fadd/fsub");
1475  assert(I.hasAllowReassoc() && I.hasNoSignedZeros() &&
1476  "FP factorization requires FMF");
1477 
1478  if (Instruction *Lerp = factorizeLerp(I, Builder))
1479  return Lerp;
1480 
1481  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1482  Value *X, *Y, *Z;
1483  bool IsFMul;
1484  if ((match(Op0, m_OneUse(m_FMul(m_Value(X), m_Value(Z)))) &&
1485  match(Op1, m_OneUse(m_c_FMul(m_Value(Y), m_Specific(Z))))) ||
1486  (match(Op0, m_OneUse(m_FMul(m_Value(Z), m_Value(X)))) &&
1487  match(Op1, m_OneUse(m_c_FMul(m_Value(Y), m_Specific(Z))))))
1488  IsFMul = true;
1489  else if (match(Op0, m_OneUse(m_FDiv(m_Value(X), m_Value(Z)))) &&
1490  match(Op1, m_OneUse(m_FDiv(m_Value(Y), m_Specific(Z)))))
1491  IsFMul = false;
1492  else
1493  return nullptr;
1494 
1495  // (X * Z) + (Y * Z) --> (X + Y) * Z
1496  // (X * Z) - (Y * Z) --> (X - Y) * Z
1497  // (X / Z) + (Y / Z) --> (X + Y) / Z
1498  // (X / Z) - (Y / Z) --> (X - Y) / Z
1499  bool IsFAdd = I.getOpcode() == Instruction::FAdd;
1500  Value *XY = IsFAdd ? Builder.CreateFAddFMF(X, Y, &I)
1501  : Builder.CreateFSubFMF(X, Y, &I);
1502 
1503  // Bail out if we just created a denormal constant.
1504  // TODO: This is copied from a previous implementation. Is it necessary?
1505  const APFloat *C;
1506  if (match(XY, m_APFloat(C)) && !C->isNormal())
1507  return nullptr;
1508 
1509  return IsFMul ? BinaryOperator::CreateFMulFMF(XY, Z, &I)
1510  : BinaryOperator::CreateFDivFMF(XY, Z, &I);
1511 }
1512 
1514  if (Value *V = SimplifyFAddInst(I.getOperand(0), I.getOperand(1),
1515  I.getFastMathFlags(),
1516  SQ.getWithInstruction(&I)))
1517  return replaceInstUsesWith(I, V);
1518 
1519  if (SimplifyAssociativeOrCommutative(I))
1520  return &I;
1521 
1522  if (Instruction *X = foldVectorBinop(I))
1523  return X;
1524 
1525  if (Instruction *FoldedFAdd = foldBinOpIntoSelectOrPhi(I))
1526  return FoldedFAdd;
1527 
1528  // (-X) + Y --> Y - X
1529  Value *X, *Y;
1530  if (match(&I, m_c_FAdd(m_FNeg(m_Value(X)), m_Value(Y))))
1531  return BinaryOperator::CreateFSubFMF(Y, X, &I);
1532 
1533  // Similar to above, but look through fmul/fdiv for the negated term.
1534  // (-X * Y) + Z --> Z - (X * Y) [4 commuted variants]
1535  Value *Z;
1537  m_Value(Z)))) {
1538  Value *XY = Builder.CreateFMulFMF(X, Y, &I);
1539  return BinaryOperator::CreateFSubFMF(Z, XY, &I);
1540  }
1541  // (-X / Y) + Z --> Z - (X / Y) [2 commuted variants]
1542  // (X / -Y) + Z --> Z - (X / Y) [2 commuted variants]
1544  m_Value(Z))) ||
1546  m_Value(Z)))) {
1547  Value *XY = Builder.CreateFDivFMF(X, Y, &I);
1548  return BinaryOperator::CreateFSubFMF(Z, XY, &I);
1549  }
1550 
1551  // Check for (fadd double (sitofp x), y), see if we can merge this into an
1552  // integer add followed by a promotion.
1553  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
1554  if (SIToFPInst *LHSConv = dyn_cast<SIToFPInst>(LHS)) {
1555  Value *LHSIntVal = LHSConv->getOperand(0);
1556  Type *FPType = LHSConv->getType();
1557 
1558  // TODO: This check is overly conservative. In many cases known bits
1559  // analysis can tell us that the result of the addition has less significant
1560  // bits than the integer type can hold.
1561  auto IsValidPromotion = [](Type *FTy, Type *ITy) {
1562  Type *FScalarTy = FTy->getScalarType();
1563  Type *IScalarTy = ITy->getScalarType();
1564 
1565  // Do we have enough bits in the significand to represent the result of
1566  // the integer addition?
1567  unsigned MaxRepresentableBits =
1569  return IScalarTy->getIntegerBitWidth() <= MaxRepresentableBits;
1570  };
1571 
1572  // (fadd double (sitofp x), fpcst) --> (sitofp (add int x, intcst))
1573  // ... if the constant fits in the integer value. This is useful for things
1574  // like (double)(x & 1234) + 4.0 -> (double)((X & 1234)+4) which no longer
1575  // requires a constant pool load, and generally allows the add to be better
1576  // instcombined.
1577  if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHS))
1578  if (IsValidPromotion(FPType, LHSIntVal->getType())) {
1579  Constant *CI =
1580  ConstantExpr::getFPToSI(CFP, LHSIntVal->getType());
1581  if (LHSConv->hasOneUse() &&
1582  ConstantExpr::getSIToFP(CI, I.getType()) == CFP &&
1583  willNotOverflowSignedAdd(LHSIntVal, CI, I)) {
1584  // Insert the new integer add.
1585  Value *NewAdd = Builder.CreateNSWAdd(LHSIntVal, CI, "addconv");
1586  return new SIToFPInst(NewAdd, I.getType());
1587  }
1588  }
1589 
1590  // (fadd double (sitofp x), (sitofp y)) --> (sitofp (add int x, y))
1591  if (SIToFPInst *RHSConv = dyn_cast<SIToFPInst>(RHS)) {
1592  Value *RHSIntVal = RHSConv->getOperand(0);
1593  // It's enough to check LHS types only because we require int types to
1594  // be the same for this transform.
1595  if (IsValidPromotion(FPType, LHSIntVal->getType())) {
1596  // Only do this if x/y have the same type, if at least one of them has a
1597  // single use (so we don't increase the number of int->fp conversions),
1598  // and if the integer add will not overflow.
1599  if (LHSIntVal->getType() == RHSIntVal->getType() &&
1600  (LHSConv->hasOneUse() || RHSConv->hasOneUse()) &&
1601  willNotOverflowSignedAdd(LHSIntVal, RHSIntVal, I)) {
1602  // Insert the new integer add.
1603  Value *NewAdd = Builder.CreateNSWAdd(LHSIntVal, RHSIntVal, "addconv");
1604  return new SIToFPInst(NewAdd, I.getType());
1605  }
1606  }
1607  }
1608  }
1609 
1610  // Handle specials cases for FAdd with selects feeding the operation
1611  if (Value *V = SimplifySelectsFeedingBinaryOp(I, LHS, RHS))
1612  return replaceInstUsesWith(I, V);
1613 
1614  if (I.hasAllowReassoc() && I.hasNoSignedZeros()) {
1616  return F;
1617  if (Value *V = FAddCombine(Builder).simplify(&I))
1618  return replaceInstUsesWith(I, V);
1619  }
1620 
1621  return nullptr;
1622 }
1623 
1624 /// Optimize pointer differences into the same array into a size. Consider:
1625 /// &A[10] - &A[0]: we should compile this to "10". LHS/RHS are the pointer
1626 /// operands to the ptrtoint instructions for the LHS/RHS of the subtract.
1628  Type *Ty, bool IsNUW) {
1629  // If LHS is a gep based on RHS or RHS is a gep based on LHS, we can optimize
1630  // this.
1631  bool Swapped = false;
1632  GEPOperator *GEP1 = nullptr, *GEP2 = nullptr;
1633  if (!isa<GEPOperator>(LHS) && isa<GEPOperator>(RHS)) {
1634  std::swap(LHS, RHS);
1635  Swapped = true;
1636  }
1637 
1638  // Require at least one GEP with a common base pointer on both sides.
1639  if (auto *LHSGEP = dyn_cast<GEPOperator>(LHS)) {
1640  // (gep X, ...) - X
1641  if (LHSGEP->getOperand(0) == RHS) {
1642  GEP1 = LHSGEP;
1643  } else if (auto *RHSGEP = dyn_cast<GEPOperator>(RHS)) {
1644  // (gep X, ...) - (gep X, ...)
1645  if (LHSGEP->getOperand(0)->stripPointerCasts() ==
1646  RHSGEP->getOperand(0)->stripPointerCasts()) {
1647  GEP1 = LHSGEP;
1648  GEP2 = RHSGEP;
1649  }
1650  }
1651  }
1652 
1653  if (!GEP1)
1654  return nullptr;
1655 
1656  if (GEP2) {
1657  // (gep X, ...) - (gep X, ...)
1658  //
1659  // Avoid duplicating the arithmetic if there are more than one non-constant
1660  // indices between the two GEPs and either GEP has a non-constant index and
1661  // multiple users. If zero non-constant index, the result is a constant and
1662  // there is no duplication. If one non-constant index, the result is an add
1663  // or sub with a constant, which is no larger than the original code, and
1664  // there's no duplicated arithmetic, even if either GEP has multiple
1665  // users. If more than one non-constant indices combined, as long as the GEP
1666  // with at least one non-constant index doesn't have multiple users, there
1667  // is no duplication.
1668  unsigned NumNonConstantIndices1 = GEP1->countNonConstantIndices();
1669  unsigned NumNonConstantIndices2 = GEP2->countNonConstantIndices();
1670  if (NumNonConstantIndices1 + NumNonConstantIndices2 > 1 &&
1671  ((NumNonConstantIndices1 > 0 && !GEP1->hasOneUse()) ||
1672  (NumNonConstantIndices2 > 0 && !GEP2->hasOneUse()))) {
1673  return nullptr;
1674  }
1675  }
1676 
1677  // Emit the offset of the GEP and an intptr_t.
1678  Value *Result = EmitGEPOffset(GEP1);
1679 
1680  // If this is a single inbounds GEP and the original sub was nuw,
1681  // then the final multiplication is also nuw.
1682  if (auto *I = dyn_cast<Instruction>(Result))
1683  if (IsNUW && !GEP2 && !Swapped && GEP1->isInBounds() &&
1684  I->getOpcode() == Instruction::Mul)
1685  I->setHasNoUnsignedWrap();
1686 
1687  // If we have a 2nd GEP of the same base pointer, subtract the offsets.
1688  // If both GEPs are inbounds, then the subtract does not have signed overflow.
1689  if (GEP2) {
1690  Value *Offset = EmitGEPOffset(GEP2);
1691  Result = Builder.CreateSub(Result, Offset, "gepdiff", /* NUW */ false,
1692  GEP1->isInBounds() && GEP2->isInBounds());
1693  }
1694 
1695  // If we have p - gep(p, ...) then we have to negate the result.
1696  if (Swapped)
1697  Result = Builder.CreateNeg(Result, "diff.neg");
1698 
1699  return Builder.CreateIntCast(Result, Ty, true);
1700 }
1701 
1703  if (Value *V = SimplifySubInst(I.getOperand(0), I.getOperand(1),
1704  I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
1705  SQ.getWithInstruction(&I)))
1706  return replaceInstUsesWith(I, V);
1707 
1708  if (Instruction *X = foldVectorBinop(I))
1709  return X;
1710 
1711  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1712 
1713  // If this is a 'B = x-(-A)', change to B = x+A.
1714  // We deal with this without involving Negator to preserve NSW flag.
1715  if (Value *V = dyn_castNegVal(Op1)) {
1717 
1718  if (const auto *BO = dyn_cast<BinaryOperator>(Op1)) {
1719  assert(BO->getOpcode() == Instruction::Sub &&
1720  "Expected a subtraction operator!");
1721  if (BO->hasNoSignedWrap() && I.hasNoSignedWrap())
1722  Res->setHasNoSignedWrap(true);
1723  } else {
1724  if (cast<Constant>(Op1)->isNotMinSignedValue() && I.hasNoSignedWrap())
1725  Res->setHasNoSignedWrap(true);
1726  }
1727 
1728  return Res;
1729  }
1730 
1731  // Try this before Negator to preserve NSW flag.
1733  return R;
1734 
1735  Constant *C;
1736  if (match(Op0, m_ImmConstant(C))) {
1737  Value *X;
1738  Constant *C2;
1739 
1740  // C-(X+C2) --> (C-C2)-X
1741  if (match(Op1, m_Add(m_Value(X), m_ImmConstant(C2))))
1742  return BinaryOperator::CreateSub(ConstantExpr::getSub(C, C2), X);
1743  }
1744 
1745  auto TryToNarrowDeduceFlags = [this, &I, &Op0, &Op1]() -> Instruction * {
1746  if (Instruction *Ext = narrowMathIfNoOverflow(I))
1747  return Ext;
1748 
1749  bool Changed = false;
1750  if (!I.hasNoSignedWrap() && willNotOverflowSignedSub(Op0, Op1, I)) {
1751  Changed = true;
1752  I.setHasNoSignedWrap(true);
1753  }
1754  if (!I.hasNoUnsignedWrap() && willNotOverflowUnsignedSub(Op0, Op1, I)) {
1755  Changed = true;
1756  I.setHasNoUnsignedWrap(true);
1757  }
1758 
1759  return Changed ? &I : nullptr;
1760  };
1761 
1762  // First, let's try to interpret `sub a, b` as `add a, (sub 0, b)`,
1763  // and let's try to sink `(sub 0, b)` into `b` itself. But only if this isn't
1764  // a pure negation used by a select that looks like abs/nabs.
1765  bool IsNegation = match(Op0, m_ZeroInt());
1766  if (!IsNegation || none_of(I.users(), [&I, Op1](const User *U) {
1767  const Instruction *UI = dyn_cast<Instruction>(U);
1768  if (!UI)
1769  return false;
1770  return match(UI,
1771  m_Select(m_Value(), m_Specific(Op1), m_Specific(&I))) ||
1772  match(UI, m_Select(m_Value(), m_Specific(&I), m_Specific(Op1)));
1773  })) {
1774  if (Value *NegOp1 = Negator::Negate(IsNegation, Op1, *this))
1775  return BinaryOperator::CreateAdd(NegOp1, Op0);
1776  }
1777  if (IsNegation)
1778  return TryToNarrowDeduceFlags(); // Should have been handled in Negator!
1779 
1780  // (A*B)-(A*C) -> A*(B-C) etc
1781  if (Value *V = SimplifyUsingDistributiveLaws(I))
1782  return replaceInstUsesWith(I, V);
1783 
1784  if (I.getType()->isIntOrIntVectorTy(1))
1785  return BinaryOperator::CreateXor(Op0, Op1);
1786 
1787  // Replace (-1 - A) with (~A).
1788  if (match(Op0, m_AllOnes()))
1789  return BinaryOperator::CreateNot(Op1);
1790 
1791  // (~X) - (~Y) --> Y - X
1792  Value *X, *Y;
1793  if (match(Op0, m_Not(m_Value(X))) && match(Op1, m_Not(m_Value(Y))))
1794  return BinaryOperator::CreateSub(Y, X);
1795 
1796  // (X + -1) - Y --> ~Y + X
1797  if (match(Op0, m_OneUse(m_Add(m_Value(X), m_AllOnes()))))
1798  return BinaryOperator::CreateAdd(Builder.CreateNot(Op1), X);
1799 
1800  // Reassociate sub/add sequences to create more add instructions and
1801  // reduce dependency chains:
1802  // ((X - Y) + Z) - Op1 --> (X + Z) - (Y + Op1)
1803  Value *Z;
1805  m_Value(Z))))) {
1806  Value *XZ = Builder.CreateAdd(X, Z);
1807  Value *YW = Builder.CreateAdd(Y, Op1);
1808  return BinaryOperator::CreateSub(XZ, YW);
1809  }
1810 
1811  // ((X - Y) - Op1) --> X - (Y + Op1)
1812  if (match(Op0, m_OneUse(m_Sub(m_Value(X), m_Value(Y))))) {
1813  Value *Add = Builder.CreateAdd(Y, Op1);
1814  return BinaryOperator::CreateSub(X, Add);
1815  }
1816 
1817  auto m_AddRdx = [](Value *&Vec) {
1818  return m_OneUse(m_Intrinsic<Intrinsic::vector_reduce_add>(m_Value(Vec)));
1819  };
1820  Value *V0, *V1;
1821  if (match(Op0, m_AddRdx(V0)) && match(Op1, m_AddRdx(V1)) &&
1822  V0->getType() == V1->getType()) {
1823  // Difference of sums is sum of differences:
1824  // add_rdx(V0) - add_rdx(V1) --> add_rdx(V0 - V1)
1825  Value *Sub = Builder.CreateSub(V0, V1);
1826  Value *Rdx = Builder.CreateIntrinsic(Intrinsic::vector_reduce_add,
1827  {Sub->getType()}, {Sub});
1828  return replaceInstUsesWith(I, Rdx);
1829  }
1830 
1831  if (Constant *C = dyn_cast<Constant>(Op0)) {
1832  Value *X;
1833  if (match(Op1, m_ZExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1))
1834  // C - (zext bool) --> bool ? C - 1 : C
1836  if (match(Op1, m_SExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1))
1837  // C - (sext bool) --> bool ? C + 1 : C
1839 
1840  // C - ~X == X + (1+C)
1841  if (match(Op1, m_Not(m_Value(X))))
1843 
1844  // Try to fold constant sub into select arguments.
1845  if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
1846  if (Instruction *R = FoldOpIntoSelect(I, SI))
1847  return R;
1848 
1849  // Try to fold constant sub into PHI values.
1850  if (PHINode *PN = dyn_cast<PHINode>(Op1))
1851  if (Instruction *R = foldOpIntoPhi(I, PN))
1852  return R;
1853 
1854  Constant *C2;
1855 
1856  // C-(C2-X) --> X+(C-C2)
1857  if (match(Op1, m_Sub(m_ImmConstant(C2), m_Value(X))))
1859  }
1860 
1861  const APInt *Op0C;
1862  if (match(Op0, m_APInt(Op0C)) && Op0C->isMask()) {
1863  // Turn this into a xor if LHS is 2^n-1 and the remaining bits are known
1864  // zero.
1865  KnownBits RHSKnown = computeKnownBits(Op1, 0, &I);
1866  if ((*Op0C | RHSKnown.Zero).isAllOnesValue())
1867  return BinaryOperator::CreateXor(Op1, Op0);
1868  }
1869 
1870  {
1871  Value *Y;
1872  // X-(X+Y) == -Y X-(Y+X) == -Y
1873  if (match(Op1, m_c_Add(m_Specific(Op0), m_Value(Y))))
1874  return BinaryOperator::CreateNeg(Y);
1875 
1876  // (X-Y)-X == -Y
1877  if (match(Op0, m_Sub(m_Specific(Op1), m_Value(Y))))
1878  return BinaryOperator::CreateNeg(Y);
1879  }
1880 
1881  // (sub (or A, B) (and A, B)) --> (xor A, B)
1882  {
1883  Value *A, *B;
1884  if (match(Op1, m_And(m_Value(A), m_Value(B))) &&
1885  match(Op0, m_c_Or(m_Specific(A), m_Specific(B))))
1886  return BinaryOperator::CreateXor(A, B);
1887  }
1888 
1889  // (sub (add A, B) (or A, B)) --> (and A, B)
1890  {
1891  Value *A, *B;
1892  if (match(Op0, m_Add(m_Value(A), m_Value(B))) &&
1893  match(Op1, m_c_Or(m_Specific(A), m_Specific(B))))
1894  return BinaryOperator::CreateAnd(A, B);
1895  }
1896 
1897  // (sub (add A, B) (and A, B)) --> (or A, B)
1898  {
1899  Value *A, *B;
1900  if (match(Op0, m_Add(m_Value(A), m_Value(B))) &&
1901  match(Op1, m_c_And(m_Specific(A), m_Specific(B))))
1902  return BinaryOperator::CreateOr(A, B);
1903  }
1904 
1905  // (sub (and A, B) (or A, B)) --> neg (xor A, B)
1906  {
1907  Value *A, *B;
1908  if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1909  match(Op1, m_c_Or(m_Specific(A), m_Specific(B))) &&
1910  (Op0->hasOneUse() || Op1->hasOneUse()))
1911  return BinaryOperator::CreateNeg(Builder.CreateXor(A, B));
1912  }
1913 
1914  // (sub (or A, B), (xor A, B)) --> (and A, B)
1915  {
1916  Value *A, *B;
1917  if (match(Op1, m_Xor(m_Value(A), m_Value(B))) &&
1918  match(Op0, m_c_Or(m_Specific(A), m_Specific(B))))
1919  return BinaryOperator::CreateAnd(A, B);
1920  }
1921 
1922  // (sub (xor A, B) (or A, B)) --> neg (and A, B)
1923  {
1924  Value *A, *B;
1925  if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
1926  match(Op1, m_c_Or(m_Specific(A), m_Specific(B))) &&
1927  (Op0->hasOneUse() || Op1->hasOneUse()))
1928  return BinaryOperator::CreateNeg(Builder.CreateAnd(A, B));
1929  }
1930 
1931  {
1932  Value *Y;
1933  // ((X | Y) - X) --> (~X & Y)
1934  if (match(Op0, m_OneUse(m_c_Or(m_Value(Y), m_Specific(Op1)))))
1935  return BinaryOperator::CreateAnd(
1936  Y, Builder.CreateNot(Op1, Op1->getName() + ".not"));
1937  }
1938 
1939  {
1940  // (sub (and Op1, (neg X)), Op1) --> neg (and Op1, (add X, -1))
1941  Value *X;
1942  if (match(Op0, m_OneUse(m_c_And(m_Specific(Op1),
1943  m_OneUse(m_Neg(m_Value(X))))))) {
1944  return BinaryOperator::CreateNeg(Builder.CreateAnd(
1945  Op1, Builder.CreateAdd(X, Constant::getAllOnesValue(I.getType()))));
1946  }
1947  }
1948 
1949  {
1950  // (sub (and Op1, C), Op1) --> neg (and Op1, ~C)
1951  Constant *C;
1952  if (match(Op0, m_OneUse(m_And(m_Specific(Op1), m_Constant(C))))) {
1954  Builder.CreateAnd(Op1, Builder.CreateNot(C)));
1955  }
1956  }
1957 
1958  {
1959  // If we have a subtraction between some value and a select between
1960  // said value and something else, sink subtraction into select hands, i.e.:
1961  // sub (select %Cond, %TrueVal, %FalseVal), %Op1
1962  // ->
1963  // select %Cond, (sub %TrueVal, %Op1), (sub %FalseVal, %Op1)
1964  // or
1965  // sub %Op0, (select %Cond, %TrueVal, %FalseVal)
1966  // ->
1967  // select %Cond, (sub %Op0, %TrueVal), (sub %Op0, %FalseVal)
1968  // This will result in select between new subtraction and 0.
1969  auto SinkSubIntoSelect =
1970  [Ty = I.getType()](Value *Select, Value *OtherHandOfSub,
1971  auto SubBuilder) -> Instruction * {
1972  Value *Cond, *TrueVal, *FalseVal;
1974  m_Value(FalseVal)))))
1975  return nullptr;
1976  if (OtherHandOfSub != TrueVal && OtherHandOfSub != FalseVal)
1977  return nullptr;
1978  // While it is really tempting to just create two subtractions and let
1979  // InstCombine fold one of those to 0, it isn't possible to do so
1980  // because of worklist visitation order. So ugly it is.
1981  bool OtherHandOfSubIsTrueVal = OtherHandOfSub == TrueVal;
1982  Value *NewSub = SubBuilder(OtherHandOfSubIsTrueVal ? FalseVal : TrueVal);
1983  Constant *Zero = Constant::getNullValue(Ty);
1984  SelectInst *NewSel =
1985  SelectInst::Create(Cond, OtherHandOfSubIsTrueVal ? Zero : NewSub,
1986  OtherHandOfSubIsTrueVal ? NewSub : Zero);
1987  // Preserve prof metadata if any.
1988  NewSel->copyMetadata(cast<Instruction>(*Select));
1989  return NewSel;
1990  };
1991  if (Instruction *NewSel = SinkSubIntoSelect(
1992  /*Select=*/Op0, /*OtherHandOfSub=*/Op1,
1993  [Builder = &Builder, Op1](Value *OtherHandOfSelect) {
1994  return Builder->CreateSub(OtherHandOfSelect,
1995  /*OtherHandOfSub=*/Op1);
1996  }))
1997  return NewSel;
1998  if (Instruction *NewSel = SinkSubIntoSelect(
1999  /*Select=*/Op1, /*OtherHandOfSub=*/Op0,
2000  [Builder = &Builder, Op0](Value *OtherHandOfSelect) {
2001  return Builder->CreateSub(/*OtherHandOfSub=*/Op0,
2002  OtherHandOfSelect);
2003  }))
2004  return NewSel;
2005  }
2006 
2007  // (X - (X & Y)) --> (X & ~Y)
2008  if (match(Op1, m_c_And(m_Specific(Op0), m_Value(Y))) &&
2009  (Op1->hasOneUse() || isa<Constant>(Y)))
2010  return BinaryOperator::CreateAnd(
2011  Op0, Builder.CreateNot(Y, Y->getName() + ".not"));
2012 
2013  {
2014  // ~A - Min/Max(~A, O) -> Max/Min(A, ~O) - A
2015  // ~A - Min/Max(O, ~A) -> Max/Min(A, ~O) - A
2016  // Min/Max(~A, O) - ~A -> A - Max/Min(A, ~O)
2017  // Min/Max(O, ~A) - ~A -> A - Max/Min(A, ~O)
2018  // So long as O here is freely invertible, this will be neutral or a win.
2019  Value *LHS, *RHS, *A;
2020  Value *NotA = Op0, *MinMax = Op1;
2022  if (!SelectPatternResult::isMinOrMax(SPF)) {
2023  NotA = Op1;
2024  MinMax = Op0;
2025  SPF = matchSelectPattern(MinMax, LHS, RHS).Flavor;
2026  }
2028  match(NotA, m_Not(m_Value(A))) && (NotA == LHS || NotA == RHS)) {
2029  if (NotA == LHS)
2030  std::swap(LHS, RHS);
2031  // LHS is now O above and expected to have at least 2 uses (the min/max)
2032  // NotA is epected to have 2 uses from the min/max and 1 from the sub.
2033  if (isFreeToInvert(LHS, !LHS->hasNUsesOrMore(3)) &&
2034  !NotA->hasNUsesOrMore(4)) {
2035  // Note: We don't generate the inverse max/min, just create the not of
2036  // it and let other folds do the rest.
2037  Value *Not = Builder.CreateNot(MinMax);
2038  if (NotA == Op0)
2039  return BinaryOperator::CreateSub(Not, A);
2040  else
2041  return BinaryOperator::CreateSub(A, Not);
2042  }
2043  }
2044  }
2045 
2046  // Optimize pointer differences into the same array into a size. Consider:
2047  // &A[10] - &A[0]: we should compile this to "10".
2048  Value *LHSOp, *RHSOp;
2049  if (match(Op0, m_PtrToInt(m_Value(LHSOp))) &&
2050  match(Op1, m_PtrToInt(m_Value(RHSOp))))
2051  if (Value *Res = OptimizePointerDifference(LHSOp, RHSOp, I.getType(),
2052  I.hasNoUnsignedWrap()))
2053  return replaceInstUsesWith(I, Res);
2054 
2055  // trunc(p)-trunc(q) -> trunc(p-q)
2056  if (match(Op0, m_Trunc(m_PtrToInt(m_Value(LHSOp)))) &&
2057  match(Op1, m_Trunc(m_PtrToInt(m_Value(RHSOp)))))
2058  if (Value *Res = OptimizePointerDifference(LHSOp, RHSOp, I.getType(),
2059  /* IsNUW */ false))
2060  return replaceInstUsesWith(I, Res);
2061 
2062  // Canonicalize a shifty way to code absolute value to the common pattern.
2063  // There are 2 potential commuted variants.
2064  // We're relying on the fact that we only do this transform when the shift has
2065  // exactly 2 uses and the xor has exactly 1 use (otherwise, we might increase
2066  // instructions).
2067  Value *A;
2068  const APInt *ShAmt;
2069  Type *Ty = I.getType();
2070  if (match(Op1, m_AShr(m_Value(A), m_APInt(ShAmt))) &&
2071  Op1->hasNUses(2) && *ShAmt == Ty->getScalarSizeInBits() - 1 &&
2072  match(Op0, m_OneUse(m_c_Xor(m_Specific(A), m_Specific(Op1))))) {
2073  // B = ashr i32 A, 31 ; smear the sign bit
2074  // sub (xor A, B), B ; flip bits if negative and subtract -1 (add 1)
2075  // --> (A < 0) ? -A : A
2076  Value *Cmp = Builder.CreateICmpSLT(A, ConstantInt::getNullValue(Ty));
2077  // Copy the nuw/nsw flags from the sub to the negate.
2078  Value *Neg = Builder.CreateNeg(A, "", I.hasNoUnsignedWrap(),
2079  I.hasNoSignedWrap());
2080  return SelectInst::Create(Cmp, Neg, A);
2081  }
2082 
2083  // If we are subtracting a low-bit masked subset of some value from an add
2084  // of that same value with no low bits changed, that is clearing some low bits
2085  // of the sum:
2086  // sub (X + AddC), (X & AndC) --> and (X + AddC), ~AndC
2087  const APInt *AddC, *AndC;
2088  if (match(Op0, m_Add(m_Value(X), m_APInt(AddC))) &&
2089  match(Op1, m_And(m_Specific(X), m_APInt(AndC)))) {
2090  unsigned BitWidth = Ty->getScalarSizeInBits();
2091  unsigned Cttz = AddC->countTrailingZeros();
2092  APInt HighMask(APInt::getHighBitsSet(BitWidth, BitWidth - Cttz));
2093  if ((HighMask & *AndC).isNullValue())
2094  return BinaryOperator::CreateAnd(Op0, ConstantInt::get(Ty, ~(*AndC)));
2095  }
2096 
2097  if (Instruction *V =
2098  canonicalizeCondSignextOfHighBitExtractToSignextHighBitExtract(I))
2099  return V;
2100 
2101  return TryToNarrowDeduceFlags();
2102 }
2103 
2104 /// This eliminates floating-point negation in either 'fneg(X)' or
2105 /// 'fsub(-0.0, X)' form by combining into a constant operand.
2107  Value *X;
2108  Constant *C;
2109 
2110  // Fold negation into constant operand. This is limited with one-use because
2111  // fneg is assumed better for analysis and cheaper in codegen than fmul/fdiv.
2112  // -(X * C) --> X * (-C)
2113  // FIXME: It's arguable whether these should be m_OneUse or not. The current
2114  // belief is that the FNeg allows for better reassociation opportunities.
2115  if (match(&I, m_FNeg(m_OneUse(m_FMul(m_Value(X), m_Constant(C))))))
2117  // -(X / C) --> X / (-C)
2118  if (match(&I, m_FNeg(m_OneUse(m_FDiv(m_Value(X), m_Constant(C))))))
2120  // -(C / X) --> (-C) / X
2121  if (match(&I, m_FNeg(m_OneUse(m_FDiv(m_Constant(C), m_Value(X))))))
2123 
2124  // With NSZ [ counter-example with -0.0: -(-0.0 + 0.0) != 0.0 + -0.0 ]:
2125  // -(X + C) --> -X + -C --> -C - X
2126  if (I.hasNoSignedZeros() &&
2129 
2130  return nullptr;
2131 }
2132 
2135  Value *FNeg;
2136  if (!match(&I, m_FNeg(m_Value(FNeg))))
2137  return nullptr;
2138 
2139  Value *X, *Y;
2140  if (match(FNeg, m_OneUse(m_FMul(m_Value(X), m_Value(Y)))))
2141  return BinaryOperator::CreateFMulFMF(Builder.CreateFNegFMF(X, &I), Y, &I);
2142 
2143  if (match(FNeg, m_OneUse(m_FDiv(m_Value(X), m_Value(Y)))))
2144  return BinaryOperator::CreateFDivFMF(Builder.CreateFNegFMF(X, &I), Y, &I);
2145 
2146  return nullptr;
2147 }
2148 
2150  Value *Op = I.getOperand(0);
2151 
2152  if (Value *V = SimplifyFNegInst(Op, I.getFastMathFlags(),
2153  getSimplifyQuery().getWithInstruction(&I)))
2154  return replaceInstUsesWith(I, V);
2155 
2157  return X;
2158 
2159  Value *X, *Y;
2160 
2161  // If we can ignore the sign of zeros: -(X - Y) --> (Y - X)
2162  if (I.hasNoSignedZeros() &&
2164  return BinaryOperator::CreateFSubFMF(Y, X, &I);
2165 
2167  return R;
2168 
2169  return nullptr;
2170 }
2171 
2173  if (Value *V = SimplifyFSubInst(I.getOperand(0), I.getOperand(1),
2174  I.getFastMathFlags(),
2175  getSimplifyQuery().getWithInstruction(&I)))
2176  return replaceInstUsesWith(I, V);
2177 
2178  if (Instruction *X = foldVectorBinop(I))
2179  return X;
2180 
2181  // Subtraction from -0.0 is the canonical form of fneg.
2182  // fsub -0.0, X ==> fneg X
2183  // fsub nsz 0.0, X ==> fneg nsz X
2184  //
2185  // FIXME This matcher does not respect FTZ or DAZ yet:
2186  // fsub -0.0, Denorm ==> +-0
2187  // fneg Denorm ==> -Denorm
2188  Value *Op;
2189  if (match(&I, m_FNeg(m_Value(Op))))
2190  return UnaryOperator::CreateFNegFMF(Op, &I);
2191 
2193  return X;
2194 
2196  return R;
2197 
2198  Value *X, *Y;
2199  Constant *C;
2200 
2201  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
2202  // If Op0 is not -0.0 or we can ignore -0.0: Z - (X - Y) --> Z + (Y - X)
2203  // Canonicalize to fadd to make analysis easier.
2204  // This can also help codegen because fadd is commutative.
2205  // Note that if this fsub was really an fneg, the fadd with -0.0 will get
2206  // killed later. We still limit that particular transform with 'hasOneUse'
2207  // because an fneg is assumed better/cheaper than a generic fsub.
2208  if (I.hasNoSignedZeros() || CannotBeNegativeZero(Op0, SQ.TLI)) {
2209  if (match(Op1, m_OneUse(m_FSub(m_Value(X), m_Value(Y))))) {
2210  Value *NewSub = Builder.CreateFSubFMF(Y, X, &I);
2211  return BinaryOperator::CreateFAddFMF(Op0, NewSub, &I);
2212  }
2213  }
2214 
2215  // (-X) - Op1 --> -(X + Op1)
2216  if (I.hasNoSignedZeros() && !isa<ConstantExpr>(Op0) &&
2217  match(Op0, m_OneUse(m_FNeg(m_Value(X))))) {
2218  Value *FAdd = Builder.CreateFAddFMF(X, Op1, &I);
2220  }
2221 
2222  if (isa<Constant>(Op0))
2223  if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
2224  if (Instruction *NV = FoldOpIntoSelect(I, SI))
2225  return NV;
2226 
2227  // X - C --> X + (-C)
2228  // But don't transform constant expressions because there's an inverse fold
2229  // for X + (-Y) --> X - Y.
2230  if (match(Op1, m_ImmConstant(C)))
2232 
2233  // X - (-Y) --> X + Y
2234  if (match(Op1, m_FNeg(m_Value(Y))))
2235  return BinaryOperator::CreateFAddFMF(Op0, Y, &I);
2236 
2237  // Similar to above, but look through a cast of the negated value:
2238  // X - (fptrunc(-Y)) --> X + fptrunc(Y)
2239  Type *Ty = I.getType();
2240  if (match(Op1, m_OneUse(m_FPTrunc(m_FNeg(m_Value(Y))))))
2241  return BinaryOperator::CreateFAddFMF(Op0, Builder.CreateFPTrunc(Y, Ty), &I);
2242 
2243  // X - (fpext(-Y)) --> X + fpext(Y)
2244  if (match(Op1, m_OneUse(m_FPExt(m_FNeg(m_Value(Y))))))
2245  return BinaryOperator::CreateFAddFMF(Op0, Builder.CreateFPExt(Y, Ty), &I);
2246 
2247  // Similar to above, but look through fmul/fdiv of the negated value:
2248  // Op0 - (-X * Y) --> Op0 + (X * Y)
2249  // Op0 - (Y * -X) --> Op0 + (X * Y)
2250  if (match(Op1, m_OneUse(m_c_FMul(m_FNeg(m_Value(X)), m_Value(Y))))) {
2251  Value *FMul = Builder.CreateFMulFMF(X, Y, &I);
2252  return BinaryOperator::CreateFAddFMF(Op0, FMul, &I);
2253  }
2254  // Op0 - (-X / Y) --> Op0 + (X / Y)
2255  // Op0 - (X / -Y) --> Op0 + (X / Y)
2256  if (match(Op1, m_OneUse(m_FDiv(m_FNeg(m_Value(X)), m_Value(Y)))) ||
2257  match(Op1, m_OneUse(m_FDiv(m_Value(X), m_FNeg(m_Value(Y)))))) {
2258  Value *FDiv = Builder.CreateFDivFMF(X, Y, &I);
2259  return BinaryOperator::CreateFAddFMF(Op0, FDiv, &I);
2260  }
2261 
2262  // Handle special cases for FSub with selects feeding the operation
2263  if (Value *V = SimplifySelectsFeedingBinaryOp(I, Op0, Op1))
2264  return replaceInstUsesWith(I, V);
2265 
2266  if (I.hasAllowReassoc() && I.hasNoSignedZeros()) {
2267  // (Y - X) - Y --> -X
2268  if (match(Op0, m_FSub(m_Specific(Op1), m_Value(X))))
2269  return UnaryOperator::CreateFNegFMF(X, &I);
2270 
2271  // Y - (X + Y) --> -X
2272  // Y - (Y + X) --> -X
2273  if (match(Op1, m_c_FAdd(m_Specific(Op0), m_Value(X))))
2274  return UnaryOperator::CreateFNegFMF(X, &I);
2275 
2276  // (X * C) - X --> X * (C - 1.0)
2277  if (match(Op0, m_FMul(m_Specific(Op1), m_Constant(C)))) {
2278  Constant *CSubOne = ConstantExpr::getFSub(C, ConstantFP::get(Ty, 1.0));
2279  return BinaryOperator::CreateFMulFMF(Op1, CSubOne, &I);
2280  }
2281  // X - (X * C) --> X * (1.0 - C)
2282  if (match(Op1, m_FMul(m_Specific(Op0), m_Constant(C)))) {
2283  Constant *OneSubC = ConstantExpr::getFSub(ConstantFP::get(Ty, 1.0), C);
2284  return BinaryOperator::CreateFMulFMF(Op0, OneSubC, &I);
2285  }
2286 
2287  // Reassociate fsub/fadd sequences to create more fadd instructions and
2288  // reduce dependency chains:
2289  // ((X - Y) + Z) - Op1 --> (X + Z) - (Y + Op1)
2290  Value *Z;
2292  m_Value(Z))))) {
2293  Value *XZ = Builder.CreateFAddFMF(X, Z, &I);
2294  Value *YW = Builder.CreateFAddFMF(Y, Op1, &I);
2295  return BinaryOperator::CreateFSubFMF(XZ, YW, &I);
2296  }
2297 
2298  auto m_FaddRdx = [](Value *&Sum, Value *&Vec) {
2299  return m_OneUse(m_Intrinsic<Intrinsic::vector_reduce_fadd>(m_Value(Sum),
2300  m_Value(Vec)));
2301  };
2302  Value *A0, *A1, *V0, *V1;
2303  if (match(Op0, m_FaddRdx(A0, V0)) && match(Op1, m_FaddRdx(A1, V1)) &&
2304  V0->getType() == V1->getType()) {
2305  // Difference of sums is sum of differences:
2306  // add_rdx(A0, V0) - add_rdx(A1, V1) --> add_rdx(A0, V0 - V1) - A1
2307  Value *Sub = Builder.CreateFSubFMF(V0, V1, &I);
2308  Value *Rdx = Builder.CreateIntrinsic(Intrinsic::vector_reduce_fadd,
2309  {Sub->getType()}, {A0, Sub}, &I);
2310  return BinaryOperator::CreateFSubFMF(Rdx, A1, &I);
2311  }
2312 
2314  return F;
2315 
2316  // TODO: This performs reassociative folds for FP ops. Some fraction of the
2317  // functionality has been subsumed by simple pattern matching here and in
2318  // InstSimplify. We should let a dedicated reassociation pass handle more
2319  // complex pattern matching and remove this from InstCombine.
2320  if (Value *V = FAddCombine(Builder).simplify(&I))
2321  return replaceInstUsesWith(I, V);
2322 
2323  // (X - Y) - Op1 --> X - (Y + Op1)
2324  if (match(Op0, m_OneUse(m_FSub(m_Value(X), m_Value(Y))))) {
2325  Value *FAdd = Builder.CreateFAddFMF(Y, Op1, &I);
2327  }
2328  }
2329 
2330  return nullptr;
2331 }
llvm::lltok::APFloat
@ APFloat
Definition: LLToken.h:487
set
We currently generate a but we really shouldn eax ecx xorl edx divl ecx eax divl ecx movl eax ret A similar code sequence works for division We currently compile i32 v2 eax eax jo LBB1_2 atomic and others It is also currently not done for read modify write instructions It is also current not done if the OF or CF flags are needed The shift operators have the complication that when the shift count is EFLAGS is not set
Definition: README.txt:1277
foldToUnsignedSaturatedAdd
static Instruction * foldToUnsignedSaturatedAdd(BinaryOperator &I)
Definition: InstCombineAddSub.cpp:1127
llvm
Definition: AllocatorList.h:23
hoistFNegAboveFMulFDiv
static Instruction * hoistFNegAboveFMulFDiv(Instruction &I, InstCombiner::BuilderTy &Builder)
Definition: InstCombineAddSub.cpp:2133
llvm::InstCombinerImpl::visitFAdd
Instruction * visitFAdd(BinaryOperator &I)
Definition: InstCombineAddSub.cpp:1513
llvm::haveNoCommonBitsSet
bool haveNoCommonBitsSet(const Value *LHS, const Value *RHS, const DataLayout &DL, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, bool UseInstrInfo=true)
Return true if LHS and RHS have no common bits set.
Definition: ValueTracking.cpp:256
llvm::PatternMatch::m_TruncOrSelf
match_combine_or< CastClass_match< OpTy, Instruction::Trunc >, OpTy > m_TruncOrSelf(const OpTy &Op)
Definition: PatternMatch.h:1578
llvm::none_of
bool none_of(R &&Range, UnaryPredicate P)
Provide wrappers to std::none_of which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1519
llvm::SimplifySubInst
Value * SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW, const SimplifyQuery &Q)
Given operands for a Sub, fold the result or return null.
Definition: InstructionSimplify.cpp:858
llvm::MaskedValueIsZero
bool MaskedValueIsZero(const Value *V, const APInt &Mask, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, bool UseInstrInfo=true)
Return true if 'V & Mask' is known to be zero.
Definition: ValueTracking.cpp:359
llvm::ConstantExpr::getSIToFP
static Constant * getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2146
llvm::Value::hasOneUse
bool hasOneUse() const
Return true if there is exactly one use of this value.
Definition: Value.h:447
InstCombiner.h
llvm::RecurKind::FMul
@ FMul
Product of floats.
llvm::Intrinsic::getDeclaration
Function * getDeclaration(Module *M, ID id, ArrayRef< Type * > Tys=None)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
Definition: Function.cpp:1295
MatchDiv
static bool MatchDiv(Value *E, Value *&Op, APInt &C, bool IsSigned)
Definition: InstCombineAddSub.cpp:1041
llvm::CmpInst::Predicate
Predicate
This enumeration lists the possible predicates for CmpInst subclasses.
Definition: InstrTypes.h:722
simplify
hexagon bit simplify
Definition: HexagonBitSimplify.cpp:261
llvm::ConstantExpr::getZExt
static Constant * getZExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2097
llvm::APInt::isMask
bool isMask(unsigned numBits) const
Definition: APInt.h:501
P
This currently compiles esp xmm0 movsd esp eax eax esp ret We should use not the dag combiner This is because dagcombine2 needs to be able to see through the X86ISD::Wrapper which DAGCombine can t really do The code for turning x load into a single vector load is target independent and should be moved to the dag combiner The code for turning x load into a vector load can only handle a direct load from a global or a direct load from the stack It should be generalized to handle any load from P
Definition: README-SSE.txt:411
llvm::BinaryOperator::CreateNot
static BinaryOperator * CreateNot(Value *Op, const Twine &Name="", Instruction *InsertBefore=nullptr)
Definition: Instructions.cpp:2605
llvm::SelectPatternResult::Flavor
SelectPatternFlavor Flavor
Definition: ValueTracking.h:681
llvm::PatternMatch::m_LShr
BinaryOp_match< LHS, RHS, Instruction::LShr > m_LShr(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1098
llvm::APInt::isPowerOf2
bool isPowerOf2() const
Check if this APInt's value is a power of two greater than zero.
Definition: APInt.h:470
llvm::KnownBits::Zero
APInt Zero
Definition: KnownBits.h:24
C1
instcombine should handle this C2 when C1
Definition: README.txt:263
llvm::PatternMatch::m_FPOne
specific_fpval m_FPOne()
Match a float 1.0 or vector with all elements equal to 1.0.
Definition: PatternMatch.h:799
llvm::Type::getScalarType
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return 'this'.
Definition: Type.h:317
llvm::ConstantExpr::getSExt
static Constant * getSExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2083
llvm::SmallVector
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1168
llvm::BinaryOperator::CreateFDivFMF
static BinaryOperator * CreateFDivFMF(Value *V1, Value *V2, Instruction *FMFSource, const Twine &Name="")
Definition: InstrTypes.h:275
llvm::PatternMatch::m_Add
BinaryOp_match< LHS, RHS, Instruction::Add > m_Add(const LHS &L, const RHS &R)
Definition: PatternMatch.h:959
llvm::IRBuilder< TargetFolder, IRBuilderCallbackInserter >
llvm::CastInst::Create
static CastInst * Create(Instruction::CastOps, Value *S, Type *Ty, const Twine &Name="", Instruction *InsertBefore=nullptr)
Provides a way to construct any of the CastInst subclasses using an opcode instead of the subclass's ...
Definition: Instructions.cpp:2945
ValueTracking.h
llvm::PatternMatch::m_APFloat
apfloat_match m_APFloat(const APFloat *&Res)
Match a ConstantFP or splatted ConstantVector, binding the specified pointer to the contained APFloat...
Definition: PatternMatch.h:243
APInt.h
llvm::ConstantFP::isZero
bool isZero() const
Return true if the value is positive or negative zero.
Definition: Constants.h:299
llvm::Type
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:46
llvm::APInt::getBitWidth
unsigned getBitWidth() const
Return the number of bits in the APInt.
Definition: APInt.h:1582
llvm::ConstantExpr::getFPToSI
static Constant * getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2168
llvm::SimplifyFNegInst
Value * SimplifyFNegInst(Value *Op, FastMathFlags FMF, const SimplifyQuery &Q)
Given operand for an FNeg, fold the result or return null.
Definition: InstructionSimplify.cpp:4853
llvm::ConstantFP::getValueAPF
const APFloat & getValueAPF() const
Definition: Constants.h:295
T
#define T
Definition: Mips16ISelLowering.cpp:341
llvm::PatternMatch::m_BinOp
class_match< BinaryOperator > m_BinOp()
Match an arbitrary binary operation and ignore it.
Definition: PatternMatch.h:84
Offset
uint64_t Offset
Definition: ELFObjHandler.cpp:81
llvm::ore::NV
DiagnosticInfoOptimizationBase::Argument NV
Definition: OptimizationRemarkEmitter.h:128
llvm::PatternMatch::m_AShr
BinaryOp_match< LHS, RHS, Instruction::AShr > m_AShr(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1104
llvm::tgtok::FalseVal
@ FalseVal
Definition: TGLexer.h:61
Operator.h
llvm::Instruction::copyMetadata
void copyMetadata(const Instruction &SrcInst, ArrayRef< unsigned > WL=ArrayRef< unsigned >())
Copy metadata from SrcInst to this instruction.
Definition: Instruction.cpp:800
AlignOf.h
STLExtras.h
llvm::matchSelectPattern
SelectPatternResult matchSelectPattern(Value *V, Value *&LHS, Value *&RHS, Instruction::CastOps *CastOp=nullptr, unsigned Depth=0)
Pattern match integer [SU]MIN, [SU]MAX and ABS idioms, returning the kind and providing the out param...
Definition: ValueTracking.cpp:6055
llvm::PatternMatch::m_c_And
BinaryOp_match< LHS, RHS, Instruction::And, true > m_c_And(const LHS &L, const RHS &R)
Matches an And with LHS and RHS in either order.
Definition: PatternMatch.h:2185
llvm::BinaryOperator::CreateNeg
NUW NUW NUW NUW Exact static Exact BinaryOperator * CreateNeg(Value *Op, const Twine &Name="", Instruction *InsertBefore=nullptr)
Helper functions to construct and inspect unary operations (NEG and NOT) via binary operators SUB and...
Definition: Instructions.cpp:2565
llvm::UnaryOperator
Definition: InstrTypes.h:103
factorizeLerp
static Instruction * factorizeLerp(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
Eliminate an op from a linear interpolation (lerp) pattern.
Definition: InstCombineAddSub.cpp:1455
llvm::PatternMatch::m_Not
BinaryOp_match< ValTy, cst_pred_ty< is_all_ones >, Instruction::Xor, true > m_Not(const ValTy &V)
Matches a 'Not' as 'xor V, -1' or 'xor -1, V'.
Definition: PatternMatch.h:2223
llvm::SelectPatternFlavor
SelectPatternFlavor
Specific patterns of select instructions we can match.
Definition: ValueTracking.h:657
llvm::isInt
constexpr bool isInt(int64_t x)
Checks if an integer fits into the given bit width.
Definition: MathExtras.h:363
llvm::InstCombinerImpl::foldAddWithConstant
Instruction * foldAddWithConstant(BinaryOperator &Add)
Definition: InstCombineAddSub.cpp:864
llvm::APFloat::getSemantics
const fltSemantics & getSemantics() const
Definition: APFloat.h:1213
llvm::AlignedCharArrayUnion
A suitably aligned and sized character array member which can hold elements of any type.
Definition: AlignOf.h:27
llvm::EmitGEPOffset
Value * EmitGEPOffset(IRBuilderTy *Builder, const DataLayout &DL, User *GEP, bool NoAssumptions=false)
Given a getelementptr instruction/constantexpr, emit the code necessary to compute the offset from th...
Definition: Local.h:29
llvm::PatternMatch::m_Deferred
deferredval_ty< Value > m_Deferred(Value *const &V)
A commutative-friendly version of m_Specific().
Definition: PatternMatch.h:771
llvm::PatternMatch::m_FDiv
BinaryOp_match< LHS, RHS, Instruction::FDiv > m_FDiv(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1050
F
#define F(x, y, z)
Definition: MD5.cpp:56
llvm::RISCVFenceField::R
@ R
Definition: RISCVBaseInfo.h:129
llvm::PatternMatch::m_FAdd
BinaryOp_match< LHS, RHS, Instruction::FAdd > m_FAdd(const LHS &L, const RHS &R)
Definition: PatternMatch.h:965
KnownBits.h
llvm::PatternMatch::m_FSub
BinaryOp_match< LHS, RHS, Instruction::FSub > m_FSub(const LHS &L, const RHS &R)
Definition: PatternMatch.h:977
factorizeFAddFSub
static Instruction * factorizeFAddFSub(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
Factor a common operand out of fadd/fsub of fmul/fdiv.
Definition: InstCombineAddSub.cpp:1471
llvm::APInt::isSignMask
bool isSignMask() const
Check if the APInt's value is returned by getSignMask.
Definition: APInt.h:479
llvm::PatternMatch::m_OneUse
OneUse_match< T > m_OneUse(const T &SubPattern)
Definition: PatternMatch.h:67
llvm::ConstantExpr::getSub
static Constant * getSub(Constant *C1, Constant *C2, bool HasNUW=false, bool HasNSW=false)
Definition: Constants.cpp:2675
llvm::APInt::isShiftedMask
bool isShiftedMask() const
Return true if this APInt value contains a sequence of ones with the remainder zero.
Definition: APInt.h:523
Instruction.h
llvm::PatternMatch::m_APInt
apint_match m_APInt(const APInt *&Res)
Match a ConstantInt or splatted ConstantVector, binding the specified pointer to the contained APInt.
Definition: PatternMatch.h:226
llvm::APInt::umul_ov
APInt umul_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1997
llvm::PatternMatch::m_c_BinOp
AnyBinaryOp_match< LHS, RHS, true > m_c_BinOp(const LHS &L, const RHS &R)
Matches a BinaryOperator with LHS and RHS in either order.
Definition: PatternMatch.h:2156
llvm::SimplifyFSubInst
Value * SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF, const SimplifyQuery &Q)
Given operands for an FSub, fold the result or return null.
Definition: InstructionSimplify.cpp:5036
llvm::APInt::isNegative
bool isNegative() const
Determine sign of this APInt.
Definition: APInt.h:365
llvm::SelectInst::Create
static SelectInst * Create(Value *C, Value *S1, Value *S2, const Twine &NameStr="", Instruction *InsertBefore=nullptr, Instruction *MDFrom=nullptr)
Definition: Instructions.h:1746
InstCombineInternal.h
llvm::PatternMatch::m_Select
ThreeOps_match< Cond, LHS, RHS, Instruction::Select > m_Select(const Cond &C, const LHS &L, const RHS &R)
Matches SelectInst.
Definition: PatternMatch.h:1423
Constants.h
llvm::PatternMatch::match
bool match(Val *V, const Pattern &P)
Definition: PatternMatch.h:49
isZero
static bool isZero(Value *V, const DataLayout &DL, DominatorTree *DT, AssumptionCache *AC)
Definition: Lint.cpp:519
E
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
llvm::Instruction::setHasNoSignedWrap
void setHasNoSignedWrap(bool b=true)
Set or clear the nsw flag on this instruction, which must be an operator which supports this flag.
Definition: Instruction.cpp:124
llvm::User
Definition: User.h:44
llvm::RoundingMode
RoundingMode
Rounding mode.
Definition: FloatingPointMode.h:34
C
(vector float) vec_cmpeq(*A, *B) C
Definition: README_ALTIVEC.txt:86
InstrTypes.h
int
Clang compiles this i1 i64 store i64 i64 store i64 i64 store i64 i64 store i64 align Which gets codegen d xmm0 movaps rbp movaps rbp movaps rbp movaps rbp rbp rbp rbp rbp It would be better to have movq s of instead of the movaps s LLVM produces ret int
Definition: README.txt:536
llvm::SelectPatternResult::isMinOrMax
static bool isMinOrMax(SelectPatternFlavor SPF)
When implementing this min/max pattern as fcmp; select, does the fcmp have to be ordered?
Definition: ValueTracking.h:689
llvm::operator+=
std::string & operator+=(std::string &buffer, StringRef string)
Definition: StringRef.h:922
Y
static GCMetadataPrinterRegistry::Add< OcamlGCMetadataPrinter > Y("ocaml", "ocaml 3.10-compatible collector")
llvm::CallInst::Create
static CallInst * Create(FunctionType *Ty, Value *F, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Definition: Instructions.h:1493
SI
@ SI
Definition: SIInstrInfo.cpp:7342
llvm::ms_demangle::QualifierMangleMode::Result
@ Result
llvm::PatternMatch::m_Instruction
bind_ty< Instruction > m_Instruction(Instruction *&I)
Match an instruction, capturing it if we match.
Definition: PatternMatch.h:704
foldFNegIntoConstant
static Instruction * foldFNegIntoConstant(Instruction &I)
This eliminates floating-point negation in either 'fneg(X)' or 'fsub(-0.0, X)' form by combining into...
Definition: InstCombineAddSub.cpp:2106
llvm::PatternMatch::m_ZExt
CastClass_match< OpTy, Instruction::ZExt > m_ZExt(const OpTy &Op)
Matches ZExt.
Definition: PatternMatch.h:1590
llvm::PatternMatch::m_c_Add
BinaryOp_match< LHS, RHS, Instruction::Add, true > m_c_Add(const LHS &L, const RHS &R)
Matches a Add with LHS and RHS in either order.
Definition: PatternMatch.h:2171
B
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
llvm::Type::getFltSemantics
const fltSemantics & getFltSemantics() const
Definition: Type.h:170
checkForNegativeOperand
static Value * checkForNegativeOperand(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
Definition: InstCombineAddSub.cpp:767
llvm::PatternMatch::m_FNeg
FNeg_match< OpTy > m_FNeg(const OpTy &X)
Match 'fneg X' as 'fsub -0.0, X'.
Definition: PatternMatch.h:1014
llvm::Constant::getAllOnesValue
static Constant * getAllOnesValue(Type *Ty)
Definition: Constants.cpp:405
llvm::PatternMatch::m_SDiv
BinaryOp_match< LHS, RHS, Instruction::SDiv > m_SDiv(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1044
llvm::Instruction
Definition: Instruction.h:45
llvm::Type::getScalarSizeInBits
unsigned getScalarSizeInBits() const LLVM_READONLY
If this is a vector type, return the getPrimitiveSizeInBits value for the element type.
Definition: Type.cpp:154
llvm::PatternMatch::m_UMin
MaxMin_match< ICmpInst, LHS, RHS, umin_pred_ty > m_UMin(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1832
llvm::PatternMatch::m_c_Or
BinaryOp_match< LHS, RHS, Instruction::Or, true > m_c_Or(const LHS &L, const RHS &R)
Matches an Or with LHS and RHS in either order.
Definition: PatternMatch.h:2192
llvm::ConstantFP
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:255
llvm::APInt::getHighBitsSet
static APInt getHighBitsSet(unsigned numBits, unsigned hiBitsSet)
Get a value with high bits set.
Definition: APInt.h:656
APFloat.h
This file declares a class to represent arbitrary precision floating point values and provide a varie...
llvm::ConstantInt::get
static Constant * get(Type *Ty, uint64_t V, bool IsSigned=false)
If Ty is a vector type, return a Constant with a splat of the given value.
Definition: Constants.cpp:885
canonicalizeLowbitMask
static Instruction * canonicalizeLowbitMask(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
Fold (1 << NBits) - 1 Into: ~(-(1 << NBits)) Because a 'not' is better for bit-tracking analysis and ...
Definition: InstCombineAddSub.cpp:1109
llvm::PatternMatch::m_URem
BinaryOp_match< LHS, RHS, Instruction::URem > m_URem(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1056
PatternMatch.h
llvm::APInt::countTrailingZeros
unsigned countTrailingZeros() const
Count the number of trailing zero bits.
Definition: APInt.h:1701
llvm::CastInst::CreateTruncOrBitCast
static CastInst * CreateTruncOrBitCast(Value *S, Type *Ty, const Twine &Name="", Instruction *InsertBefore=nullptr)
Create a Trunc or BitCast cast instruction.
Definition: Instructions.cpp:3021
llvm::array_lengthof
constexpr size_t array_lengthof(T(&)[N])
Find the length of an array.
Definition: STLExtras.h:1348
llvm::Type::getIntegerBitWidth
unsigned getIntegerBitWidth() const
Definition: DerivedTypes.h:96
llvm::InstCombiner::SubOne
static Constant * SubOne(Constant *C)
Subtract one from a Constant.
Definition: InstCombiner.h:205
Type.h
llvm::ConstantExpr::getFNeg
static Constant * getFNeg(Constant *C)
Definition: Constants.cpp:2652
X
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
llvm::PatternMatch::m_One
cst_pred_ty< is_one > m_One()
Match an integer 1 or a vector with all elements equal to 1.
Definition: PatternMatch.h:469
one
the resulting code requires compare and branches when and if the revised code is with conditional branches instead of More there is a byte word extend before each where there should be only one
Definition: README.txt:401
llvm::PatternMatch::m_NSWAdd
OverflowingBinaryOp_match< LHS, RHS, Instruction::Add, OverflowingBinaryOperator::NoSignedWrap > m_NSWAdd(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1137
llvm::APFloat::multiply
opStatus multiply(const APFloat &RHS, roundingMode RM)
Definition: APFloat.h:990
llvm::PatternMatch::m_Xor
BinaryOp_match< LHS, RHS, Instruction::Xor > m_Xor(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1086
llvm::InstCombinerImpl::visitFNeg
Instruction * visitFNeg(UnaryOperator &I)
Definition: InstCombineAddSub.cpp:2149
llvm::PatternMatch::m_FPTrunc
CastClass_match< OpTy, Instruction::FPTrunc > m_FPTrunc(const OpTy &Op)
Definition: PatternMatch.h:1643
llvm::PatternMatch::m_ZExtOrSelf
match_combine_or< CastClass_match< OpTy, Instruction::ZExt >, OpTy > m_ZExtOrSelf(const OpTy &Op)
Definition: PatternMatch.h:1596
llvm::APFloat
Definition: APFloat.h:701
llvm::PatternMatch::m_Zero
is_zero m_Zero()
Match any null constant or a vector with all elements equal to 0.
Definition: PatternMatch.h:491
llvm::PatternMatch::m_NUWAdd
OverflowingBinaryOp_match< LHS, RHS, Instruction::Add, OverflowingBinaryOperator::NoUnsignedWrap > m_NUWAdd(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1170
llvm::MipsISD::Ext
@ Ext
Definition: MipsISelLowering.h:156
llvm::Constant
This is an important base class in LLVM.
Definition: Constant.h:41
llvm::InstCombinerImpl::visitAdd
Instruction * visitAdd(BinaryOperator &I)
Definition: InstCombineAddSub.cpp:1287
llvm::UnaryOperator::CreateFNegFMF
static UnaryOperator * CreateFNegFMF(Value *Op, Instruction *FMFSource, const Twine &Name="", Instruction *InsertBefore=nullptr)
Definition: InstrTypes.h:166
llvm::PatternMatch::m_ImmConstant
match_combine_and< class_match< Constant >, match_unless< class_match< ConstantExpr > > > m_ImmConstant()
Match an arbitrary immediate Constant and ignore it.
Definition: PatternMatch.h:737
llvm::InstCombiner::AddOne
static Constant * AddOne(Constant *C)
Add one to a Constant.
Definition: InstCombiner.h:200
llvm::BinaryOperator::CreateFMulFMF
static BinaryOperator * CreateFMulFMF(Value *V1, Value *V2, Instruction *FMFSource, const Twine &Name="")
Definition: InstrTypes.h:270
llvm::InstCombinerImpl::canonicalizeCondSignextOfHighBitExtractToSignextHighBitExtract
Instruction * canonicalizeCondSignextOfHighBitExtractToSignextHighBitExtract(BinaryOperator &I)
Definition: InstCombineAddSub.cpp:1150
llvm::GEPOperator::countNonConstantIndices
unsigned countNonConstantIndices() const
Definition: Operator.h:545
llvm::APInt::logBase2
unsigned logBase2() const
Definition: APInt.h:1817
llvm::PatternMatch::m_Or
BinaryOp_match< LHS, RHS, Instruction::Or > m_Or(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1080
llvm::PatternMatch::m_AllOnes
cst_pred_ty< is_all_ones > m_AllOnes()
Match an integer or vector with all bits set.
Definition: PatternMatch.h:401
llvm::Value::hasNUsesOrMore
bool hasNUsesOrMore(unsigned N) const
Return true if this value has N uses or more.
Definition: Value.cpp:154
isConstant
static bool isConstant(const MachineInstr &MI)
Definition: AMDGPUInstructionSelector.cpp:2267
I
#define I(x, y, z)
Definition: MD5.cpp:59
llvm::ConstantExpr::getFSub
static Constant * getFSub(Constant *C1, Constant *C2)
Definition: Constants.cpp:2682
llvm::PatternMatch::m_And
BinaryOp_match< LHS, RHS, Instruction::And > m_And(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1074
llvm::SimplifyFAddInst
Value * SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF, const SimplifyQuery &Q)
Given operands for an FAdd, fold the result or return null.
Definition: InstructionSimplify.cpp:5030
llvm::Instruction::setDebugLoc
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:362
llvm::PatternMatch::m_SRem
BinaryOp_match< LHS, RHS, Instruction::SRem > m_SRem(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1062
llvm::InstCombinerImpl::SimplifyAddWithRemainder
Value * SimplifyAddWithRemainder(BinaryOperator &I)
Tries to simplify add operations using the definition of remainder.
Definition: InstCombineAddSub.cpp:1073
llvm::computeKnownBits
void computeKnownBits(const Value *V, KnownBits &Known, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, OptimizationRemarkEmitter *ORE=nullptr, bool UseInstrInfo=true)
Determine which bits of V are known to be either zero or one and return them in the KnownZero/KnownOn...
Definition: ValueTracking.cpp:211
llvm::InstCombinerImpl::visitFSub
Instruction * visitFSub(BinaryOperator &I)
Definition: InstCombineAddSub.cpp:2172
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::PatternMatch::m_Sub
BinaryOp_match< LHS, RHS, Instruction::Sub > m_Sub(const LHS &L, const RHS &R)
Definition: PatternMatch.h:971
std::swap
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:840
llvm::Negator::Negate
static LLVM_NODISCARD Value * Negate(bool LHSIsZero, Value *Root, InstCombinerImpl &IC)
Attempt to negate Root.
Definition: InstCombineNegator.cpp:489
llvm::SelectInst
This class represents the LLVM 'select' instruction.
Definition: Instructions.h:1715
llvm::WinEH::EncodingType::CE
@ CE
Windows NT (Windows on ARM)
llvm::PatternMatch::m_Constant
class_match< Constant > m_Constant()
Match an arbitrary Constant and ignore it.
Definition: PatternMatch.h:98
llvm::GEPOperator
Definition: Operator.h:457
Builder
assume Assume Builder
Definition: AssumeBundleBuilder.cpp:649
llvm::PatternMatch::m_Value
class_match< Value > m_Value()
Match an arbitrary value and ignore it.
Definition: PatternMatch.h:76
llvm::ZExtInst
This class represents zero extension of integer types.
Definition: Instructions.h:4730
llvm::APInt
Class for arbitrary precision integers.
Definition: APInt.h:71
llvm::PatternMatch::m_SExt
CastClass_match< OpTy, Instruction::SExt > m_SExt(const OpTy &Op)
Matches SExt.
Definition: PatternMatch.h:1584
llvm::PatternMatch::m_CombineAnd
match_combine_and< LTy, RTy > m_CombineAnd(const LTy &L, const RTy &R)
Combine two pattern matchers matching L && R.
Definition: PatternMatch.h:172
llvm::BinaryOperator
Definition: InstrTypes.h:190
llvm::PatternMatch::m_SpecificInt_ICMP
cst_pred_ty< icmp_pred_with_threshold > m_SpecificInt_ICMP(ICmpInst::Predicate Predicate, const APInt &Threshold)
Match an integer or vector with every element comparing 'pred' (eg/ne/...) to Threshold.
Definition: PatternMatch.h:582
Cond
SmallVector< MachineOperand, 4 > Cond
Definition: BasicBlockSections.cpp:167
llvm::Value::getType
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:256
llvm::MinMax
Definition: AssumeBundleQueries.h:72
DL
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
Definition: AArch64SLSHardening.cpp:76
foldNoWrapAdd
static Instruction * foldNoWrapAdd(BinaryOperator &Add, InstCombiner::BuilderTy &Builder)
Wrapping flags may allow combining constants separated by an extend.
Definition: InstCombineAddSub.cpp:824
S
add sub stmia L5 ldr r0 bl L_printf $stub Instead of a and a wouldn t it be better to do three moves *Return an aggregate type is even return S
Definition: README.txt:210
MatchMul
static bool MatchMul(Value *E, Value *&Op, APInt &C)
Definition: InstCombineAddSub.cpp:1001
factorizeMathWithShlOps
static Instruction * factorizeMathWithShlOps(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
This is a specialization of a more general transform from SimplifyUsingDistributiveLaws.
Definition: InstCombineAddSub.cpp:1253
llvm::Value::getName
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:298
llvm::InstCombinerImpl::OptimizePointerDifference
Value * OptimizePointerDifference(Value *LHS, Value *RHS, Type *Ty, bool isNUW)
Optimize pointer differences into the same array into a size.
Definition: InstCombineAddSub.cpp:1627
llvm::MCID::Select
@ Select
Definition: MCInstrDesc.h:163
llvm::PatternMatch::m_FPExt
CastClass_match< OpTy, Instruction::FPExt > m_FPExt(const OpTy &Op)
Definition: PatternMatch.h:1648
llvm::tgtok::IntVal
@ IntVal
Definition: TGLexer.h:64
llvm::APIntOps::umax
const APInt & umax(const APInt &A, const APInt &B)
Determine the larger of two APInts considered to be unsigned.
Definition: APInt.h:2189
llvm::Instruction::setFastMathFlags
void setFastMathFlags(FastMathFlags FMF)
Convenience function for setting multiple fast-math flags on this instruction, which must be an opera...
Definition: Instruction.cpp:209
Constant.h
llvm::PatternMatch::m_SExtOrSelf
match_combine_or< CastClass_match< OpTy, Instruction::SExt >, OpTy > m_SExtOrSelf(const OpTy &Op)
Definition: PatternMatch.h:1602
llvm::Constant::getNullValue
static Constant * getNullValue(Type *Ty)
Constructor to create a '0' constant of arbitrary type.
Definition: Constants.cpp:347
llvm::KnownBits
Definition: KnownBits.h:23
llvm::PatternMatch::m_UDiv
BinaryOp_match< LHS, RHS, Instruction::UDiv > m_UDiv(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1038
llvm::APInt::isMinSignedValue
bool isMinSignedValue() const
Determine if this is the smallest signed value.
Definition: APInt.h:449
llvm::BinaryOperator::CreateFAddFMF
static BinaryOperator * CreateFAddFMF(Value *V1, Value *V2, Instruction *FMFSource, const Twine &Name="")
Definition: InstrTypes.h:260
get
Should compile to something r4 addze r3 instead we get
Definition: README.txt:24
llvm::AMDGPU::SendMsg::Op
Op
Definition: SIDefines.h:314
llvm::GEPOperator::isInBounds
bool isInBounds() const
Test whether this is an inbounds GEP, as defined by LangRef.html.
Definition: Operator.h:474
llvm::ConstantExpr::getAdd
static Constant * getAdd(Constant *C1, Constant *C2, bool HasNUW=false, bool HasNSW=false)
Definition: Constants.cpp:2664
llvm::Type::isIntOrIntVectorTy
bool isIntOrIntVectorTy() const
Return true if this is an integer type or a vector of integer types.
Definition: Type.h:208
llvm::ConstantFP::get
static Constant * get(Type *Ty, double V)
This returns a ConstantFP, or a vector containing a splat of a ConstantFP, for the specified value in...
Definition: Constants.cpp:932
Casting.h
llvm::fltSemantics
Definition: APFloat.cpp:54
llvm::BitWidth
constexpr unsigned BitWidth
Definition: BitmaskEnum.h:147
llvm::APInt::smul_ov
APInt smul_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1987
MulWillOverflow
static bool MulWillOverflow(APInt &C0, APInt &C1, bool IsSigned)
Definition: InstCombineAddSub.cpp:1062
llvm::PatternMatch::m_ZeroInt
cst_pred_ty< is_zero_int > m_ZeroInt()
Match an integer 0 or a vector with all elements equal to 0.
Definition: PatternMatch.h:478
llvm::PatternMatch::m_PtrToInt
CastClass_match< OpTy, Instruction::PtrToInt > m_PtrToInt(const OpTy &Op)
Matches PtrToInt.
Definition: PatternMatch.h:1560
llvm::MCID::Add
@ Add
Definition: MCInstrDesc.h:184
llvm::InstCombinerImpl::visitSub
Instruction * visitSub(BinaryOperator &I)
Definition: InstCombineAddSub.cpp:1702
llvm::PatternMatch::m_c_Xor
BinaryOp_match< LHS, RHS, Instruction::Xor, true > m_c_Xor(const LHS &L, const RHS &R)
Matches an Xor with LHS and RHS in either order.
Definition: PatternMatch.h:2199
llvm::APInt::sext
APInt sext(unsigned width) const
Sign extend to a new width.
Definition: APInt.cpp:906
llvm::CannotBeNegativeZero
bool CannotBeNegativeZero(const Value *V, const TargetLibraryInfo *TLI, unsigned Depth=0)
Return true if we can prove that the specified FP value is never equal to -0.0.
Definition: ValueTracking.cpp:3356
llvm::APFloatBase::rmNearestTiesToEven
static constexpr roundingMode rmNearestTiesToEven
Definition: APFloat.h:190
llvm::RecurKind::FAdd
@ FAdd
Sum of floats.
llvm::PatternMatch::m_c_FMul
BinaryOp_match< LHS, RHS, Instruction::FMul, true > m_c_FMul(const LHS &L, const RHS &R)
Matches FMul with LHS and RHS in either order.
Definition: PatternMatch.h:2273
Instructions.h
llvm::PatternMatch::m_c_FAdd
BinaryOp_match< LHS, RHS, Instruction::FAdd, true > m_c_FAdd(const LHS &L, const RHS &R)
Matches FAdd with LHS and RHS in either order.
Definition: PatternMatch.h:2266
SmallVector.h
llvm::PatternMatch::m_Specific
specificval_ty m_Specific(const Value *V)
Match if we have a specific specified value.
Definition: PatternMatch.h:758
llvm::SIToFPInst
This class represents a cast from signed integer to floating point.
Definition: Instructions.h:4925
llvm::PatternMatch::m_ICmp
CmpClass_match< LHS, RHS, ICmpInst, ICmpInst::Predicate > m_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R)
Definition: PatternMatch.h:1355
N
#define N
MatchRem
static bool MatchRem(Value *E, Value *&Op, APInt &C, bool &IsSigned)
Definition: InstCombineAddSub.cpp:1019
InstructionSimplify.h
llvm::APFloatBase::semanticsPrecision
static unsigned int semanticsPrecision(const fltSemantics &)
Definition: APFloat.cpp:204
llvm::PHINode
Definition: Instructions.h:2572
llvm::PatternMatch::m_Neg
BinaryOp_match< cst_pred_ty< is_zero_int >, ValTy, Instruction::Sub > m_Neg(const ValTy &V)
Matches a 'Neg' as 'sub 0, V'.
Definition: PatternMatch.h:2207
CreateAdd
static BinaryOperator * CreateAdd(Value *S1, Value *S2, const Twine &Name, Instruction *InsertBefore, Value *FlagsOp)
Definition: Reassociate.cpp:234
llvm::PatternMatch::m_Trunc
CastClass_match< OpTy, Instruction::Trunc > m_Trunc(const OpTy &Op)
Matches Trunc.
Definition: PatternMatch.h:1572
llvm::SimplifyAddInst
Value * SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW, const SimplifyQuery &Q)
Given operands for an Add, fold the result or return null.
Definition: InstructionSimplify.cpp:675
llvm::PatternMatch::m_FMul
BinaryOp_match< LHS, RHS, Instruction::FMul > m_FMul(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1032
llvm::tgtok::TrueVal
@ TrueVal
Definition: TGLexer.h:61
Value.h
llvm::RoundingMode::NearestTiesToEven
@ NearestTiesToEven
roundTiesToEven.
llvm::Value
LLVM Value Representation.
Definition: Value.h:75
llvm::PatternMatch::m_Shl
BinaryOp_match< LHS, RHS, Instruction::Shl > m_Shl(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1092
llvm::BinaryOperator::CreateFSubFMF
static BinaryOperator * CreateFSubFMF(Value *V1, Value *V2, Instruction *FMFSource, const Twine &Name="")
Definition: InstrTypes.h:265
llvm::PatternMatch::m_c_UMin
MaxMin_match< ICmpInst, LHS, RHS, umin_pred_ty, true > m_c_UMin(const LHS &L, const RHS &R)
Matches a UMin with LHS and RHS in either order.
Definition: PatternMatch.h:2242
llvm::PatternMatch::m_Mul
BinaryOp_match< LHS, RHS, Instruction::Mul > m_Mul(const LHS &L, const RHS &R)
Definition: PatternMatch.h:1026