LLVM  10.0.0svn
InstCombineAndOrXor.cpp
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1 //===- InstCombineAndOrXor.cpp --------------------------------------------===//
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 visitAnd, visitOr, and visitXor functions.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "InstCombineInternal.h"
17 #include "llvm/IR/ConstantRange.h"
18 #include "llvm/IR/Intrinsics.h"
19 #include "llvm/IR/PatternMatch.h"
20 using namespace llvm;
21 using namespace PatternMatch;
22 
23 #define DEBUG_TYPE "instcombine"
24 
25 /// Similar to getICmpCode but for FCmpInst. This encodes a fcmp predicate into
26 /// a four bit mask.
27 static unsigned getFCmpCode(FCmpInst::Predicate CC) {
29  "Unexpected FCmp predicate!");
30  // Take advantage of the bit pattern of FCmpInst::Predicate here.
31  // U L G E
32  static_assert(FCmpInst::FCMP_FALSE == 0, ""); // 0 0 0 0
33  static_assert(FCmpInst::FCMP_OEQ == 1, ""); // 0 0 0 1
34  static_assert(FCmpInst::FCMP_OGT == 2, ""); // 0 0 1 0
35  static_assert(FCmpInst::FCMP_OGE == 3, ""); // 0 0 1 1
36  static_assert(FCmpInst::FCMP_OLT == 4, ""); // 0 1 0 0
37  static_assert(FCmpInst::FCMP_OLE == 5, ""); // 0 1 0 1
38  static_assert(FCmpInst::FCMP_ONE == 6, ""); // 0 1 1 0
39  static_assert(FCmpInst::FCMP_ORD == 7, ""); // 0 1 1 1
40  static_assert(FCmpInst::FCMP_UNO == 8, ""); // 1 0 0 0
41  static_assert(FCmpInst::FCMP_UEQ == 9, ""); // 1 0 0 1
42  static_assert(FCmpInst::FCMP_UGT == 10, ""); // 1 0 1 0
43  static_assert(FCmpInst::FCMP_UGE == 11, ""); // 1 0 1 1
44  static_assert(FCmpInst::FCMP_ULT == 12, ""); // 1 1 0 0
45  static_assert(FCmpInst::FCMP_ULE == 13, ""); // 1 1 0 1
46  static_assert(FCmpInst::FCMP_UNE == 14, ""); // 1 1 1 0
47  static_assert(FCmpInst::FCMP_TRUE == 15, ""); // 1 1 1 1
48  return CC;
49 }
50 
51 /// This is the complement of getICmpCode, which turns an opcode and two
52 /// operands into either a constant true or false, or a brand new ICmp
53 /// instruction. The sign is passed in to determine which kind of predicate to
54 /// use in the new icmp instruction.
55 static Value *getNewICmpValue(unsigned Code, bool Sign, Value *LHS, Value *RHS,
56  InstCombiner::BuilderTy &Builder) {
57  ICmpInst::Predicate NewPred;
58  if (Constant *TorF = getPredForICmpCode(Code, Sign, LHS->getType(), NewPred))
59  return TorF;
60  return Builder.CreateICmp(NewPred, LHS, RHS);
61 }
62 
63 /// This is the complement of getFCmpCode, which turns an opcode and two
64 /// operands into either a FCmp instruction, or a true/false constant.
65 static Value *getFCmpValue(unsigned Code, Value *LHS, Value *RHS,
66  InstCombiner::BuilderTy &Builder) {
67  const auto Pred = static_cast<FCmpInst::Predicate>(Code);
68  assert(FCmpInst::FCMP_FALSE <= Pred && Pred <= FCmpInst::FCMP_TRUE &&
69  "Unexpected FCmp predicate!");
70  if (Pred == FCmpInst::FCMP_FALSE)
72  if (Pred == FCmpInst::FCMP_TRUE)
74  return Builder.CreateFCmp(Pred, LHS, RHS);
75 }
76 
77 /// Transform BITWISE_OP(BSWAP(A),BSWAP(B)) or
78 /// BITWISE_OP(BSWAP(A), Constant) to BSWAP(BITWISE_OP(A, B))
79 /// \param I Binary operator to transform.
80 /// \return Pointer to node that must replace the original binary operator, or
81 /// null pointer if no transformation was made.
83  InstCombiner::BuilderTy &Builder) {
84  assert(I.isBitwiseLogicOp() && "Unexpected opcode for bswap simplifying");
85 
86  Value *OldLHS = I.getOperand(0);
87  Value *OldRHS = I.getOperand(1);
88 
89  Value *NewLHS;
90  if (!match(OldLHS, m_BSwap(m_Value(NewLHS))))
91  return nullptr;
92 
93  Value *NewRHS;
94  const APInt *C;
95 
96  if (match(OldRHS, m_BSwap(m_Value(NewRHS)))) {
97  // OP( BSWAP(x), BSWAP(y) ) -> BSWAP( OP(x, y) )
98  if (!OldLHS->hasOneUse() && !OldRHS->hasOneUse())
99  return nullptr;
100  // NewRHS initialized by the matcher.
101  } else if (match(OldRHS, m_APInt(C))) {
102  // OP( BSWAP(x), CONSTANT ) -> BSWAP( OP(x, BSWAP(CONSTANT) ) )
103  if (!OldLHS->hasOneUse())
104  return nullptr;
105  NewRHS = ConstantInt::get(I.getType(), C->byteSwap());
106  } else
107  return nullptr;
108 
109  Value *BinOp = Builder.CreateBinOp(I.getOpcode(), NewLHS, NewRHS);
110  Function *F = Intrinsic::getDeclaration(I.getModule(), Intrinsic::bswap,
111  I.getType());
112  return Builder.CreateCall(F, BinOp);
113 }
114 
115 /// This handles expressions of the form ((val OP C1) & C2). Where
116 /// the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'.
117 Instruction *InstCombiner::OptAndOp(BinaryOperator *Op,
118  ConstantInt *OpRHS,
119  ConstantInt *AndRHS,
120  BinaryOperator &TheAnd) {
121  Value *X = Op->getOperand(0);
122 
123  switch (Op->getOpcode()) {
124  default: break;
125  case Instruction::Add:
126  if (Op->hasOneUse()) {
127  // Adding a one to a single bit bit-field should be turned into an XOR
128  // of the bit. First thing to check is to see if this AND is with a
129  // single bit constant.
130  const APInt &AndRHSV = AndRHS->getValue();
131 
132  // If there is only one bit set.
133  if (AndRHSV.isPowerOf2()) {
134  // Ok, at this point, we know that we are masking the result of the
135  // ADD down to exactly one bit. If the constant we are adding has
136  // no bits set below this bit, then we can eliminate the ADD.
137  const APInt& AddRHS = OpRHS->getValue();
138 
139  // Check to see if any bits below the one bit set in AndRHSV are set.
140  if ((AddRHS & (AndRHSV - 1)).isNullValue()) {
141  // If not, the only thing that can effect the output of the AND is
142  // the bit specified by AndRHSV. If that bit is set, the effect of
143  // the XOR is to toggle the bit. If it is clear, then the ADD has
144  // no effect.
145  if ((AddRHS & AndRHSV).isNullValue()) { // Bit is not set, noop
146  TheAnd.setOperand(0, X);
147  return &TheAnd;
148  } else {
149  // Pull the XOR out of the AND.
150  Value *NewAnd = Builder.CreateAnd(X, AndRHS);
151  NewAnd->takeName(Op);
152  return BinaryOperator::CreateXor(NewAnd, AndRHS);
153  }
154  }
155  }
156  }
157  break;
158  }
159  return nullptr;
160 }
161 
162 /// Emit a computation of: (V >= Lo && V < Hi) if Inside is true, otherwise
163 /// (V < Lo || V >= Hi). This method expects that Lo <= Hi. IsSigned indicates
164 /// whether to treat V, Lo, and Hi as signed or not.
165 Value *InstCombiner::insertRangeTest(Value *V, const APInt &Lo, const APInt &Hi,
166  bool isSigned, bool Inside) {
167  assert((isSigned ? Lo.sle(Hi) : Lo.ule(Hi)) &&
168  "Lo is not <= Hi in range emission code!");
169 
170  Type *Ty = V->getType();
171  if (Lo == Hi)
172  return Inside ? ConstantInt::getFalse(Ty) : ConstantInt::getTrue(Ty);
173 
174  // V >= Min && V < Hi --> V < Hi
175  // V < Min || V >= Hi --> V >= Hi
177  if (isSigned ? Lo.isMinSignedValue() : Lo.isMinValue()) {
178  Pred = isSigned ? ICmpInst::getSignedPredicate(Pred) : Pred;
179  return Builder.CreateICmp(Pred, V, ConstantInt::get(Ty, Hi));
180  }
181 
182  // V >= Lo && V < Hi --> V - Lo u< Hi - Lo
183  // V < Lo || V >= Hi --> V - Lo u>= Hi - Lo
184  Value *VMinusLo =
185  Builder.CreateSub(V, ConstantInt::get(Ty, Lo), V->getName() + ".off");
186  Constant *HiMinusLo = ConstantInt::get(Ty, Hi - Lo);
187  return Builder.CreateICmp(Pred, VMinusLo, HiMinusLo);
188 }
189 
190 /// Classify (icmp eq (A & B), C) and (icmp ne (A & B), C) as matching patterns
191 /// that can be simplified.
192 /// One of A and B is considered the mask. The other is the value. This is
193 /// described as the "AMask" or "BMask" part of the enum. If the enum contains
194 /// only "Mask", then both A and B can be considered masks. If A is the mask,
195 /// then it was proven that (A & C) == C. This is trivial if C == A or C == 0.
196 /// If both A and C are constants, this proof is also easy.
197 /// For the following explanations, we assume that A is the mask.
198 ///
199 /// "AllOnes" declares that the comparison is true only if (A & B) == A or all
200 /// bits of A are set in B.
201 /// Example: (icmp eq (A & 3), 3) -> AMask_AllOnes
202 ///
203 /// "AllZeros" declares that the comparison is true only if (A & B) == 0 or all
204 /// bits of A are cleared in B.
205 /// Example: (icmp eq (A & 3), 0) -> Mask_AllZeroes
206 ///
207 /// "Mixed" declares that (A & B) == C and C might or might not contain any
208 /// number of one bits and zero bits.
209 /// Example: (icmp eq (A & 3), 1) -> AMask_Mixed
210 ///
211 /// "Not" means that in above descriptions "==" should be replaced by "!=".
212 /// Example: (icmp ne (A & 3), 3) -> AMask_NotAllOnes
213 ///
214 /// If the mask A contains a single bit, then the following is equivalent:
215 /// (icmp eq (A & B), A) equals (icmp ne (A & B), 0)
216 /// (icmp ne (A & B), A) equals (icmp eq (A & B), 0)
226  BMask_Mixed = 256,
228 };
229 
230 /// Return the set of patterns (from MaskedICmpType) that (icmp SCC (A & B), C)
231 /// satisfies.
232 static unsigned getMaskedICmpType(Value *A, Value *B, Value *C,
233  ICmpInst::Predicate Pred) {
234  ConstantInt *ACst = dyn_cast<ConstantInt>(A);
235  ConstantInt *BCst = dyn_cast<ConstantInt>(B);
236  ConstantInt *CCst = dyn_cast<ConstantInt>(C);
237  bool IsEq = (Pred == ICmpInst::ICMP_EQ);
238  bool IsAPow2 = (ACst && !ACst->isZero() && ACst->getValue().isPowerOf2());
239  bool IsBPow2 = (BCst && !BCst->isZero() && BCst->getValue().isPowerOf2());
240  unsigned MaskVal = 0;
241  if (CCst && CCst->isZero()) {
242  // if C is zero, then both A and B qualify as mask
243  MaskVal |= (IsEq ? (Mask_AllZeros | AMask_Mixed | BMask_Mixed)
245  if (IsAPow2)
246  MaskVal |= (IsEq ? (AMask_NotAllOnes | AMask_NotMixed)
247  : (AMask_AllOnes | AMask_Mixed));
248  if (IsBPow2)
249  MaskVal |= (IsEq ? (BMask_NotAllOnes | BMask_NotMixed)
250  : (BMask_AllOnes | BMask_Mixed));
251  return MaskVal;
252  }
253 
254  if (A == C) {
255  MaskVal |= (IsEq ? (AMask_AllOnes | AMask_Mixed)
257  if (IsAPow2)
258  MaskVal |= (IsEq ? (Mask_NotAllZeros | AMask_NotMixed)
259  : (Mask_AllZeros | AMask_Mixed));
260  } else if (ACst && CCst && ConstantExpr::getAnd(ACst, CCst) == CCst) {
261  MaskVal |= (IsEq ? AMask_Mixed : AMask_NotMixed);
262  }
263 
264  if (B == C) {
265  MaskVal |= (IsEq ? (BMask_AllOnes | BMask_Mixed)
267  if (IsBPow2)
268  MaskVal |= (IsEq ? (Mask_NotAllZeros | BMask_NotMixed)
269  : (Mask_AllZeros | BMask_Mixed));
270  } else if (BCst && CCst && ConstantExpr::getAnd(BCst, CCst) == CCst) {
271  MaskVal |= (IsEq ? BMask_Mixed : BMask_NotMixed);
272  }
273 
274  return MaskVal;
275 }
276 
277 /// Convert an analysis of a masked ICmp into its equivalent if all boolean
278 /// operations had the opposite sense. Since each "NotXXX" flag (recording !=)
279 /// is adjacent to the corresponding normal flag (recording ==), this just
280 /// involves swapping those bits over.
281 static unsigned conjugateICmpMask(unsigned Mask) {
282  unsigned NewMask;
283  NewMask = (Mask & (AMask_AllOnes | BMask_AllOnes | Mask_AllZeros |
285  << 1;
286 
287  NewMask |= (Mask & (AMask_NotAllOnes | BMask_NotAllOnes | Mask_NotAllZeros |
289  >> 1;
290 
291  return NewMask;
292 }
293 
294 // Adapts the external decomposeBitTestICmp for local use.
295 static bool decomposeBitTestICmp(Value *LHS, Value *RHS, CmpInst::Predicate &Pred,
296  Value *&X, Value *&Y, Value *&Z) {
297  APInt Mask;
298  if (!llvm::decomposeBitTestICmp(LHS, RHS, Pred, X, Mask))
299  return false;
300 
301  Y = ConstantInt::get(X->getType(), Mask);
302  Z = ConstantInt::get(X->getType(), 0);
303  return true;
304 }
305 
306 /// Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E).
307 /// Return the pattern classes (from MaskedICmpType) for the left hand side and
308 /// the right hand side as a pair.
309 /// LHS and RHS are the left hand side and the right hand side ICmps and PredL
310 /// and PredR are their predicates, respectively.
311 static
314  Value *&D, Value *&E, ICmpInst *LHS,
315  ICmpInst *RHS,
316  ICmpInst::Predicate &PredL,
317  ICmpInst::Predicate &PredR) {
318  // vectors are not (yet?) supported. Don't support pointers either.
319  if (!LHS->getOperand(0)->getType()->isIntegerTy() ||
320  !RHS->getOperand(0)->getType()->isIntegerTy())
321  return None;
322 
323  // Here comes the tricky part:
324  // LHS might be of the form L11 & L12 == X, X == L21 & L22,
325  // and L11 & L12 == L21 & L22. The same goes for RHS.
326  // Now we must find those components L** and R**, that are equal, so
327  // that we can extract the parameters A, B, C, D, and E for the canonical
328  // above.
329  Value *L1 = LHS->getOperand(0);
330  Value *L2 = LHS->getOperand(1);
331  Value *L11, *L12, *L21, *L22;
332  // Check whether the icmp can be decomposed into a bit test.
333  if (decomposeBitTestICmp(L1, L2, PredL, L11, L12, L2)) {
334  L21 = L22 = L1 = nullptr;
335  } else {
336  // Look for ANDs in the LHS icmp.
337  if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) {
338  // Any icmp can be viewed as being trivially masked; if it allows us to
339  // remove one, it's worth it.
340  L11 = L1;
341  L12 = Constant::getAllOnesValue(L1->getType());
342  }
343 
344  if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) {
345  L21 = L2;
346  L22 = Constant::getAllOnesValue(L2->getType());
347  }
348  }
349 
350  // Bail if LHS was a icmp that can't be decomposed into an equality.
351  if (!ICmpInst::isEquality(PredL))
352  return None;
353 
354  Value *R1 = RHS->getOperand(0);
355  Value *R2 = RHS->getOperand(1);
356  Value *R11, *R12;
357  bool Ok = false;
358  if (decomposeBitTestICmp(R1, R2, PredR, R11, R12, R2)) {
359  if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
360  A = R11;
361  D = R12;
362  } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
363  A = R12;
364  D = R11;
365  } else {
366  return None;
367  }
368  E = R2;
369  R1 = nullptr;
370  Ok = true;
371  } else {
372  if (!match(R1, m_And(m_Value(R11), m_Value(R12)))) {
373  // As before, model no mask as a trivial mask if it'll let us do an
374  // optimization.
375  R11 = R1;
376  R12 = Constant::getAllOnesValue(R1->getType());
377  }
378 
379  if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
380  A = R11;
381  D = R12;
382  E = R2;
383  Ok = true;
384  } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
385  A = R12;
386  D = R11;
387  E = R2;
388  Ok = true;
389  }
390  }
391 
392  // Bail if RHS was a icmp that can't be decomposed into an equality.
393  if (!ICmpInst::isEquality(PredR))
394  return None;
395 
396  // Look for ANDs on the right side of the RHS icmp.
397  if (!Ok) {
398  if (!match(R2, m_And(m_Value(R11), m_Value(R12)))) {
399  R11 = R2;
400  R12 = Constant::getAllOnesValue(R2->getType());
401  }
402 
403  if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
404  A = R11;
405  D = R12;
406  E = R1;
407  Ok = true;
408  } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
409  A = R12;
410  D = R11;
411  E = R1;
412  Ok = true;
413  } else {
414  return None;
415  }
416  }
417  if (!Ok)
418  return None;
419 
420  if (L11 == A) {
421  B = L12;
422  C = L2;
423  } else if (L12 == A) {
424  B = L11;
425  C = L2;
426  } else if (L21 == A) {
427  B = L22;
428  C = L1;
429  } else if (L22 == A) {
430  B = L21;
431  C = L1;
432  }
433 
434  unsigned LeftType = getMaskedICmpType(A, B, C, PredL);
435  unsigned RightType = getMaskedICmpType(A, D, E, PredR);
436  return Optional<std::pair<unsigned, unsigned>>(std::make_pair(LeftType, RightType));
437 }
438 
439 /// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single
440 /// (icmp(A & X) ==/!= Y), where the left-hand side is of type Mask_NotAllZeros
441 /// and the right hand side is of type BMask_Mixed. For example,
442 /// (icmp (A & 12) != 0) & (icmp (A & 15) == 8) -> (icmp (A & 15) == 8).
444  ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
445  Value *A, Value *B, Value *C, Value *D, Value *E,
448  // We are given the canonical form:
449  // (icmp ne (A & B), 0) & (icmp eq (A & D), E).
450  // where D & E == E.
451  //
452  // If IsAnd is false, we get it in negated form:
453  // (icmp eq (A & B), 0) | (icmp ne (A & D), E) ->
454  // !((icmp ne (A & B), 0) & (icmp eq (A & D), E)).
455  //
456  // We currently handle the case of B, C, D, E are constant.
457  //
458  ConstantInt *BCst = dyn_cast<ConstantInt>(B);
459  if (!BCst)
460  return nullptr;
461  ConstantInt *CCst = dyn_cast<ConstantInt>(C);
462  if (!CCst)
463  return nullptr;
464  ConstantInt *DCst = dyn_cast<ConstantInt>(D);
465  if (!DCst)
466  return nullptr;
467  ConstantInt *ECst = dyn_cast<ConstantInt>(E);
468  if (!ECst)
469  return nullptr;
470 
472 
473  // Update E to the canonical form when D is a power of two and RHS is
474  // canonicalized as,
475  // (icmp ne (A & D), 0) -> (icmp eq (A & D), D) or
476  // (icmp ne (A & D), D) -> (icmp eq (A & D), 0).
477  if (PredR != NewCC)
478  ECst = cast<ConstantInt>(ConstantExpr::getXor(DCst, ECst));
479 
480  // If B or D is zero, skip because if LHS or RHS can be trivially folded by
481  // other folding rules and this pattern won't apply any more.
482  if (BCst->getValue() == 0 || DCst->getValue() == 0)
483  return nullptr;
484 
485  // If B and D don't intersect, ie. (B & D) == 0, no folding because we can't
486  // deduce anything from it.
487  // For example,
488  // (icmp ne (A & 12), 0) & (icmp eq (A & 3), 1) -> no folding.
489  if ((BCst->getValue() & DCst->getValue()) == 0)
490  return nullptr;
491 
492  // If the following two conditions are met:
493  //
494  // 1. mask B covers only a single bit that's not covered by mask D, that is,
495  // (B & (B ^ D)) is a power of 2 (in other words, B minus the intersection of
496  // B and D has only one bit set) and,
497  //
498  // 2. RHS (and E) indicates that the rest of B's bits are zero (in other
499  // words, the intersection of B and D is zero), that is, ((B & D) & E) == 0
500  //
501  // then that single bit in B must be one and thus the whole expression can be
502  // folded to
503  // (A & (B | D)) == (B & (B ^ D)) | E.
504  //
505  // For example,
506  // (icmp ne (A & 12), 0) & (icmp eq (A & 7), 1) -> (icmp eq (A & 15), 9)
507  // (icmp ne (A & 15), 0) & (icmp eq (A & 7), 0) -> (icmp eq (A & 15), 8)
508  if ((((BCst->getValue() & DCst->getValue()) & ECst->getValue()) == 0) &&
509  (BCst->getValue() & (BCst->getValue() ^ DCst->getValue())).isPowerOf2()) {
510  APInt BorD = BCst->getValue() | DCst->getValue();
511  APInt BandBxorDorE = (BCst->getValue() & (BCst->getValue() ^ DCst->getValue())) |
512  ECst->getValue();
513  Value *NewMask = ConstantInt::get(BCst->getType(), BorD);
514  Value *NewMaskedValue = ConstantInt::get(BCst->getType(), BandBxorDorE);
515  Value *NewAnd = Builder.CreateAnd(A, NewMask);
516  return Builder.CreateICmp(NewCC, NewAnd, NewMaskedValue);
517  }
518 
519  auto IsSubSetOrEqual = [](ConstantInt *C1, ConstantInt *C2) {
520  return (C1->getValue() & C2->getValue()) == C1->getValue();
521  };
522  auto IsSuperSetOrEqual = [](ConstantInt *C1, ConstantInt *C2) {
523  return (C1->getValue() & C2->getValue()) == C2->getValue();
524  };
525 
526  // In the following, we consider only the cases where B is a superset of D, B
527  // is a subset of D, or B == D because otherwise there's at least one bit
528  // covered by B but not D, in which case we can't deduce much from it, so
529  // no folding (aside from the single must-be-one bit case right above.)
530  // For example,
531  // (icmp ne (A & 14), 0) & (icmp eq (A & 3), 1) -> no folding.
532  if (!IsSubSetOrEqual(BCst, DCst) && !IsSuperSetOrEqual(BCst, DCst))
533  return nullptr;
534 
535  // At this point, either B is a superset of D, B is a subset of D or B == D.
536 
537  // If E is zero, if B is a subset of (or equal to) D, LHS and RHS contradict
538  // and the whole expression becomes false (or true if negated), otherwise, no
539  // folding.
540  // For example,
541  // (icmp ne (A & 3), 0) & (icmp eq (A & 7), 0) -> false.
542  // (icmp ne (A & 15), 0) & (icmp eq (A & 3), 0) -> no folding.
543  if (ECst->isZero()) {
544  if (IsSubSetOrEqual(BCst, DCst))
545  return ConstantInt::get(LHS->getType(), !IsAnd);
546  return nullptr;
547  }
548 
549  // At this point, B, D, E aren't zero and (B & D) == B, (B & D) == D or B ==
550  // D. If B is a superset of (or equal to) D, since E is not zero, LHS is
551  // subsumed by RHS (RHS implies LHS.) So the whole expression becomes
552  // RHS. For example,
553  // (icmp ne (A & 255), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
554  // (icmp ne (A & 15), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
555  if (IsSuperSetOrEqual(BCst, DCst))
556  return RHS;
557  // Otherwise, B is a subset of D. If B and E have a common bit set,
558  // ie. (B & E) != 0, then LHS is subsumed by RHS. For example.
559  // (icmp ne (A & 12), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
560  assert(IsSubSetOrEqual(BCst, DCst) && "Precondition due to above code");
561  if ((BCst->getValue() & ECst->getValue()) != 0)
562  return RHS;
563  // Otherwise, LHS and RHS contradict and the whole expression becomes false
564  // (or true if negated.) For example,
565  // (icmp ne (A & 7), 0) & (icmp eq (A & 15), 8) -> false.
566  // (icmp ne (A & 6), 0) & (icmp eq (A & 15), 8) -> false.
567  return ConstantInt::get(LHS->getType(), !IsAnd);
568 }
569 
570 /// Try to fold (icmp(A & B) ==/!= 0) &/| (icmp(A & D) ==/!= E) into a single
571 /// (icmp(A & X) ==/!= Y), where the left-hand side and the right hand side
572 /// aren't of the common mask pattern type.
574  ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
575  Value *A, Value *B, Value *C, Value *D, Value *E,
577  unsigned LHSMask, unsigned RHSMask,
580  "Expected equality predicates for masked type of icmps.");
581  // Handle Mask_NotAllZeros-BMask_Mixed cases.
582  // (icmp ne/eq (A & B), C) &/| (icmp eq/ne (A & D), E), or
583  // (icmp eq/ne (A & B), C) &/| (icmp ne/eq (A & D), E)
584  // which gets swapped to
585  // (icmp ne/eq (A & D), E) &/| (icmp eq/ne (A & B), C).
586  if (!IsAnd) {
587  LHSMask = conjugateICmpMask(LHSMask);
588  RHSMask = conjugateICmpMask(RHSMask);
589  }
590  if ((LHSMask & Mask_NotAllZeros) && (RHSMask & BMask_Mixed)) {
592  LHS, RHS, IsAnd, A, B, C, D, E,
593  PredL, PredR, Builder)) {
594  return V;
595  }
596  } else if ((LHSMask & BMask_Mixed) && (RHSMask & Mask_NotAllZeros)) {
598  RHS, LHS, IsAnd, A, D, E, B, C,
599  PredR, PredL, Builder)) {
600  return V;
601  }
602  }
603  return nullptr;
604 }
605 
606 /// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
607 /// into a single (icmp(A & X) ==/!= Y).
608 static Value *foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
610  Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
611  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
613  getMaskedTypeForICmpPair(A, B, C, D, E, LHS, RHS, PredL, PredR);
614  if (!MaskPair)
615  return nullptr;
617  "Expected equality predicates for masked type of icmps.");
618  unsigned LHSMask = MaskPair->first;
619  unsigned RHSMask = MaskPair->second;
620  unsigned Mask = LHSMask & RHSMask;
621  if (Mask == 0) {
622  // Even if the two sides don't share a common pattern, check if folding can
623  // still happen.
625  LHS, RHS, IsAnd, A, B, C, D, E, PredL, PredR, LHSMask, RHSMask,
626  Builder))
627  return V;
628  return nullptr;
629  }
630 
631  // In full generality:
632  // (icmp (A & B) Op C) | (icmp (A & D) Op E)
633  // == ![ (icmp (A & B) !Op C) & (icmp (A & D) !Op E) ]
634  //
635  // If the latter can be converted into (icmp (A & X) Op Y) then the former is
636  // equivalent to (icmp (A & X) !Op Y).
637  //
638  // Therefore, we can pretend for the rest of this function that we're dealing
639  // with the conjunction, provided we flip the sense of any comparisons (both
640  // input and output).
641 
642  // In most cases we're going to produce an EQ for the "&&" case.
644  if (!IsAnd) {
645  // Convert the masking analysis into its equivalent with negated
646  // comparisons.
647  Mask = conjugateICmpMask(Mask);
648  }
649 
650  if (Mask & Mask_AllZeros) {
651  // (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
652  // -> (icmp eq (A & (B|D)), 0)
653  Value *NewOr = Builder.CreateOr(B, D);
654  Value *NewAnd = Builder.CreateAnd(A, NewOr);
655  // We can't use C as zero because we might actually handle
656  // (icmp ne (A & B), B) & (icmp ne (A & D), D)
657  // with B and D, having a single bit set.
658  Value *Zero = Constant::getNullValue(A->getType());
659  return Builder.CreateICmp(NewCC, NewAnd, Zero);
660  }
661  if (Mask & BMask_AllOnes) {
662  // (icmp eq (A & B), B) & (icmp eq (A & D), D)
663  // -> (icmp eq (A & (B|D)), (B|D))
664  Value *NewOr = Builder.CreateOr(B, D);
665  Value *NewAnd = Builder.CreateAnd(A, NewOr);
666  return Builder.CreateICmp(NewCC, NewAnd, NewOr);
667  }
668  if (Mask & AMask_AllOnes) {
669  // (icmp eq (A & B), A) & (icmp eq (A & D), A)
670  // -> (icmp eq (A & (B&D)), A)
671  Value *NewAnd1 = Builder.CreateAnd(B, D);
672  Value *NewAnd2 = Builder.CreateAnd(A, NewAnd1);
673  return Builder.CreateICmp(NewCC, NewAnd2, A);
674  }
675 
676  // Remaining cases assume at least that B and D are constant, and depend on
677  // their actual values. This isn't strictly necessary, just a "handle the
678  // easy cases for now" decision.
679  ConstantInt *BCst = dyn_cast<ConstantInt>(B);
680  if (!BCst)
681  return nullptr;
682  ConstantInt *DCst = dyn_cast<ConstantInt>(D);
683  if (!DCst)
684  return nullptr;
685 
686  if (Mask & (Mask_NotAllZeros | BMask_NotAllOnes)) {
687  // (icmp ne (A & B), 0) & (icmp ne (A & D), 0) and
688  // (icmp ne (A & B), B) & (icmp ne (A & D), D)
689  // -> (icmp ne (A & B), 0) or (icmp ne (A & D), 0)
690  // Only valid if one of the masks is a superset of the other (check "B&D" is
691  // the same as either B or D).
692  APInt NewMask = BCst->getValue() & DCst->getValue();
693 
694  if (NewMask == BCst->getValue())
695  return LHS;
696  else if (NewMask == DCst->getValue())
697  return RHS;
698  }
699 
700  if (Mask & AMask_NotAllOnes) {
701  // (icmp ne (A & B), B) & (icmp ne (A & D), D)
702  // -> (icmp ne (A & B), A) or (icmp ne (A & D), A)
703  // Only valid if one of the masks is a superset of the other (check "B|D" is
704  // the same as either B or D).
705  APInt NewMask = BCst->getValue() | DCst->getValue();
706 
707  if (NewMask == BCst->getValue())
708  return LHS;
709  else if (NewMask == DCst->getValue())
710  return RHS;
711  }
712 
713  if (Mask & BMask_Mixed) {
714  // (icmp eq (A & B), C) & (icmp eq (A & D), E)
715  // We already know that B & C == C && D & E == E.
716  // If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of
717  // C and E, which are shared by both the mask B and the mask D, don't
718  // contradict, then we can transform to
719  // -> (icmp eq (A & (B|D)), (C|E))
720  // Currently, we only handle the case of B, C, D, and E being constant.
721  // We can't simply use C and E because we might actually handle
722  // (icmp ne (A & B), B) & (icmp eq (A & D), D)
723  // with B and D, having a single bit set.
724  ConstantInt *CCst = dyn_cast<ConstantInt>(C);
725  if (!CCst)
726  return nullptr;
727  ConstantInt *ECst = dyn_cast<ConstantInt>(E);
728  if (!ECst)
729  return nullptr;
730  if (PredL != NewCC)
731  CCst = cast<ConstantInt>(ConstantExpr::getXor(BCst, CCst));
732  if (PredR != NewCC)
733  ECst = cast<ConstantInt>(ConstantExpr::getXor(DCst, ECst));
734 
735  // If there is a conflict, we should actually return a false for the
736  // whole construct.
737  if (((BCst->getValue() & DCst->getValue()) &
738  (CCst->getValue() ^ ECst->getValue())).getBoolValue())
739  return ConstantInt::get(LHS->getType(), !IsAnd);
740 
741  Value *NewOr1 = Builder.CreateOr(B, D);
742  Value *NewOr2 = ConstantExpr::getOr(CCst, ECst);
743  Value *NewAnd = Builder.CreateAnd(A, NewOr1);
744  return Builder.CreateICmp(NewCC, NewAnd, NewOr2);
745  }
746 
747  return nullptr;
748 }
749 
750 /// Try to fold a signed range checked with lower bound 0 to an unsigned icmp.
751 /// Example: (icmp sge x, 0) & (icmp slt x, n) --> icmp ult x, n
752 /// If \p Inverted is true then the check is for the inverted range, e.g.
753 /// (icmp slt x, 0) | (icmp sgt x, n) --> icmp ugt x, n
755  bool Inverted) {
756  // Check the lower range comparison, e.g. x >= 0
757  // InstCombine already ensured that if there is a constant it's on the RHS.
758  ConstantInt *RangeStart = dyn_cast<ConstantInt>(Cmp0->getOperand(1));
759  if (!RangeStart)
760  return nullptr;
761 
762  ICmpInst::Predicate Pred0 = (Inverted ? Cmp0->getInversePredicate() :
763  Cmp0->getPredicate());
764 
765  // Accept x > -1 or x >= 0 (after potentially inverting the predicate).
766  if (!((Pred0 == ICmpInst::ICMP_SGT && RangeStart->isMinusOne()) ||
767  (Pred0 == ICmpInst::ICMP_SGE && RangeStart->isZero())))
768  return nullptr;
769 
770  ICmpInst::Predicate Pred1 = (Inverted ? Cmp1->getInversePredicate() :
771  Cmp1->getPredicate());
772 
773  Value *Input = Cmp0->getOperand(0);
774  Value *RangeEnd;
775  if (Cmp1->getOperand(0) == Input) {
776  // For the upper range compare we have: icmp x, n
777  RangeEnd = Cmp1->getOperand(1);
778  } else if (Cmp1->getOperand(1) == Input) {
779  // For the upper range compare we have: icmp n, x
780  RangeEnd = Cmp1->getOperand(0);
781  Pred1 = ICmpInst::getSwappedPredicate(Pred1);
782  } else {
783  return nullptr;
784  }
785 
786  // Check the upper range comparison, e.g. x < n
787  ICmpInst::Predicate NewPred;
788  switch (Pred1) {
789  case ICmpInst::ICMP_SLT: NewPred = ICmpInst::ICMP_ULT; break;
790  case ICmpInst::ICMP_SLE: NewPred = ICmpInst::ICMP_ULE; break;
791  default: return nullptr;
792  }
793 
794  // This simplification is only valid if the upper range is not negative.
795  KnownBits Known = computeKnownBits(RangeEnd, /*Depth=*/0, Cmp1);
796  if (!Known.isNonNegative())
797  return nullptr;
798 
799  if (Inverted)
800  NewPred = ICmpInst::getInversePredicate(NewPred);
801 
802  return Builder.CreateICmp(NewPred, Input, RangeEnd);
803 }
804 
805 static Value *
807  bool JoinedByAnd,
808  InstCombiner::BuilderTy &Builder) {
809  Value *X = LHS->getOperand(0);
810  if (X != RHS->getOperand(0))
811  return nullptr;
812 
813  const APInt *C1, *C2;
814  if (!match(LHS->getOperand(1), m_APInt(C1)) ||
815  !match(RHS->getOperand(1), m_APInt(C2)))
816  return nullptr;
817 
818  // We only handle (X != C1 && X != C2) and (X == C1 || X == C2).
819  ICmpInst::Predicate Pred = LHS->getPredicate();
820  if (Pred != RHS->getPredicate())
821  return nullptr;
822  if (JoinedByAnd && Pred != ICmpInst::ICMP_NE)
823  return nullptr;
824  if (!JoinedByAnd && Pred != ICmpInst::ICMP_EQ)
825  return nullptr;
826 
827  // The larger unsigned constant goes on the right.
828  if (C1->ugt(*C2))
829  std::swap(C1, C2);
830 
831  APInt Xor = *C1 ^ *C2;
832  if (Xor.isPowerOf2()) {
833  // If LHSC and RHSC differ by only one bit, then set that bit in X and
834  // compare against the larger constant:
835  // (X == C1 || X == C2) --> (X | (C1 ^ C2)) == C2
836  // (X != C1 && X != C2) --> (X | (C1 ^ C2)) != C2
837  // We choose an 'or' with a Pow2 constant rather than the inverse mask with
838  // 'and' because that may lead to smaller codegen from a smaller constant.
839  Value *Or = Builder.CreateOr(X, ConstantInt::get(X->getType(), Xor));
840  return Builder.CreateICmp(Pred, Or, ConstantInt::get(X->getType(), *C2));
841  }
842 
843  // Special case: get the ordering right when the values wrap around zero.
844  // Ie, we assumed the constants were unsigned when swapping earlier.
845  if (C1->isNullValue() && C2->isAllOnesValue())
846  std::swap(C1, C2);
847 
848  if (*C1 == *C2 - 1) {
849  // (X == 13 || X == 14) --> X - 13 <=u 1
850  // (X != 13 && X != 14) --> X - 13 >u 1
851  // An 'add' is the canonical IR form, so favor that over a 'sub'.
852  Value *Add = Builder.CreateAdd(X, ConstantInt::get(X->getType(), -(*C1)));
853  auto NewPred = JoinedByAnd ? ICmpInst::ICMP_UGT : ICmpInst::ICMP_ULE;
854  return Builder.CreateICmp(NewPred, Add, ConstantInt::get(X->getType(), 1));
855  }
856 
857  return nullptr;
858 }
859 
860 // Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2)
861 // Fold (!iszero(A & K1) & !iszero(A & K2)) -> (A & (K1 | K2)) == (K1 | K2)
862 Value *InstCombiner::foldAndOrOfICmpsOfAndWithPow2(ICmpInst *LHS, ICmpInst *RHS,
863  bool JoinedByAnd,
864  Instruction &CxtI) {
865  ICmpInst::Predicate Pred = LHS->getPredicate();
866  if (Pred != RHS->getPredicate())
867  return nullptr;
868  if (JoinedByAnd && Pred != ICmpInst::ICMP_NE)
869  return nullptr;
870  if (!JoinedByAnd && Pred != ICmpInst::ICMP_EQ)
871  return nullptr;
872 
873  // TODO support vector splats
874  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
875  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
876  if (!LHSC || !RHSC || !LHSC->isZero() || !RHSC->isZero())
877  return nullptr;
878 
879  Value *A, *B, *C, *D;
880  if (match(LHS->getOperand(0), m_And(m_Value(A), m_Value(B))) &&
881  match(RHS->getOperand(0), m_And(m_Value(C), m_Value(D)))) {
882  if (A == D || B == D)
883  std::swap(C, D);
884  if (B == C)
885  std::swap(A, B);
886 
887  if (A == C &&
888  isKnownToBeAPowerOfTwo(B, false, 0, &CxtI) &&
889  isKnownToBeAPowerOfTwo(D, false, 0, &CxtI)) {
890  Value *Mask = Builder.CreateOr(B, D);
891  Value *Masked = Builder.CreateAnd(A, Mask);
892  auto NewPred = JoinedByAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
893  return Builder.CreateICmp(NewPred, Masked, Mask);
894  }
895  }
896 
897  return nullptr;
898 }
899 
900 /// General pattern:
901 /// X & Y
902 ///
903 /// Where Y is checking that all the high bits (covered by a mask 4294967168)
904 /// are uniform, i.e. %arg & 4294967168 can be either 4294967168 or 0
905 /// Pattern can be one of:
906 /// %t = add i32 %arg, 128
907 /// %r = icmp ult i32 %t, 256
908 /// Or
909 /// %t0 = shl i32 %arg, 24
910 /// %t1 = ashr i32 %t0, 24
911 /// %r = icmp eq i32 %t1, %arg
912 /// Or
913 /// %t0 = trunc i32 %arg to i8
914 /// %t1 = sext i8 %t0 to i32
915 /// %r = icmp eq i32 %t1, %arg
916 /// This pattern is a signed truncation check.
917 ///
918 /// And X is checking that some bit in that same mask is zero.
919 /// I.e. can be one of:
920 /// %r = icmp sgt i32 %arg, -1
921 /// Or
922 /// %t = and i32 %arg, 2147483648
923 /// %r = icmp eq i32 %t, 0
924 ///
925 /// Since we are checking that all the bits in that mask are the same,
926 /// and a particular bit is zero, what we are really checking is that all the
927 /// masked bits are zero.
928 /// So this should be transformed to:
929 /// %r = icmp ult i32 %arg, 128
931  Instruction &CxtI,
932  InstCombiner::BuilderTy &Builder) {
933  assert(CxtI.getOpcode() == Instruction::And);
934 
935  // Match icmp ult (add %arg, C01), C1 (C1 == C01 << 1; powers of two)
936  auto tryToMatchSignedTruncationCheck = [](ICmpInst *ICmp, Value *&X,
937  APInt &SignBitMask) -> bool {
938  CmpInst::Predicate Pred;
939  const APInt *I01, *I1; // powers of two; I1 == I01 << 1
940  if (!(match(ICmp,
941  m_ICmp(Pred, m_Add(m_Value(X), m_Power2(I01)), m_Power2(I1))) &&
942  Pred == ICmpInst::ICMP_ULT && I1->ugt(*I01) && I01->shl(1) == *I1))
943  return false;
944  // Which bit is the new sign bit as per the 'signed truncation' pattern?
945  SignBitMask = *I01;
946  return true;
947  };
948 
949  // One icmp needs to be 'signed truncation check'.
950  // We need to match this first, else we will mismatch commutative cases.
951  Value *X1;
952  APInt HighestBit;
953  ICmpInst *OtherICmp;
954  if (tryToMatchSignedTruncationCheck(ICmp1, X1, HighestBit))
955  OtherICmp = ICmp0;
956  else if (tryToMatchSignedTruncationCheck(ICmp0, X1, HighestBit))
957  OtherICmp = ICmp1;
958  else
959  return nullptr;
960 
961  assert(HighestBit.isPowerOf2() && "expected to be power of two (non-zero)");
962 
963  // Try to match/decompose into: icmp eq (X & Mask), 0
964  auto tryToDecompose = [](ICmpInst *ICmp, Value *&X,
965  APInt &UnsetBitsMask) -> bool {
966  CmpInst::Predicate Pred = ICmp->getPredicate();
967  // Can it be decomposed into icmp eq (X & Mask), 0 ?
968  if (llvm::decomposeBitTestICmp(ICmp->getOperand(0), ICmp->getOperand(1),
969  Pred, X, UnsetBitsMask,
970  /*LookThroughTrunc=*/false) &&
971  Pred == ICmpInst::ICMP_EQ)
972  return true;
973  // Is it icmp eq (X & Mask), 0 already?
974  const APInt *Mask;
975  if (match(ICmp, m_ICmp(Pred, m_And(m_Value(X), m_APInt(Mask)), m_Zero())) &&
976  Pred == ICmpInst::ICMP_EQ) {
977  UnsetBitsMask = *Mask;
978  return true;
979  }
980  return false;
981  };
982 
983  // And the other icmp needs to be decomposable into a bit test.
984  Value *X0;
985  APInt UnsetBitsMask;
986  if (!tryToDecompose(OtherICmp, X0, UnsetBitsMask))
987  return nullptr;
988 
989  assert(!UnsetBitsMask.isNullValue() && "empty mask makes no sense.");
990 
991  // Are they working on the same value?
992  Value *X;
993  if (X1 == X0) {
994  // Ok as is.
995  X = X1;
996  } else if (match(X0, m_Trunc(m_Specific(X1)))) {
997  UnsetBitsMask = UnsetBitsMask.zext(X1->getType()->getScalarSizeInBits());
998  X = X1;
999  } else
1000  return nullptr;
1001 
1002  // So which bits should be uniform as per the 'signed truncation check'?
1003  // (all the bits starting with (i.e. including) HighestBit)
1004  APInt SignBitsMask = ~(HighestBit - 1U);
1005 
1006  // UnsetBitsMask must have some common bits with SignBitsMask,
1007  if (!UnsetBitsMask.intersects(SignBitsMask))
1008  return nullptr;
1009 
1010  // Does UnsetBitsMask contain any bits outside of SignBitsMask?
1011  if (!UnsetBitsMask.isSubsetOf(SignBitsMask)) {
1012  APInt OtherHighestBit = (~UnsetBitsMask) + 1U;
1013  if (!OtherHighestBit.isPowerOf2())
1014  return nullptr;
1015  HighestBit = APIntOps::umin(HighestBit, OtherHighestBit);
1016  }
1017  // Else, if it does not, then all is ok as-is.
1018 
1019  // %r = icmp ult %X, SignBit
1020  return Builder.CreateICmpULT(X, ConstantInt::get(X->getType(), HighestBit),
1021  CxtI.getName() + ".simplified");
1022 }
1023 
1024 /// Reduce a pair of compares that check if a value has exactly 1 bit set.
1025 static Value *foldIsPowerOf2(ICmpInst *Cmp0, ICmpInst *Cmp1, bool JoinedByAnd,
1026  InstCombiner::BuilderTy &Builder) {
1027  // Handle 'and' / 'or' commutation: make the equality check the first operand.
1028  if (JoinedByAnd && Cmp1->getPredicate() == ICmpInst::ICMP_NE)
1029  std::swap(Cmp0, Cmp1);
1030  else if (!JoinedByAnd && Cmp1->getPredicate() == ICmpInst::ICMP_EQ)
1031  std::swap(Cmp0, Cmp1);
1032 
1033  // (X != 0) && (ctpop(X) u< 2) --> ctpop(X) == 1
1034  CmpInst::Predicate Pred0, Pred1;
1035  Value *X;
1036  if (JoinedByAnd && match(Cmp0, m_ICmp(Pred0, m_Value(X), m_ZeroInt())) &&
1037  match(Cmp1, m_ICmp(Pred1, m_Intrinsic<Intrinsic::ctpop>(m_Specific(X)),
1038  m_SpecificInt(2))) &&
1039  Pred0 == ICmpInst::ICMP_NE && Pred1 == ICmpInst::ICMP_ULT) {
1040  Value *CtPop = Cmp1->getOperand(0);
1041  return Builder.CreateICmpEQ(CtPop, ConstantInt::get(CtPop->getType(), 1));
1042  }
1043  // (X == 0) || (ctpop(X) u> 1) --> ctpop(X) != 1
1044  if (!JoinedByAnd && match(Cmp0, m_ICmp(Pred0, m_Value(X), m_ZeroInt())) &&
1045  match(Cmp1, m_ICmp(Pred1, m_Intrinsic<Intrinsic::ctpop>(m_Specific(X)),
1046  m_SpecificInt(1))) &&
1047  Pred0 == ICmpInst::ICMP_EQ && Pred1 == ICmpInst::ICMP_UGT) {
1048  Value *CtPop = Cmp1->getOperand(0);
1049  return Builder.CreateICmpNE(CtPop, ConstantInt::get(CtPop->getType(), 1));
1050  }
1051  return nullptr;
1052 }
1053 
1054 /// Fold (icmp)&(icmp) if possible.
1055 Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
1056  Instruction &CxtI) {
1057  // Fold (!iszero(A & K1) & !iszero(A & K2)) -> (A & (K1 | K2)) == (K1 | K2)
1058  // if K1 and K2 are a one-bit mask.
1059  if (Value *V = foldAndOrOfICmpsOfAndWithPow2(LHS, RHS, true, CxtI))
1060  return V;
1061 
1062  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
1063 
1064  // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
1065  if (predicatesFoldable(PredL, PredR)) {
1066  if (LHS->getOperand(0) == RHS->getOperand(1) &&
1067  LHS->getOperand(1) == RHS->getOperand(0))
1068  LHS->swapOperands();
1069  if (LHS->getOperand(0) == RHS->getOperand(0) &&
1070  LHS->getOperand(1) == RHS->getOperand(1)) {
1071  Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
1072  unsigned Code = getICmpCode(LHS) & getICmpCode(RHS);
1073  bool IsSigned = LHS->isSigned() || RHS->isSigned();
1074  return getNewICmpValue(Code, IsSigned, Op0, Op1, Builder);
1075  }
1076  }
1077 
1078  // handle (roughly): (icmp eq (A & B), C) & (icmp eq (A & D), E)
1079  if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, true, Builder))
1080  return V;
1081 
1082  // E.g. (icmp sge x, 0) & (icmp slt x, n) --> icmp ult x, n
1083  if (Value *V = simplifyRangeCheck(LHS, RHS, /*Inverted=*/false))
1084  return V;
1085 
1086  // E.g. (icmp slt x, n) & (icmp sge x, 0) --> icmp ult x, n
1087  if (Value *V = simplifyRangeCheck(RHS, LHS, /*Inverted=*/false))
1088  return V;
1089 
1090  if (Value *V = foldAndOrOfEqualityCmpsWithConstants(LHS, RHS, true, Builder))
1091  return V;
1092 
1093  if (Value *V = foldSignedTruncationCheck(LHS, RHS, CxtI, Builder))
1094  return V;
1095 
1096  if (Value *V = foldIsPowerOf2(LHS, RHS, true /* JoinedByAnd */, Builder))
1097  return V;
1098 
1099  // This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2).
1100  Value *LHS0 = LHS->getOperand(0), *RHS0 = RHS->getOperand(0);
1101  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
1102  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
1103  if (!LHSC || !RHSC)
1104  return nullptr;
1105 
1106  if (LHSC == RHSC && PredL == PredR) {
1107  // (icmp ult A, C) & (icmp ult B, C) --> (icmp ult (A|B), C)
1108  // where C is a power of 2 or
1109  // (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0)
1110  if ((PredL == ICmpInst::ICMP_ULT && LHSC->getValue().isPowerOf2()) ||
1111  (PredL == ICmpInst::ICMP_EQ && LHSC->isZero())) {
1112  Value *NewOr = Builder.CreateOr(LHS0, RHS0);
1113  return Builder.CreateICmp(PredL, NewOr, LHSC);
1114  }
1115  }
1116 
1117  // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2
1118  // where CMAX is the all ones value for the truncated type,
1119  // iff the lower bits of C2 and CA are zero.
1120  if (PredL == ICmpInst::ICMP_EQ && PredL == PredR && LHS->hasOneUse() &&
1121  RHS->hasOneUse()) {
1122  Value *V;
1123  ConstantInt *AndC, *SmallC = nullptr, *BigC = nullptr;
1124 
1125  // (trunc x) == C1 & (and x, CA) == C2
1126  // (and x, CA) == C2 & (trunc x) == C1
1127  if (match(RHS0, m_Trunc(m_Value(V))) &&
1128  match(LHS0, m_And(m_Specific(V), m_ConstantInt(AndC)))) {
1129  SmallC = RHSC;
1130  BigC = LHSC;
1131  } else if (match(LHS0, m_Trunc(m_Value(V))) &&
1132  match(RHS0, m_And(m_Specific(V), m_ConstantInt(AndC)))) {
1133  SmallC = LHSC;
1134  BigC = RHSC;
1135  }
1136 
1137  if (SmallC && BigC) {
1138  unsigned BigBitSize = BigC->getType()->getBitWidth();
1139  unsigned SmallBitSize = SmallC->getType()->getBitWidth();
1140 
1141  // Check that the low bits are zero.
1142  APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize);
1143  if ((Low & AndC->getValue()).isNullValue() &&
1144  (Low & BigC->getValue()).isNullValue()) {
1145  Value *NewAnd = Builder.CreateAnd(V, Low | AndC->getValue());
1146  APInt N = SmallC->getValue().zext(BigBitSize) | BigC->getValue();
1147  Value *NewVal = ConstantInt::get(AndC->getType()->getContext(), N);
1148  return Builder.CreateICmp(PredL, NewAnd, NewVal);
1149  }
1150  }
1151  }
1152 
1153  // From here on, we only handle:
1154  // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
1155  if (LHS0 != RHS0)
1156  return nullptr;
1157 
1158  // ICMP_[US][GL]E X, C is folded to ICMP_[US][GL]T elsewhere.
1159  if (PredL == ICmpInst::ICMP_UGE || PredL == ICmpInst::ICMP_ULE ||
1160  PredR == ICmpInst::ICMP_UGE || PredR == ICmpInst::ICMP_ULE ||
1161  PredL == ICmpInst::ICMP_SGE || PredL == ICmpInst::ICMP_SLE ||
1162  PredR == ICmpInst::ICMP_SGE || PredR == ICmpInst::ICMP_SLE)
1163  return nullptr;
1164 
1165  // We can't fold (ugt x, C) & (sgt x, C2).
1166  if (!predicatesFoldable(PredL, PredR))
1167  return nullptr;
1168 
1169  // Ensure that the larger constant is on the RHS.
1170  bool ShouldSwap;
1171  if (CmpInst::isSigned(PredL) ||
1172  (ICmpInst::isEquality(PredL) && CmpInst::isSigned(PredR)))
1173  ShouldSwap = LHSC->getValue().sgt(RHSC->getValue());
1174  else
1175  ShouldSwap = LHSC->getValue().ugt(RHSC->getValue());
1176 
1177  if (ShouldSwap) {
1178  std::swap(LHS, RHS);
1179  std::swap(LHSC, RHSC);
1180  std::swap(PredL, PredR);
1181  }
1182 
1183  // At this point, we know we have two icmp instructions
1184  // comparing a value against two constants and and'ing the result
1185  // together. Because of the above check, we know that we only have
1186  // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
1187  // (from the icmp folding check above), that the two constants
1188  // are not equal and that the larger constant is on the RHS
1189  assert(LHSC != RHSC && "Compares not folded above?");
1190 
1191  switch (PredL) {
1192  default:
1193  llvm_unreachable("Unknown integer condition code!");
1194  case ICmpInst::ICMP_NE:
1195  switch (PredR) {
1196  default:
1197  llvm_unreachable("Unknown integer condition code!");
1198  case ICmpInst::ICMP_ULT:
1199  if (LHSC == SubOne(RHSC)) // (X != 13 & X u< 14) -> X < 13
1200  return Builder.CreateICmpULT(LHS0, LHSC);
1201  if (LHSC->isZero()) // (X != 0 & X u< 14) -> X-1 u< 13
1202  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1203  false, true);
1204  break; // (X != 13 & X u< 15) -> no change
1205  case ICmpInst::ICMP_SLT:
1206  if (LHSC == SubOne(RHSC)) // (X != 13 & X s< 14) -> X < 13
1207  return Builder.CreateICmpSLT(LHS0, LHSC);
1208  break; // (X != 13 & X s< 15) -> no change
1209  case ICmpInst::ICMP_NE:
1210  // Potential folds for this case should already be handled.
1211  break;
1212  }
1213  break;
1214  case ICmpInst::ICMP_UGT:
1215  switch (PredR) {
1216  default:
1217  llvm_unreachable("Unknown integer condition code!");
1218  case ICmpInst::ICMP_NE:
1219  if (RHSC == AddOne(LHSC)) // (X u> 13 & X != 14) -> X u> 14
1220  return Builder.CreateICmp(PredL, LHS0, RHSC);
1221  break; // (X u> 13 & X != 15) -> no change
1222  case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) <u 1
1223  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1224  false, true);
1225  }
1226  break;
1227  case ICmpInst::ICMP_SGT:
1228  switch (PredR) {
1229  default:
1230  llvm_unreachable("Unknown integer condition code!");
1231  case ICmpInst::ICMP_NE:
1232  if (RHSC == AddOne(LHSC)) // (X s> 13 & X != 14) -> X s> 14
1233  return Builder.CreateICmp(PredL, LHS0, RHSC);
1234  break; // (X s> 13 & X != 15) -> no change
1235  case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) s< 1
1236  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(), true,
1237  true);
1238  }
1239  break;
1240  }
1241 
1242  return nullptr;
1243 }
1244 
1245 Value *InstCombiner::foldLogicOfFCmps(FCmpInst *LHS, FCmpInst *RHS, bool IsAnd) {
1246  Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
1247  Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
1248  FCmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
1249 
1250  if (LHS0 == RHS1 && RHS0 == LHS1) {
1251  // Swap RHS operands to match LHS.
1252  PredR = FCmpInst::getSwappedPredicate(PredR);
1253  std::swap(RHS0, RHS1);
1254  }
1255 
1256  // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y).
1257  // Suppose the relation between x and y is R, where R is one of
1258  // U(1000), L(0100), G(0010) or E(0001), and CC0 and CC1 are the bitmasks for
1259  // testing the desired relations.
1260  //
1261  // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this:
1262  // bool(R & CC0) && bool(R & CC1)
1263  // = bool((R & CC0) & (R & CC1))
1264  // = bool(R & (CC0 & CC1)) <= by re-association, commutation, and idempotency
1265  //
1266  // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this:
1267  // bool(R & CC0) || bool(R & CC1)
1268  // = bool((R & CC0) | (R & CC1))
1269  // = bool(R & (CC0 | CC1)) <= by reversed distribution (contribution? ;)
1270  if (LHS0 == RHS0 && LHS1 == RHS1) {
1271  unsigned FCmpCodeL = getFCmpCode(PredL);
1272  unsigned FCmpCodeR = getFCmpCode(PredR);
1273  unsigned NewPred = IsAnd ? FCmpCodeL & FCmpCodeR : FCmpCodeL | FCmpCodeR;
1274  return getFCmpValue(NewPred, LHS0, LHS1, Builder);
1275  }
1276 
1277  if ((PredL == FCmpInst::FCMP_ORD && PredR == FCmpInst::FCMP_ORD && IsAnd) ||
1278  (PredL == FCmpInst::FCMP_UNO && PredR == FCmpInst::FCMP_UNO && !IsAnd)) {
1279  if (LHS0->getType() != RHS0->getType())
1280  return nullptr;
1281 
1282  // FCmp canonicalization ensures that (fcmp ord/uno X, X) and
1283  // (fcmp ord/uno X, C) will be transformed to (fcmp X, +0.0).
1284  if (match(LHS1, m_PosZeroFP()) && match(RHS1, m_PosZeroFP()))
1285  // Ignore the constants because they are obviously not NANs:
1286  // (fcmp ord x, 0.0) & (fcmp ord y, 0.0) -> (fcmp ord x, y)
1287  // (fcmp uno x, 0.0) | (fcmp uno y, 0.0) -> (fcmp uno x, y)
1288  return Builder.CreateFCmp(PredL, LHS0, RHS0);
1289  }
1290 
1291  return nullptr;
1292 }
1293 
1294 /// This a limited reassociation for a special case (see above) where we are
1295 /// checking if two values are either both NAN (unordered) or not-NAN (ordered).
1296 /// This could be handled more generally in '-reassociation', but it seems like
1297 /// an unlikely pattern for a large number of logic ops and fcmps.
1299  InstCombiner::BuilderTy &Builder) {
1300  Instruction::BinaryOps Opcode = BO.getOpcode();
1301  assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
1302  "Expecting and/or op for fcmp transform");
1303 
1304  // There are 4 commuted variants of the pattern. Canonicalize operands of this
1305  // logic op so an fcmp is operand 0 and a matching logic op is operand 1.
1306  Value *Op0 = BO.getOperand(0), *Op1 = BO.getOperand(1), *X;
1307  FCmpInst::Predicate Pred;
1308  if (match(Op1, m_FCmp(Pred, m_Value(), m_AnyZeroFP())))
1309  std::swap(Op0, Op1);
1310 
1311  // Match inner binop and the predicate for combining 2 NAN checks into 1.
1312  BinaryOperator *BO1;
1313  FCmpInst::Predicate NanPred = Opcode == Instruction::And ? FCmpInst::FCMP_ORD
1315  if (!match(Op0, m_FCmp(Pred, m_Value(X), m_AnyZeroFP())) || Pred != NanPred ||
1316  !match(Op1, m_BinOp(BO1)) || BO1->getOpcode() != Opcode)
1317  return nullptr;
1318 
1319  // The inner logic op must have a matching fcmp operand.
1320  Value *BO10 = BO1->getOperand(0), *BO11 = BO1->getOperand(1), *Y;
1321  if (!match(BO10, m_FCmp(Pred, m_Value(Y), m_AnyZeroFP())) ||
1322  Pred != NanPred || X->getType() != Y->getType())
1323  std::swap(BO10, BO11);
1324 
1325  if (!match(BO10, m_FCmp(Pred, m_Value(Y), m_AnyZeroFP())) ||
1326  Pred != NanPred || X->getType() != Y->getType())
1327  return nullptr;
1328 
1329  // and (fcmp ord X, 0), (and (fcmp ord Y, 0), Z) --> and (fcmp ord X, Y), Z
1330  // or (fcmp uno X, 0), (or (fcmp uno Y, 0), Z) --> or (fcmp uno X, Y), Z
1331  Value *NewFCmp = Builder.CreateFCmp(Pred, X, Y);
1332  if (auto *NewFCmpInst = dyn_cast<FCmpInst>(NewFCmp)) {
1333  // Intersect FMF from the 2 source fcmps.
1334  NewFCmpInst->copyIRFlags(Op0);
1335  NewFCmpInst->andIRFlags(BO10);
1336  }
1337  return BinaryOperator::Create(Opcode, NewFCmp, BO11);
1338 }
1339 
1340 /// Match De Morgan's Laws:
1341 /// (~A & ~B) == (~(A | B))
1342 /// (~A | ~B) == (~(A & B))
1344  InstCombiner::BuilderTy &Builder) {
1345  auto Opcode = I.getOpcode();
1346  assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
1347  "Trying to match De Morgan's Laws with something other than and/or");
1348 
1349  // Flip the logic operation.
1350  Opcode = (Opcode == Instruction::And) ? Instruction::Or : Instruction::And;
1351 
1352  Value *A, *B;
1353  if (match(I.getOperand(0), m_OneUse(m_Not(m_Value(A)))) &&
1354  match(I.getOperand(1), m_OneUse(m_Not(m_Value(B)))) &&
1355  !IsFreeToInvert(A, A->hasOneUse()) &&
1356  !IsFreeToInvert(B, B->hasOneUse())) {
1357  Value *AndOr = Builder.CreateBinOp(Opcode, A, B, I.getName() + ".demorgan");
1358  return BinaryOperator::CreateNot(AndOr);
1359  }
1360 
1361  return nullptr;
1362 }
1363 
1364 bool InstCombiner::shouldOptimizeCast(CastInst *CI) {
1365  Value *CastSrc = CI->getOperand(0);
1366 
1367  // Noop casts and casts of constants should be eliminated trivially.
1368  if (CI->getSrcTy() == CI->getDestTy() || isa<Constant>(CastSrc))
1369  return false;
1370 
1371  // If this cast is paired with another cast that can be eliminated, we prefer
1372  // to have it eliminated.
1373  if (const auto *PrecedingCI = dyn_cast<CastInst>(CastSrc))
1374  if (isEliminableCastPair(PrecedingCI, CI))
1375  return false;
1376 
1377  return true;
1378 }
1379 
1380 /// Fold {and,or,xor} (cast X), C.
1382  InstCombiner::BuilderTy &Builder) {
1383  Constant *C = dyn_cast<Constant>(Logic.getOperand(1));
1384  if (!C)
1385  return nullptr;
1386 
1387  auto LogicOpc = Logic.getOpcode();
1388  Type *DestTy = Logic.getType();
1389  Type *SrcTy = Cast->getSrcTy();
1390 
1391  // Move the logic operation ahead of a zext or sext if the constant is
1392  // unchanged in the smaller source type. Performing the logic in a smaller
1393  // type may provide more information to later folds, and the smaller logic
1394  // instruction may be cheaper (particularly in the case of vectors).
1395  Value *X;
1396  if (match(Cast, m_OneUse(m_ZExt(m_Value(X))))) {
1397  Constant *TruncC = ConstantExpr::getTrunc(C, SrcTy);
1398  Constant *ZextTruncC = ConstantExpr::getZExt(TruncC, DestTy);
1399  if (ZextTruncC == C) {
1400  // LogicOpc (zext X), C --> zext (LogicOpc X, C)
1401  Value *NewOp = Builder.CreateBinOp(LogicOpc, X, TruncC);
1402  return new ZExtInst(NewOp, DestTy);
1403  }
1404  }
1405 
1406  if (match(Cast, m_OneUse(m_SExt(m_Value(X))))) {
1407  Constant *TruncC = ConstantExpr::getTrunc(C, SrcTy);
1408  Constant *SextTruncC = ConstantExpr::getSExt(TruncC, DestTy);
1409  if (SextTruncC == C) {
1410  // LogicOpc (sext X), C --> sext (LogicOpc X, C)
1411  Value *NewOp = Builder.CreateBinOp(LogicOpc, X, TruncC);
1412  return new SExtInst(NewOp, DestTy);
1413  }
1414  }
1415 
1416  return nullptr;
1417 }
1418 
1419 /// Fold {and,or,xor} (cast X), Y.
1420 Instruction *InstCombiner::foldCastedBitwiseLogic(BinaryOperator &I) {
1421  auto LogicOpc = I.getOpcode();
1422  assert(I.isBitwiseLogicOp() && "Unexpected opcode for bitwise logic folding");
1423 
1424  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1425  CastInst *Cast0 = dyn_cast<CastInst>(Op0);
1426  if (!Cast0)
1427  return nullptr;
1428 
1429  // This must be a cast from an integer or integer vector source type to allow
1430  // transformation of the logic operation to the source type.
1431  Type *DestTy = I.getType();
1432  Type *SrcTy = Cast0->getSrcTy();
1433  if (!SrcTy->isIntOrIntVectorTy())
1434  return nullptr;
1435 
1436  if (Instruction *Ret = foldLogicCastConstant(I, Cast0, Builder))
1437  return Ret;
1438 
1439  CastInst *Cast1 = dyn_cast<CastInst>(Op1);
1440  if (!Cast1)
1441  return nullptr;
1442 
1443  // Both operands of the logic operation are casts. The casts must be of the
1444  // same type for reduction.
1445  auto CastOpcode = Cast0->getOpcode();
1446  if (CastOpcode != Cast1->getOpcode() || SrcTy != Cast1->getSrcTy())
1447  return nullptr;
1448 
1449  Value *Cast0Src = Cast0->getOperand(0);
1450  Value *Cast1Src = Cast1->getOperand(0);
1451 
1452  // fold logic(cast(A), cast(B)) -> cast(logic(A, B))
1453  if (shouldOptimizeCast(Cast0) && shouldOptimizeCast(Cast1)) {
1454  Value *NewOp = Builder.CreateBinOp(LogicOpc, Cast0Src, Cast1Src,
1455  I.getName());
1456  return CastInst::Create(CastOpcode, NewOp, DestTy);
1457  }
1458 
1459  // For now, only 'and'/'or' have optimizations after this.
1460  if (LogicOpc == Instruction::Xor)
1461  return nullptr;
1462 
1463  // If this is logic(cast(icmp), cast(icmp)), try to fold this even if the
1464  // cast is otherwise not optimizable. This happens for vector sexts.
1465  ICmpInst *ICmp0 = dyn_cast<ICmpInst>(Cast0Src);
1466  ICmpInst *ICmp1 = dyn_cast<ICmpInst>(Cast1Src);
1467  if (ICmp0 && ICmp1) {
1468  Value *Res = LogicOpc == Instruction::And ? foldAndOfICmps(ICmp0, ICmp1, I)
1469  : foldOrOfICmps(ICmp0, ICmp1, I);
1470  if (Res)
1471  return CastInst::Create(CastOpcode, Res, DestTy);
1472  return nullptr;
1473  }
1474 
1475  // If this is logic(cast(fcmp), cast(fcmp)), try to fold this even if the
1476  // cast is otherwise not optimizable. This happens for vector sexts.
1477  FCmpInst *FCmp0 = dyn_cast<FCmpInst>(Cast0Src);
1478  FCmpInst *FCmp1 = dyn_cast<FCmpInst>(Cast1Src);
1479  if (FCmp0 && FCmp1)
1480  if (Value *R = foldLogicOfFCmps(FCmp0, FCmp1, LogicOpc == Instruction::And))
1481  return CastInst::Create(CastOpcode, R, DestTy);
1482 
1483  return nullptr;
1484 }
1485 
1487  InstCombiner::BuilderTy &Builder) {
1488  assert(I.getOpcode() == Instruction::And);
1489  Value *Op0 = I.getOperand(0);
1490  Value *Op1 = I.getOperand(1);
1491  Value *A, *B;
1492 
1493  // Operand complexity canonicalization guarantees that the 'or' is Op0.
1494  // (A | B) & ~(A & B) --> A ^ B
1495  // (A | B) & ~(B & A) --> A ^ B
1496  if (match(&I, m_BinOp(m_Or(m_Value(A), m_Value(B)),
1497  m_Not(m_c_And(m_Deferred(A), m_Deferred(B))))))
1498  return BinaryOperator::CreateXor(A, B);
1499 
1500  // (A | ~B) & (~A | B) --> ~(A ^ B)
1501  // (A | ~B) & (B | ~A) --> ~(A ^ B)
1502  // (~B | A) & (~A | B) --> ~(A ^ B)
1503  // (~B | A) & (B | ~A) --> ~(A ^ B)
1504  if (Op0->hasOneUse() || Op1->hasOneUse())
1505  if (match(&I, m_BinOp(m_c_Or(m_Value(A), m_Not(m_Value(B))),
1506  m_c_Or(m_Not(m_Deferred(A)), m_Deferred(B)))))
1507  return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
1508 
1509  return nullptr;
1510 }
1511 
1513  InstCombiner::BuilderTy &Builder) {
1514  assert(I.getOpcode() == Instruction::Or);
1515  Value *Op0 = I.getOperand(0);
1516  Value *Op1 = I.getOperand(1);
1517  Value *A, *B;
1518 
1519  // Operand complexity canonicalization guarantees that the 'and' is Op0.
1520  // (A & B) | ~(A | B) --> ~(A ^ B)
1521  // (A & B) | ~(B | A) --> ~(A ^ B)
1522  if (Op0->hasOneUse() || Op1->hasOneUse())
1523  if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1524  match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B)))))
1525  return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
1526 
1527  // (A & ~B) | (~A & B) --> A ^ B
1528  // (A & ~B) | (B & ~A) --> A ^ B
1529  // (~B & A) | (~A & B) --> A ^ B
1530  // (~B & A) | (B & ~A) --> A ^ B
1531  if (match(Op0, m_c_And(m_Value(A), m_Not(m_Value(B)))) &&
1532  match(Op1, m_c_And(m_Not(m_Specific(A)), m_Specific(B))))
1533  return BinaryOperator::CreateXor(A, B);
1534 
1535  return nullptr;
1536 }
1537 
1538 /// Return true if a constant shift amount is always less than the specified
1539 /// bit-width. If not, the shift could create poison in the narrower type.
1540 static bool canNarrowShiftAmt(Constant *C, unsigned BitWidth) {
1541  if (auto *ScalarC = dyn_cast<ConstantInt>(C))
1542  return ScalarC->getZExtValue() < BitWidth;
1543 
1544  if (C->getType()->isVectorTy()) {
1545  // Check each element of a constant vector.
1546  unsigned NumElts = C->getType()->getVectorNumElements();
1547  for (unsigned i = 0; i != NumElts; ++i) {
1548  Constant *Elt = C->getAggregateElement(i);
1549  if (!Elt)
1550  return false;
1551  if (isa<UndefValue>(Elt))
1552  continue;
1553  auto *CI = dyn_cast<ConstantInt>(Elt);
1554  if (!CI || CI->getZExtValue() >= BitWidth)
1555  return false;
1556  }
1557  return true;
1558  }
1559 
1560  // The constant is a constant expression or unknown.
1561  return false;
1562 }
1563 
1564 /// Try to use narrower ops (sink zext ops) for an 'and' with binop operand and
1565 /// a common zext operand: and (binop (zext X), C), (zext X).
1566 Instruction *InstCombiner::narrowMaskedBinOp(BinaryOperator &And) {
1567  // This transform could also apply to {or, and, xor}, but there are better
1568  // folds for those cases, so we don't expect those patterns here. AShr is not
1569  // handled because it should always be transformed to LShr in this sequence.
1570  // The subtract transform is different because it has a constant on the left.
1571  // Add/mul commute the constant to RHS; sub with constant RHS becomes add.
1572  Value *Op0 = And.getOperand(0), *Op1 = And.getOperand(1);
1573  Constant *C;
1574  if (!match(Op0, m_OneUse(m_Add(m_Specific(Op1), m_Constant(C)))) &&
1575  !match(Op0, m_OneUse(m_Mul(m_Specific(Op1), m_Constant(C)))) &&
1576  !match(Op0, m_OneUse(m_LShr(m_Specific(Op1), m_Constant(C)))) &&
1577  !match(Op0, m_OneUse(m_Shl(m_Specific(Op1), m_Constant(C)))) &&
1578  !match(Op0, m_OneUse(m_Sub(m_Constant(C), m_Specific(Op1)))))
1579  return nullptr;
1580 
1581  Value *X;
1582  if (!match(Op1, m_ZExt(m_Value(X))) || Op1->hasNUsesOrMore(3))
1583  return nullptr;
1584 
1585  Type *Ty = And.getType();
1586  if (!isa<VectorType>(Ty) && !shouldChangeType(Ty, X->getType()))
1587  return nullptr;
1588 
1589  // If we're narrowing a shift, the shift amount must be safe (less than the
1590  // width) in the narrower type. If the shift amount is greater, instsimplify
1591  // usually handles that case, but we can't guarantee/assert it.
1592  Instruction::BinaryOps Opc = cast<BinaryOperator>(Op0)->getOpcode();
1593  if (Opc == Instruction::LShr || Opc == Instruction::Shl)
1595  return nullptr;
1596 
1597  // and (sub C, (zext X)), (zext X) --> zext (and (sub C', X), X)
1598  // and (binop (zext X), C), (zext X) --> zext (and (binop X, C'), X)
1599  Value *NewC = ConstantExpr::getTrunc(C, X->getType());
1600  Value *NewBO = Opc == Instruction::Sub ? Builder.CreateBinOp(Opc, NewC, X)
1601  : Builder.CreateBinOp(Opc, X, NewC);
1602  return new ZExtInst(Builder.CreateAnd(NewBO, X), Ty);
1603 }
1604 
1605 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
1606 // here. We should standardize that construct where it is needed or choose some
1607 // other way to ensure that commutated variants of patterns are not missed.
1609  if (Value *V = SimplifyAndInst(I.getOperand(0), I.getOperand(1),
1610  SQ.getWithInstruction(&I)))
1611  return replaceInstUsesWith(I, V);
1612 
1613  if (SimplifyAssociativeOrCommutative(I))
1614  return &I;
1615 
1616  if (Instruction *X = foldVectorBinop(I))
1617  return X;
1618 
1619  // See if we can simplify any instructions used by the instruction whose sole
1620  // purpose is to compute bits we don't care about.
1621  if (SimplifyDemandedInstructionBits(I))
1622  return &I;
1623 
1624  // Do this before using distributive laws to catch simple and/or/not patterns.
1625  if (Instruction *Xor = foldAndToXor(I, Builder))
1626  return Xor;
1627 
1628  // (A|B)&(A|C) -> A|(B&C) etc
1629  if (Value *V = SimplifyUsingDistributiveLaws(I))
1630  return replaceInstUsesWith(I, V);
1631 
1632  if (Value *V = SimplifyBSwap(I, Builder))
1633  return replaceInstUsesWith(I, V);
1634 
1635  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1636  const APInt *C;
1637  if (match(Op1, m_APInt(C))) {
1638  Value *X, *Y;
1639  if (match(Op0, m_OneUse(m_LogicalShift(m_One(), m_Value(X)))) &&
1640  C->isOneValue()) {
1641  // (1 << X) & 1 --> zext(X == 0)
1642  // (1 >> X) & 1 --> zext(X == 0)
1643  Value *IsZero = Builder.CreateICmpEQ(X, ConstantInt::get(I.getType(), 0));
1644  return new ZExtInst(IsZero, I.getType());
1645  }
1646 
1647  const APInt *XorC;
1648  if (match(Op0, m_OneUse(m_Xor(m_Value(X), m_APInt(XorC))))) {
1649  // (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
1650  Constant *NewC = ConstantInt::get(I.getType(), *C & *XorC);
1651  Value *And = Builder.CreateAnd(X, Op1);
1652  And->takeName(Op0);
1653  return BinaryOperator::CreateXor(And, NewC);
1654  }
1655 
1656  const APInt *OrC;
1657  if (match(Op0, m_OneUse(m_Or(m_Value(X), m_APInt(OrC))))) {
1658  // (X | C1) & C2 --> (X & C2^(C1&C2)) | (C1&C2)
1659  // NOTE: This reduces the number of bits set in the & mask, which
1660  // can expose opportunities for store narrowing for scalars.
1661  // NOTE: SimplifyDemandedBits should have already removed bits from C1
1662  // that aren't set in C2. Meaning we can replace (C1&C2) with C1 in
1663  // above, but this feels safer.
1664  APInt Together = *C & *OrC;
1665  Value *And = Builder.CreateAnd(X, ConstantInt::get(I.getType(),
1666  Together ^ *C));
1667  And->takeName(Op0);
1668  return BinaryOperator::CreateOr(And, ConstantInt::get(I.getType(),
1669  Together));
1670  }
1671 
1672  // If the mask is only needed on one incoming arm, push the 'and' op up.
1673  if (match(Op0, m_OneUse(m_Xor(m_Value(X), m_Value(Y)))) ||
1674  match(Op0, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
1675  APInt NotAndMask(~(*C));
1676  BinaryOperator::BinaryOps BinOp = cast<BinaryOperator>(Op0)->getOpcode();
1677  if (MaskedValueIsZero(X, NotAndMask, 0, &I)) {
1678  // Not masking anything out for the LHS, move mask to RHS.
1679  // and ({x}or X, Y), C --> {x}or X, (and Y, C)
1680  Value *NewRHS = Builder.CreateAnd(Y, Op1, Y->getName() + ".masked");
1681  return BinaryOperator::Create(BinOp, X, NewRHS);
1682  }
1683  if (!isa<Constant>(Y) && MaskedValueIsZero(Y, NotAndMask, 0, &I)) {
1684  // Not masking anything out for the RHS, move mask to LHS.
1685  // and ({x}or X, Y), C --> {x}or (and X, C), Y
1686  Value *NewLHS = Builder.CreateAnd(X, Op1, X->getName() + ".masked");
1687  return BinaryOperator::Create(BinOp, NewLHS, Y);
1688  }
1689  }
1690 
1691  }
1692 
1693  if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
1694  const APInt &AndRHSMask = AndRHS->getValue();
1695 
1696  // Optimize a variety of ((val OP C1) & C2) combinations...
1697  if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
1698  // ((C1 OP zext(X)) & C2) -> zext((C1-X) & C2) if C2 fits in the bitwidth
1699  // of X and OP behaves well when given trunc(C1) and X.
1700  // TODO: Do this for vectors by using m_APInt isntead of m_ConstantInt.
1701  switch (Op0I->getOpcode()) {
1702  default:
1703  break;
1704  case Instruction::Xor:
1705  case Instruction::Or:
1706  case Instruction::Mul:
1707  case Instruction::Add:
1708  case Instruction::Sub:
1709  Value *X;
1710  ConstantInt *C1;
1711  // TODO: The one use restrictions could be relaxed a little if the AND
1712  // is going to be removed.
1713  if (match(Op0I, m_OneUse(m_c_BinOp(m_OneUse(m_ZExt(m_Value(X))),
1714  m_ConstantInt(C1))))) {
1715  if (AndRHSMask.isIntN(X->getType()->getScalarSizeInBits())) {
1716  auto *TruncC1 = ConstantExpr::getTrunc(C1, X->getType());
1717  Value *BinOp;
1718  Value *Op0LHS = Op0I->getOperand(0);
1719  if (isa<ZExtInst>(Op0LHS))
1720  BinOp = Builder.CreateBinOp(Op0I->getOpcode(), X, TruncC1);
1721  else
1722  BinOp = Builder.CreateBinOp(Op0I->getOpcode(), TruncC1, X);
1723  auto *TruncC2 = ConstantExpr::getTrunc(AndRHS, X->getType());
1724  auto *And = Builder.CreateAnd(BinOp, TruncC2);
1725  return new ZExtInst(And, I.getType());
1726  }
1727  }
1728  }
1729 
1730  if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
1731  if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I))
1732  return Res;
1733  }
1734 
1735  // If this is an integer truncation, and if the source is an 'and' with
1736  // immediate, transform it. This frequently occurs for bitfield accesses.
1737  {
1738  Value *X = nullptr; ConstantInt *YC = nullptr;
1739  if (match(Op0, m_Trunc(m_And(m_Value(X), m_ConstantInt(YC))))) {
1740  // Change: and (trunc (and X, YC) to T), C2
1741  // into : and (trunc X to T), trunc(YC) & C2
1742  // This will fold the two constants together, which may allow
1743  // other simplifications.
1744  Value *NewCast = Builder.CreateTrunc(X, I.getType(), "and.shrunk");
1745  Constant *C3 = ConstantExpr::getTrunc(YC, I.getType());
1746  C3 = ConstantExpr::getAnd(C3, AndRHS);
1747  return BinaryOperator::CreateAnd(NewCast, C3);
1748  }
1749  }
1750  }
1751 
1752  if (Instruction *Z = narrowMaskedBinOp(I))
1753  return Z;
1754 
1755  if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
1756  return FoldedLogic;
1757 
1758  if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
1759  return DeMorgan;
1760 
1761  {
1762  Value *A, *B, *C;
1763  // A & (A ^ B) --> A & ~B
1764  if (match(Op1, m_OneUse(m_c_Xor(m_Specific(Op0), m_Value(B)))))
1765  return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(B));
1766  // (A ^ B) & A --> A & ~B
1767  if (match(Op0, m_OneUse(m_c_Xor(m_Specific(Op1), m_Value(B)))))
1768  return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(B));
1769 
1770  // (A ^ B) & ((B ^ C) ^ A) -> (A ^ B) & ~C
1771  if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
1772  if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
1773  if (Op1->hasOneUse() || IsFreeToInvert(C, C->hasOneUse()))
1774  return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(C));
1775 
1776  // ((A ^ C) ^ B) & (B ^ A) -> (B ^ A) & ~C
1777  if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
1778  if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
1779  if (Op0->hasOneUse() || IsFreeToInvert(C, C->hasOneUse()))
1780  return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(C));
1781 
1782  // (A | B) & ((~A) ^ B) -> (A & B)
1783  // (A | B) & (B ^ (~A)) -> (A & B)
1784  // (B | A) & ((~A) ^ B) -> (A & B)
1785  // (B | A) & (B ^ (~A)) -> (A & B)
1786  if (match(Op1, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) &&
1787  match(Op0, m_c_Or(m_Specific(A), m_Specific(B))))
1788  return BinaryOperator::CreateAnd(A, B);
1789 
1790  // ((~A) ^ B) & (A | B) -> (A & B)
1791  // ((~A) ^ B) & (B | A) -> (A & B)
1792  // (B ^ (~A)) & (A | B) -> (A & B)
1793  // (B ^ (~A)) & (B | A) -> (A & B)
1794  if (match(Op0, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) &&
1795  match(Op1, m_c_Or(m_Specific(A), m_Specific(B))))
1796  return BinaryOperator::CreateAnd(A, B);
1797  }
1798 
1799  {
1800  ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
1801  ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
1802  if (LHS && RHS)
1803  if (Value *Res = foldAndOfICmps(LHS, RHS, I))
1804  return replaceInstUsesWith(I, Res);
1805 
1806  // TODO: Make this recursive; it's a little tricky because an arbitrary
1807  // number of 'and' instructions might have to be created.
1808  Value *X, *Y;
1809  if (LHS && match(Op1, m_OneUse(m_And(m_Value(X), m_Value(Y))))) {
1810  if (auto *Cmp = dyn_cast<ICmpInst>(X))
1811  if (Value *Res = foldAndOfICmps(LHS, Cmp, I))
1812  return replaceInstUsesWith(I, Builder.CreateAnd(Res, Y));
1813  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
1814  if (Value *Res = foldAndOfICmps(LHS, Cmp, I))
1815  return replaceInstUsesWith(I, Builder.CreateAnd(Res, X));
1816  }
1817  if (RHS && match(Op0, m_OneUse(m_And(m_Value(X), m_Value(Y))))) {
1818  if (auto *Cmp = dyn_cast<ICmpInst>(X))
1819  if (Value *Res = foldAndOfICmps(Cmp, RHS, I))
1820  return replaceInstUsesWith(I, Builder.CreateAnd(Res, Y));
1821  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
1822  if (Value *Res = foldAndOfICmps(Cmp, RHS, I))
1823  return replaceInstUsesWith(I, Builder.CreateAnd(Res, X));
1824  }
1825  }
1826 
1827  if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
1828  if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
1829  if (Value *Res = foldLogicOfFCmps(LHS, RHS, true))
1830  return replaceInstUsesWith(I, Res);
1831 
1832  if (Instruction *FoldedFCmps = reassociateFCmps(I, Builder))
1833  return FoldedFCmps;
1834 
1835  if (Instruction *CastedAnd = foldCastedBitwiseLogic(I))
1836  return CastedAnd;
1837 
1838  // and(sext(A), B) / and(B, sext(A)) --> A ? B : 0, where A is i1 or <N x i1>.
1839  Value *A;
1840  if (match(Op0, m_OneUse(m_SExt(m_Value(A)))) &&
1841  A->getType()->isIntOrIntVectorTy(1))
1842  return SelectInst::Create(A, Op1, Constant::getNullValue(I.getType()));
1843  if (match(Op1, m_OneUse(m_SExt(m_Value(A)))) &&
1844  A->getType()->isIntOrIntVectorTy(1))
1845  return SelectInst::Create(A, Op0, Constant::getNullValue(I.getType()));
1846 
1847  return nullptr;
1848 }
1849 
1850 Instruction *InstCombiner::matchBSwap(BinaryOperator &Or) {
1851  assert(Or.getOpcode() == Instruction::Or && "bswap requires an 'or'");
1852  Value *Op0 = Or.getOperand(0), *Op1 = Or.getOperand(1);
1853 
1854  // Look through zero extends.
1855  if (Instruction *Ext = dyn_cast<ZExtInst>(Op0))
1856  Op0 = Ext->getOperand(0);
1857 
1858  if (Instruction *Ext = dyn_cast<ZExtInst>(Op1))
1859  Op1 = Ext->getOperand(0);
1860 
1861  // (A | B) | C and A | (B | C) -> bswap if possible.
1862  bool OrOfOrs = match(Op0, m_Or(m_Value(), m_Value())) ||
1863  match(Op1, m_Or(m_Value(), m_Value()));
1864 
1865  // (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible.
1866  bool OrOfShifts = match(Op0, m_LogicalShift(m_Value(), m_Value())) &&
1867  match(Op1, m_LogicalShift(m_Value(), m_Value()));
1868 
1869  // (A & B) | (C & D) -> bswap if possible.
1870  bool OrOfAnds = match(Op0, m_And(m_Value(), m_Value())) &&
1871  match(Op1, m_And(m_Value(), m_Value()));
1872 
1873  // (A << B) | (C & D) -> bswap if possible.
1874  // The bigger pattern here is ((A & C1) << C2) | ((B >> C2) & C1), which is a
1875  // part of the bswap idiom for specific values of C1, C2 (e.g. C1 = 16711935,
1876  // C2 = 8 for i32).
1877  // This pattern can occur when the operands of the 'or' are not canonicalized
1878  // for some reason (not having only one use, for example).
1879  bool OrOfAndAndSh = (match(Op0, m_LogicalShift(m_Value(), m_Value())) &&
1880  match(Op1, m_And(m_Value(), m_Value()))) ||
1881  (match(Op0, m_And(m_Value(), m_Value())) &&
1882  match(Op1, m_LogicalShift(m_Value(), m_Value())));
1883 
1884  if (!OrOfOrs && !OrOfShifts && !OrOfAnds && !OrOfAndAndSh)
1885  return nullptr;
1886 
1888  if (!recognizeBSwapOrBitReverseIdiom(&Or, true, false, Insts))
1889  return nullptr;
1890  Instruction *LastInst = Insts.pop_back_val();
1891  LastInst->removeFromParent();
1892 
1893  for (auto *Inst : Insts)
1894  Worklist.Add(Inst);
1895  return LastInst;
1896 }
1897 
1898 /// Transform UB-safe variants of bitwise rotate to the funnel shift intrinsic.
1900  // TODO: Can we reduce the code duplication between this and the related
1901  // rotate matching code under visitSelect and visitTrunc?
1902  unsigned Width = Or.getType()->getScalarSizeInBits();
1903  if (!isPowerOf2_32(Width))
1904  return nullptr;
1905 
1906  // First, find an or'd pair of opposite shifts with the same shifted operand:
1907  // or (lshr ShVal, ShAmt0), (shl ShVal, ShAmt1)
1908  BinaryOperator *Or0, *Or1;
1909  if (!match(Or.getOperand(0), m_BinOp(Or0)) ||
1910  !match(Or.getOperand(1), m_BinOp(Or1)))
1911  return nullptr;
1912 
1913  Value *ShVal, *ShAmt0, *ShAmt1;
1914  if (!match(Or0, m_OneUse(m_LogicalShift(m_Value(ShVal), m_Value(ShAmt0)))) ||
1915  !match(Or1, m_OneUse(m_LogicalShift(m_Specific(ShVal), m_Value(ShAmt1)))))
1916  return nullptr;
1917 
1918  BinaryOperator::BinaryOps ShiftOpcode0 = Or0->getOpcode();
1919  BinaryOperator::BinaryOps ShiftOpcode1 = Or1->getOpcode();
1920  if (ShiftOpcode0 == ShiftOpcode1)
1921  return nullptr;
1922 
1923  // Match the shift amount operands for a rotate pattern. This always matches
1924  // a subtraction on the R operand.
1925  auto matchShiftAmount = [](Value *L, Value *R, unsigned Width) -> Value * {
1926  // The shift amount may be masked with negation:
1927  // (shl ShVal, (X & (Width - 1))) | (lshr ShVal, ((-X) & (Width - 1)))
1928  Value *X;
1929  unsigned Mask = Width - 1;
1930  if (match(L, m_And(m_Value(X), m_SpecificInt(Mask))) &&
1931  match(R, m_And(m_Neg(m_Specific(X)), m_SpecificInt(Mask))))
1932  return X;
1933 
1934  // Similar to above, but the shift amount may be extended after masking,
1935  // so return the extended value as the parameter for the intrinsic.
1936  if (match(L, m_ZExt(m_And(m_Value(X), m_SpecificInt(Mask)))) &&
1938  m_SpecificInt(Mask))))
1939  return L;
1940 
1941  return nullptr;
1942  };
1943 
1944  Value *ShAmt = matchShiftAmount(ShAmt0, ShAmt1, Width);
1945  bool SubIsOnLHS = false;
1946  if (!ShAmt) {
1947  ShAmt = matchShiftAmount(ShAmt1, ShAmt0, Width);
1948  SubIsOnLHS = true;
1949  }
1950  if (!ShAmt)
1951  return nullptr;
1952 
1953  bool IsFshl = (!SubIsOnLHS && ShiftOpcode0 == BinaryOperator::Shl) ||
1954  (SubIsOnLHS && ShiftOpcode1 == BinaryOperator::Shl);
1955  Intrinsic::ID IID = IsFshl ? Intrinsic::fshl : Intrinsic::fshr;
1957  return IntrinsicInst::Create(F, { ShVal, ShVal, ShAmt });
1958 }
1959 
1960 /// If all elements of two constant vectors are 0/-1 and inverses, return true.
1962  unsigned NumElts = C1->getType()->getVectorNumElements();
1963  for (unsigned i = 0; i != NumElts; ++i) {
1964  Constant *EltC1 = C1->getAggregateElement(i);
1965  Constant *EltC2 = C2->getAggregateElement(i);
1966  if (!EltC1 || !EltC2)
1967  return false;
1968 
1969  // One element must be all ones, and the other must be all zeros.
1970  if (!((match(EltC1, m_Zero()) && match(EltC2, m_AllOnes())) ||
1971  (match(EltC2, m_Zero()) && match(EltC1, m_AllOnes()))))
1972  return false;
1973  }
1974  return true;
1975 }
1976 
1977 /// We have an expression of the form (A & C) | (B & D). If A is a scalar or
1978 /// vector composed of all-zeros or all-ones values and is the bitwise 'not' of
1979 /// B, it can be used as the condition operand of a select instruction.
1980 Value *InstCombiner::getSelectCondition(Value *A, Value *B) {
1981  // Step 1: We may have peeked through bitcasts in the caller.
1982  // Exit immediately if we don't have (vector) integer types.
1983  Type *Ty = A->getType();
1984  if (!Ty->isIntOrIntVectorTy() || !B->getType()->isIntOrIntVectorTy())
1985  return nullptr;
1986 
1987  // Step 2: We need 0 or all-1's bitmasks.
1988  if (ComputeNumSignBits(A) != Ty->getScalarSizeInBits())
1989  return nullptr;
1990 
1991  // Step 3: If B is the 'not' value of A, we have our answer.
1992  if (match(A, m_Not(m_Specific(B)))) {
1993  // If these are scalars or vectors of i1, A can be used directly.
1994  if (Ty->isIntOrIntVectorTy(1))
1995  return A;
1996  return Builder.CreateTrunc(A, CmpInst::makeCmpResultType(Ty));
1997  }
1998 
1999  // If both operands are constants, see if the constants are inverse bitmasks.
2000  Constant *AConst, *BConst;
2001  if (match(A, m_Constant(AConst)) && match(B, m_Constant(BConst)))
2002  if (AConst == ConstantExpr::getNot(BConst))
2003  return Builder.CreateZExtOrTrunc(A, CmpInst::makeCmpResultType(Ty));
2004 
2005  // Look for more complex patterns. The 'not' op may be hidden behind various
2006  // casts. Look through sexts and bitcasts to find the booleans.
2007  Value *Cond;
2008  Value *NotB;
2009  if (match(A, m_SExt(m_Value(Cond))) &&
2010  Cond->getType()->isIntOrIntVectorTy(1) &&
2011  match(B, m_OneUse(m_Not(m_Value(NotB))))) {
2012  NotB = peekThroughBitcast(NotB, true);
2013  if (match(NotB, m_SExt(m_Specific(Cond))))
2014  return Cond;
2015  }
2016 
2017  // All scalar (and most vector) possibilities should be handled now.
2018  // Try more matches that only apply to non-splat constant vectors.
2019  if (!Ty->isVectorTy())
2020  return nullptr;
2021 
2022  // If both operands are xor'd with constants using the same sexted boolean
2023  // operand, see if the constants are inverse bitmasks.
2024  // TODO: Use ConstantExpr::getNot()?
2025  if (match(A, (m_Xor(m_SExt(m_Value(Cond)), m_Constant(AConst)))) &&
2026  match(B, (m_Xor(m_SExt(m_Specific(Cond)), m_Constant(BConst)))) &&
2027  Cond->getType()->isIntOrIntVectorTy(1) &&
2028  areInverseVectorBitmasks(AConst, BConst)) {
2029  AConst = ConstantExpr::getTrunc(AConst, CmpInst::makeCmpResultType(Ty));
2030  return Builder.CreateXor(Cond, AConst);
2031  }
2032  return nullptr;
2033 }
2034 
2035 /// We have an expression of the form (A & C) | (B & D). Try to simplify this
2036 /// to "A' ? C : D", where A' is a boolean or vector of booleans.
2037 Value *InstCombiner::matchSelectFromAndOr(Value *A, Value *C, Value *B,
2038  Value *D) {
2039  // The potential condition of the select may be bitcasted. In that case, look
2040  // through its bitcast and the corresponding bitcast of the 'not' condition.
2041  Type *OrigType = A->getType();
2042  A = peekThroughBitcast(A, true);
2043  B = peekThroughBitcast(B, true);
2044  if (Value *Cond = getSelectCondition(A, B)) {
2045  // ((bc Cond) & C) | ((bc ~Cond) & D) --> bc (select Cond, (bc C), (bc D))
2046  // The bitcasts will either all exist or all not exist. The builder will
2047  // not create unnecessary casts if the types already match.
2048  Value *BitcastC = Builder.CreateBitCast(C, A->getType());
2049  Value *BitcastD = Builder.CreateBitCast(D, A->getType());
2050  Value *Select = Builder.CreateSelect(Cond, BitcastC, BitcastD);
2051  return Builder.CreateBitCast(Select, OrigType);
2052  }
2053 
2054  return nullptr;
2055 }
2056 
2057 /// Fold (icmp)|(icmp) if possible.
2058 Value *InstCombiner::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
2059  Instruction &CxtI) {
2060  // Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2)
2061  // if K1 and K2 are a one-bit mask.
2062  if (Value *V = foldAndOrOfICmpsOfAndWithPow2(LHS, RHS, false, CxtI))
2063  return V;
2064 
2065  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
2066 
2067  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
2068  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
2069 
2070  // Fold (icmp ult/ule (A + C1), C3) | (icmp ult/ule (A + C2), C3)
2071  // --> (icmp ult/ule ((A & ~(C1 ^ C2)) + max(C1, C2)), C3)
2072  // The original condition actually refers to the following two ranges:
2073  // [MAX_UINT-C1+1, MAX_UINT-C1+1+C3] and [MAX_UINT-C2+1, MAX_UINT-C2+1+C3]
2074  // We can fold these two ranges if:
2075  // 1) C1 and C2 is unsigned greater than C3.
2076  // 2) The two ranges are separated.
2077  // 3) C1 ^ C2 is one-bit mask.
2078  // 4) LowRange1 ^ LowRange2 and HighRange1 ^ HighRange2 are one-bit mask.
2079  // This implies all values in the two ranges differ by exactly one bit.
2080 
2081  if ((PredL == ICmpInst::ICMP_ULT || PredL == ICmpInst::ICMP_ULE) &&
2082  PredL == PredR && LHSC && RHSC && LHS->hasOneUse() && RHS->hasOneUse() &&
2083  LHSC->getType() == RHSC->getType() &&
2084  LHSC->getValue() == (RHSC->getValue())) {
2085 
2086  Value *LAdd = LHS->getOperand(0);
2087  Value *RAdd = RHS->getOperand(0);
2088 
2089  Value *LAddOpnd, *RAddOpnd;
2090  ConstantInt *LAddC, *RAddC;
2091  if (match(LAdd, m_Add(m_Value(LAddOpnd), m_ConstantInt(LAddC))) &&
2092  match(RAdd, m_Add(m_Value(RAddOpnd), m_ConstantInt(RAddC))) &&
2093  LAddC->getValue().ugt(LHSC->getValue()) &&
2094  RAddC->getValue().ugt(LHSC->getValue())) {
2095 
2096  APInt DiffC = LAddC->getValue() ^ RAddC->getValue();
2097  if (LAddOpnd == RAddOpnd && DiffC.isPowerOf2()) {
2098  ConstantInt *MaxAddC = nullptr;
2099  if (LAddC->getValue().ult(RAddC->getValue()))
2100  MaxAddC = RAddC;
2101  else
2102  MaxAddC = LAddC;
2103 
2104  APInt RRangeLow = -RAddC->getValue();
2105  APInt RRangeHigh = RRangeLow + LHSC->getValue();
2106  APInt LRangeLow = -LAddC->getValue();
2107  APInt LRangeHigh = LRangeLow + LHSC->getValue();
2108  APInt LowRangeDiff = RRangeLow ^ LRangeLow;
2109  APInt HighRangeDiff = RRangeHigh ^ LRangeHigh;
2110  APInt RangeDiff = LRangeLow.sgt(RRangeLow) ? LRangeLow - RRangeLow
2111  : RRangeLow - LRangeLow;
2112 
2113  if (LowRangeDiff.isPowerOf2() && LowRangeDiff == HighRangeDiff &&
2114  RangeDiff.ugt(LHSC->getValue())) {
2115  Value *MaskC = ConstantInt::get(LAddC->getType(), ~DiffC);
2116 
2117  Value *NewAnd = Builder.CreateAnd(LAddOpnd, MaskC);
2118  Value *NewAdd = Builder.CreateAdd(NewAnd, MaxAddC);
2119  return Builder.CreateICmp(LHS->getPredicate(), NewAdd, LHSC);
2120  }
2121  }
2122  }
2123  }
2124 
2125  // (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
2126  if (predicatesFoldable(PredL, PredR)) {
2127  if (LHS->getOperand(0) == RHS->getOperand(1) &&
2128  LHS->getOperand(1) == RHS->getOperand(0))
2129  LHS->swapOperands();
2130  if (LHS->getOperand(0) == RHS->getOperand(0) &&
2131  LHS->getOperand(1) == RHS->getOperand(1)) {
2132  Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
2133  unsigned Code = getICmpCode(LHS) | getICmpCode(RHS);
2134  bool IsSigned = LHS->isSigned() || RHS->isSigned();
2135  return getNewICmpValue(Code, IsSigned, Op0, Op1, Builder);
2136  }
2137  }
2138 
2139  // handle (roughly):
2140  // (icmp ne (A & B), C) | (icmp ne (A & D), E)
2141  if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, false, Builder))
2142  return V;
2143 
2144  Value *LHS0 = LHS->getOperand(0), *RHS0 = RHS->getOperand(0);
2145  if (LHS->hasOneUse() || RHS->hasOneUse()) {
2146  // (icmp eq B, 0) | (icmp ult A, B) -> (icmp ule A, B-1)
2147  // (icmp eq B, 0) | (icmp ugt B, A) -> (icmp ule A, B-1)
2148  Value *A = nullptr, *B = nullptr;
2149  if (PredL == ICmpInst::ICMP_EQ && LHSC && LHSC->isZero()) {
2150  B = LHS0;
2151  if (PredR == ICmpInst::ICMP_ULT && LHS0 == RHS->getOperand(1))
2152  A = RHS0;
2153  else if (PredR == ICmpInst::ICMP_UGT && LHS0 == RHS0)
2154  A = RHS->getOperand(1);
2155  }
2156  // (icmp ult A, B) | (icmp eq B, 0) -> (icmp ule A, B-1)
2157  // (icmp ugt B, A) | (icmp eq B, 0) -> (icmp ule A, B-1)
2158  else if (PredR == ICmpInst::ICMP_EQ && RHSC && RHSC->isZero()) {
2159  B = RHS0;
2160  if (PredL == ICmpInst::ICMP_ULT && RHS0 == LHS->getOperand(1))
2161  A = LHS0;
2162  else if (PredL == ICmpInst::ICMP_UGT && LHS0 == RHS0)
2163  A = LHS->getOperand(1);
2164  }
2165  if (A && B)
2166  return Builder.CreateICmp(
2168  Builder.CreateAdd(B, ConstantInt::getSigned(B->getType(), -1)), A);
2169  }
2170 
2171  // E.g. (icmp slt x, 0) | (icmp sgt x, n) --> icmp ugt x, n
2172  if (Value *V = simplifyRangeCheck(LHS, RHS, /*Inverted=*/true))
2173  return V;
2174 
2175  // E.g. (icmp sgt x, n) | (icmp slt x, 0) --> icmp ugt x, n
2176  if (Value *V = simplifyRangeCheck(RHS, LHS, /*Inverted=*/true))
2177  return V;
2178 
2179  if (Value *V = foldAndOrOfEqualityCmpsWithConstants(LHS, RHS, false, Builder))
2180  return V;
2181 
2182  if (Value *V = foldIsPowerOf2(LHS, RHS, false /* JoinedByAnd */, Builder))
2183  return V;
2184 
2185  // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
2186  if (!LHSC || !RHSC)
2187  return nullptr;
2188 
2189  if (LHSC == RHSC && PredL == PredR) {
2190  // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
2191  if (PredL == ICmpInst::ICMP_NE && LHSC->isZero()) {
2192  Value *NewOr = Builder.CreateOr(LHS0, RHS0);
2193  return Builder.CreateICmp(PredL, NewOr, LHSC);
2194  }
2195  }
2196 
2197  // (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1)
2198  // iff C2 + CA == C1.
2199  if (PredL == ICmpInst::ICMP_ULT && PredR == ICmpInst::ICMP_EQ) {
2200  ConstantInt *AddC;
2201  if (match(LHS0, m_Add(m_Specific(RHS0), m_ConstantInt(AddC))))
2202  if (RHSC->getValue() + AddC->getValue() == LHSC->getValue())
2203  return Builder.CreateICmpULE(LHS0, LHSC);
2204  }
2205 
2206  // From here on, we only handle:
2207  // (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
2208  if (LHS0 != RHS0)
2209  return nullptr;
2210 
2211  // ICMP_[US][GL]E X, C is folded to ICMP_[US][GL]T elsewhere.
2212  if (PredL == ICmpInst::ICMP_UGE || PredL == ICmpInst::ICMP_ULE ||
2213  PredR == ICmpInst::ICMP_UGE || PredR == ICmpInst::ICMP_ULE ||
2214  PredL == ICmpInst::ICMP_SGE || PredL == ICmpInst::ICMP_SLE ||
2215  PredR == ICmpInst::ICMP_SGE || PredR == ICmpInst::ICMP_SLE)
2216  return nullptr;
2217 
2218  // We can't fold (ugt x, C) | (sgt x, C2).
2219  if (!predicatesFoldable(PredL, PredR))
2220  return nullptr;
2221 
2222  // Ensure that the larger constant is on the RHS.
2223  bool ShouldSwap;
2224  if (CmpInst::isSigned(PredL) ||
2225  (ICmpInst::isEquality(PredL) && CmpInst::isSigned(PredR)))
2226  ShouldSwap = LHSC->getValue().sgt(RHSC->getValue());
2227  else
2228  ShouldSwap = LHSC->getValue().ugt(RHSC->getValue());
2229 
2230  if (ShouldSwap) {
2231  std::swap(LHS, RHS);
2232  std::swap(LHSC, RHSC);
2233  std::swap(PredL, PredR);
2234  }
2235 
2236  // At this point, we know we have two icmp instructions
2237  // comparing a value against two constants and or'ing the result
2238  // together. Because of the above check, we know that we only have
2239  // ICMP_EQ, ICMP_NE, ICMP_LT, and ICMP_GT here. We also know (from the
2240  // icmp folding check above), that the two constants are not
2241  // equal.
2242  assert(LHSC != RHSC && "Compares not folded above?");
2243 
2244  switch (PredL) {
2245  default:
2246  llvm_unreachable("Unknown integer condition code!");
2247  case ICmpInst::ICMP_EQ:
2248  switch (PredR) {
2249  default:
2250  llvm_unreachable("Unknown integer condition code!");
2251  case ICmpInst::ICMP_EQ:
2252  // Potential folds for this case should already be handled.
2253  break;
2254  case ICmpInst::ICMP_UGT: // (X == 13 | X u> 14) -> no change
2255  case ICmpInst::ICMP_SGT: // (X == 13 | X s> 14) -> no change
2256  break;
2257  }
2258  break;
2259  case ICmpInst::ICMP_ULT:
2260  switch (PredR) {
2261  default:
2262  llvm_unreachable("Unknown integer condition code!");
2263  case ICmpInst::ICMP_EQ: // (X u< 13 | X == 14) -> no change
2264  break;
2265  case ICmpInst::ICMP_UGT: // (X u< 13 | X u> 15) -> (X-13) u> 2
2266  assert(!RHSC->isMaxValue(false) && "Missed icmp simplification");
2267  return insertRangeTest(LHS0, LHSC->getValue(), RHSC->getValue() + 1,
2268  false, false);
2269  }
2270  break;
2271  case ICmpInst::ICMP_SLT:
2272  switch (PredR) {
2273  default:
2274  llvm_unreachable("Unknown integer condition code!");
2275  case ICmpInst::ICMP_EQ: // (X s< 13 | X == 14) -> no change
2276  break;
2277  case ICmpInst::ICMP_SGT: // (X s< 13 | X s> 15) -> (X-13) s> 2
2278  assert(!RHSC->isMaxValue(true) && "Missed icmp simplification");
2279  return insertRangeTest(LHS0, LHSC->getValue(), RHSC->getValue() + 1, true,
2280  false);
2281  }
2282  break;
2283  }
2284  return nullptr;
2285 }
2286 
2287 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
2288 // here. We should standardize that construct where it is needed or choose some
2289 // other way to ensure that commutated variants of patterns are not missed.
2291  if (Value *V = SimplifyOrInst(I.getOperand(0), I.getOperand(1),
2292  SQ.getWithInstruction(&I)))
2293  return replaceInstUsesWith(I, V);
2294 
2295  if (SimplifyAssociativeOrCommutative(I))
2296  return &I;
2297 
2298  if (Instruction *X = foldVectorBinop(I))
2299  return X;
2300 
2301  // See if we can simplify any instructions used by the instruction whose sole
2302  // purpose is to compute bits we don't care about.
2303  if (SimplifyDemandedInstructionBits(I))
2304  return &I;
2305 
2306  // Do this before using distributive laws to catch simple and/or/not patterns.
2307  if (Instruction *Xor = foldOrToXor(I, Builder))
2308  return Xor;
2309 
2310  // (A&B)|(A&C) -> A&(B|C) etc
2311  if (Value *V = SimplifyUsingDistributiveLaws(I))
2312  return replaceInstUsesWith(I, V);
2313 
2314  if (Value *V = SimplifyBSwap(I, Builder))
2315  return replaceInstUsesWith(I, V);
2316 
2317  if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
2318  return FoldedLogic;
2319 
2320  if (Instruction *BSwap = matchBSwap(I))
2321  return BSwap;
2322 
2323  if (Instruction *Rotate = matchRotate(I))
2324  return Rotate;
2325 
2326  Value *X, *Y;
2327  const APInt *CV;
2328  if (match(&I, m_c_Or(m_OneUse(m_Xor(m_Value(X), m_APInt(CV))), m_Value(Y))) &&
2329  !CV->isAllOnesValue() && MaskedValueIsZero(Y, *CV, 0, &I)) {
2330  // (X ^ C) | Y -> (X | Y) ^ C iff Y & C == 0
2331  // The check for a 'not' op is for efficiency (if Y is known zero --> ~X).
2332  Value *Or = Builder.CreateOr(X, Y);
2333  return BinaryOperator::CreateXor(Or, ConstantInt::get(I.getType(), *CV));
2334  }
2335 
2336  // (A & C)|(B & D)
2337  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
2338  Value *A, *B, *C, *D;
2339  if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
2340  match(Op1, m_And(m_Value(B), m_Value(D)))) {
2343  if (C1 && C2) { // (A & C1)|(B & C2)
2344  Value *V1 = nullptr, *V2 = nullptr;
2345  if ((C1->getValue() & C2->getValue()).isNullValue()) {
2346  // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2)
2347  // iff (C1&C2) == 0 and (N&~C1) == 0
2348  if (match(A, m_Or(m_Value(V1), m_Value(V2))) &&
2349  ((V1 == B &&
2350  MaskedValueIsZero(V2, ~C1->getValue(), 0, &I)) || // (V|N)
2351  (V2 == B &&
2352  MaskedValueIsZero(V1, ~C1->getValue(), 0, &I)))) // (N|V)
2353  return BinaryOperator::CreateAnd(A,
2354  Builder.getInt(C1->getValue()|C2->getValue()));
2355  // Or commutes, try both ways.
2356  if (match(B, m_Or(m_Value(V1), m_Value(V2))) &&
2357  ((V1 == A &&
2358  MaskedValueIsZero(V2, ~C2->getValue(), 0, &I)) || // (V|N)
2359  (V2 == A &&
2360  MaskedValueIsZero(V1, ~C2->getValue(), 0, &I)))) // (N|V)
2361  return BinaryOperator::CreateAnd(B,
2362  Builder.getInt(C1->getValue()|C2->getValue()));
2363 
2364  // ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2)
2365  // iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0.
2366  ConstantInt *C3 = nullptr, *C4 = nullptr;
2367  if (match(A, m_Or(m_Value(V1), m_ConstantInt(C3))) &&
2368  (C3->getValue() & ~C1->getValue()).isNullValue() &&
2369  match(B, m_Or(m_Specific(V1), m_ConstantInt(C4))) &&
2370  (C4->getValue() & ~C2->getValue()).isNullValue()) {
2371  V2 = Builder.CreateOr(V1, ConstantExpr::getOr(C3, C4), "bitfield");
2372  return BinaryOperator::CreateAnd(V2,
2373  Builder.getInt(C1->getValue()|C2->getValue()));
2374  }
2375  }
2376 
2377  if (C1->getValue() == ~C2->getValue()) {
2378  Value *X;
2379 
2380  // ((X|B)&C1)|(B&C2) -> (X&C1) | B iff C1 == ~C2
2381  if (match(A, m_c_Or(m_Value(X), m_Specific(B))))
2382  return BinaryOperator::CreateOr(Builder.CreateAnd(X, C1), B);
2383  // (A&C2)|((X|A)&C1) -> (X&C2) | A iff C1 == ~C2
2384  if (match(B, m_c_Or(m_Specific(A), m_Value(X))))
2385  return BinaryOperator::CreateOr(Builder.CreateAnd(X, C2), A);
2386 
2387  // ((X^B)&C1)|(B&C2) -> (X&C1) ^ B iff C1 == ~C2
2388  if (match(A, m_c_Xor(m_Value(X), m_Specific(B))))
2389  return BinaryOperator::CreateXor(Builder.CreateAnd(X, C1), B);
2390  // (A&C2)|((X^A)&C1) -> (X&C2) ^ A iff C1 == ~C2
2391  if (match(B, m_c_Xor(m_Specific(A), m_Value(X))))
2392  return BinaryOperator::CreateXor(Builder.CreateAnd(X, C2), A);
2393  }
2394  }
2395 
2396  // Don't try to form a select if it's unlikely that we'll get rid of at
2397  // least one of the operands. A select is generally more expensive than the
2398  // 'or' that it is replacing.
2399  if (Op0->hasOneUse() || Op1->hasOneUse()) {
2400  // (Cond & C) | (~Cond & D) -> Cond ? C : D, and commuted variants.
2401  if (Value *V = matchSelectFromAndOr(A, C, B, D))
2402  return replaceInstUsesWith(I, V);
2403  if (Value *V = matchSelectFromAndOr(A, C, D, B))
2404  return replaceInstUsesWith(I, V);
2405  if (Value *V = matchSelectFromAndOr(C, A, B, D))
2406  return replaceInstUsesWith(I, V);
2407  if (Value *V = matchSelectFromAndOr(C, A, D, B))
2408  return replaceInstUsesWith(I, V);
2409  if (Value *V = matchSelectFromAndOr(B, D, A, C))
2410  return replaceInstUsesWith(I, V);
2411  if (Value *V = matchSelectFromAndOr(B, D, C, A))
2412  return replaceInstUsesWith(I, V);
2413  if (Value *V = matchSelectFromAndOr(D, B, A, C))
2414  return replaceInstUsesWith(I, V);
2415  if (Value *V = matchSelectFromAndOr(D, B, C, A))
2416  return replaceInstUsesWith(I, V);
2417  }
2418  }
2419 
2420  // (A ^ B) | ((B ^ C) ^ A) -> (A ^ B) | C
2421  if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
2422  if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
2423  return BinaryOperator::CreateOr(Op0, C);
2424 
2425  // ((A ^ C) ^ B) | (B ^ A) -> (B ^ A) | C
2426  if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
2427  if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
2428  return BinaryOperator::CreateOr(Op1, C);
2429 
2430  // ((B | C) & A) | B -> B | (A & C)
2431  if (match(Op0, m_And(m_Or(m_Specific(Op1), m_Value(C)), m_Value(A))))
2432  return BinaryOperator::CreateOr(Op1, Builder.CreateAnd(A, C));
2433 
2434  if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
2435  return DeMorgan;
2436 
2437  // Canonicalize xor to the RHS.
2438  bool SwappedForXor = false;
2439  if (match(Op0, m_Xor(m_Value(), m_Value()))) {
2440  std::swap(Op0, Op1);
2441  SwappedForXor = true;
2442  }
2443 
2444  // A | ( A ^ B) -> A | B
2445  // A | (~A ^ B) -> A | ~B
2446  // (A & B) | (A ^ B)
2447  if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
2448  if (Op0 == A || Op0 == B)
2449  return BinaryOperator::CreateOr(A, B);
2450 
2451  if (match(Op0, m_And(m_Specific(A), m_Specific(B))) ||
2452  match(Op0, m_And(m_Specific(B), m_Specific(A))))
2453  return BinaryOperator::CreateOr(A, B);
2454 
2455  if (Op1->hasOneUse() && match(A, m_Not(m_Specific(Op0)))) {
2456  Value *Not = Builder.CreateNot(B, B->getName() + ".not");
2457  return BinaryOperator::CreateOr(Not, Op0);
2458  }
2459  if (Op1->hasOneUse() && match(B, m_Not(m_Specific(Op0)))) {
2460  Value *Not = Builder.CreateNot(A, A->getName() + ".not");
2461  return BinaryOperator::CreateOr(Not, Op0);
2462  }
2463  }
2464 
2465  // A | ~(A | B) -> A | ~B
2466  // A | ~(A ^ B) -> A | ~B
2467  if (match(Op1, m_Not(m_Value(A))))
2468  if (BinaryOperator *B = dyn_cast<BinaryOperator>(A))
2469  if ((Op0 == B->getOperand(0) || Op0 == B->getOperand(1)) &&
2470  Op1->hasOneUse() && (B->getOpcode() == Instruction::Or ||
2471  B->getOpcode() == Instruction::Xor)) {
2472  Value *NotOp = Op0 == B->getOperand(0) ? B->getOperand(1) :
2473  B->getOperand(0);
2474  Value *Not = Builder.CreateNot(NotOp, NotOp->getName() + ".not");
2475  return BinaryOperator::CreateOr(Not, Op0);
2476  }
2477 
2478  if (SwappedForXor)
2479  std::swap(Op0, Op1);
2480 
2481  {
2482  ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
2483  ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
2484  if (LHS && RHS)
2485  if (Value *Res = foldOrOfICmps(LHS, RHS, I))
2486  return replaceInstUsesWith(I, Res);
2487 
2488  // TODO: Make this recursive; it's a little tricky because an arbitrary
2489  // number of 'or' instructions might have to be created.
2490  Value *X, *Y;
2491  if (LHS && match(Op1, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
2492  if (auto *Cmp = dyn_cast<ICmpInst>(X))
2493  if (Value *Res = foldOrOfICmps(LHS, Cmp, I))
2494  return replaceInstUsesWith(I, Builder.CreateOr(Res, Y));
2495  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
2496  if (Value *Res = foldOrOfICmps(LHS, Cmp, I))
2497  return replaceInstUsesWith(I, Builder.CreateOr(Res, X));
2498  }
2499  if (RHS && match(Op0, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
2500  if (auto *Cmp = dyn_cast<ICmpInst>(X))
2501  if (Value *Res = foldOrOfICmps(Cmp, RHS, I))
2502  return replaceInstUsesWith(I, Builder.CreateOr(Res, Y));
2503  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
2504  if (Value *Res = foldOrOfICmps(Cmp, RHS, I))
2505  return replaceInstUsesWith(I, Builder.CreateOr(Res, X));
2506  }
2507  }
2508 
2509  if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
2510  if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
2511  if (Value *Res = foldLogicOfFCmps(LHS, RHS, false))
2512  return replaceInstUsesWith(I, Res);
2513 
2514  if (Instruction *FoldedFCmps = reassociateFCmps(I, Builder))
2515  return FoldedFCmps;
2516 
2517  if (Instruction *CastedOr = foldCastedBitwiseLogic(I))
2518  return CastedOr;
2519 
2520  // or(sext(A), B) / or(B, sext(A)) --> A ? -1 : B, where A is i1 or <N x i1>.
2521  if (match(Op0, m_OneUse(m_SExt(m_Value(A)))) &&
2522  A->getType()->isIntOrIntVectorTy(1))
2523  return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op1);
2524  if (match(Op1, m_OneUse(m_SExt(m_Value(A)))) &&
2525  A->getType()->isIntOrIntVectorTy(1))
2526  return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op0);
2527 
2528  // Note: If we've gotten to the point of visiting the outer OR, then the
2529  // inner one couldn't be simplified. If it was a constant, then it won't
2530  // be simplified by a later pass either, so we try swapping the inner/outer
2531  // ORs in the hopes that we'll be able to simplify it this way.
2532  // (X|C) | V --> (X|V) | C
2533  ConstantInt *CI;
2534  if (Op0->hasOneUse() && !isa<ConstantInt>(Op1) &&
2535  match(Op0, m_Or(m_Value(A), m_ConstantInt(CI)))) {
2536  Value *Inner = Builder.CreateOr(A, Op1);
2537  Inner->takeName(Op0);
2538  return BinaryOperator::CreateOr(Inner, CI);
2539  }
2540 
2541  // Change (or (bool?A:B),(bool?C:D)) --> (bool?(or A,C):(or B,D))
2542  // Since this OR statement hasn't been optimized further yet, we hope
2543  // that this transformation will allow the new ORs to be optimized.
2544  {
2545  Value *X = nullptr, *Y = nullptr;
2546  if (Op0->hasOneUse() && Op1->hasOneUse() &&
2547  match(Op0, m_Select(m_Value(X), m_Value(A), m_Value(B))) &&
2548  match(Op1, m_Select(m_Value(Y), m_Value(C), m_Value(D))) && X == Y) {
2549  Value *orTrue = Builder.CreateOr(A, C);
2550  Value *orFalse = Builder.CreateOr(B, D);
2551  return SelectInst::Create(X, orTrue, orFalse);
2552  }
2553  }
2554 
2555  return nullptr;
2556 }
2557 
2558 /// A ^ B can be specified using other logic ops in a variety of patterns. We
2559 /// can fold these early and efficiently by morphing an existing instruction.
2561  InstCombiner::BuilderTy &Builder) {
2562  assert(I.getOpcode() == Instruction::Xor);
2563  Value *Op0 = I.getOperand(0);
2564  Value *Op1 = I.getOperand(1);
2565  Value *A, *B;
2566 
2567  // There are 4 commuted variants for each of the basic patterns.
2568 
2569  // (A & B) ^ (A | B) -> A ^ B
2570  // (A & B) ^ (B | A) -> A ^ B
2571  // (A | B) ^ (A & B) -> A ^ B
2572  // (A | B) ^ (B & A) -> A ^ B
2573  if (match(&I, m_c_Xor(m_And(m_Value(A), m_Value(B)),
2574  m_c_Or(m_Deferred(A), m_Deferred(B))))) {
2575  I.setOperand(0, A);
2576  I.setOperand(1, B);
2577  return &I;
2578  }
2579 
2580  // (A | ~B) ^ (~A | B) -> A ^ B
2581  // (~B | A) ^ (~A | B) -> A ^ B
2582  // (~A | B) ^ (A | ~B) -> A ^ B
2583  // (B | ~A) ^ (A | ~B) -> A ^ B
2584  if (match(&I, m_Xor(m_c_Or(m_Value(A), m_Not(m_Value(B))),
2585  m_c_Or(m_Not(m_Deferred(A)), m_Deferred(B))))) {
2586  I.setOperand(0, A);
2587  I.setOperand(1, B);
2588  return &I;
2589  }
2590 
2591  // (A & ~B) ^ (~A & B) -> A ^ B
2592  // (~B & A) ^ (~A & B) -> A ^ B
2593  // (~A & B) ^ (A & ~B) -> A ^ B
2594  // (B & ~A) ^ (A & ~B) -> A ^ B
2595  if (match(&I, m_Xor(m_c_And(m_Value(A), m_Not(m_Value(B))),
2596  m_c_And(m_Not(m_Deferred(A)), m_Deferred(B))))) {
2597  I.setOperand(0, A);
2598  I.setOperand(1, B);
2599  return &I;
2600  }
2601 
2602  // For the remaining cases we need to get rid of one of the operands.
2603  if (!Op0->hasOneUse() && !Op1->hasOneUse())
2604  return nullptr;
2605 
2606  // (A | B) ^ ~(A & B) -> ~(A ^ B)
2607  // (A | B) ^ ~(B & A) -> ~(A ^ B)
2608  // (A & B) ^ ~(A | B) -> ~(A ^ B)
2609  // (A & B) ^ ~(B | A) -> ~(A ^ B)
2610  // Complexity sorting ensures the not will be on the right side.
2611  if ((match(Op0, m_Or(m_Value(A), m_Value(B))) &&
2612  match(Op1, m_Not(m_c_And(m_Specific(A), m_Specific(B))))) ||
2613  (match(Op0, m_And(m_Value(A), m_Value(B))) &&
2614  match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B))))))
2615  return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
2616 
2617  return nullptr;
2618 }
2619 
2620 Value *InstCombiner::foldXorOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
2621  if (predicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
2622  if (LHS->getOperand(0) == RHS->getOperand(1) &&
2623  LHS->getOperand(1) == RHS->getOperand(0))
2624  LHS->swapOperands();
2625  if (LHS->getOperand(0) == RHS->getOperand(0) &&
2626  LHS->getOperand(1) == RHS->getOperand(1)) {
2627  // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
2628  Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
2629  unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
2630  bool IsSigned = LHS->isSigned() || RHS->isSigned();
2631  return getNewICmpValue(Code, IsSigned, Op0, Op1, Builder);
2632  }
2633  }
2634 
2635  // TODO: This can be generalized to compares of non-signbits using
2636  // decomposeBitTestICmp(). It could be enhanced more by using (something like)
2637  // foldLogOpOfMaskedICmps().
2638  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
2639  Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
2640  Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
2641  if ((LHS->hasOneUse() || RHS->hasOneUse()) &&
2642  LHS0->getType() == RHS0->getType() &&
2643  LHS0->getType()->isIntOrIntVectorTy()) {
2644  // (X > -1) ^ (Y > -1) --> (X ^ Y) < 0
2645  // (X < 0) ^ (Y < 0) --> (X ^ Y) < 0
2646  if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_AllOnes()) &&
2647  PredR == CmpInst::ICMP_SGT && match(RHS1, m_AllOnes())) ||
2648  (PredL == CmpInst::ICMP_SLT && match(LHS1, m_Zero()) &&
2649  PredR == CmpInst::ICMP_SLT && match(RHS1, m_Zero()))) {
2650  Value *Zero = ConstantInt::getNullValue(LHS0->getType());
2651  return Builder.CreateICmpSLT(Builder.CreateXor(LHS0, RHS0), Zero);
2652  }
2653  // (X > -1) ^ (Y < 0) --> (X ^ Y) > -1
2654  // (X < 0) ^ (Y > -1) --> (X ^ Y) > -1
2655  if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_AllOnes()) &&
2656  PredR == CmpInst::ICMP_SLT && match(RHS1, m_Zero())) ||
2657  (PredL == CmpInst::ICMP_SLT && match(LHS1, m_Zero()) &&
2658  PredR == CmpInst::ICMP_SGT && match(RHS1, m_AllOnes()))) {
2659  Value *MinusOne = ConstantInt::getAllOnesValue(LHS0->getType());
2660  return Builder.CreateICmpSGT(Builder.CreateXor(LHS0, RHS0), MinusOne);
2661  }
2662  }
2663 
2664  // Instead of trying to imitate the folds for and/or, decompose this 'xor'
2665  // into those logic ops. That is, try to turn this into an and-of-icmps
2666  // because we have many folds for that pattern.
2667  //
2668  // This is based on a truth table definition of xor:
2669  // X ^ Y --> (X | Y) & !(X & Y)
2670  if (Value *OrICmp = SimplifyBinOp(Instruction::Or, LHS, RHS, SQ)) {
2671  // TODO: If OrICmp is true, then the definition of xor simplifies to !(X&Y).
2672  // TODO: If OrICmp is false, the whole thing is false (InstSimplify?).
2673  if (Value *AndICmp = SimplifyBinOp(Instruction::And, LHS, RHS, SQ)) {
2674  // TODO: Independently handle cases where the 'and' side is a constant.
2675  if (OrICmp == LHS && AndICmp == RHS && RHS->hasOneUse()) {
2676  // (LHS | RHS) & !(LHS & RHS) --> LHS & !RHS
2677  RHS->setPredicate(RHS->getInversePredicate());
2678  return Builder.CreateAnd(LHS, RHS);
2679  }
2680  if (OrICmp == RHS && AndICmp == LHS && LHS->hasOneUse()) {
2681  // !(LHS & RHS) & (LHS | RHS) --> !LHS & RHS
2682  LHS->setPredicate(LHS->getInversePredicate());
2683  return Builder.CreateAnd(LHS, RHS);
2684  }
2685  }
2686  }
2687 
2688  return nullptr;
2689 }
2690 
2691 /// If we have a masked merge, in the canonical form of:
2692 /// (assuming that A only has one use.)
2693 /// | A | |B|
2694 /// ((x ^ y) & M) ^ y
2695 /// | D |
2696 /// * If M is inverted:
2697 /// | D |
2698 /// ((x ^ y) & ~M) ^ y
2699 /// We can canonicalize by swapping the final xor operand
2700 /// to eliminate the 'not' of the mask.
2701 /// ((x ^ y) & M) ^ x
2702 /// * If M is a constant, and D has one use, we transform to 'and' / 'or' ops
2703 /// because that shortens the dependency chain and improves analysis:
2704 /// (x & M) | (y & ~M)
2706  InstCombiner::BuilderTy &Builder) {
2707  Value *B, *X, *D;
2708  Value *M;
2709  if (!match(&I, m_c_Xor(m_Value(B),
2710  m_OneUse(m_c_And(
2712  m_Value(D)),
2713  m_Value(M))))))
2714  return nullptr;
2715 
2716  Value *NotM;
2717  if (match(M, m_Not(m_Value(NotM)))) {
2718  // De-invert the mask and swap the value in B part.
2719  Value *NewA = Builder.CreateAnd(D, NotM);
2720  return BinaryOperator::CreateXor(NewA, X);
2721  }
2722 
2723  Constant *C;
2724  if (D->hasOneUse() && match(M, m_Constant(C))) {
2725  // Unfold.
2726  Value *LHS = Builder.CreateAnd(X, C);
2727  Value *NotC = Builder.CreateNot(C);
2728  Value *RHS = Builder.CreateAnd(B, NotC);
2729  return BinaryOperator::CreateOr(LHS, RHS);
2730  }
2731 
2732  return nullptr;
2733 }
2734 
2735 // Transform
2736 // ~(x ^ y)
2737 // into:
2738 // (~x) ^ y
2739 // or into
2740 // x ^ (~y)
2742  InstCombiner::BuilderTy &Builder) {
2743  Value *X, *Y;
2744  // FIXME: one-use check is not needed in general, but currently we are unable
2745  // to fold 'not' into 'icmp', if that 'icmp' has multiple uses. (D35182)
2746  if (!match(&I, m_Not(m_OneUse(m_Xor(m_Value(X), m_Value(Y))))))
2747  return nullptr;
2748 
2749  // We only want to do the transform if it is free to do.
2750  if (IsFreeToInvert(X, X->hasOneUse())) {
2751  // Ok, good.
2752  } else if (IsFreeToInvert(Y, Y->hasOneUse())) {
2753  std::swap(X, Y);
2754  } else
2755  return nullptr;
2756 
2757  Value *NotX = Builder.CreateNot(X, X->getName() + ".not");
2758  return BinaryOperator::CreateXor(NotX, Y, I.getName() + ".demorgan");
2759 }
2760 
2761 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
2762 // here. We should standardize that construct where it is needed or choose some
2763 // other way to ensure that commutated variants of patterns are not missed.
2765  if (Value *V = SimplifyXorInst(I.getOperand(0), I.getOperand(1),
2766  SQ.getWithInstruction(&I)))
2767  return replaceInstUsesWith(I, V);
2768 
2769  if (SimplifyAssociativeOrCommutative(I))
2770  return &I;
2771 
2772  if (Instruction *X = foldVectorBinop(I))
2773  return X;
2774 
2775  if (Instruction *NewXor = foldXorToXor(I, Builder))
2776  return NewXor;
2777 
2778  // (A&B)^(A&C) -> A&(B^C) etc
2779  if (Value *V = SimplifyUsingDistributiveLaws(I))
2780  return replaceInstUsesWith(I, V);
2781 
2782  // See if we can simplify any instructions used by the instruction whose sole
2783  // purpose is to compute bits we don't care about.
2784  if (SimplifyDemandedInstructionBits(I))
2785  return &I;
2786 
2787  if (Value *V = SimplifyBSwap(I, Builder))
2788  return replaceInstUsesWith(I, V);
2789 
2790  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
2791 
2792  // Fold (X & M) ^ (Y & ~M) -> (X & M) | (Y & ~M)
2793  // This it a special case in haveNoCommonBitsSet, but the computeKnownBits
2794  // calls in there are unnecessary as SimplifyDemandedInstructionBits should
2795  // have already taken care of those cases.
2796  Value *M;
2797  if (match(&I, m_c_Xor(m_c_And(m_Not(m_Value(M)), m_Value()),
2798  m_c_And(m_Deferred(M), m_Value()))))
2799  return BinaryOperator::CreateOr(Op0, Op1);
2800 
2801  // Apply DeMorgan's Law for 'nand' / 'nor' logic with an inverted operand.
2802  Value *X, *Y;
2803 
2804  // We must eliminate the and/or (one-use) for these transforms to not increase
2805  // the instruction count.
2806  // ~(~X & Y) --> (X | ~Y)
2807  // ~(Y & ~X) --> (X | ~Y)
2808  if (match(&I, m_Not(m_OneUse(m_c_And(m_Not(m_Value(X)), m_Value(Y)))))) {
2809  Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
2810  return BinaryOperator::CreateOr(X, NotY);
2811  }
2812  // ~(~X | Y) --> (X & ~Y)
2813  // ~(Y | ~X) --> (X & ~Y)
2814  if (match(&I, m_Not(m_OneUse(m_c_Or(m_Not(m_Value(X)), m_Value(Y)))))) {
2815  Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
2816  return BinaryOperator::CreateAnd(X, NotY);
2817  }
2818 
2819  if (Instruction *Xor = visitMaskedMerge(I, Builder))
2820  return Xor;
2821 
2822  // Is this a 'not' (~) fed by a binary operator?
2823  BinaryOperator *NotVal;
2824  if (match(&I, m_Not(m_BinOp(NotVal)))) {
2825  if (NotVal->getOpcode() == Instruction::And ||
2826  NotVal->getOpcode() == Instruction::Or) {
2827  // Apply DeMorgan's Law when inverts are free:
2828  // ~(X & Y) --> (~X | ~Y)
2829  // ~(X | Y) --> (~X & ~Y)
2830  if (IsFreeToInvert(NotVal->getOperand(0),
2831  NotVal->getOperand(0)->hasOneUse()) &&
2832  IsFreeToInvert(NotVal->getOperand(1),
2833  NotVal->getOperand(1)->hasOneUse())) {
2834  Value *NotX = Builder.CreateNot(NotVal->getOperand(0), "notlhs");
2835  Value *NotY = Builder.CreateNot(NotVal->getOperand(1), "notrhs");
2836  if (NotVal->getOpcode() == Instruction::And)
2837  return BinaryOperator::CreateOr(NotX, NotY);
2838  return BinaryOperator::CreateAnd(NotX, NotY);
2839  }
2840  }
2841 
2842  // ~(X - Y) --> ~X + Y
2843  if (match(NotVal, m_Sub(m_Value(X), m_Value(Y))))
2844  if (isa<Constant>(X) || NotVal->hasOneUse())
2845  return BinaryOperator::CreateAdd(Builder.CreateNot(X), Y);
2846 
2847  // ~(~X >>s Y) --> (X >>s Y)
2848  if (match(NotVal, m_AShr(m_Not(m_Value(X)), m_Value(Y))))
2849  return BinaryOperator::CreateAShr(X, Y);
2850 
2851  // If we are inverting a right-shifted constant, we may be able to eliminate
2852  // the 'not' by inverting the constant and using the opposite shift type.
2853  // Canonicalization rules ensure that only a negative constant uses 'ashr',
2854  // but we must check that in case that transform has not fired yet.
2855 
2856  // ~(C >>s Y) --> ~C >>u Y (when inverting the replicated sign bits)
2857  Constant *C;
2858  if (match(NotVal, m_AShr(m_Constant(C), m_Value(Y))) &&
2859  match(C, m_Negative()))
2860  return BinaryOperator::CreateLShr(ConstantExpr::getNot(C), Y);
2861 
2862  // ~(C >>u Y) --> ~C >>s Y (when inverting the replicated sign bits)
2863  if (match(NotVal, m_LShr(m_Constant(C), m_Value(Y))) &&
2864  match(C, m_NonNegative()))
2865  return BinaryOperator::CreateAShr(ConstantExpr::getNot(C), Y);
2866 
2867  // ~(X + C) --> -(C + 1) - X
2868  if (match(Op0, m_Add(m_Value(X), m_Constant(C))))
2869  return BinaryOperator::CreateSub(ConstantExpr::getNeg(AddOne(C)), X);
2870  }
2871 
2872  // Use DeMorgan and reassociation to eliminate a 'not' op.
2873  Constant *C1;
2874  if (match(Op1, m_Constant(C1))) {
2875  Constant *C2;
2876  if (match(Op0, m_OneUse(m_Or(m_Not(m_Value(X)), m_Constant(C2))))) {
2877  // (~X | C2) ^ C1 --> ((X & ~C2) ^ -1) ^ C1 --> (X & ~C2) ^ ~C1
2878  Value *And = Builder.CreateAnd(X, ConstantExpr::getNot(C2));
2879  return BinaryOperator::CreateXor(And, ConstantExpr::getNot(C1));
2880  }
2881  if (match(Op0, m_OneUse(m_And(m_Not(m_Value(X)), m_Constant(C2))))) {
2882  // (~X & C2) ^ C1 --> ((X | ~C2) ^ -1) ^ C1 --> (X | ~C2) ^ ~C1
2883  Value *Or = Builder.CreateOr(X, ConstantExpr::getNot(C2));
2884  return BinaryOperator::CreateXor(Or, ConstantExpr::getNot(C1));
2885  }
2886  }
2887 
2888  // not (cmp A, B) = !cmp A, B
2889  CmpInst::Predicate Pred;
2890  if (match(&I, m_Not(m_OneUse(m_Cmp(Pred, m_Value(), m_Value()))))) {
2891  cast<CmpInst>(Op0)->setPredicate(CmpInst::getInversePredicate(Pred));
2892  return replaceInstUsesWith(I, Op0);
2893  }
2894 
2895  {
2896  const APInt *RHSC;
2897  if (match(Op1, m_APInt(RHSC))) {
2898  Value *X;
2899  const APInt *C;
2900  if (RHSC->isSignMask() && match(Op0, m_Sub(m_APInt(C), m_Value(X)))) {
2901  // (C - X) ^ signmask -> (C + signmask - X)
2902  Constant *NewC = ConstantInt::get(I.getType(), *C + *RHSC);
2903  return BinaryOperator::CreateSub(NewC, X);
2904  }
2905  if (RHSC->isSignMask() && match(Op0, m_Add(m_Value(X), m_APInt(C)))) {
2906  // (X + C) ^ signmask -> (X + C + signmask)
2907  Constant *NewC = ConstantInt::get(I.getType(), *C + *RHSC);
2908  return BinaryOperator::CreateAdd(X, NewC);
2909  }
2910 
2911  // (X|C1)^C2 -> X^(C1^C2) iff X&~C1 == 0
2912  if (match(Op0, m_Or(m_Value(X), m_APInt(C))) &&
2913  MaskedValueIsZero(X, *C, 0, &I)) {
2914  Constant *NewC = ConstantInt::get(I.getType(), *C ^ *RHSC);
2915  Worklist.Add(cast<Instruction>(Op0));
2916  I.setOperand(0, X);
2917  I.setOperand(1, NewC);
2918  return &I;
2919  }
2920  }
2921  }
2922 
2923  if (ConstantInt *RHSC = dyn_cast<ConstantInt>(Op1)) {
2924  if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
2925  if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
2926  if (Op0I->getOpcode() == Instruction::LShr) {
2927  // ((X^C1) >> C2) ^ C3 -> (X>>C2) ^ ((C1>>C2)^C3)
2928  // E1 = "X ^ C1"
2929  BinaryOperator *E1;
2930  ConstantInt *C1;
2931  if (Op0I->hasOneUse() &&
2932  (E1 = dyn_cast<BinaryOperator>(Op0I->getOperand(0))) &&
2933  E1->getOpcode() == Instruction::Xor &&
2934  (C1 = dyn_cast<ConstantInt>(E1->getOperand(1)))) {
2935  // fold (C1 >> C2) ^ C3
2936  ConstantInt *C2 = Op0CI, *C3 = RHSC;
2937  APInt FoldConst = C1->getValue().lshr(C2->getValue());
2938  FoldConst ^= C3->getValue();
2939  // Prepare the two operands.
2940  Value *Opnd0 = Builder.CreateLShr(E1->getOperand(0), C2);
2941  Opnd0->takeName(Op0I);
2942  cast<Instruction>(Opnd0)->setDebugLoc(I.getDebugLoc());
2943  Value *FoldVal = ConstantInt::get(Opnd0->getType(), FoldConst);
2944 
2945  return BinaryOperator::CreateXor(Opnd0, FoldVal);
2946  }
2947  }
2948  }
2949  }
2950  }
2951 
2952  if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
2953  return FoldedLogic;
2954 
2955  // Y ^ (X | Y) --> X & ~Y
2956  // Y ^ (Y | X) --> X & ~Y
2957  if (match(Op1, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op0)))))
2958  return BinaryOperator::CreateAnd(X, Builder.CreateNot(Op0));
2959  // (X | Y) ^ Y --> X & ~Y
2960  // (Y | X) ^ Y --> X & ~Y
2961  if (match(Op0, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op1)))))
2962  return BinaryOperator::CreateAnd(X, Builder.CreateNot(Op1));
2963 
2964  // Y ^ (X & Y) --> ~X & Y
2965  // Y ^ (Y & X) --> ~X & Y
2966  if (match(Op1, m_OneUse(m_c_And(m_Value(X), m_Specific(Op0)))))
2967  return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(X));
2968  // (X & Y) ^ Y --> ~X & Y
2969  // (Y & X) ^ Y --> ~X & Y
2970  // Canonical form is (X & C) ^ C; don't touch that.
2971  // TODO: A 'not' op is better for analysis and codegen, but demanded bits must
2972  // be fixed to prefer that (otherwise we get infinite looping).
2973  if (!match(Op1, m_Constant()) &&
2974  match(Op0, m_OneUse(m_c_And(m_Value(X), m_Specific(Op1)))))
2975  return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(X));
2976 
2977  Value *A, *B, *C;
2978  // (A ^ B) ^ (A | C) --> (~A & C) ^ B -- There are 4 commuted variants.
2979  if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_Value(A), m_Value(B))),
2980  m_OneUse(m_c_Or(m_Deferred(A), m_Value(C))))))
2981  return BinaryOperator::CreateXor(
2982  Builder.CreateAnd(Builder.CreateNot(A), C), B);
2983 
2984  // (A ^ B) ^ (B | C) --> (~B & C) ^ A -- There are 4 commuted variants.
2985  if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_Value(A), m_Value(B))),
2986  m_OneUse(m_c_Or(m_Deferred(B), m_Value(C))))))
2987  return BinaryOperator::CreateXor(
2988  Builder.CreateAnd(Builder.CreateNot(B), C), A);
2989 
2990  // (A & B) ^ (A ^ B) -> (A | B)
2991  if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
2992  match(Op1, m_c_Xor(m_Specific(A), m_Specific(B))))
2993  return BinaryOperator::CreateOr(A, B);
2994  // (A ^ B) ^ (A & B) -> (A | B)
2995  if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
2996  match(Op1, m_c_And(m_Specific(A), m_Specific(B))))
2997  return BinaryOperator::CreateOr(A, B);
2998 
2999  // (A & ~B) ^ ~A -> ~(A & B)
3000  // (~B & A) ^ ~A -> ~(A & B)
3001  if (match(Op0, m_c_And(m_Value(A), m_Not(m_Value(B)))) &&
3002  match(Op1, m_Not(m_Specific(A))))
3003  return BinaryOperator::CreateNot(Builder.CreateAnd(A, B));
3004 
3005  if (auto *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
3006  if (auto *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
3007  if (Value *V = foldXorOfICmps(LHS, RHS))
3008  return replaceInstUsesWith(I, V);
3009 
3010  if (Instruction *CastedXor = foldCastedBitwiseLogic(I))
3011  return CastedXor;
3012 
3013  // Canonicalize a shifty way to code absolute value to the common pattern.
3014  // There are 4 potential commuted variants. Move the 'ashr' candidate to Op1.
3015  // We're relying on the fact that we only do this transform when the shift has
3016  // exactly 2 uses and the add has exactly 1 use (otherwise, we might increase
3017  // instructions).
3018  if (Op0->hasNUses(2))
3019  std::swap(Op0, Op1);
3020 
3021  const APInt *ShAmt;
3022  Type *Ty = I.getType();
3023  if (match(Op1, m_AShr(m_Value(A), m_APInt(ShAmt))) &&
3024  Op1->hasNUses(2) && *ShAmt == Ty->getScalarSizeInBits() - 1 &&
3025  match(Op0, m_OneUse(m_c_Add(m_Specific(A), m_Specific(Op1))))) {
3026  // B = ashr i32 A, 31 ; smear the sign bit
3027  // xor (add A, B), B ; add -1 and flip bits if negative
3028  // --> (A < 0) ? -A : A
3029  Value *Cmp = Builder.CreateICmpSLT(A, ConstantInt::getNullValue(Ty));
3030  // Copy the nuw/nsw flags from the add to the negate.
3031  auto *Add = cast<BinaryOperator>(Op0);
3032  Value *Neg = Builder.CreateNeg(A, "", Add->hasNoUnsignedWrap(),
3033  Add->hasNoSignedWrap());
3034  return SelectInst::Create(Cmp, Neg, A);
3035  }
3036 
3037  // Eliminate a bitwise 'not' op of 'not' min/max by inverting the min/max:
3038  //
3039  // %notx = xor i32 %x, -1
3040  // %cmp1 = icmp sgt i32 %notx, %y
3041  // %smax = select i1 %cmp1, i32 %notx, i32 %y
3042  // %res = xor i32 %smax, -1
3043  // =>
3044  // %noty = xor i32 %y, -1
3045  // %cmp2 = icmp slt %x, %noty
3046  // %res = select i1 %cmp2, i32 %x, i32 %noty
3047  //
3048  // Same is applicable for smin/umax/umin.
3049  if (match(Op1, m_AllOnes()) && Op0->hasOneUse()) {
3050  Value *LHS, *RHS;
3051  SelectPatternFlavor SPF = matchSelectPattern(Op0, LHS, RHS).Flavor;
3053  // It's possible we get here before the not has been simplified, so make
3054  // sure the input to the not isn't freely invertible.
3055  if (match(LHS, m_Not(m_Value(X))) && !IsFreeToInvert(X, X->hasOneUse())) {
3056  Value *NotY = Builder.CreateNot(RHS);
3057  return SelectInst::Create(
3058  Builder.CreateICmp(getInverseMinMaxPred(SPF), X, NotY), X, NotY);
3059  }
3060 
3061  // It's possible we get here before the not has been simplified, so make
3062  // sure the input to the not isn't freely invertible.
3063  if (match(RHS, m_Not(m_Value(Y))) && !IsFreeToInvert(Y, Y->hasOneUse())) {
3064  Value *NotX = Builder.CreateNot(LHS);
3065  return SelectInst::Create(
3066  Builder.CreateICmp(getInverseMinMaxPred(SPF), NotX, Y), NotX, Y);
3067  }
3068 
3069  // If both sides are freely invertible, then we can get rid of the xor
3070  // completely.
3071  if (IsFreeToInvert(LHS, !LHS->hasNUsesOrMore(3)) &&
3072  IsFreeToInvert(RHS, !RHS->hasNUsesOrMore(3))) {
3073  Value *NotLHS = Builder.CreateNot(LHS);
3074  Value *NotRHS = Builder.CreateNot(RHS);
3075  return SelectInst::Create(
3076  Builder.CreateICmp(getInverseMinMaxPred(SPF), NotLHS, NotRHS),
3077  NotLHS, NotRHS);
3078  }
3079  }
3080  }
3081 
3082  if (Instruction *NewXor = sinkNotIntoXor(I, Builder))
3083  return NewXor;
3084 
3085  return nullptr;
3086 }
const NoneType None
Definition: None.h:23
BinaryOp_match< LHS, RHS, Instruction::And > m_And(const LHS &L, const RHS &R)
Definition: PatternMatch.h:796
uint64_t CallInst * C
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...
IntegerType * getType() const
getType - Specialize the getType() method to always return an IntegerType, which reduces the amount o...
Definition: Constants.h:171
Constant * getPredForICmpCode(unsigned Code, bool Sign, Type *OpTy, CmpInst::Predicate &Pred)
This is the complement of getICmpCode.
cst_pred_ty< is_nonnegative > m_NonNegative()
Match an integer or vector of nonnegative values.
Definition: PatternMatch.h:342
static ConstantInt * getFalse(LLVMContext &Context)
Definition: Constants.cpp:606
class_match< Value > m_Value()
Match an arbitrary value and ignore it.
Definition: PatternMatch.h:70
Value * CreateICmp(CmpInst::Predicate P, Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2198
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
bool isSignMask() const
Check if the APInt&#39;s value is returned by getSignMask.
Definition: APInt.h:472
Type * getSrcTy() const
Return the source type, as a convenience.
Definition: InstrTypes.h:697
static bool IsFreeToInvert(Value *V, bool WillInvertAllUses)
Return true if the specified value is free to invert (apply ~ to).
class_match< CmpInst > m_Cmp()
Matches any compare instruction and ignore it.
Definition: PatternMatch.h:78
static Value * getFCmpValue(unsigned Code, Value *LHS, Value *RHS, InstCombiner::BuilderTy &Builder)
This is the complement of getFCmpCode, which turns an opcode and two operands into either a FCmp inst...
Instruction * visitXor(BinaryOperator &I)
Value * CreateBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:1458
ThreeOps_match< Cond, LHS, RHS, Instruction::Select > m_Select(const Cond &C, const LHS &L, const RHS &R)
Matches SelectInst.
static Value * foldSignedTruncationCheck(ICmpInst *ICmp0, ICmpInst *ICmp1, Instruction &CxtI, InstCombiner::BuilderTy &Builder)
General pattern: X & Y.
BinaryOp_match< LHS, RHS, Instruction::Sub > m_Sub(const LHS &L, const RHS &R)
Definition: PatternMatch.h:693
Instruction * visitOr(BinaryOperator &I)
is_zero m_Zero()
Match any null constant or a vector with all elements equal to 0.
Definition: PatternMatch.h:375
static BinaryOperator * CreateNot(Value *Op, const Twine &Name="", Instruction *InsertBefore=nullptr)
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2092
static Type * makeCmpResultType(Type *opnd_type)
Create a result type for fcmp/icmp.
Definition: InstrTypes.h:975
This class represents lattice values for constants.
Definition: AllocatorList.h:23
BinaryOps getOpcode() const
Definition: InstrTypes.h:402
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.
Value * CreateICmpULT(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2104
Value * CreateXor(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1320
bool decomposeBitTestICmp(Value *LHS, Value *RHS, CmpInst::Predicate &Pred, Value *&X, APInt &Mask, bool LookThroughTrunc=true)
Decompose an icmp into the form ((X & Mask) pred 0) if possible.
static CallInst * Create(FunctionType *Ty, Value *F, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
static unsigned getFCmpCode(FCmpInst::Predicate CC)
Similar to getICmpCode but for FCmpInst.
This class represents zero extension of integer types.
unsigned getICmpCode(const ICmpInst *ICI, bool InvertPred=false)
Encode a icmp predicate into a three bit mask.
BinaryOp_match< LHS, RHS, Instruction::Mul > m_Mul(const LHS &L, const RHS &R)
Definition: PatternMatch.h:748
static bool areInverseVectorBitmasks(Constant *C1, Constant *C2)
If all elements of two constant vectors are 0/-1 and inverses, return true.
APInt zext(unsigned width) const
Zero extend to a new width.
Definition: APInt.cpp:860
static APInt getLowBitsSet(unsigned numBits, unsigned loBitsSet)
Get a value with low bits set.
Definition: APInt.h:647
class_match< Constant > m_Constant()
Match an arbitrary Constant and ignore it.
Definition: PatternMatch.h:89
m_Intrinsic_Ty< Opnd0 >::Ty m_BSwap(const Opnd0 &Op0)
unsigned less or equal
Definition: InstrTypes.h:758
unsigned less than
Definition: InstrTypes.h:757
BinaryOp_match< LHS, RHS, Instruction::AShr > m_AShr(const LHS &L, const RHS &R)
Definition: PatternMatch.h:826
bool isSubsetOf(const APInt &RHS) const
This operation checks that all bits set in this APInt are also set in RHS.
Definition: APInt.h:1328
0 1 0 0 True if ordered and less than
Definition: InstrTypes.h:738
static SelectInst * Create(Value *C, Value *S1, Value *S2, const Twine &NameStr="", Instruction *InsertBefore=nullptr, Instruction *MDFrom=nullptr)
1 1 1 0 True if unordered or not equal
Definition: InstrTypes.h:748
bool sgt(const APInt &RHS) const
Signed greather than comparison.
Definition: APInt.h:1273
static Instruction * reassociateFCmps(BinaryOperator &BO, InstCombiner::BuilderTy &Builder)
This a limited reassociation for a special case (see above) where we are checking if two values are e...
MaskedICmpType
Classify (icmp eq (A & B), C) and (icmp ne (A & B), C) as matching patterns that can be simplified...
static Value * SimplifyBSwap(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
Transform BITWISE_OP(BSWAP(A),BSWAP(B)) or BITWISE_OP(BSWAP(A), Constant) to BSWAP(BITWISE_OP(A, B))
F(f)
This class represents a sign extension of integer types.
#define R2(n)
bool isVectorTy() const
True if this is an instance of VectorType.
Definition: Type.h:229
bool sle(const APInt &RHS) const
Signed less or equal comparison.
Definition: APInt.h:1238
AnyBinaryOp_match< LHS, RHS, true > m_c_BinOp(const LHS &L, const RHS &R)
Matches a BinaryOperator with LHS and RHS in either order.
static bool isBitwiseLogicOp(unsigned Opcode)
Determine if the Opcode is and/or/xor.
Definition: Instruction.h:175
cst_pred_ty< is_zero_int > m_ZeroInt()
Match an integer 0 or a vector with all elements equal to 0.
Definition: PatternMatch.h:363
Value * SimplifyOrInst(Value *LHS, Value *RHS, const SimplifyQuery &Q)
Given operands for an Or, fold the result or return null.
BinOpPred_match< LHS, RHS, is_logical_shift_op > m_LogicalShift(const LHS &L, const RHS &R)
Matches logical shift operations.
Definition: PatternMatch.h:988
LLVMContext & getContext() const
Return the LLVMContext in which this type was uniqued.
Definition: Type.h:129
static Constant * getNullValue(Type *Ty)
Constructor to create a &#39;0&#39; constant of arbitrary type.
Definition: Constants.cpp:274
Value * CreateNot(Value *V, const Twine &Name="")
Definition: IRBuilder.h:1524
1 0 0 1 True if unordered or equal
Definition: InstrTypes.h:743
static GCMetadataPrinterRegistry::Add< OcamlGCMetadataPrinter > Y("ocaml", "ocaml 3.10-compatible collector")
bool match(Val *V, const Pattern &P)
Definition: PatternMatch.h:47
1 0 0 0 True if unordered: isnan(X) | isnan(Y)
Definition: InstrTypes.h:742
CmpClass_match< LHS, RHS, FCmpInst, FCmpInst::Predicate > m_FCmp(FCmpInst::Predicate &Pred, const LHS &L, const RHS &R)
bool isSigned() const
Definition: InstrTypes.h:902
BinaryOp_match< LHS, RHS, Instruction::Xor > m_Xor(const LHS &L, const RHS &R)
Definition: PatternMatch.h:808
bool isKnownToBeAPowerOfTwo(const Value *V, const DataLayout &DL, bool OrZero=false, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, bool UseInstrInfo=true)
Return true if the given value is known to have exactly one bit set when defined. ...
Predicate getInversePredicate() const
For example, EQ -> NE, UGT -> ULE, SLT -> SGE, OEQ -> UNE, UGT -> OLE, OLT -> UGE, etc.
Definition: InstrTypes.h:831
This is the base class for all instructions that perform data casts.
Definition: InstrTypes.h:439
static Value * getNewICmpValue(unsigned Code, bool Sign, Value *LHS, Value *RHS, InstCombiner::BuilderTy &Builder)
This is the complement of getICmpCode, which turns an opcode and two operands into either a constant ...
APInt shl(unsigned shiftAmt) const
Left-shift function.
Definition: APInt.h:992
static Optional< unsigned > getOpcode(ArrayRef< VPValue *> Values)
Returns the opcode of Values or ~0 if they do not all agree.
Definition: VPlanSLP.cpp:196
CastClass_match< OpTy, Instruction::Trunc > m_Trunc(const OpTy &Op)
Matches Trunc.
bool isIntegerTy() const
True if this is an instance of IntegerType.
Definition: Type.h:196
static Constant * AddOne(Constant *C)
Add one to a Constant.
0 1 0 1 True if ordered and less than or equal
Definition: InstrTypes.h:739
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 &#39;V & Mask&#39; is known to be zero.
static Constant * getSExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1672
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1118
BinaryOp_match< LHS, RHS, Instruction::Add > m_Add(const LHS &L, const RHS &R)
Definition: PatternMatch.h:681
static Constant * getZExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1686
static Value * foldLogOpOfMaskedICmps_NotAllZeros_BMask_Mixed(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd, Value *A, Value *B, Value *C, Value *D, Value *E, ICmpInst::Predicate PredL, ICmpInst::Predicate PredR, llvm::InstCombiner::BuilderTy &Builder)
Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y)...
static Value * peekThroughBitcast(Value *V, bool OneUseOnly=false)
Return the source operand of a potentially bitcasted value while optionally checking if it has one us...
Instruction::CastOps getOpcode() const
Return the opcode of this CastInst.
Definition: InstrTypes.h:692
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:244
CastClass_match< OpTy, Instruction::ZExt > m_ZExt(const OpTy &Op)
Matches ZExt.
This instruction compares its operands according to the predicate given to the constructor.
static Value * foldIsPowerOf2(ICmpInst *Cmp0, ICmpInst *Cmp1, bool JoinedByAnd, InstCombiner::BuilderTy &Builder)
Reduce a pair of compares that check if a value has exactly 1 bit set.
class_match< ConstantInt > m_ConstantInt()
Match an arbitrary ConstantInt and ignore it.
Definition: PatternMatch.h:81
static Value * foldAndOrOfEqualityCmpsWithConstants(ICmpInst *LHS, ICmpInst *RHS, bool JoinedByAnd, InstCombiner::BuilderTy &Builder)
const APInt & getValue() const
Return the constant as an APInt value reference.
Definition: Constants.h:137
unsigned getOpcode() const
Returns a member of one of the enums like Instruction::Add.
Definition: Instruction.h:125
cstfp_pred_ty< is_pos_zero_fp > m_PosZeroFP()
Match a floating-point positive zero.
Definition: PatternMatch.h:484
bool isMinusOne() const
This function will return true iff every bit in this constant is set to true.
Definition: Constants.h:208
bool isIntOrIntVectorTy() const
Return true if this is an integer type or a vector of integer types.
Definition: Type.h:202
cst_pred_ty< is_power2 > m_Power2()
Match an integer or vector power-of-2.
Definition: PatternMatch.h:384
unsigned getBitWidth() const
Get the number of bits in this IntegerType.
Definition: DerivedTypes.h:66
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:291
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:1043
static BinaryOperator * CreateAdd(Value *S1, Value *S2, const Twine &Name, Instruction *InsertBefore, Value *FlagsOp)
Value * getOperand(unsigned i) const
Definition: User.h:169
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1294
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:344
Value * CreateFCmp(CmpInst::Predicate P, Value *LHS, Value *RHS, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2206
OneUse_match< T > m_OneUse(const T &SubPattern)
Definition: PatternMatch.h:61
static Optional< std::pair< unsigned, unsigned > > getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C, Value *&D, Value *&E, ICmpInst *LHS, ICmpInst *RHS, ICmpInst::Predicate &PredL, ICmpInst::Predicate &PredR)
Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E).
unsigned ComputeNumSignBits(const Value *Op, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr, bool UseInstrInfo=true)
Return the number of times the sign bit of the register is replicated into the other bits...
BinaryOp_match< LHS, RHS, Instruction::LShr > m_LShr(const LHS &L, const RHS &R)
Definition: PatternMatch.h:820
bool hasNUsesOrMore(unsigned N) const
Return true if this value has N users or more.
Definition: Value.cpp:135
static Instruction * foldOrToXor(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
bool isAllOnesValue() const
Determine if all bits are set.
Definition: APInt.h:395
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
bool hasNUses(unsigned N) const
Return true if this Value has exactly N users.
Definition: Value.cpp:131
apint_match m_APInt(const APInt *&Res)
Match a ConstantInt or splatted ConstantVector, binding the specified pointer to the contained APInt...
Definition: PatternMatch.h:175
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.
static unsigned getMaskedICmpType(Value *A, Value *B, Value *C, ICmpInst::Predicate Pred)
Return the set of patterns (from MaskedICmpType) that (icmp SCC (A & B), C) satisfies.
constexpr bool isPowerOf2_32(uint32_t Value)
Return true if the argument is a power of two > 0.
Definition: MathExtras.h:428
static Instruction * matchRotate(Instruction &Or)
Transform UB-safe variants of bitwise rotate to the funnel shift intrinsic.
static bool canNarrowShiftAmt(Constant *C, unsigned BitWidth)
Return true if a constant shift amount is always less than the specified bit-width.
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
BinaryOp_match< LHS, RHS, Instruction::Or > m_Or(const LHS &L, const RHS &R)
Definition: PatternMatch.h:802
bool ult(const APInt &RHS) const
Unsigned less than comparison.
Definition: APInt.h:1184
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
This is an important base class in LLVM.
Definition: Constant.h:41
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.
static Constant * getAnd(Constant *C1, Constant *C2)
Definition: Constants.cpp:2299
bool isOneValue() const
Determine if this is a value of 1.
Definition: APInt.h:410
cst_pred_ty< is_all_ones > m_AllOnes()
Match an integer or vector with all bits set.
Definition: PatternMatch.h:308
specificval_ty m_Specific(const Value *V)
Match if we have a specific specified value.
Definition: PatternMatch.h:541
bool isMinSignedValue() const
Determine if this is the smallest signed value.
Definition: APInt.h:442
BinaryOp_match< LHS, RHS, Instruction::Shl > m_Shl(const LHS &L, const RHS &R)
Definition: PatternMatch.h:814
This instruction compares its operands according to the predicate given to the constructor.
Predicate
This enumeration lists the possible predicates for CmpInst subclasses.
Definition: InstrTypes.h:732
0 1 1 1 True if ordered (no nans)
Definition: InstrTypes.h:741
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2088
class_match< BinaryOperator > m_BinOp()
Match an arbitrary binary operation and ignore it.
Definition: PatternMatch.h:73
static unsigned conjugateICmpMask(unsigned Mask)
Convert an analysis of a masked ICmp into its equivalent if all boolean operations had the opposite s...
bool isIntN(unsigned N) const
Check if this APInt has an N-bits unsigned integer value.
Definition: APInt.h:449
CmpInst::Predicate getInverseMinMaxPred(SelectPatternFlavor SPF)
Return the canonical inverse comparison predicate for the specified minimum/maximum flavor...
static Constant * getNot(Constant *C)
Definition: Constants.cpp:2234
static Constant * getAllOnesValue(Type *Ty)
Definition: Constants.cpp:328
1 1 1 1 Always true (always folded)
Definition: InstrTypes.h:749
void swapOperands()
Exchange the two operands to this instruction in such a way that it does not modify the semantics of ...
static Instruction * matchDeMorgansLaws(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
Match De Morgan&#39;s Laws: (~A & ~B) == (~(A | B)) (~A | ~B) == (~(A & B))
1 1 0 1 True if unordered, less than, or equal
Definition: InstrTypes.h:747
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
deferredval_ty< Value > m_Deferred(Value *const &V)
A commutative-friendly version of m_Specific().
Definition: PatternMatch.h:554
APInt lshr(unsigned shiftAmt) const
Logical right-shift function.
Definition: APInt.h:970
signed greater than
Definition: InstrTypes.h:759
Instruction * visitAnd(BinaryOperator &I)
const APInt & umin(const APInt &A, const APInt &B)
Determine the smaller of two APInts considered to be signed.
Definition: APInt.h:2114
CastClass_match< OpTy, Instruction::SExt > m_SExt(const OpTy &Op)
Matches SExt.
static Value * foldLogOpOfMaskedICmpsAsymmetric(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd, Value *A, Value *B, Value *C, Value *D, Value *E, ICmpInst::Predicate PredL, ICmpInst::Predicate PredR, unsigned LHSMask, unsigned RHSMask, llvm::InstCombiner::BuilderTy &Builder)
Try to fold (icmp(A & B) ==/!= 0) &/| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y), where the left-hand ...
0 0 1 0 True if ordered and greater than
Definition: InstrTypes.h:736
cst_pred_ty< is_negative > m_Negative()
Match an integer or vector of negative values.
Definition: PatternMatch.h:330
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.
This is the shared class of boolean and integer constants.
Definition: Constants.h:83
SelectPatternFlavor Flavor
unsigned getScalarSizeInBits() const LLVM_READONLY
If this is a vector type, return the getPrimitiveSizeInBits value for the element type...
Definition: Type.cpp:129
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
1 1 0 0 True if unordered or less than
Definition: InstrTypes.h:746
SelectPatternFlavor
Specific patterns of select instructions we can match.
signed less than
Definition: InstrTypes.h:761
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:374
static Constant * getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1658
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
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:643
static ConstantInt * getSigned(IntegerType *Ty, int64_t V)
Return a ConstantInt with the specified value for the specified type.
Definition: Constants.cpp:657
Predicate getSignedPredicate() const
For example, EQ->EQ, SLE->SLE, UGT->SGT, etc.
Type * getDestTy() const
Return the destination type, as a convenience.
Definition: InstrTypes.h:699
static ConstantInt * getTrue(LLVMContext &Context)
Definition: Constants.cpp:599
void setPredicate(Predicate P)
Set the predicate for this instruction to the specified value.
Definition: InstrTypes.h:812
void setOperand(unsigned i, Value *Val)
Definition: User.h:174
BinaryOp_match< cst_pred_ty< is_zero_int >, ValTy, Instruction::Sub > m_Neg(const ValTy &V)
Matches a &#39;Neg&#39; as &#39;sub 0, V&#39;.
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:940
unsigned getVectorNumElements() const
Definition: DerivedTypes.h:535
signed less or equal
Definition: InstrTypes.h:762
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
Definition: Instruction.cpp:55
Class for arbitrary precision integers.
Definition: APInt.h:69
bool ule(const APInt &RHS) const
Unsigned less or equal comparison.
Definition: APInt.h:1222
bool isPowerOf2() const
Check if this APInt&#39;s value is a power of two greater than zero.
Definition: APInt.h:463
static Instruction * sinkNotIntoXor(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static BinaryOperator * Create(BinaryOps Op, Value *S1, Value *S2, const Twine &Name=Twine(), Instruction *InsertBefore=nullptr)
Construct a binary instruction, given the opcode and the two operands.
void removeFromParent()
This method unlinks &#39;this&#39; from the containing basic block, but does not delete it.
Definition: Instruction.cpp:63
static Instruction * foldAndToXor(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static Constant * getNeg(Constant *C, bool HasNUW=false, bool HasNSW=false)
Definition: Constants.cpp:2221
Value * SimplifyAndInst(Value *LHS, Value *RHS, const SimplifyQuery &Q)
Given operands for an And, fold the result or return null.
static Value * foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd, llvm::InstCombiner::BuilderTy &Builder)
Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single (icmp(A & X) ==/!= Y)...
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&#39;s ...
bool ugt(const APInt &RHS) const
Unsigned greather than comparison.
Definition: APInt.h:1254
Predicate getPredicate() const
Return the predicate for this instruction.
Definition: InstrTypes.h:807
const DebugLoc & getDebugLoc() const
Return the debug location for this node as a DebugLoc.
Definition: Instruction.h:321
bool intersects(const APInt &RHS) const
This operation tests if there are any pairs of corresponding bits between this APInt and RHS that are...
Definition: APInt.h:1320
static bool isMinOrMax(SelectPatternFlavor SPF)
When implementing this min/max pattern as fcmp; select, does the fcmp have to be ordered?
unsigned greater or equal
Definition: InstrTypes.h:756
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:214
bool isEquality() const
Return true if this predicate is either EQ or NE.
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
static Constant * getOr(Constant *C1, Constant *C2)
Definition: Constants.cpp:2303
bool isZero() const
This is just a convenience method to make client code smaller for a common code.
Definition: Constants.h:192
0 1 1 0 True if ordered and operands are unequal
Definition: InstrTypes.h:740
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:332
Value * SimplifyXorInst(Value *LHS, Value *RHS, const SimplifyQuery &Q)
Given operands for an Xor, fold the result or return null.
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value *> Args=None, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2223
1 0 1 0 True if unordered or greater than
Definition: InstrTypes.h:744
APInt byteSwap() const
Definition: APInt.cpp:620
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1268
bool isMinValue() const
Determine if this is the smallest unsigned value.
Definition: APInt.h:436
Value * SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, const SimplifyQuery &Q)
Given operands for a BinaryOperator, fold the result or return null.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
0 0 0 1 True if ordered and equal
Definition: InstrTypes.h:735
LLVM Value Representation.
Definition: Value.h:72
This file provides internal interfaces used to implement the InstCombine.
1 0 1 1 True if unordered, greater than, or equal
Definition: InstrTypes.h:745
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...
cst_pred_ty< is_one > m_One()
Match an integer 1 or a vector with all elements equal to 1.
Definition: PatternMatch.h:354
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:80
match_combine_and< LTy, RTy > m_CombineAnd(const LTy &L, const RTy &R)
Combine two pattern matchers matching L && R.
Definition: PatternMatch.h:129
static Instruction * visitMaskedMerge(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
If we have a masked merge, in the canonical form of: (assuming that A only has one use...
bool hasOneUse() const
Return true if there is exactly one user of this value.
Definition: Value.h:412
unsigned greater than
Definition: InstrTypes.h:755
Predicate getSwappedPredicate() const
For example, EQ->EQ, SLE->SGE, ULT->UGT, OEQ->OEQ, ULE->UGE, OLT->OGT, etc.
Definition: InstrTypes.h:847
bool isNonNegative() const
Returns true if this value is known to be non-negative.
Definition: KnownBits.h:98
Value * simplifyRangeCheck(ICmpInst *Cmp0, ICmpInst *Cmp1, bool Inverted)
Try to fold a signed range checked with lower bound 0 to an unsigned icmp.
bool recognizeBSwapOrBitReverseIdiom(Instruction *I, bool MatchBSwaps, bool MatchBitReversals, SmallVectorImpl< Instruction *> &InsertedInsts)
Try to match a bswap or bitreverse idiom.
Definition: Local.cpp:2782
specific_intval m_SpecificInt(uint64_t V)
Match a specific integer value or vector with all elements equal to the value.
Definition: PatternMatch.h:618
cstfp_pred_ty< is_any_zero_fp > m_AnyZeroFP()
Match a floating-point negative zero or positive zero.
Definition: PatternMatch.h:475
0 0 1 1 True if ordered and greater than or equal
Definition: InstrTypes.h:737
static Instruction * foldLogicCastConstant(BinaryOperator &Logic, CastInst *Cast, InstCombiner::BuilderTy &Builder)
Fold {and,or,xor} (cast X), C.
static Constant * SubOne(Constant *C)
Subtract one from a Constant.
bool predicatesFoldable(CmpInst::Predicate P1, CmpInst::Predicate P2)
Return true if both predicates match sign or if at least one of them is an equality comparison (which...
static Instruction * foldXorToXor(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
A ^ B can be specified using other logic ops in a variety of patterns.
BinaryOp_match< ValTy, cst_pred_ty< is_all_ones >, Instruction::Xor, true > m_Not(const ValTy &V)
Matches a &#39;Not&#39; as &#39;xor V, -1&#39; or &#39;xor -1, V&#39;.
bool isNullValue() const
Determine if all bits are clear.
Definition: APInt.h:405
0 0 0 0 Always false (always folded)
Definition: InstrTypes.h:734
signed greater or equal
Definition: InstrTypes.h:760
CmpClass_match< LHS, RHS, ICmpInst, ICmpInst::Predicate > m_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R)
static Constant * getXor(Constant *C1, Constant *C2)
Definition: Constants.cpp:2307