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.slt(Hi) : Lo.ult(Hi)) &&
168  "Lo is not < Hi in range emission code!");
169 
170  Type *Ty = V->getType();
171 
172  // V >= Min && V < Hi --> V < Hi
173  // V < Min || V >= Hi --> V >= Hi
175  if (isSigned ? Lo.isMinSignedValue() : Lo.isMinValue()) {
176  Pred = isSigned ? ICmpInst::getSignedPredicate(Pred) : Pred;
177  return Builder.CreateICmp(Pred, V, ConstantInt::get(Ty, Hi));
178  }
179 
180  // V >= Lo && V < Hi --> V - Lo u< Hi - Lo
181  // V < Lo || V >= Hi --> V - Lo u>= Hi - Lo
182  Value *VMinusLo =
183  Builder.CreateSub(V, ConstantInt::get(Ty, Lo), V->getName() + ".off");
184  Constant *HiMinusLo = ConstantInt::get(Ty, Hi - Lo);
185  return Builder.CreateICmp(Pred, VMinusLo, HiMinusLo);
186 }
187 
188 /// Classify (icmp eq (A & B), C) and (icmp ne (A & B), C) as matching patterns
189 /// that can be simplified.
190 /// One of A and B is considered the mask. The other is the value. This is
191 /// described as the "AMask" or "BMask" part of the enum. If the enum contains
192 /// only "Mask", then both A and B can be considered masks. If A is the mask,
193 /// then it was proven that (A & C) == C. This is trivial if C == A or C == 0.
194 /// If both A and C are constants, this proof is also easy.
195 /// For the following explanations, we assume that A is the mask.
196 ///
197 /// "AllOnes" declares that the comparison is true only if (A & B) == A or all
198 /// bits of A are set in B.
199 /// Example: (icmp eq (A & 3), 3) -> AMask_AllOnes
200 ///
201 /// "AllZeros" declares that the comparison is true only if (A & B) == 0 or all
202 /// bits of A are cleared in B.
203 /// Example: (icmp eq (A & 3), 0) -> Mask_AllZeroes
204 ///
205 /// "Mixed" declares that (A & B) == C and C might or might not contain any
206 /// number of one bits and zero bits.
207 /// Example: (icmp eq (A & 3), 1) -> AMask_Mixed
208 ///
209 /// "Not" means that in above descriptions "==" should be replaced by "!=".
210 /// Example: (icmp ne (A & 3), 3) -> AMask_NotAllOnes
211 ///
212 /// If the mask A contains a single bit, then the following is equivalent:
213 /// (icmp eq (A & B), A) equals (icmp ne (A & B), 0)
214 /// (icmp ne (A & B), A) equals (icmp eq (A & B), 0)
224  BMask_Mixed = 256,
226 };
227 
228 /// Return the set of patterns (from MaskedICmpType) that (icmp SCC (A & B), C)
229 /// satisfies.
230 static unsigned getMaskedICmpType(Value *A, Value *B, Value *C,
231  ICmpInst::Predicate Pred) {
232  ConstantInt *ACst = dyn_cast<ConstantInt>(A);
233  ConstantInt *BCst = dyn_cast<ConstantInt>(B);
234  ConstantInt *CCst = dyn_cast<ConstantInt>(C);
235  bool IsEq = (Pred == ICmpInst::ICMP_EQ);
236  bool IsAPow2 = (ACst && !ACst->isZero() && ACst->getValue().isPowerOf2());
237  bool IsBPow2 = (BCst && !BCst->isZero() && BCst->getValue().isPowerOf2());
238  unsigned MaskVal = 0;
239  if (CCst && CCst->isZero()) {
240  // if C is zero, then both A and B qualify as mask
241  MaskVal |= (IsEq ? (Mask_AllZeros | AMask_Mixed | BMask_Mixed)
243  if (IsAPow2)
244  MaskVal |= (IsEq ? (AMask_NotAllOnes | AMask_NotMixed)
245  : (AMask_AllOnes | AMask_Mixed));
246  if (IsBPow2)
247  MaskVal |= (IsEq ? (BMask_NotAllOnes | BMask_NotMixed)
248  : (BMask_AllOnes | BMask_Mixed));
249  return MaskVal;
250  }
251 
252  if (A == C) {
253  MaskVal |= (IsEq ? (AMask_AllOnes | AMask_Mixed)
255  if (IsAPow2)
256  MaskVal |= (IsEq ? (Mask_NotAllZeros | AMask_NotMixed)
257  : (Mask_AllZeros | AMask_Mixed));
258  } else if (ACst && CCst && ConstantExpr::getAnd(ACst, CCst) == CCst) {
259  MaskVal |= (IsEq ? AMask_Mixed : AMask_NotMixed);
260  }
261 
262  if (B == C) {
263  MaskVal |= (IsEq ? (BMask_AllOnes | BMask_Mixed)
265  if (IsBPow2)
266  MaskVal |= (IsEq ? (Mask_NotAllZeros | BMask_NotMixed)
267  : (Mask_AllZeros | BMask_Mixed));
268  } else if (BCst && CCst && ConstantExpr::getAnd(BCst, CCst) == CCst) {
269  MaskVal |= (IsEq ? BMask_Mixed : BMask_NotMixed);
270  }
271 
272  return MaskVal;
273 }
274 
275 /// Convert an analysis of a masked ICmp into its equivalent if all boolean
276 /// operations had the opposite sense. Since each "NotXXX" flag (recording !=)
277 /// is adjacent to the corresponding normal flag (recording ==), this just
278 /// involves swapping those bits over.
279 static unsigned conjugateICmpMask(unsigned Mask) {
280  unsigned NewMask;
281  NewMask = (Mask & (AMask_AllOnes | BMask_AllOnes | Mask_AllZeros |
283  << 1;
284 
285  NewMask |= (Mask & (AMask_NotAllOnes | BMask_NotAllOnes | Mask_NotAllZeros |
287  >> 1;
288 
289  return NewMask;
290 }
291 
292 // Adapts the external decomposeBitTestICmp for local use.
293 static bool decomposeBitTestICmp(Value *LHS, Value *RHS, CmpInst::Predicate &Pred,
294  Value *&X, Value *&Y, Value *&Z) {
295  APInt Mask;
296  if (!llvm::decomposeBitTestICmp(LHS, RHS, Pred, X, Mask))
297  return false;
298 
299  Y = ConstantInt::get(X->getType(), Mask);
300  Z = ConstantInt::get(X->getType(), 0);
301  return true;
302 }
303 
304 /// Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E).
305 /// Return the pattern classes (from MaskedICmpType) for the left hand side and
306 /// the right hand side as a pair.
307 /// LHS and RHS are the left hand side and the right hand side ICmps and PredL
308 /// and PredR are their predicates, respectively.
309 static
312  Value *&D, Value *&E, ICmpInst *LHS,
313  ICmpInst *RHS,
314  ICmpInst::Predicate &PredL,
315  ICmpInst::Predicate &PredR) {
316  // vectors are not (yet?) supported. Don't support pointers either.
317  if (!LHS->getOperand(0)->getType()->isIntegerTy() ||
318  !RHS->getOperand(0)->getType()->isIntegerTy())
319  return None;
320 
321  // Here comes the tricky part:
322  // LHS might be of the form L11 & L12 == X, X == L21 & L22,
323  // and L11 & L12 == L21 & L22. The same goes for RHS.
324  // Now we must find those components L** and R**, that are equal, so
325  // that we can extract the parameters A, B, C, D, and E for the canonical
326  // above.
327  Value *L1 = LHS->getOperand(0);
328  Value *L2 = LHS->getOperand(1);
329  Value *L11, *L12, *L21, *L22;
330  // Check whether the icmp can be decomposed into a bit test.
331  if (decomposeBitTestICmp(L1, L2, PredL, L11, L12, L2)) {
332  L21 = L22 = L1 = nullptr;
333  } else {
334  // Look for ANDs in the LHS icmp.
335  if (!match(L1, m_And(m_Value(L11), m_Value(L12)))) {
336  // Any icmp can be viewed as being trivially masked; if it allows us to
337  // remove one, it's worth it.
338  L11 = L1;
339  L12 = Constant::getAllOnesValue(L1->getType());
340  }
341 
342  if (!match(L2, m_And(m_Value(L21), m_Value(L22)))) {
343  L21 = L2;
344  L22 = Constant::getAllOnesValue(L2->getType());
345  }
346  }
347 
348  // Bail if LHS was a icmp that can't be decomposed into an equality.
349  if (!ICmpInst::isEquality(PredL))
350  return None;
351 
352  Value *R1 = RHS->getOperand(0);
353  Value *R2 = RHS->getOperand(1);
354  Value *R11, *R12;
355  bool Ok = false;
356  if (decomposeBitTestICmp(R1, R2, PredR, R11, R12, R2)) {
357  if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
358  A = R11;
359  D = R12;
360  } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
361  A = R12;
362  D = R11;
363  } else {
364  return None;
365  }
366  E = R2;
367  R1 = nullptr;
368  Ok = true;
369  } else {
370  if (!match(R1, m_And(m_Value(R11), m_Value(R12)))) {
371  // As before, model no mask as a trivial mask if it'll let us do an
372  // optimization.
373  R11 = R1;
374  R12 = Constant::getAllOnesValue(R1->getType());
375  }
376 
377  if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
378  A = R11;
379  D = R12;
380  E = R2;
381  Ok = true;
382  } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
383  A = R12;
384  D = R11;
385  E = R2;
386  Ok = true;
387  }
388  }
389 
390  // Bail if RHS was a icmp that can't be decomposed into an equality.
391  if (!ICmpInst::isEquality(PredR))
392  return None;
393 
394  // Look for ANDs on the right side of the RHS icmp.
395  if (!Ok) {
396  if (!match(R2, m_And(m_Value(R11), m_Value(R12)))) {
397  R11 = R2;
398  R12 = Constant::getAllOnesValue(R2->getType());
399  }
400 
401  if (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22) {
402  A = R11;
403  D = R12;
404  E = R1;
405  Ok = true;
406  } else if (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22) {
407  A = R12;
408  D = R11;
409  E = R1;
410  Ok = true;
411  } else {
412  return None;
413  }
414  }
415  if (!Ok)
416  return None;
417 
418  if (L11 == A) {
419  B = L12;
420  C = L2;
421  } else if (L12 == A) {
422  B = L11;
423  C = L2;
424  } else if (L21 == A) {
425  B = L22;
426  C = L1;
427  } else if (L22 == A) {
428  B = L21;
429  C = L1;
430  }
431 
432  unsigned LeftType = getMaskedICmpType(A, B, C, PredL);
433  unsigned RightType = getMaskedICmpType(A, D, E, PredR);
434  return Optional<std::pair<unsigned, unsigned>>(std::make_pair(LeftType, RightType));
435 }
436 
437 /// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E) into a single
438 /// (icmp(A & X) ==/!= Y), where the left-hand side is of type Mask_NotAllZeros
439 /// and the right hand side is of type BMask_Mixed. For example,
440 /// (icmp (A & 12) != 0) & (icmp (A & 15) == 8) -> (icmp (A & 15) == 8).
442  ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
443  Value *A, Value *B, Value *C, Value *D, Value *E,
446  // We are given the canonical form:
447  // (icmp ne (A & B), 0) & (icmp eq (A & D), E).
448  // where D & E == E.
449  //
450  // If IsAnd is false, we get it in negated form:
451  // (icmp eq (A & B), 0) | (icmp ne (A & D), E) ->
452  // !((icmp ne (A & B), 0) & (icmp eq (A & D), E)).
453  //
454  // We currently handle the case of B, C, D, E are constant.
455  //
456  ConstantInt *BCst = dyn_cast<ConstantInt>(B);
457  if (!BCst)
458  return nullptr;
459  ConstantInt *CCst = dyn_cast<ConstantInt>(C);
460  if (!CCst)
461  return nullptr;
462  ConstantInt *DCst = dyn_cast<ConstantInt>(D);
463  if (!DCst)
464  return nullptr;
465  ConstantInt *ECst = dyn_cast<ConstantInt>(E);
466  if (!ECst)
467  return nullptr;
468 
470 
471  // Update E to the canonical form when D is a power of two and RHS is
472  // canonicalized as,
473  // (icmp ne (A & D), 0) -> (icmp eq (A & D), D) or
474  // (icmp ne (A & D), D) -> (icmp eq (A & D), 0).
475  if (PredR != NewCC)
476  ECst = cast<ConstantInt>(ConstantExpr::getXor(DCst, ECst));
477 
478  // If B or D is zero, skip because if LHS or RHS can be trivially folded by
479  // other folding rules and this pattern won't apply any more.
480  if (BCst->getValue() == 0 || DCst->getValue() == 0)
481  return nullptr;
482 
483  // If B and D don't intersect, ie. (B & D) == 0, no folding because we can't
484  // deduce anything from it.
485  // For example,
486  // (icmp ne (A & 12), 0) & (icmp eq (A & 3), 1) -> no folding.
487  if ((BCst->getValue() & DCst->getValue()) == 0)
488  return nullptr;
489 
490  // If the following two conditions are met:
491  //
492  // 1. mask B covers only a single bit that's not covered by mask D, that is,
493  // (B & (B ^ D)) is a power of 2 (in other words, B minus the intersection of
494  // B and D has only one bit set) and,
495  //
496  // 2. RHS (and E) indicates that the rest of B's bits are zero (in other
497  // words, the intersection of B and D is zero), that is, ((B & D) & E) == 0
498  //
499  // then that single bit in B must be one and thus the whole expression can be
500  // folded to
501  // (A & (B | D)) == (B & (B ^ D)) | E.
502  //
503  // For example,
504  // (icmp ne (A & 12), 0) & (icmp eq (A & 7), 1) -> (icmp eq (A & 15), 9)
505  // (icmp ne (A & 15), 0) & (icmp eq (A & 7), 0) -> (icmp eq (A & 15), 8)
506  if ((((BCst->getValue() & DCst->getValue()) & ECst->getValue()) == 0) &&
507  (BCst->getValue() & (BCst->getValue() ^ DCst->getValue())).isPowerOf2()) {
508  APInt BorD = BCst->getValue() | DCst->getValue();
509  APInt BandBxorDorE = (BCst->getValue() & (BCst->getValue() ^ DCst->getValue())) |
510  ECst->getValue();
511  Value *NewMask = ConstantInt::get(BCst->getType(), BorD);
512  Value *NewMaskedValue = ConstantInt::get(BCst->getType(), BandBxorDorE);
513  Value *NewAnd = Builder.CreateAnd(A, NewMask);
514  return Builder.CreateICmp(NewCC, NewAnd, NewMaskedValue);
515  }
516 
517  auto IsSubSetOrEqual = [](ConstantInt *C1, ConstantInt *C2) {
518  return (C1->getValue() & C2->getValue()) == C1->getValue();
519  };
520  auto IsSuperSetOrEqual = [](ConstantInt *C1, ConstantInt *C2) {
521  return (C1->getValue() & C2->getValue()) == C2->getValue();
522  };
523 
524  // In the following, we consider only the cases where B is a superset of D, B
525  // is a subset of D, or B == D because otherwise there's at least one bit
526  // covered by B but not D, in which case we can't deduce much from it, so
527  // no folding (aside from the single must-be-one bit case right above.)
528  // For example,
529  // (icmp ne (A & 14), 0) & (icmp eq (A & 3), 1) -> no folding.
530  if (!IsSubSetOrEqual(BCst, DCst) && !IsSuperSetOrEqual(BCst, DCst))
531  return nullptr;
532 
533  // At this point, either B is a superset of D, B is a subset of D or B == D.
534 
535  // If E is zero, if B is a subset of (or equal to) D, LHS and RHS contradict
536  // and the whole expression becomes false (or true if negated), otherwise, no
537  // folding.
538  // For example,
539  // (icmp ne (A & 3), 0) & (icmp eq (A & 7), 0) -> false.
540  // (icmp ne (A & 15), 0) & (icmp eq (A & 3), 0) -> no folding.
541  if (ECst->isZero()) {
542  if (IsSubSetOrEqual(BCst, DCst))
543  return ConstantInt::get(LHS->getType(), !IsAnd);
544  return nullptr;
545  }
546 
547  // At this point, B, D, E aren't zero and (B & D) == B, (B & D) == D or B ==
548  // D. If B is a superset of (or equal to) D, since E is not zero, LHS is
549  // subsumed by RHS (RHS implies LHS.) So the whole expression becomes
550  // RHS. For example,
551  // (icmp ne (A & 255), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
552  // (icmp ne (A & 15), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
553  if (IsSuperSetOrEqual(BCst, DCst))
554  return RHS;
555  // Otherwise, B is a subset of D. If B and E have a common bit set,
556  // ie. (B & E) != 0, then LHS is subsumed by RHS. For example.
557  // (icmp ne (A & 12), 0) & (icmp eq (A & 15), 8) -> (icmp eq (A & 15), 8).
558  assert(IsSubSetOrEqual(BCst, DCst) && "Precondition due to above code");
559  if ((BCst->getValue() & ECst->getValue()) != 0)
560  return RHS;
561  // Otherwise, LHS and RHS contradict and the whole expression becomes false
562  // (or true if negated.) For example,
563  // (icmp ne (A & 7), 0) & (icmp eq (A & 15), 8) -> false.
564  // (icmp ne (A & 6), 0) & (icmp eq (A & 15), 8) -> false.
565  return ConstantInt::get(LHS->getType(), !IsAnd);
566 }
567 
568 /// Try to fold (icmp(A & B) ==/!= 0) &/| (icmp(A & D) ==/!= E) into a single
569 /// (icmp(A & X) ==/!= Y), where the left-hand side and the right hand side
570 /// aren't of the common mask pattern type.
572  ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
573  Value *A, Value *B, Value *C, Value *D, Value *E,
575  unsigned LHSMask, unsigned RHSMask,
578  "Expected equality predicates for masked type of icmps.");
579  // Handle Mask_NotAllZeros-BMask_Mixed cases.
580  // (icmp ne/eq (A & B), C) &/| (icmp eq/ne (A & D), E), or
581  // (icmp eq/ne (A & B), C) &/| (icmp ne/eq (A & D), E)
582  // which gets swapped to
583  // (icmp ne/eq (A & D), E) &/| (icmp eq/ne (A & B), C).
584  if (!IsAnd) {
585  LHSMask = conjugateICmpMask(LHSMask);
586  RHSMask = conjugateICmpMask(RHSMask);
587  }
588  if ((LHSMask & Mask_NotAllZeros) && (RHSMask & BMask_Mixed)) {
590  LHS, RHS, IsAnd, A, B, C, D, E,
591  PredL, PredR, Builder)) {
592  return V;
593  }
594  } else if ((LHSMask & BMask_Mixed) && (RHSMask & Mask_NotAllZeros)) {
596  RHS, LHS, IsAnd, A, D, E, B, C,
597  PredR, PredL, Builder)) {
598  return V;
599  }
600  }
601  return nullptr;
602 }
603 
604 /// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
605 /// into a single (icmp(A & X) ==/!= Y).
606 static Value *foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
608  Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
609  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
611  getMaskedTypeForICmpPair(A, B, C, D, E, LHS, RHS, PredL, PredR);
612  if (!MaskPair)
613  return nullptr;
615  "Expected equality predicates for masked type of icmps.");
616  unsigned LHSMask = MaskPair->first;
617  unsigned RHSMask = MaskPair->second;
618  unsigned Mask = LHSMask & RHSMask;
619  if (Mask == 0) {
620  // Even if the two sides don't share a common pattern, check if folding can
621  // still happen.
623  LHS, RHS, IsAnd, A, B, C, D, E, PredL, PredR, LHSMask, RHSMask,
624  Builder))
625  return V;
626  return nullptr;
627  }
628 
629  // In full generality:
630  // (icmp (A & B) Op C) | (icmp (A & D) Op E)
631  // == ![ (icmp (A & B) !Op C) & (icmp (A & D) !Op E) ]
632  //
633  // If the latter can be converted into (icmp (A & X) Op Y) then the former is
634  // equivalent to (icmp (A & X) !Op Y).
635  //
636  // Therefore, we can pretend for the rest of this function that we're dealing
637  // with the conjunction, provided we flip the sense of any comparisons (both
638  // input and output).
639 
640  // In most cases we're going to produce an EQ for the "&&" case.
642  if (!IsAnd) {
643  // Convert the masking analysis into its equivalent with negated
644  // comparisons.
645  Mask = conjugateICmpMask(Mask);
646  }
647 
648  if (Mask & Mask_AllZeros) {
649  // (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
650  // -> (icmp eq (A & (B|D)), 0)
651  Value *NewOr = Builder.CreateOr(B, D);
652  Value *NewAnd = Builder.CreateAnd(A, NewOr);
653  // We can't use C as zero because we might actually handle
654  // (icmp ne (A & B), B) & (icmp ne (A & D), D)
655  // with B and D, having a single bit set.
656  Value *Zero = Constant::getNullValue(A->getType());
657  return Builder.CreateICmp(NewCC, NewAnd, Zero);
658  }
659  if (Mask & BMask_AllOnes) {
660  // (icmp eq (A & B), B) & (icmp eq (A & D), D)
661  // -> (icmp eq (A & (B|D)), (B|D))
662  Value *NewOr = Builder.CreateOr(B, D);
663  Value *NewAnd = Builder.CreateAnd(A, NewOr);
664  return Builder.CreateICmp(NewCC, NewAnd, NewOr);
665  }
666  if (Mask & AMask_AllOnes) {
667  // (icmp eq (A & B), A) & (icmp eq (A & D), A)
668  // -> (icmp eq (A & (B&D)), A)
669  Value *NewAnd1 = Builder.CreateAnd(B, D);
670  Value *NewAnd2 = Builder.CreateAnd(A, NewAnd1);
671  return Builder.CreateICmp(NewCC, NewAnd2, A);
672  }
673 
674  // Remaining cases assume at least that B and D are constant, and depend on
675  // their actual values. This isn't strictly necessary, just a "handle the
676  // easy cases for now" decision.
677  ConstantInt *BCst = dyn_cast<ConstantInt>(B);
678  if (!BCst)
679  return nullptr;
680  ConstantInt *DCst = dyn_cast<ConstantInt>(D);
681  if (!DCst)
682  return nullptr;
683 
684  if (Mask & (Mask_NotAllZeros | BMask_NotAllOnes)) {
685  // (icmp ne (A & B), 0) & (icmp ne (A & D), 0) and
686  // (icmp ne (A & B), B) & (icmp ne (A & D), D)
687  // -> (icmp ne (A & B), 0) or (icmp ne (A & D), 0)
688  // Only valid if one of the masks is a superset of the other (check "B&D" is
689  // the same as either B or D).
690  APInt NewMask = BCst->getValue() & DCst->getValue();
691 
692  if (NewMask == BCst->getValue())
693  return LHS;
694  else if (NewMask == DCst->getValue())
695  return RHS;
696  }
697 
698  if (Mask & AMask_NotAllOnes) {
699  // (icmp ne (A & B), B) & (icmp ne (A & D), D)
700  // -> (icmp ne (A & B), A) or (icmp ne (A & D), A)
701  // Only valid if one of the masks is a superset of the other (check "B|D" is
702  // the same as either B or D).
703  APInt NewMask = BCst->getValue() | DCst->getValue();
704 
705  if (NewMask == BCst->getValue())
706  return LHS;
707  else if (NewMask == DCst->getValue())
708  return RHS;
709  }
710 
711  if (Mask & BMask_Mixed) {
712  // (icmp eq (A & B), C) & (icmp eq (A & D), E)
713  // We already know that B & C == C && D & E == E.
714  // If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of
715  // C and E, which are shared by both the mask B and the mask D, don't
716  // contradict, then we can transform to
717  // -> (icmp eq (A & (B|D)), (C|E))
718  // Currently, we only handle the case of B, C, D, and E being constant.
719  // We can't simply use C and E because we might actually handle
720  // (icmp ne (A & B), B) & (icmp eq (A & D), D)
721  // with B and D, having a single bit set.
722  ConstantInt *CCst = dyn_cast<ConstantInt>(C);
723  if (!CCst)
724  return nullptr;
725  ConstantInt *ECst = dyn_cast<ConstantInt>(E);
726  if (!ECst)
727  return nullptr;
728  if (PredL != NewCC)
729  CCst = cast<ConstantInt>(ConstantExpr::getXor(BCst, CCst));
730  if (PredR != NewCC)
731  ECst = cast<ConstantInt>(ConstantExpr::getXor(DCst, ECst));
732 
733  // If there is a conflict, we should actually return a false for the
734  // whole construct.
735  if (((BCst->getValue() & DCst->getValue()) &
736  (CCst->getValue() ^ ECst->getValue())).getBoolValue())
737  return ConstantInt::get(LHS->getType(), !IsAnd);
738 
739  Value *NewOr1 = Builder.CreateOr(B, D);
740  Value *NewOr2 = ConstantExpr::getOr(CCst, ECst);
741  Value *NewAnd = Builder.CreateAnd(A, NewOr1);
742  return Builder.CreateICmp(NewCC, NewAnd, NewOr2);
743  }
744 
745  return nullptr;
746 }
747 
748 /// Try to fold a signed range checked with lower bound 0 to an unsigned icmp.
749 /// Example: (icmp sge x, 0) & (icmp slt x, n) --> icmp ult x, n
750 /// If \p Inverted is true then the check is for the inverted range, e.g.
751 /// (icmp slt x, 0) | (icmp sgt x, n) --> icmp ugt x, n
753  bool Inverted) {
754  // Check the lower range comparison, e.g. x >= 0
755  // InstCombine already ensured that if there is a constant it's on the RHS.
756  ConstantInt *RangeStart = dyn_cast<ConstantInt>(Cmp0->getOperand(1));
757  if (!RangeStart)
758  return nullptr;
759 
760  ICmpInst::Predicate Pred0 = (Inverted ? Cmp0->getInversePredicate() :
761  Cmp0->getPredicate());
762 
763  // Accept x > -1 or x >= 0 (after potentially inverting the predicate).
764  if (!((Pred0 == ICmpInst::ICMP_SGT && RangeStart->isMinusOne()) ||
765  (Pred0 == ICmpInst::ICMP_SGE && RangeStart->isZero())))
766  return nullptr;
767 
768  ICmpInst::Predicate Pred1 = (Inverted ? Cmp1->getInversePredicate() :
769  Cmp1->getPredicate());
770 
771  Value *Input = Cmp0->getOperand(0);
772  Value *RangeEnd;
773  if (Cmp1->getOperand(0) == Input) {
774  // For the upper range compare we have: icmp x, n
775  RangeEnd = Cmp1->getOperand(1);
776  } else if (Cmp1->getOperand(1) == Input) {
777  // For the upper range compare we have: icmp n, x
778  RangeEnd = Cmp1->getOperand(0);
779  Pred1 = ICmpInst::getSwappedPredicate(Pred1);
780  } else {
781  return nullptr;
782  }
783 
784  // Check the upper range comparison, e.g. x < n
785  ICmpInst::Predicate NewPred;
786  switch (Pred1) {
787  case ICmpInst::ICMP_SLT: NewPred = ICmpInst::ICMP_ULT; break;
788  case ICmpInst::ICMP_SLE: NewPred = ICmpInst::ICMP_ULE; break;
789  default: return nullptr;
790  }
791 
792  // This simplification is only valid if the upper range is not negative.
793  KnownBits Known = computeKnownBits(RangeEnd, /*Depth=*/0, Cmp1);
794  if (!Known.isNonNegative())
795  return nullptr;
796 
797  if (Inverted)
798  NewPred = ICmpInst::getInversePredicate(NewPred);
799 
800  return Builder.CreateICmp(NewPred, Input, RangeEnd);
801 }
802 
803 static Value *
805  bool JoinedByAnd,
806  InstCombiner::BuilderTy &Builder) {
807  Value *X = LHS->getOperand(0);
808  if (X != RHS->getOperand(0))
809  return nullptr;
810 
811  const APInt *C1, *C2;
812  if (!match(LHS->getOperand(1), m_APInt(C1)) ||
813  !match(RHS->getOperand(1), m_APInt(C2)))
814  return nullptr;
815 
816  // We only handle (X != C1 && X != C2) and (X == C1 || X == C2).
817  ICmpInst::Predicate Pred = LHS->getPredicate();
818  if (Pred != RHS->getPredicate())
819  return nullptr;
820  if (JoinedByAnd && Pred != ICmpInst::ICMP_NE)
821  return nullptr;
822  if (!JoinedByAnd && Pred != ICmpInst::ICMP_EQ)
823  return nullptr;
824 
825  // The larger unsigned constant goes on the right.
826  if (C1->ugt(*C2))
827  std::swap(C1, C2);
828 
829  APInt Xor = *C1 ^ *C2;
830  if (Xor.isPowerOf2()) {
831  // If LHSC and RHSC differ by only one bit, then set that bit in X and
832  // compare against the larger constant:
833  // (X == C1 || X == C2) --> (X | (C1 ^ C2)) == C2
834  // (X != C1 && X != C2) --> (X | (C1 ^ C2)) != C2
835  // We choose an 'or' with a Pow2 constant rather than the inverse mask with
836  // 'and' because that may lead to smaller codegen from a smaller constant.
837  Value *Or = Builder.CreateOr(X, ConstantInt::get(X->getType(), Xor));
838  return Builder.CreateICmp(Pred, Or, ConstantInt::get(X->getType(), *C2));
839  }
840 
841  // Special case: get the ordering right when the values wrap around zero.
842  // Ie, we assumed the constants were unsigned when swapping earlier.
843  if (C1->isNullValue() && C2->isAllOnesValue())
844  std::swap(C1, C2);
845 
846  if (*C1 == *C2 - 1) {
847  // (X == 13 || X == 14) --> X - 13 <=u 1
848  // (X != 13 && X != 14) --> X - 13 >u 1
849  // An 'add' is the canonical IR form, so favor that over a 'sub'.
850  Value *Add = Builder.CreateAdd(X, ConstantInt::get(X->getType(), -(*C1)));
851  auto NewPred = JoinedByAnd ? ICmpInst::ICMP_UGT : ICmpInst::ICMP_ULE;
852  return Builder.CreateICmp(NewPred, Add, ConstantInt::get(X->getType(), 1));
853  }
854 
855  return nullptr;
856 }
857 
858 // Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2)
859 // Fold (!iszero(A & K1) & !iszero(A & K2)) -> (A & (K1 | K2)) == (K1 | K2)
860 Value *InstCombiner::foldAndOrOfICmpsOfAndWithPow2(ICmpInst *LHS, ICmpInst *RHS,
861  bool JoinedByAnd,
862  Instruction &CxtI) {
863  ICmpInst::Predicate Pred = LHS->getPredicate();
864  if (Pred != RHS->getPredicate())
865  return nullptr;
866  if (JoinedByAnd && Pred != ICmpInst::ICMP_NE)
867  return nullptr;
868  if (!JoinedByAnd && Pred != ICmpInst::ICMP_EQ)
869  return nullptr;
870 
871  // TODO support vector splats
872  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
873  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
874  if (!LHSC || !RHSC || !LHSC->isZero() || !RHSC->isZero())
875  return nullptr;
876 
877  Value *A, *B, *C, *D;
878  if (match(LHS->getOperand(0), m_And(m_Value(A), m_Value(B))) &&
879  match(RHS->getOperand(0), m_And(m_Value(C), m_Value(D)))) {
880  if (A == D || B == D)
881  std::swap(C, D);
882  if (B == C)
883  std::swap(A, B);
884 
885  if (A == C &&
886  isKnownToBeAPowerOfTwo(B, false, 0, &CxtI) &&
887  isKnownToBeAPowerOfTwo(D, false, 0, &CxtI)) {
888  Value *Mask = Builder.CreateOr(B, D);
889  Value *Masked = Builder.CreateAnd(A, Mask);
890  auto NewPred = JoinedByAnd ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE;
891  return Builder.CreateICmp(NewPred, Masked, Mask);
892  }
893  }
894 
895  return nullptr;
896 }
897 
898 /// General pattern:
899 /// X & Y
900 ///
901 /// Where Y is checking that all the high bits (covered by a mask 4294967168)
902 /// are uniform, i.e. %arg & 4294967168 can be either 4294967168 or 0
903 /// Pattern can be one of:
904 /// %t = add i32 %arg, 128
905 /// %r = icmp ult i32 %t, 256
906 /// Or
907 /// %t0 = shl i32 %arg, 24
908 /// %t1 = ashr i32 %t0, 24
909 /// %r = icmp eq i32 %t1, %arg
910 /// Or
911 /// %t0 = trunc i32 %arg to i8
912 /// %t1 = sext i8 %t0 to i32
913 /// %r = icmp eq i32 %t1, %arg
914 /// This pattern is a signed truncation check.
915 ///
916 /// And X is checking that some bit in that same mask is zero.
917 /// I.e. can be one of:
918 /// %r = icmp sgt i32 %arg, -1
919 /// Or
920 /// %t = and i32 %arg, 2147483648
921 /// %r = icmp eq i32 %t, 0
922 ///
923 /// Since we are checking that all the bits in that mask are the same,
924 /// and a particular bit is zero, what we are really checking is that all the
925 /// masked bits are zero.
926 /// So this should be transformed to:
927 /// %r = icmp ult i32 %arg, 128
929  Instruction &CxtI,
930  InstCombiner::BuilderTy &Builder) {
931  assert(CxtI.getOpcode() == Instruction::And);
932 
933  // Match icmp ult (add %arg, C01), C1 (C1 == C01 << 1; powers of two)
934  auto tryToMatchSignedTruncationCheck = [](ICmpInst *ICmp, Value *&X,
935  APInt &SignBitMask) -> bool {
936  CmpInst::Predicate Pred;
937  const APInt *I01, *I1; // powers of two; I1 == I01 << 1
938  if (!(match(ICmp,
939  m_ICmp(Pred, m_Add(m_Value(X), m_Power2(I01)), m_Power2(I1))) &&
940  Pred == ICmpInst::ICMP_ULT && I1->ugt(*I01) && I01->shl(1) == *I1))
941  return false;
942  // Which bit is the new sign bit as per the 'signed truncation' pattern?
943  SignBitMask = *I01;
944  return true;
945  };
946 
947  // One icmp needs to be 'signed truncation check'.
948  // We need to match this first, else we will mismatch commutative cases.
949  Value *X1;
950  APInt HighestBit;
951  ICmpInst *OtherICmp;
952  if (tryToMatchSignedTruncationCheck(ICmp1, X1, HighestBit))
953  OtherICmp = ICmp0;
954  else if (tryToMatchSignedTruncationCheck(ICmp0, X1, HighestBit))
955  OtherICmp = ICmp1;
956  else
957  return nullptr;
958 
959  assert(HighestBit.isPowerOf2() && "expected to be power of two (non-zero)");
960 
961  // Try to match/decompose into: icmp eq (X & Mask), 0
962  auto tryToDecompose = [](ICmpInst *ICmp, Value *&X,
963  APInt &UnsetBitsMask) -> bool {
964  CmpInst::Predicate Pred = ICmp->getPredicate();
965  // Can it be decomposed into icmp eq (X & Mask), 0 ?
966  if (llvm::decomposeBitTestICmp(ICmp->getOperand(0), ICmp->getOperand(1),
967  Pred, X, UnsetBitsMask,
968  /*LookThroughTrunc=*/false) &&
969  Pred == ICmpInst::ICMP_EQ)
970  return true;
971  // Is it icmp eq (X & Mask), 0 already?
972  const APInt *Mask;
973  if (match(ICmp, m_ICmp(Pred, m_And(m_Value(X), m_APInt(Mask)), m_Zero())) &&
974  Pred == ICmpInst::ICMP_EQ) {
975  UnsetBitsMask = *Mask;
976  return true;
977  }
978  return false;
979  };
980 
981  // And the other icmp needs to be decomposable into a bit test.
982  Value *X0;
983  APInt UnsetBitsMask;
984  if (!tryToDecompose(OtherICmp, X0, UnsetBitsMask))
985  return nullptr;
986 
987  assert(!UnsetBitsMask.isNullValue() && "empty mask makes no sense.");
988 
989  // Are they working on the same value?
990  Value *X;
991  if (X1 == X0) {
992  // Ok as is.
993  X = X1;
994  } else if (match(X0, m_Trunc(m_Specific(X1)))) {
995  UnsetBitsMask = UnsetBitsMask.zext(X1->getType()->getScalarSizeInBits());
996  X = X1;
997  } else
998  return nullptr;
999 
1000  // So which bits should be uniform as per the 'signed truncation check'?
1001  // (all the bits starting with (i.e. including) HighestBit)
1002  APInt SignBitsMask = ~(HighestBit - 1U);
1003 
1004  // UnsetBitsMask must have some common bits with SignBitsMask,
1005  if (!UnsetBitsMask.intersects(SignBitsMask))
1006  return nullptr;
1007 
1008  // Does UnsetBitsMask contain any bits outside of SignBitsMask?
1009  if (!UnsetBitsMask.isSubsetOf(SignBitsMask)) {
1010  APInt OtherHighestBit = (~UnsetBitsMask) + 1U;
1011  if (!OtherHighestBit.isPowerOf2())
1012  return nullptr;
1013  HighestBit = APIntOps::umin(HighestBit, OtherHighestBit);
1014  }
1015  // Else, if it does not, then all is ok as-is.
1016 
1017  // %r = icmp ult %X, SignBit
1018  return Builder.CreateICmpULT(X, ConstantInt::get(X->getType(), HighestBit),
1019  CxtI.getName() + ".simplified");
1020 }
1021 
1022 /// Reduce a pair of compares that check if a value has exactly 1 bit set.
1023 static Value *foldIsPowerOf2(ICmpInst *Cmp0, ICmpInst *Cmp1, bool JoinedByAnd,
1024  InstCombiner::BuilderTy &Builder) {
1025  // Handle 'and' / 'or' commutation: make the equality check the first operand.
1026  if (JoinedByAnd && Cmp1->getPredicate() == ICmpInst::ICMP_NE)
1027  std::swap(Cmp0, Cmp1);
1028  else if (!JoinedByAnd && Cmp1->getPredicate() == ICmpInst::ICMP_EQ)
1029  std::swap(Cmp0, Cmp1);
1030 
1031  // (X != 0) && (ctpop(X) u< 2) --> ctpop(X) == 1
1032  CmpInst::Predicate Pred0, Pred1;
1033  Value *X;
1034  if (JoinedByAnd && match(Cmp0, m_ICmp(Pred0, m_Value(X), m_ZeroInt())) &&
1035  match(Cmp1, m_ICmp(Pred1, m_Intrinsic<Intrinsic::ctpop>(m_Specific(X)),
1036  m_SpecificInt(2))) &&
1037  Pred0 == ICmpInst::ICMP_NE && Pred1 == ICmpInst::ICMP_ULT) {
1038  Value *CtPop = Cmp1->getOperand(0);
1039  return Builder.CreateICmpEQ(CtPop, ConstantInt::get(CtPop->getType(), 1));
1040  }
1041  // (X == 0) || (ctpop(X) u> 1) --> ctpop(X) != 1
1042  if (!JoinedByAnd && match(Cmp0, m_ICmp(Pred0, m_Value(X), m_ZeroInt())) &&
1043  match(Cmp1, m_ICmp(Pred1, m_Intrinsic<Intrinsic::ctpop>(m_Specific(X)),
1044  m_SpecificInt(1))) &&
1045  Pred0 == ICmpInst::ICMP_EQ && Pred1 == ICmpInst::ICMP_UGT) {
1046  Value *CtPop = Cmp1->getOperand(0);
1047  return Builder.CreateICmpNE(CtPop, ConstantInt::get(CtPop->getType(), 1));
1048  }
1049  return nullptr;
1050 }
1051 
1052 /// Fold (icmp)&(icmp) if possible.
1053 Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
1054  Instruction &CxtI) {
1055  // Fold (!iszero(A & K1) & !iszero(A & K2)) -> (A & (K1 | K2)) == (K1 | K2)
1056  // if K1 and K2 are a one-bit mask.
1057  if (Value *V = foldAndOrOfICmpsOfAndWithPow2(LHS, RHS, true, CxtI))
1058  return V;
1059 
1060  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
1061 
1062  // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
1063  if (predicatesFoldable(PredL, PredR)) {
1064  if (LHS->getOperand(0) == RHS->getOperand(1) &&
1065  LHS->getOperand(1) == RHS->getOperand(0))
1066  LHS->swapOperands();
1067  if (LHS->getOperand(0) == RHS->getOperand(0) &&
1068  LHS->getOperand(1) == RHS->getOperand(1)) {
1069  Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
1070  unsigned Code = getICmpCode(LHS) & getICmpCode(RHS);
1071  bool IsSigned = LHS->isSigned() || RHS->isSigned();
1072  return getNewICmpValue(Code, IsSigned, Op0, Op1, Builder);
1073  }
1074  }
1075 
1076  // handle (roughly): (icmp eq (A & B), C) & (icmp eq (A & D), E)
1077  if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, true, Builder))
1078  return V;
1079 
1080  // E.g. (icmp sge x, 0) & (icmp slt x, n) --> icmp ult x, n
1081  if (Value *V = simplifyRangeCheck(LHS, RHS, /*Inverted=*/false))
1082  return V;
1083 
1084  // E.g. (icmp slt x, n) & (icmp sge x, 0) --> icmp ult x, n
1085  if (Value *V = simplifyRangeCheck(RHS, LHS, /*Inverted=*/false))
1086  return V;
1087 
1088  if (Value *V = foldAndOrOfEqualityCmpsWithConstants(LHS, RHS, true, Builder))
1089  return V;
1090 
1091  if (Value *V = foldSignedTruncationCheck(LHS, RHS, CxtI, Builder))
1092  return V;
1093 
1094  if (Value *V = foldIsPowerOf2(LHS, RHS, true /* JoinedByAnd */, Builder))
1095  return V;
1096 
1097  // This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2).
1098  Value *LHS0 = LHS->getOperand(0), *RHS0 = RHS->getOperand(0);
1099  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
1100  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
1101  if (!LHSC || !RHSC)
1102  return nullptr;
1103 
1104  if (LHSC == RHSC && PredL == PredR) {
1105  // (icmp ult A, C) & (icmp ult B, C) --> (icmp ult (A|B), C)
1106  // where C is a power of 2 or
1107  // (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0)
1108  if ((PredL == ICmpInst::ICMP_ULT && LHSC->getValue().isPowerOf2()) ||
1109  (PredL == ICmpInst::ICMP_EQ && LHSC->isZero())) {
1110  Value *NewOr = Builder.CreateOr(LHS0, RHS0);
1111  return Builder.CreateICmp(PredL, NewOr, LHSC);
1112  }
1113  }
1114 
1115  // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2
1116  // where CMAX is the all ones value for the truncated type,
1117  // iff the lower bits of C2 and CA are zero.
1118  if (PredL == ICmpInst::ICMP_EQ && PredL == PredR && LHS->hasOneUse() &&
1119  RHS->hasOneUse()) {
1120  Value *V;
1121  ConstantInt *AndC, *SmallC = nullptr, *BigC = nullptr;
1122 
1123  // (trunc x) == C1 & (and x, CA) == C2
1124  // (and x, CA) == C2 & (trunc x) == C1
1125  if (match(RHS0, m_Trunc(m_Value(V))) &&
1126  match(LHS0, m_And(m_Specific(V), m_ConstantInt(AndC)))) {
1127  SmallC = RHSC;
1128  BigC = LHSC;
1129  } else if (match(LHS0, m_Trunc(m_Value(V))) &&
1130  match(RHS0, m_And(m_Specific(V), m_ConstantInt(AndC)))) {
1131  SmallC = LHSC;
1132  BigC = RHSC;
1133  }
1134 
1135  if (SmallC && BigC) {
1136  unsigned BigBitSize = BigC->getType()->getBitWidth();
1137  unsigned SmallBitSize = SmallC->getType()->getBitWidth();
1138 
1139  // Check that the low bits are zero.
1140  APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize);
1141  if ((Low & AndC->getValue()).isNullValue() &&
1142  (Low & BigC->getValue()).isNullValue()) {
1143  Value *NewAnd = Builder.CreateAnd(V, Low | AndC->getValue());
1144  APInt N = SmallC->getValue().zext(BigBitSize) | BigC->getValue();
1145  Value *NewVal = ConstantInt::get(AndC->getType()->getContext(), N);
1146  return Builder.CreateICmp(PredL, NewAnd, NewVal);
1147  }
1148  }
1149  }
1150 
1151  // From here on, we only handle:
1152  // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
1153  if (LHS0 != RHS0)
1154  return nullptr;
1155 
1156  // ICMP_[US][GL]E X, C is folded to ICMP_[US][GL]T elsewhere.
1157  if (PredL == ICmpInst::ICMP_UGE || PredL == ICmpInst::ICMP_ULE ||
1158  PredR == ICmpInst::ICMP_UGE || PredR == ICmpInst::ICMP_ULE ||
1159  PredL == ICmpInst::ICMP_SGE || PredL == ICmpInst::ICMP_SLE ||
1160  PredR == ICmpInst::ICMP_SGE || PredR == ICmpInst::ICMP_SLE)
1161  return nullptr;
1162 
1163  // We can't fold (ugt x, C) & (sgt x, C2).
1164  if (!predicatesFoldable(PredL, PredR))
1165  return nullptr;
1166 
1167  // Ensure that the larger constant is on the RHS.
1168  bool ShouldSwap;
1169  if (CmpInst::isSigned(PredL) ||
1170  (ICmpInst::isEquality(PredL) && CmpInst::isSigned(PredR)))
1171  ShouldSwap = LHSC->getValue().sgt(RHSC->getValue());
1172  else
1173  ShouldSwap = LHSC->getValue().ugt(RHSC->getValue());
1174 
1175  if (ShouldSwap) {
1176  std::swap(LHS, RHS);
1177  std::swap(LHSC, RHSC);
1178  std::swap(PredL, PredR);
1179  }
1180 
1181  // At this point, we know we have two icmp instructions
1182  // comparing a value against two constants and and'ing the result
1183  // together. Because of the above check, we know that we only have
1184  // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
1185  // (from the icmp folding check above), that the two constants
1186  // are not equal and that the larger constant is on the RHS
1187  assert(LHSC != RHSC && "Compares not folded above?");
1188 
1189  switch (PredL) {
1190  default:
1191  llvm_unreachable("Unknown integer condition code!");
1192  case ICmpInst::ICMP_NE:
1193  switch (PredR) {
1194  default:
1195  llvm_unreachable("Unknown integer condition code!");
1196  case ICmpInst::ICMP_ULT:
1197  // (X != 13 & X u< 14) -> X < 13
1198  if (LHSC->getValue() == (RHSC->getValue() - 1))
1199  return Builder.CreateICmpULT(LHS0, LHSC);
1200  if (LHSC->isZero()) // (X != 0 & X u< C) -> X-1 u< C-1
1201  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1202  false, true);
1203  break; // (X != 13 & X u< 15) -> no change
1204  case ICmpInst::ICMP_SLT:
1205  // (X != 13 & X s< 14) -> X < 13
1206  if (LHSC->getValue() == (RHSC->getValue() - 1))
1207  return Builder.CreateICmpSLT(LHS0, LHSC);
1208  // (X != INT_MIN & X s< C) -> X-(INT_MIN+1) u< (C-(INT_MIN+1))
1209  if (LHSC->isMinValue(true))
1210  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1211  true, true);
1212  break; // (X != 13 & X s< 15) -> no change
1213  case ICmpInst::ICMP_NE:
1214  // Potential folds for this case should already be handled.
1215  break;
1216  }
1217  break;
1218  case ICmpInst::ICMP_UGT:
1219  switch (PredR) {
1220  default:
1221  llvm_unreachable("Unknown integer condition code!");
1222  case ICmpInst::ICMP_NE:
1223  // (X u> 13 & X != 14) -> X u> 14
1224  if (RHSC->getValue() == (LHSC->getValue() + 1))
1225  return Builder.CreateICmp(PredL, LHS0, RHSC);
1226  // X u> C & X != UINT_MAX -> (X-(C+1)) u< UINT_MAX-(C+1)
1227  if (RHSC->isMaxValue(false))
1228  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1229  false, true);
1230  break; // (X u> 13 & X != 15) -> no change
1231  case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) u< 1
1232  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1233  false, true);
1234  }
1235  break;
1236  case ICmpInst::ICMP_SGT:
1237  switch (PredR) {
1238  default:
1239  llvm_unreachable("Unknown integer condition code!");
1240  case ICmpInst::ICMP_NE:
1241  // (X s> 13 & X != 14) -> X s> 14
1242  if (RHSC->getValue() == (LHSC->getValue() + 1))
1243  return Builder.CreateICmp(PredL, LHS0, RHSC);
1244  // X s> C & X != INT_MAX -> (X-(C+1)) u< INT_MAX-(C+1)
1245  if (RHSC->isMaxValue(true))
1246  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
1247  true, true);
1248  break; // (X s> 13 & X != 15) -> no change
1249  case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) u< 1
1250  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(), true,
1251  true);
1252  }
1253  break;
1254  }
1255 
1256  return nullptr;
1257 }
1258 
1259 Value *InstCombiner::foldLogicOfFCmps(FCmpInst *LHS, FCmpInst *RHS, bool IsAnd) {
1260  Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
1261  Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
1262  FCmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
1263 
1264  if (LHS0 == RHS1 && RHS0 == LHS1) {
1265  // Swap RHS operands to match LHS.
1266  PredR = FCmpInst::getSwappedPredicate(PredR);
1267  std::swap(RHS0, RHS1);
1268  }
1269 
1270  // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y).
1271  // Suppose the relation between x and y is R, where R is one of
1272  // U(1000), L(0100), G(0010) or E(0001), and CC0 and CC1 are the bitmasks for
1273  // testing the desired relations.
1274  //
1275  // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this:
1276  // bool(R & CC0) && bool(R & CC1)
1277  // = bool((R & CC0) & (R & CC1))
1278  // = bool(R & (CC0 & CC1)) <= by re-association, commutation, and idempotency
1279  //
1280  // Since (R & CC0) and (R & CC1) are either R or 0, we actually have this:
1281  // bool(R & CC0) || bool(R & CC1)
1282  // = bool((R & CC0) | (R & CC1))
1283  // = bool(R & (CC0 | CC1)) <= by reversed distribution (contribution? ;)
1284  if (LHS0 == RHS0 && LHS1 == RHS1) {
1285  unsigned FCmpCodeL = getFCmpCode(PredL);
1286  unsigned FCmpCodeR = getFCmpCode(PredR);
1287  unsigned NewPred = IsAnd ? FCmpCodeL & FCmpCodeR : FCmpCodeL | FCmpCodeR;
1288  return getFCmpValue(NewPred, LHS0, LHS1, Builder);
1289  }
1290 
1291  if ((PredL == FCmpInst::FCMP_ORD && PredR == FCmpInst::FCMP_ORD && IsAnd) ||
1292  (PredL == FCmpInst::FCMP_UNO && PredR == FCmpInst::FCMP_UNO && !IsAnd)) {
1293  if (LHS0->getType() != RHS0->getType())
1294  return nullptr;
1295 
1296  // FCmp canonicalization ensures that (fcmp ord/uno X, X) and
1297  // (fcmp ord/uno X, C) will be transformed to (fcmp X, +0.0).
1298  if (match(LHS1, m_PosZeroFP()) && match(RHS1, m_PosZeroFP()))
1299  // Ignore the constants because they are obviously not NANs:
1300  // (fcmp ord x, 0.0) & (fcmp ord y, 0.0) -> (fcmp ord x, y)
1301  // (fcmp uno x, 0.0) | (fcmp uno y, 0.0) -> (fcmp uno x, y)
1302  return Builder.CreateFCmp(PredL, LHS0, RHS0);
1303  }
1304 
1305  return nullptr;
1306 }
1307 
1308 /// This a limited reassociation for a special case (see above) where we are
1309 /// checking if two values are either both NAN (unordered) or not-NAN (ordered).
1310 /// This could be handled more generally in '-reassociation', but it seems like
1311 /// an unlikely pattern for a large number of logic ops and fcmps.
1313  InstCombiner::BuilderTy &Builder) {
1314  Instruction::BinaryOps Opcode = BO.getOpcode();
1315  assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
1316  "Expecting and/or op for fcmp transform");
1317 
1318  // There are 4 commuted variants of the pattern. Canonicalize operands of this
1319  // logic op so an fcmp is operand 0 and a matching logic op is operand 1.
1320  Value *Op0 = BO.getOperand(0), *Op1 = BO.getOperand(1), *X;
1321  FCmpInst::Predicate Pred;
1322  if (match(Op1, m_FCmp(Pred, m_Value(), m_AnyZeroFP())))
1323  std::swap(Op0, Op1);
1324 
1325  // Match inner binop and the predicate for combining 2 NAN checks into 1.
1326  BinaryOperator *BO1;
1327  FCmpInst::Predicate NanPred = Opcode == Instruction::And ? FCmpInst::FCMP_ORD
1329  if (!match(Op0, m_FCmp(Pred, m_Value(X), m_AnyZeroFP())) || Pred != NanPred ||
1330  !match(Op1, m_BinOp(BO1)) || BO1->getOpcode() != Opcode)
1331  return nullptr;
1332 
1333  // The inner logic op must have a matching fcmp operand.
1334  Value *BO10 = BO1->getOperand(0), *BO11 = BO1->getOperand(1), *Y;
1335  if (!match(BO10, m_FCmp(Pred, m_Value(Y), m_AnyZeroFP())) ||
1336  Pred != NanPred || X->getType() != Y->getType())
1337  std::swap(BO10, BO11);
1338 
1339  if (!match(BO10, m_FCmp(Pred, m_Value(Y), m_AnyZeroFP())) ||
1340  Pred != NanPred || X->getType() != Y->getType())
1341  return nullptr;
1342 
1343  // and (fcmp ord X, 0), (and (fcmp ord Y, 0), Z) --> and (fcmp ord X, Y), Z
1344  // or (fcmp uno X, 0), (or (fcmp uno Y, 0), Z) --> or (fcmp uno X, Y), Z
1345  Value *NewFCmp = Builder.CreateFCmp(Pred, X, Y);
1346  if (auto *NewFCmpInst = dyn_cast<FCmpInst>(NewFCmp)) {
1347  // Intersect FMF from the 2 source fcmps.
1348  NewFCmpInst->copyIRFlags(Op0);
1349  NewFCmpInst->andIRFlags(BO10);
1350  }
1351  return BinaryOperator::Create(Opcode, NewFCmp, BO11);
1352 }
1353 
1354 /// Match De Morgan's Laws:
1355 /// (~A & ~B) == (~(A | B))
1356 /// (~A | ~B) == (~(A & B))
1358  InstCombiner::BuilderTy &Builder) {
1359  auto Opcode = I.getOpcode();
1360  assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
1361  "Trying to match De Morgan's Laws with something other than and/or");
1362 
1363  // Flip the logic operation.
1364  Opcode = (Opcode == Instruction::And) ? Instruction::Or : Instruction::And;
1365 
1366  Value *A, *B;
1367  if (match(I.getOperand(0), m_OneUse(m_Not(m_Value(A)))) &&
1368  match(I.getOperand(1), m_OneUse(m_Not(m_Value(B)))) &&
1369  !isFreeToInvert(A, A->hasOneUse()) &&
1370  !isFreeToInvert(B, B->hasOneUse())) {
1371  Value *AndOr = Builder.CreateBinOp(Opcode, A, B, I.getName() + ".demorgan");
1372  return BinaryOperator::CreateNot(AndOr);
1373  }
1374 
1375  return nullptr;
1376 }
1377 
1378 bool InstCombiner::shouldOptimizeCast(CastInst *CI) {
1379  Value *CastSrc = CI->getOperand(0);
1380 
1381  // Noop casts and casts of constants should be eliminated trivially.
1382  if (CI->getSrcTy() == CI->getDestTy() || isa<Constant>(CastSrc))
1383  return false;
1384 
1385  // If this cast is paired with another cast that can be eliminated, we prefer
1386  // to have it eliminated.
1387  if (const auto *PrecedingCI = dyn_cast<CastInst>(CastSrc))
1388  if (isEliminableCastPair(PrecedingCI, CI))
1389  return false;
1390 
1391  return true;
1392 }
1393 
1394 /// Fold {and,or,xor} (cast X), C.
1396  InstCombiner::BuilderTy &Builder) {
1397  Constant *C = dyn_cast<Constant>(Logic.getOperand(1));
1398  if (!C)
1399  return nullptr;
1400 
1401  auto LogicOpc = Logic.getOpcode();
1402  Type *DestTy = Logic.getType();
1403  Type *SrcTy = Cast->getSrcTy();
1404 
1405  // Move the logic operation ahead of a zext or sext if the constant is
1406  // unchanged in the smaller source type. Performing the logic in a smaller
1407  // type may provide more information to later folds, and the smaller logic
1408  // instruction may be cheaper (particularly in the case of vectors).
1409  Value *X;
1410  if (match(Cast, m_OneUse(m_ZExt(m_Value(X))))) {
1411  Constant *TruncC = ConstantExpr::getTrunc(C, SrcTy);
1412  Constant *ZextTruncC = ConstantExpr::getZExt(TruncC, DestTy);
1413  if (ZextTruncC == C) {
1414  // LogicOpc (zext X), C --> zext (LogicOpc X, C)
1415  Value *NewOp = Builder.CreateBinOp(LogicOpc, X, TruncC);
1416  return new ZExtInst(NewOp, DestTy);
1417  }
1418  }
1419 
1420  if (match(Cast, m_OneUse(m_SExt(m_Value(X))))) {
1421  Constant *TruncC = ConstantExpr::getTrunc(C, SrcTy);
1422  Constant *SextTruncC = ConstantExpr::getSExt(TruncC, DestTy);
1423  if (SextTruncC == C) {
1424  // LogicOpc (sext X), C --> sext (LogicOpc X, C)
1425  Value *NewOp = Builder.CreateBinOp(LogicOpc, X, TruncC);
1426  return new SExtInst(NewOp, DestTy);
1427  }
1428  }
1429 
1430  return nullptr;
1431 }
1432 
1433 /// Fold {and,or,xor} (cast X), Y.
1434 Instruction *InstCombiner::foldCastedBitwiseLogic(BinaryOperator &I) {
1435  auto LogicOpc = I.getOpcode();
1436  assert(I.isBitwiseLogicOp() && "Unexpected opcode for bitwise logic folding");
1437 
1438  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1439  CastInst *Cast0 = dyn_cast<CastInst>(Op0);
1440  if (!Cast0)
1441  return nullptr;
1442 
1443  // This must be a cast from an integer or integer vector source type to allow
1444  // transformation of the logic operation to the source type.
1445  Type *DestTy = I.getType();
1446  Type *SrcTy = Cast0->getSrcTy();
1447  if (!SrcTy->isIntOrIntVectorTy())
1448  return nullptr;
1449 
1450  if (Instruction *Ret = foldLogicCastConstant(I, Cast0, Builder))
1451  return Ret;
1452 
1453  CastInst *Cast1 = dyn_cast<CastInst>(Op1);
1454  if (!Cast1)
1455  return nullptr;
1456 
1457  // Both operands of the logic operation are casts. The casts must be of the
1458  // same type for reduction.
1459  auto CastOpcode = Cast0->getOpcode();
1460  if (CastOpcode != Cast1->getOpcode() || SrcTy != Cast1->getSrcTy())
1461  return nullptr;
1462 
1463  Value *Cast0Src = Cast0->getOperand(0);
1464  Value *Cast1Src = Cast1->getOperand(0);
1465 
1466  // fold logic(cast(A), cast(B)) -> cast(logic(A, B))
1467  if (shouldOptimizeCast(Cast0) && shouldOptimizeCast(Cast1)) {
1468  Value *NewOp = Builder.CreateBinOp(LogicOpc, Cast0Src, Cast1Src,
1469  I.getName());
1470  return CastInst::Create(CastOpcode, NewOp, DestTy);
1471  }
1472 
1473  // For now, only 'and'/'or' have optimizations after this.
1474  if (LogicOpc == Instruction::Xor)
1475  return nullptr;
1476 
1477  // If this is logic(cast(icmp), cast(icmp)), try to fold this even if the
1478  // cast is otherwise not optimizable. This happens for vector sexts.
1479  ICmpInst *ICmp0 = dyn_cast<ICmpInst>(Cast0Src);
1480  ICmpInst *ICmp1 = dyn_cast<ICmpInst>(Cast1Src);
1481  if (ICmp0 && ICmp1) {
1482  Value *Res = LogicOpc == Instruction::And ? foldAndOfICmps(ICmp0, ICmp1, I)
1483  : foldOrOfICmps(ICmp0, ICmp1, I);
1484  if (Res)
1485  return CastInst::Create(CastOpcode, Res, DestTy);
1486  return nullptr;
1487  }
1488 
1489  // If this is logic(cast(fcmp), cast(fcmp)), try to fold this even if the
1490  // cast is otherwise not optimizable. This happens for vector sexts.
1491  FCmpInst *FCmp0 = dyn_cast<FCmpInst>(Cast0Src);
1492  FCmpInst *FCmp1 = dyn_cast<FCmpInst>(Cast1Src);
1493  if (FCmp0 && FCmp1)
1494  if (Value *R = foldLogicOfFCmps(FCmp0, FCmp1, LogicOpc == Instruction::And))
1495  return CastInst::Create(CastOpcode, R, DestTy);
1496 
1497  return nullptr;
1498 }
1499 
1501  InstCombiner::BuilderTy &Builder) {
1502  assert(I.getOpcode() == Instruction::And);
1503  Value *Op0 = I.getOperand(0);
1504  Value *Op1 = I.getOperand(1);
1505  Value *A, *B;
1506 
1507  // Operand complexity canonicalization guarantees that the 'or' is Op0.
1508  // (A | B) & ~(A & B) --> A ^ B
1509  // (A | B) & ~(B & A) --> A ^ B
1510  if (match(&I, m_BinOp(m_Or(m_Value(A), m_Value(B)),
1511  m_Not(m_c_And(m_Deferred(A), m_Deferred(B))))))
1512  return BinaryOperator::CreateXor(A, B);
1513 
1514  // (A | ~B) & (~A | B) --> ~(A ^ B)
1515  // (A | ~B) & (B | ~A) --> ~(A ^ B)
1516  // (~B | A) & (~A | B) --> ~(A ^ B)
1517  // (~B | A) & (B | ~A) --> ~(A ^ B)
1518  if (Op0->hasOneUse() || Op1->hasOneUse())
1519  if (match(&I, m_BinOp(m_c_Or(m_Value(A), m_Not(m_Value(B))),
1520  m_c_Or(m_Not(m_Deferred(A)), m_Deferred(B)))))
1521  return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
1522 
1523  return nullptr;
1524 }
1525 
1527  InstCombiner::BuilderTy &Builder) {
1528  assert(I.getOpcode() == Instruction::Or);
1529  Value *Op0 = I.getOperand(0);
1530  Value *Op1 = I.getOperand(1);
1531  Value *A, *B;
1532 
1533  // Operand complexity canonicalization guarantees that the 'and' is Op0.
1534  // (A & B) | ~(A | B) --> ~(A ^ B)
1535  // (A & B) | ~(B | A) --> ~(A ^ B)
1536  if (Op0->hasOneUse() || Op1->hasOneUse())
1537  if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1538  match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B)))))
1539  return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
1540 
1541  // (A & ~B) | (~A & B) --> A ^ B
1542  // (A & ~B) | (B & ~A) --> A ^ B
1543  // (~B & A) | (~A & B) --> A ^ B
1544  // (~B & A) | (B & ~A) --> A ^ B
1545  if (match(Op0, m_c_And(m_Value(A), m_Not(m_Value(B)))) &&
1546  match(Op1, m_c_And(m_Not(m_Specific(A)), m_Specific(B))))
1547  return BinaryOperator::CreateXor(A, B);
1548 
1549  return nullptr;
1550 }
1551 
1552 /// Return true if a constant shift amount is always less than the specified
1553 /// bit-width. If not, the shift could create poison in the narrower type.
1554 static bool canNarrowShiftAmt(Constant *C, unsigned BitWidth) {
1555  if (auto *ScalarC = dyn_cast<ConstantInt>(C))
1556  return ScalarC->getZExtValue() < BitWidth;
1557 
1558  if (C->getType()->isVectorTy()) {
1559  // Check each element of a constant vector.
1560  unsigned NumElts = C->getType()->getVectorNumElements();
1561  for (unsigned i = 0; i != NumElts; ++i) {
1562  Constant *Elt = C->getAggregateElement(i);
1563  if (!Elt)
1564  return false;
1565  if (isa<UndefValue>(Elt))
1566  continue;
1567  auto *CI = dyn_cast<ConstantInt>(Elt);
1568  if (!CI || CI->getZExtValue() >= BitWidth)
1569  return false;
1570  }
1571  return true;
1572  }
1573 
1574  // The constant is a constant expression or unknown.
1575  return false;
1576 }
1577 
1578 /// Try to use narrower ops (sink zext ops) for an 'and' with binop operand and
1579 /// a common zext operand: and (binop (zext X), C), (zext X).
1580 Instruction *InstCombiner::narrowMaskedBinOp(BinaryOperator &And) {
1581  // This transform could also apply to {or, and, xor}, but there are better
1582  // folds for those cases, so we don't expect those patterns here. AShr is not
1583  // handled because it should always be transformed to LShr in this sequence.
1584  // The subtract transform is different because it has a constant on the left.
1585  // Add/mul commute the constant to RHS; sub with constant RHS becomes add.
1586  Value *Op0 = And.getOperand(0), *Op1 = And.getOperand(1);
1587  Constant *C;
1588  if (!match(Op0, m_OneUse(m_Add(m_Specific(Op1), m_Constant(C)))) &&
1589  !match(Op0, m_OneUse(m_Mul(m_Specific(Op1), m_Constant(C)))) &&
1590  !match(Op0, m_OneUse(m_LShr(m_Specific(Op1), m_Constant(C)))) &&
1591  !match(Op0, m_OneUse(m_Shl(m_Specific(Op1), m_Constant(C)))) &&
1592  !match(Op0, m_OneUse(m_Sub(m_Constant(C), m_Specific(Op1)))))
1593  return nullptr;
1594 
1595  Value *X;
1596  if (!match(Op1, m_ZExt(m_Value(X))) || Op1->hasNUsesOrMore(3))
1597  return nullptr;
1598 
1599  Type *Ty = And.getType();
1600  if (!isa<VectorType>(Ty) && !shouldChangeType(Ty, X->getType()))
1601  return nullptr;
1602 
1603  // If we're narrowing a shift, the shift amount must be safe (less than the
1604  // width) in the narrower type. If the shift amount is greater, instsimplify
1605  // usually handles that case, but we can't guarantee/assert it.
1606  Instruction::BinaryOps Opc = cast<BinaryOperator>(Op0)->getOpcode();
1607  if (Opc == Instruction::LShr || Opc == Instruction::Shl)
1609  return nullptr;
1610 
1611  // and (sub C, (zext X)), (zext X) --> zext (and (sub C', X), X)
1612  // and (binop (zext X), C), (zext X) --> zext (and (binop X, C'), X)
1613  Value *NewC = ConstantExpr::getTrunc(C, X->getType());
1614  Value *NewBO = Opc == Instruction::Sub ? Builder.CreateBinOp(Opc, NewC, X)
1615  : Builder.CreateBinOp(Opc, X, NewC);
1616  return new ZExtInst(Builder.CreateAnd(NewBO, X), Ty);
1617 }
1618 
1619 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
1620 // here. We should standardize that construct where it is needed or choose some
1621 // other way to ensure that commutated variants of patterns are not missed.
1623  if (Value *V = SimplifyAndInst(I.getOperand(0), I.getOperand(1),
1624  SQ.getWithInstruction(&I)))
1625  return replaceInstUsesWith(I, V);
1626 
1627  if (SimplifyAssociativeOrCommutative(I))
1628  return &I;
1629 
1630  if (Instruction *X = foldVectorBinop(I))
1631  return X;
1632 
1633  // See if we can simplify any instructions used by the instruction whose sole
1634  // purpose is to compute bits we don't care about.
1635  if (SimplifyDemandedInstructionBits(I))
1636  return &I;
1637 
1638  // Do this before using distributive laws to catch simple and/or/not patterns.
1639  if (Instruction *Xor = foldAndToXor(I, Builder))
1640  return Xor;
1641 
1642  // (A|B)&(A|C) -> A|(B&C) etc
1643  if (Value *V = SimplifyUsingDistributiveLaws(I))
1644  return replaceInstUsesWith(I, V);
1645 
1646  if (Value *V = SimplifyBSwap(I, Builder))
1647  return replaceInstUsesWith(I, V);
1648 
1649  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1650  const APInt *C;
1651  if (match(Op1, m_APInt(C))) {
1652  Value *X, *Y;
1653  if (match(Op0, m_OneUse(m_LogicalShift(m_One(), m_Value(X)))) &&
1654  C->isOneValue()) {
1655  // (1 << X) & 1 --> zext(X == 0)
1656  // (1 >> X) & 1 --> zext(X == 0)
1657  Value *IsZero = Builder.CreateICmpEQ(X, ConstantInt::get(I.getType(), 0));
1658  return new ZExtInst(IsZero, I.getType());
1659  }
1660 
1661  const APInt *XorC;
1662  if (match(Op0, m_OneUse(m_Xor(m_Value(X), m_APInt(XorC))))) {
1663  // (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
1664  Constant *NewC = ConstantInt::get(I.getType(), *C & *XorC);
1665  Value *And = Builder.CreateAnd(X, Op1);
1666  And->takeName(Op0);
1667  return BinaryOperator::CreateXor(And, NewC);
1668  }
1669 
1670  const APInt *OrC;
1671  if (match(Op0, m_OneUse(m_Or(m_Value(X), m_APInt(OrC))))) {
1672  // (X | C1) & C2 --> (X & C2^(C1&C2)) | (C1&C2)
1673  // NOTE: This reduces the number of bits set in the & mask, which
1674  // can expose opportunities for store narrowing for scalars.
1675  // NOTE: SimplifyDemandedBits should have already removed bits from C1
1676  // that aren't set in C2. Meaning we can replace (C1&C2) with C1 in
1677  // above, but this feels safer.
1678  APInt Together = *C & *OrC;
1679  Value *And = Builder.CreateAnd(X, ConstantInt::get(I.getType(),
1680  Together ^ *C));
1681  And->takeName(Op0);
1682  return BinaryOperator::CreateOr(And, ConstantInt::get(I.getType(),
1683  Together));
1684  }
1685 
1686  // If the mask is only needed on one incoming arm, push the 'and' op up.
1687  if (match(Op0, m_OneUse(m_Xor(m_Value(X), m_Value(Y)))) ||
1688  match(Op0, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
1689  APInt NotAndMask(~(*C));
1690  BinaryOperator::BinaryOps BinOp = cast<BinaryOperator>(Op0)->getOpcode();
1691  if (MaskedValueIsZero(X, NotAndMask, 0, &I)) {
1692  // Not masking anything out for the LHS, move mask to RHS.
1693  // and ({x}or X, Y), C --> {x}or X, (and Y, C)
1694  Value *NewRHS = Builder.CreateAnd(Y, Op1, Y->getName() + ".masked");
1695  return BinaryOperator::Create(BinOp, X, NewRHS);
1696  }
1697  if (!isa<Constant>(Y) && MaskedValueIsZero(Y, NotAndMask, 0, &I)) {
1698  // Not masking anything out for the RHS, move mask to LHS.
1699  // and ({x}or X, Y), C --> {x}or (and X, C), Y
1700  Value *NewLHS = Builder.CreateAnd(X, Op1, X->getName() + ".masked");
1701  return BinaryOperator::Create(BinOp, NewLHS, Y);
1702  }
1703  }
1704 
1705  }
1706 
1707  if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
1708  const APInt &AndRHSMask = AndRHS->getValue();
1709 
1710  // Optimize a variety of ((val OP C1) & C2) combinations...
1711  if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
1712  // ((C1 OP zext(X)) & C2) -> zext((C1-X) & C2) if C2 fits in the bitwidth
1713  // of X and OP behaves well when given trunc(C1) and X.
1714  // TODO: Do this for vectors by using m_APInt isntead of m_ConstantInt.
1715  switch (Op0I->getOpcode()) {
1716  default:
1717  break;
1718  case Instruction::Xor:
1719  case Instruction::Or:
1720  case Instruction::Mul:
1721  case Instruction::Add:
1722  case Instruction::Sub:
1723  Value *X;
1724  ConstantInt *C1;
1725  // TODO: The one use restrictions could be relaxed a little if the AND
1726  // is going to be removed.
1727  if (match(Op0I, m_OneUse(m_c_BinOp(m_OneUse(m_ZExt(m_Value(X))),
1728  m_ConstantInt(C1))))) {
1729  if (AndRHSMask.isIntN(X->getType()->getScalarSizeInBits())) {
1730  auto *TruncC1 = ConstantExpr::getTrunc(C1, X->getType());
1731  Value *BinOp;
1732  Value *Op0LHS = Op0I->getOperand(0);
1733  if (isa<ZExtInst>(Op0LHS))
1734  BinOp = Builder.CreateBinOp(Op0I->getOpcode(), X, TruncC1);
1735  else
1736  BinOp = Builder.CreateBinOp(Op0I->getOpcode(), TruncC1, X);
1737  auto *TruncC2 = ConstantExpr::getTrunc(AndRHS, X->getType());
1738  auto *And = Builder.CreateAnd(BinOp, TruncC2);
1739  return new ZExtInst(And, I.getType());
1740  }
1741  }
1742  }
1743 
1744  if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
1745  if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I))
1746  return Res;
1747  }
1748 
1749  // If this is an integer truncation, and if the source is an 'and' with
1750  // immediate, transform it. This frequently occurs for bitfield accesses.
1751  {
1752  Value *X = nullptr; ConstantInt *YC = nullptr;
1753  if (match(Op0, m_Trunc(m_And(m_Value(X), m_ConstantInt(YC))))) {
1754  // Change: and (trunc (and X, YC) to T), C2
1755  // into : and (trunc X to T), trunc(YC) & C2
1756  // This will fold the two constants together, which may allow
1757  // other simplifications.
1758  Value *NewCast = Builder.CreateTrunc(X, I.getType(), "and.shrunk");
1759  Constant *C3 = ConstantExpr::getTrunc(YC, I.getType());
1760  C3 = ConstantExpr::getAnd(C3, AndRHS);
1761  return BinaryOperator::CreateAnd(NewCast, C3);
1762  }
1763  }
1764  }
1765 
1766  if (Instruction *Z = narrowMaskedBinOp(I))
1767  return Z;
1768 
1769  if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
1770  return FoldedLogic;
1771 
1772  if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
1773  return DeMorgan;
1774 
1775  {
1776  Value *A, *B, *C;
1777  // A & (A ^ B) --> A & ~B
1778  if (match(Op1, m_OneUse(m_c_Xor(m_Specific(Op0), m_Value(B)))))
1779  return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(B));
1780  // (A ^ B) & A --> A & ~B
1781  if (match(Op0, m_OneUse(m_c_Xor(m_Specific(Op1), m_Value(B)))))
1782  return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(B));
1783 
1784  // (A ^ B) & ((B ^ C) ^ A) -> (A ^ B) & ~C
1785  if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
1786  if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
1787  if (Op1->hasOneUse() || isFreeToInvert(C, C->hasOneUse()))
1788  return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(C));
1789 
1790  // ((A ^ C) ^ B) & (B ^ A) -> (B ^ A) & ~C
1791  if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
1792  if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
1793  if (Op0->hasOneUse() || isFreeToInvert(C, C->hasOneUse()))
1794  return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(C));
1795 
1796  // (A | B) & ((~A) ^ B) -> (A & B)
1797  // (A | B) & (B ^ (~A)) -> (A & B)
1798  // (B | A) & ((~A) ^ B) -> (A & B)
1799  // (B | A) & (B ^ (~A)) -> (A & B)
1800  if (match(Op1, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) &&
1801  match(Op0, m_c_Or(m_Specific(A), m_Specific(B))))
1802  return BinaryOperator::CreateAnd(A, B);
1803 
1804  // ((~A) ^ B) & (A | B) -> (A & B)
1805  // ((~A) ^ B) & (B | A) -> (A & B)
1806  // (B ^ (~A)) & (A | B) -> (A & B)
1807  // (B ^ (~A)) & (B | A) -> (A & B)
1808  if (match(Op0, m_c_Xor(m_Not(m_Value(A)), m_Value(B))) &&
1809  match(Op1, m_c_Or(m_Specific(A), m_Specific(B))))
1810  return BinaryOperator::CreateAnd(A, B);
1811  }
1812 
1813  {
1814  ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
1815  ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
1816  if (LHS && RHS)
1817  if (Value *Res = foldAndOfICmps(LHS, RHS, I))
1818  return replaceInstUsesWith(I, Res);
1819 
1820  // TODO: Make this recursive; it's a little tricky because an arbitrary
1821  // number of 'and' instructions might have to be created.
1822  Value *X, *Y;
1823  if (LHS && match(Op1, m_OneUse(m_And(m_Value(X), m_Value(Y))))) {
1824  if (auto *Cmp = dyn_cast<ICmpInst>(X))
1825  if (Value *Res = foldAndOfICmps(LHS, Cmp, I))
1826  return replaceInstUsesWith(I, Builder.CreateAnd(Res, Y));
1827  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
1828  if (Value *Res = foldAndOfICmps(LHS, Cmp, I))
1829  return replaceInstUsesWith(I, Builder.CreateAnd(Res, X));
1830  }
1831  if (RHS && match(Op0, m_OneUse(m_And(m_Value(X), m_Value(Y))))) {
1832  if (auto *Cmp = dyn_cast<ICmpInst>(X))
1833  if (Value *Res = foldAndOfICmps(Cmp, RHS, I))
1834  return replaceInstUsesWith(I, Builder.CreateAnd(Res, Y));
1835  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
1836  if (Value *Res = foldAndOfICmps(Cmp, RHS, I))
1837  return replaceInstUsesWith(I, Builder.CreateAnd(Res, X));
1838  }
1839  }
1840 
1841  if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
1842  if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
1843  if (Value *Res = foldLogicOfFCmps(LHS, RHS, true))
1844  return replaceInstUsesWith(I, Res);
1845 
1846  if (Instruction *FoldedFCmps = reassociateFCmps(I, Builder))
1847  return FoldedFCmps;
1848 
1849  if (Instruction *CastedAnd = foldCastedBitwiseLogic(I))
1850  return CastedAnd;
1851 
1852  // and(sext(A), B) / and(B, sext(A)) --> A ? B : 0, where A is i1 or <N x i1>.
1853  Value *A;
1854  if (match(Op0, m_OneUse(m_SExt(m_Value(A)))) &&
1855  A->getType()->isIntOrIntVectorTy(1))
1856  return SelectInst::Create(A, Op1, Constant::getNullValue(I.getType()));
1857  if (match(Op1, m_OneUse(m_SExt(m_Value(A)))) &&
1858  A->getType()->isIntOrIntVectorTy(1))
1859  return SelectInst::Create(A, Op0, Constant::getNullValue(I.getType()));
1860 
1861  return nullptr;
1862 }
1863 
1864 Instruction *InstCombiner::matchBSwap(BinaryOperator &Or) {
1865  assert(Or.getOpcode() == Instruction::Or && "bswap requires an 'or'");
1866  Value *Op0 = Or.getOperand(0), *Op1 = Or.getOperand(1);
1867 
1868  // Look through zero extends.
1869  if (Instruction *Ext = dyn_cast<ZExtInst>(Op0))
1870  Op0 = Ext->getOperand(0);
1871 
1872  if (Instruction *Ext = dyn_cast<ZExtInst>(Op1))
1873  Op1 = Ext->getOperand(0);
1874 
1875  // (A | B) | C and A | (B | C) -> bswap if possible.
1876  bool OrOfOrs = match(Op0, m_Or(m_Value(), m_Value())) ||
1877  match(Op1, m_Or(m_Value(), m_Value()));
1878 
1879  // (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible.
1880  bool OrOfShifts = match(Op0, m_LogicalShift(m_Value(), m_Value())) &&
1881  match(Op1, m_LogicalShift(m_Value(), m_Value()));
1882 
1883  // (A & B) | (C & D) -> bswap if possible.
1884  bool OrOfAnds = match(Op0, m_And(m_Value(), m_Value())) &&
1885  match(Op1, m_And(m_Value(), m_Value()));
1886 
1887  // (A << B) | (C & D) -> bswap if possible.
1888  // The bigger pattern here is ((A & C1) << C2) | ((B >> C2) & C1), which is a
1889  // part of the bswap idiom for specific values of C1, C2 (e.g. C1 = 16711935,
1890  // C2 = 8 for i32).
1891  // This pattern can occur when the operands of the 'or' are not canonicalized
1892  // for some reason (not having only one use, for example).
1893  bool OrOfAndAndSh = (match(Op0, m_LogicalShift(m_Value(), m_Value())) &&
1894  match(Op1, m_And(m_Value(), m_Value()))) ||
1895  (match(Op0, m_And(m_Value(), m_Value())) &&
1896  match(Op1, m_LogicalShift(m_Value(), m_Value())));
1897 
1898  if (!OrOfOrs && !OrOfShifts && !OrOfAnds && !OrOfAndAndSh)
1899  return nullptr;
1900 
1902  if (!recognizeBSwapOrBitReverseIdiom(&Or, true, false, Insts))
1903  return nullptr;
1904  Instruction *LastInst = Insts.pop_back_val();
1905  LastInst->removeFromParent();
1906 
1907  for (auto *Inst : Insts)
1908  Worklist.Add(Inst);
1909  return LastInst;
1910 }
1911 
1912 /// Transform UB-safe variants of bitwise rotate to the funnel shift intrinsic.
1914  // TODO: Can we reduce the code duplication between this and the related
1915  // rotate matching code under visitSelect and visitTrunc?
1916  unsigned Width = Or.getType()->getScalarSizeInBits();
1917  if (!isPowerOf2_32(Width))
1918  return nullptr;
1919 
1920  // First, find an or'd pair of opposite shifts with the same shifted operand:
1921  // or (lshr ShVal, ShAmt0), (shl ShVal, ShAmt1)
1922  BinaryOperator *Or0, *Or1;
1923  if (!match(Or.getOperand(0), m_BinOp(Or0)) ||
1924  !match(Or.getOperand(1), m_BinOp(Or1)))
1925  return nullptr;
1926 
1927  Value *ShVal, *ShAmt0, *ShAmt1;
1928  if (!match(Or0, m_OneUse(m_LogicalShift(m_Value(ShVal), m_Value(ShAmt0)))) ||
1929  !match(Or1, m_OneUse(m_LogicalShift(m_Specific(ShVal), m_Value(ShAmt1)))))
1930  return nullptr;
1931 
1932  BinaryOperator::BinaryOps ShiftOpcode0 = Or0->getOpcode();
1933  BinaryOperator::BinaryOps ShiftOpcode1 = Or1->getOpcode();
1934  if (ShiftOpcode0 == ShiftOpcode1)
1935  return nullptr;
1936 
1937  // Match the shift amount operands for a rotate pattern. This always matches
1938  // a subtraction on the R operand.
1939  auto matchShiftAmount = [](Value *L, Value *R, unsigned Width) -> Value * {
1940  // The shift amount may be masked with negation:
1941  // (shl ShVal, (X & (Width - 1))) | (lshr ShVal, ((-X) & (Width - 1)))
1942  Value *X;
1943  unsigned Mask = Width - 1;
1944  if (match(L, m_And(m_Value(X), m_SpecificInt(Mask))) &&
1945  match(R, m_And(m_Neg(m_Specific(X)), m_SpecificInt(Mask))))
1946  return X;
1947 
1948  // Similar to above, but the shift amount may be extended after masking,
1949  // so return the extended value as the parameter for the intrinsic.
1950  if (match(L, m_ZExt(m_And(m_Value(X), m_SpecificInt(Mask)))) &&
1952  m_SpecificInt(Mask))))
1953  return L;
1954 
1955  return nullptr;
1956  };
1957 
1958  Value *ShAmt = matchShiftAmount(ShAmt0, ShAmt1, Width);
1959  bool SubIsOnLHS = false;
1960  if (!ShAmt) {
1961  ShAmt = matchShiftAmount(ShAmt1, ShAmt0, Width);
1962  SubIsOnLHS = true;
1963  }
1964  if (!ShAmt)
1965  return nullptr;
1966 
1967  bool IsFshl = (!SubIsOnLHS && ShiftOpcode0 == BinaryOperator::Shl) ||
1968  (SubIsOnLHS && ShiftOpcode1 == BinaryOperator::Shl);
1969  Intrinsic::ID IID = IsFshl ? Intrinsic::fshl : Intrinsic::fshr;
1971  return IntrinsicInst::Create(F, { ShVal, ShVal, ShAmt });
1972 }
1973 
1974 /// If all elements of two constant vectors are 0/-1 and inverses, return true.
1976  unsigned NumElts = C1->getType()->getVectorNumElements();
1977  for (unsigned i = 0; i != NumElts; ++i) {
1978  Constant *EltC1 = C1->getAggregateElement(i);
1979  Constant *EltC2 = C2->getAggregateElement(i);
1980  if (!EltC1 || !EltC2)
1981  return false;
1982 
1983  // One element must be all ones, and the other must be all zeros.
1984  if (!((match(EltC1, m_Zero()) && match(EltC2, m_AllOnes())) ||
1985  (match(EltC2, m_Zero()) && match(EltC1, m_AllOnes()))))
1986  return false;
1987  }
1988  return true;
1989 }
1990 
1991 /// We have an expression of the form (A & C) | (B & D). If A is a scalar or
1992 /// vector composed of all-zeros or all-ones values and is the bitwise 'not' of
1993 /// B, it can be used as the condition operand of a select instruction.
1994 Value *InstCombiner::getSelectCondition(Value *A, Value *B) {
1995  // Step 1: We may have peeked through bitcasts in the caller.
1996  // Exit immediately if we don't have (vector) integer types.
1997  Type *Ty = A->getType();
1998  if (!Ty->isIntOrIntVectorTy() || !B->getType()->isIntOrIntVectorTy())
1999  return nullptr;
2000 
2001  // Step 2: We need 0 or all-1's bitmasks.
2002  if (ComputeNumSignBits(A) != Ty->getScalarSizeInBits())
2003  return nullptr;
2004 
2005  // Step 3: If B is the 'not' value of A, we have our answer.
2006  if (match(A, m_Not(m_Specific(B)))) {
2007  // If these are scalars or vectors of i1, A can be used directly.
2008  if (Ty->isIntOrIntVectorTy(1))
2009  return A;
2010  return Builder.CreateTrunc(A, CmpInst::makeCmpResultType(Ty));
2011  }
2012 
2013  // If both operands are constants, see if the constants are inverse bitmasks.
2014  Constant *AConst, *BConst;
2015  if (match(A, m_Constant(AConst)) && match(B, m_Constant(BConst)))
2016  if (AConst == ConstantExpr::getNot(BConst))
2017  return Builder.CreateZExtOrTrunc(A, CmpInst::makeCmpResultType(Ty));
2018 
2019  // Look for more complex patterns. The 'not' op may be hidden behind various
2020  // casts. Look through sexts and bitcasts to find the booleans.
2021  Value *Cond;
2022  Value *NotB;
2023  if (match(A, m_SExt(m_Value(Cond))) &&
2024  Cond->getType()->isIntOrIntVectorTy(1) &&
2025  match(B, m_OneUse(m_Not(m_Value(NotB))))) {
2026  NotB = peekThroughBitcast(NotB, true);
2027  if (match(NotB, m_SExt(m_Specific(Cond))))
2028  return Cond;
2029  }
2030 
2031  // All scalar (and most vector) possibilities should be handled now.
2032  // Try more matches that only apply to non-splat constant vectors.
2033  if (!Ty->isVectorTy())
2034  return nullptr;
2035 
2036  // If both operands are xor'd with constants using the same sexted boolean
2037  // operand, see if the constants are inverse bitmasks.
2038  // TODO: Use ConstantExpr::getNot()?
2039  if (match(A, (m_Xor(m_SExt(m_Value(Cond)), m_Constant(AConst)))) &&
2040  match(B, (m_Xor(m_SExt(m_Specific(Cond)), m_Constant(BConst)))) &&
2041  Cond->getType()->isIntOrIntVectorTy(1) &&
2042  areInverseVectorBitmasks(AConst, BConst)) {
2043  AConst = ConstantExpr::getTrunc(AConst, CmpInst::makeCmpResultType(Ty));
2044  return Builder.CreateXor(Cond, AConst);
2045  }
2046  return nullptr;
2047 }
2048 
2049 /// We have an expression of the form (A & C) | (B & D). Try to simplify this
2050 /// to "A' ? C : D", where A' is a boolean or vector of booleans.
2051 Value *InstCombiner::matchSelectFromAndOr(Value *A, Value *C, Value *B,
2052  Value *D) {
2053  // The potential condition of the select may be bitcasted. In that case, look
2054  // through its bitcast and the corresponding bitcast of the 'not' condition.
2055  Type *OrigType = A->getType();
2056  A = peekThroughBitcast(A, true);
2057  B = peekThroughBitcast(B, true);
2058  if (Value *Cond = getSelectCondition(A, B)) {
2059  // ((bc Cond) & C) | ((bc ~Cond) & D) --> bc (select Cond, (bc C), (bc D))
2060  // The bitcasts will either all exist or all not exist. The builder will
2061  // not create unnecessary casts if the types already match.
2062  Value *BitcastC = Builder.CreateBitCast(C, A->getType());
2063  Value *BitcastD = Builder.CreateBitCast(D, A->getType());
2064  Value *Select = Builder.CreateSelect(Cond, BitcastC, BitcastD);
2065  return Builder.CreateBitCast(Select, OrigType);
2066  }
2067 
2068  return nullptr;
2069 }
2070 
2071 /// Fold (icmp)|(icmp) if possible.
2072 Value *InstCombiner::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
2073  Instruction &CxtI) {
2074  // Fold (iszero(A & K1) | iszero(A & K2)) -> (A & (K1 | K2)) != (K1 | K2)
2075  // if K1 and K2 are a one-bit mask.
2076  if (Value *V = foldAndOrOfICmpsOfAndWithPow2(LHS, RHS, false, CxtI))
2077  return V;
2078 
2079  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
2080 
2081  ConstantInt *LHSC = dyn_cast<ConstantInt>(LHS->getOperand(1));
2082  ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS->getOperand(1));
2083 
2084  // Fold (icmp ult/ule (A + C1), C3) | (icmp ult/ule (A + C2), C3)
2085  // --> (icmp ult/ule ((A & ~(C1 ^ C2)) + max(C1, C2)), C3)
2086  // The original condition actually refers to the following two ranges:
2087  // [MAX_UINT-C1+1, MAX_UINT-C1+1+C3] and [MAX_UINT-C2+1, MAX_UINT-C2+1+C3]
2088  // We can fold these two ranges if:
2089  // 1) C1 and C2 is unsigned greater than C3.
2090  // 2) The two ranges are separated.
2091  // 3) C1 ^ C2 is one-bit mask.
2092  // 4) LowRange1 ^ LowRange2 and HighRange1 ^ HighRange2 are one-bit mask.
2093  // This implies all values in the two ranges differ by exactly one bit.
2094 
2095  if ((PredL == ICmpInst::ICMP_ULT || PredL == ICmpInst::ICMP_ULE) &&
2096  PredL == PredR && LHSC && RHSC && LHS->hasOneUse() && RHS->hasOneUse() &&
2097  LHSC->getType() == RHSC->getType() &&
2098  LHSC->getValue() == (RHSC->getValue())) {
2099 
2100  Value *LAdd = LHS->getOperand(0);
2101  Value *RAdd = RHS->getOperand(0);
2102 
2103  Value *LAddOpnd, *RAddOpnd;
2104  ConstantInt *LAddC, *RAddC;
2105  if (match(LAdd, m_Add(m_Value(LAddOpnd), m_ConstantInt(LAddC))) &&
2106  match(RAdd, m_Add(m_Value(RAddOpnd), m_ConstantInt(RAddC))) &&
2107  LAddC->getValue().ugt(LHSC->getValue()) &&
2108  RAddC->getValue().ugt(LHSC->getValue())) {
2109 
2110  APInt DiffC = LAddC->getValue() ^ RAddC->getValue();
2111  if (LAddOpnd == RAddOpnd && DiffC.isPowerOf2()) {
2112  ConstantInt *MaxAddC = nullptr;
2113  if (LAddC->getValue().ult(RAddC->getValue()))
2114  MaxAddC = RAddC;
2115  else
2116  MaxAddC = LAddC;
2117 
2118  APInt RRangeLow = -RAddC->getValue();
2119  APInt RRangeHigh = RRangeLow + LHSC->getValue();
2120  APInt LRangeLow = -LAddC->getValue();
2121  APInt LRangeHigh = LRangeLow + LHSC->getValue();
2122  APInt LowRangeDiff = RRangeLow ^ LRangeLow;
2123  APInt HighRangeDiff = RRangeHigh ^ LRangeHigh;
2124  APInt RangeDiff = LRangeLow.sgt(RRangeLow) ? LRangeLow - RRangeLow
2125  : RRangeLow - LRangeLow;
2126 
2127  if (LowRangeDiff.isPowerOf2() && LowRangeDiff == HighRangeDiff &&
2128  RangeDiff.ugt(LHSC->getValue())) {
2129  Value *MaskC = ConstantInt::get(LAddC->getType(), ~DiffC);
2130 
2131  Value *NewAnd = Builder.CreateAnd(LAddOpnd, MaskC);
2132  Value *NewAdd = Builder.CreateAdd(NewAnd, MaxAddC);
2133  return Builder.CreateICmp(LHS->getPredicate(), NewAdd, LHSC);
2134  }
2135  }
2136  }
2137  }
2138 
2139  // (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
2140  if (predicatesFoldable(PredL, PredR)) {
2141  if (LHS->getOperand(0) == RHS->getOperand(1) &&
2142  LHS->getOperand(1) == RHS->getOperand(0))
2143  LHS->swapOperands();
2144  if (LHS->getOperand(0) == RHS->getOperand(0) &&
2145  LHS->getOperand(1) == RHS->getOperand(1)) {
2146  Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
2147  unsigned Code = getICmpCode(LHS) | getICmpCode(RHS);
2148  bool IsSigned = LHS->isSigned() || RHS->isSigned();
2149  return getNewICmpValue(Code, IsSigned, Op0, Op1, Builder);
2150  }
2151  }
2152 
2153  // handle (roughly):
2154  // (icmp ne (A & B), C) | (icmp ne (A & D), E)
2155  if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, false, Builder))
2156  return V;
2157 
2158  Value *LHS0 = LHS->getOperand(0), *RHS0 = RHS->getOperand(0);
2159  if (LHS->hasOneUse() || RHS->hasOneUse()) {
2160  // (icmp eq B, 0) | (icmp ult A, B) -> (icmp ule A, B-1)
2161  // (icmp eq B, 0) | (icmp ugt B, A) -> (icmp ule A, B-1)
2162  Value *A = nullptr, *B = nullptr;
2163  if (PredL == ICmpInst::ICMP_EQ && LHSC && LHSC->isZero()) {
2164  B = LHS0;
2165  if (PredR == ICmpInst::ICMP_ULT && LHS0 == RHS->getOperand(1))
2166  A = RHS0;
2167  else if (PredR == ICmpInst::ICMP_UGT && LHS0 == RHS0)
2168  A = RHS->getOperand(1);
2169  }
2170  // (icmp ult A, B) | (icmp eq B, 0) -> (icmp ule A, B-1)
2171  // (icmp ugt B, A) | (icmp eq B, 0) -> (icmp ule A, B-1)
2172  else if (PredR == ICmpInst::ICMP_EQ && RHSC && RHSC->isZero()) {
2173  B = RHS0;
2174  if (PredL == ICmpInst::ICMP_ULT && RHS0 == LHS->getOperand(1))
2175  A = LHS0;
2176  else if (PredL == ICmpInst::ICMP_UGT && LHS0 == RHS0)
2177  A = LHS->getOperand(1);
2178  }
2179  if (A && B)
2180  return Builder.CreateICmp(
2182  Builder.CreateAdd(B, ConstantInt::getSigned(B->getType(), -1)), A);
2183  }
2184 
2185  // E.g. (icmp slt x, 0) | (icmp sgt x, n) --> icmp ugt x, n
2186  if (Value *V = simplifyRangeCheck(LHS, RHS, /*Inverted=*/true))
2187  return V;
2188 
2189  // E.g. (icmp sgt x, n) | (icmp slt x, 0) --> icmp ugt x, n
2190  if (Value *V = simplifyRangeCheck(RHS, LHS, /*Inverted=*/true))
2191  return V;
2192 
2193  if (Value *V = foldAndOrOfEqualityCmpsWithConstants(LHS, RHS, false, Builder))
2194  return V;
2195 
2196  if (Value *V = foldIsPowerOf2(LHS, RHS, false /* JoinedByAnd */, Builder))
2197  return V;
2198 
2199  // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
2200  if (!LHSC || !RHSC)
2201  return nullptr;
2202 
2203  if (LHSC == RHSC && PredL == PredR) {
2204  // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
2205  if (PredL == ICmpInst::ICMP_NE && LHSC->isZero()) {
2206  Value *NewOr = Builder.CreateOr(LHS0, RHS0);
2207  return Builder.CreateICmp(PredL, NewOr, LHSC);
2208  }
2209  }
2210 
2211  // (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1)
2212  // iff C2 + CA == C1.
2213  if (PredL == ICmpInst::ICMP_ULT && PredR == ICmpInst::ICMP_EQ) {
2214  ConstantInt *AddC;
2215  if (match(LHS0, m_Add(m_Specific(RHS0), m_ConstantInt(AddC))))
2216  if (RHSC->getValue() + AddC->getValue() == LHSC->getValue())
2217  return Builder.CreateICmpULE(LHS0, LHSC);
2218  }
2219 
2220  // From here on, we only handle:
2221  // (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
2222  if (LHS0 != RHS0)
2223  return nullptr;
2224 
2225  // ICMP_[US][GL]E X, C is folded to ICMP_[US][GL]T elsewhere.
2226  if (PredL == ICmpInst::ICMP_UGE || PredL == ICmpInst::ICMP_ULE ||
2227  PredR == ICmpInst::ICMP_UGE || PredR == ICmpInst::ICMP_ULE ||
2228  PredL == ICmpInst::ICMP_SGE || PredL == ICmpInst::ICMP_SLE ||
2229  PredR == ICmpInst::ICMP_SGE || PredR == ICmpInst::ICMP_SLE)
2230  return nullptr;
2231 
2232  // We can't fold (ugt x, C) | (sgt x, C2).
2233  if (!predicatesFoldable(PredL, PredR))
2234  return nullptr;
2235 
2236  // Ensure that the larger constant is on the RHS.
2237  bool ShouldSwap;
2238  if (CmpInst::isSigned(PredL) ||
2239  (ICmpInst::isEquality(PredL) && CmpInst::isSigned(PredR)))
2240  ShouldSwap = LHSC->getValue().sgt(RHSC->getValue());
2241  else
2242  ShouldSwap = LHSC->getValue().ugt(RHSC->getValue());
2243 
2244  if (ShouldSwap) {
2245  std::swap(LHS, RHS);
2246  std::swap(LHSC, RHSC);
2247  std::swap(PredL, PredR);
2248  }
2249 
2250  // At this point, we know we have two icmp instructions
2251  // comparing a value against two constants and or'ing the result
2252  // together. Because of the above check, we know that we only have
2253  // ICMP_EQ, ICMP_NE, ICMP_LT, and ICMP_GT here. We also know (from the
2254  // icmp folding check above), that the two constants are not
2255  // equal.
2256  assert(LHSC != RHSC && "Compares not folded above?");
2257 
2258  switch (PredL) {
2259  default:
2260  llvm_unreachable("Unknown integer condition code!");
2261  case ICmpInst::ICMP_EQ:
2262  switch (PredR) {
2263  default:
2264  llvm_unreachable("Unknown integer condition code!");
2265  case ICmpInst::ICMP_EQ:
2266  // Potential folds for this case should already be handled.
2267  break;
2268  case ICmpInst::ICMP_UGT:
2269  // (X == 0 || X u> C) -> (X-1) u>= C
2270  if (LHSC->isMinValue(false))
2271  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue() + 1,
2272  false, false);
2273  // (X == 13 | X u> 14) -> no change
2274  break;
2275  case ICmpInst::ICMP_SGT:
2276  // (X == INT_MIN || X s> C) -> (X-(INT_MIN+1)) u>= C-INT_MIN
2277  if (LHSC->isMinValue(true))
2278  return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue() + 1,
2279  true, false);
2280  // (X == 13 | X s> 14) -> no change
2281  break;
2282  }
2283  break;
2284  case ICmpInst::ICMP_ULT:
2285  switch (PredR) {
2286  default:
2287  llvm_unreachable("Unknown integer condition code!");
2288  case ICmpInst::ICMP_EQ: // (X u< 13 | X == 14) -> no change
2289  // (X u< C || X == UINT_MAX) => (X-C) u>= UINT_MAX-C
2290  if (RHSC->isMaxValue(false))
2291  return insertRangeTest(LHS0, LHSC->getValue(), RHSC->getValue(),
2292  false, false);
2293  break;
2294  case ICmpInst::ICMP_UGT: // (X u< 13 | X u> 15) -> (X-13) u> 2
2295  assert(!RHSC->isMaxValue(false) && "Missed icmp simplification");
2296  return insertRangeTest(LHS0, LHSC->getValue(), RHSC->getValue() + 1,
2297  false, false);
2298  }
2299  break;
2300  case ICmpInst::ICMP_SLT:
2301  switch (PredR) {
2302  default:
2303  llvm_unreachable("Unknown integer condition code!");
2304  case ICmpInst::ICMP_EQ:
2305  // (X s< C || X == INT_MAX) => (X-C) u>= INT_MAX-C
2306  if (RHSC->isMaxValue(true))
2307  return insertRangeTest(LHS0, LHSC->getValue(), RHSC->getValue(),
2308  true, false);
2309  // (X s< 13 | X == 14) -> no change
2310  break;
2311  case ICmpInst::ICMP_SGT: // (X s< 13 | X s> 15) -> (X-13) u> 2
2312  assert(!RHSC->isMaxValue(true) && "Missed icmp simplification");
2313  return insertRangeTest(LHS0, LHSC->getValue(), RHSC->getValue() + 1, true,
2314  false);
2315  }
2316  break;
2317  }
2318  return nullptr;
2319 }
2320 
2321 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
2322 // here. We should standardize that construct where it is needed or choose some
2323 // other way to ensure that commutated variants of patterns are not missed.
2325  if (Value *V = SimplifyOrInst(I.getOperand(0), I.getOperand(1),
2326  SQ.getWithInstruction(&I)))
2327  return replaceInstUsesWith(I, V);
2328 
2329  if (SimplifyAssociativeOrCommutative(I))
2330  return &I;
2331 
2332  if (Instruction *X = foldVectorBinop(I))
2333  return X;
2334 
2335  // See if we can simplify any instructions used by the instruction whose sole
2336  // purpose is to compute bits we don't care about.
2337  if (SimplifyDemandedInstructionBits(I))
2338  return &I;
2339 
2340  // Do this before using distributive laws to catch simple and/or/not patterns.
2341  if (Instruction *Xor = foldOrToXor(I, Builder))
2342  return Xor;
2343 
2344  // (A&B)|(A&C) -> A&(B|C) etc
2345  if (Value *V = SimplifyUsingDistributiveLaws(I))
2346  return replaceInstUsesWith(I, V);
2347 
2348  if (Value *V = SimplifyBSwap(I, Builder))
2349  return replaceInstUsesWith(I, V);
2350 
2351  if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
2352  return FoldedLogic;
2353 
2354  if (Instruction *BSwap = matchBSwap(I))
2355  return BSwap;
2356 
2357  if (Instruction *Rotate = matchRotate(I))
2358  return Rotate;
2359 
2360  Value *X, *Y;
2361  const APInt *CV;
2362  if (match(&I, m_c_Or(m_OneUse(m_Xor(m_Value(X), m_APInt(CV))), m_Value(Y))) &&
2363  !CV->isAllOnesValue() && MaskedValueIsZero(Y, *CV, 0, &I)) {
2364  // (X ^ C) | Y -> (X | Y) ^ C iff Y & C == 0
2365  // The check for a 'not' op is for efficiency (if Y is known zero --> ~X).
2366  Value *Or = Builder.CreateOr(X, Y);
2367  return BinaryOperator::CreateXor(Or, ConstantInt::get(I.getType(), *CV));
2368  }
2369 
2370  // (A & C)|(B & D)
2371  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
2372  Value *A, *B, *C, *D;
2373  if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
2374  match(Op1, m_And(m_Value(B), m_Value(D)))) {
2377  if (C1 && C2) { // (A & C1)|(B & C2)
2378  Value *V1 = nullptr, *V2 = nullptr;
2379  if ((C1->getValue() & C2->getValue()).isNullValue()) {
2380  // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2)
2381  // iff (C1&C2) == 0 and (N&~C1) == 0
2382  if (match(A, m_Or(m_Value(V1), m_Value(V2))) &&
2383  ((V1 == B &&
2384  MaskedValueIsZero(V2, ~C1->getValue(), 0, &I)) || // (V|N)
2385  (V2 == B &&
2386  MaskedValueIsZero(V1, ~C1->getValue(), 0, &I)))) // (N|V)
2387  return BinaryOperator::CreateAnd(A,
2388  Builder.getInt(C1->getValue()|C2->getValue()));
2389  // Or commutes, try both ways.
2390  if (match(B, m_Or(m_Value(V1), m_Value(V2))) &&
2391  ((V1 == A &&
2392  MaskedValueIsZero(V2, ~C2->getValue(), 0, &I)) || // (V|N)
2393  (V2 == A &&
2394  MaskedValueIsZero(V1, ~C2->getValue(), 0, &I)))) // (N|V)
2395  return BinaryOperator::CreateAnd(B,
2396  Builder.getInt(C1->getValue()|C2->getValue()));
2397 
2398  // ((V|C3)&C1) | ((V|C4)&C2) --> (V|C3|C4)&(C1|C2)
2399  // iff (C1&C2) == 0 and (C3&~C1) == 0 and (C4&~C2) == 0.
2400  ConstantInt *C3 = nullptr, *C4 = nullptr;
2401  if (match(A, m_Or(m_Value(V1), m_ConstantInt(C3))) &&
2402  (C3->getValue() & ~C1->getValue()).isNullValue() &&
2403  match(B, m_Or(m_Specific(V1), m_ConstantInt(C4))) &&
2404  (C4->getValue() & ~C2->getValue()).isNullValue()) {
2405  V2 = Builder.CreateOr(V1, ConstantExpr::getOr(C3, C4), "bitfield");
2406  return BinaryOperator::CreateAnd(V2,
2407  Builder.getInt(C1->getValue()|C2->getValue()));
2408  }
2409  }
2410 
2411  if (C1->getValue() == ~C2->getValue()) {
2412  Value *X;
2413 
2414  // ((X|B)&C1)|(B&C2) -> (X&C1) | B iff C1 == ~C2
2415  if (match(A, m_c_Or(m_Value(X), m_Specific(B))))
2416  return BinaryOperator::CreateOr(Builder.CreateAnd(X, C1), B);
2417  // (A&C2)|((X|A)&C1) -> (X&C2) | A iff C1 == ~C2
2418  if (match(B, m_c_Or(m_Specific(A), m_Value(X))))
2419  return BinaryOperator::CreateOr(Builder.CreateAnd(X, C2), A);
2420 
2421  // ((X^B)&C1)|(B&C2) -> (X&C1) ^ B iff C1 == ~C2
2422  if (match(A, m_c_Xor(m_Value(X), m_Specific(B))))
2423  return BinaryOperator::CreateXor(Builder.CreateAnd(X, C1), B);
2424  // (A&C2)|((X^A)&C1) -> (X&C2) ^ A iff C1 == ~C2
2425  if (match(B, m_c_Xor(m_Specific(A), m_Value(X))))
2426  return BinaryOperator::CreateXor(Builder.CreateAnd(X, C2), A);
2427  }
2428  }
2429 
2430  // Don't try to form a select if it's unlikely that we'll get rid of at
2431  // least one of the operands. A select is generally more expensive than the
2432  // 'or' that it is replacing.
2433  if (Op0->hasOneUse() || Op1->hasOneUse()) {
2434  // (Cond & C) | (~Cond & D) -> Cond ? C : D, and commuted variants.
2435  if (Value *V = matchSelectFromAndOr(A, C, B, D))
2436  return replaceInstUsesWith(I, V);
2437  if (Value *V = matchSelectFromAndOr(A, C, D, B))
2438  return replaceInstUsesWith(I, V);
2439  if (Value *V = matchSelectFromAndOr(C, A, B, D))
2440  return replaceInstUsesWith(I, V);
2441  if (Value *V = matchSelectFromAndOr(C, A, D, B))
2442  return replaceInstUsesWith(I, V);
2443  if (Value *V = matchSelectFromAndOr(B, D, A, C))
2444  return replaceInstUsesWith(I, V);
2445  if (Value *V = matchSelectFromAndOr(B, D, C, A))
2446  return replaceInstUsesWith(I, V);
2447  if (Value *V = matchSelectFromAndOr(D, B, A, C))
2448  return replaceInstUsesWith(I, V);
2449  if (Value *V = matchSelectFromAndOr(D, B, C, A))
2450  return replaceInstUsesWith(I, V);
2451  }
2452  }
2453 
2454  // (A ^ B) | ((B ^ C) ^ A) -> (A ^ B) | C
2455  if (match(Op0, m_Xor(m_Value(A), m_Value(B))))
2456  if (match(Op1, m_Xor(m_Xor(m_Specific(B), m_Value(C)), m_Specific(A))))
2457  return BinaryOperator::CreateOr(Op0, C);
2458 
2459  // ((A ^ C) ^ B) | (B ^ A) -> (B ^ A) | C
2460  if (match(Op0, m_Xor(m_Xor(m_Value(A), m_Value(C)), m_Value(B))))
2461  if (match(Op1, m_Xor(m_Specific(B), m_Specific(A))))
2462  return BinaryOperator::CreateOr(Op1, C);
2463 
2464  // ((B | C) & A) | B -> B | (A & C)
2465  if (match(Op0, m_And(m_Or(m_Specific(Op1), m_Value(C)), m_Value(A))))
2466  return BinaryOperator::CreateOr(Op1, Builder.CreateAnd(A, C));
2467 
2468  if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
2469  return DeMorgan;
2470 
2471  // Canonicalize xor to the RHS.
2472  bool SwappedForXor = false;
2473  if (match(Op0, m_Xor(m_Value(), m_Value()))) {
2474  std::swap(Op0, Op1);
2475  SwappedForXor = true;
2476  }
2477 
2478  // A | ( A ^ B) -> A | B
2479  // A | (~A ^ B) -> A | ~B
2480  // (A & B) | (A ^ B)
2481  if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
2482  if (Op0 == A || Op0 == B)
2483  return BinaryOperator::CreateOr(A, B);
2484 
2485  if (match(Op0, m_And(m_Specific(A), m_Specific(B))) ||
2486  match(Op0, m_And(m_Specific(B), m_Specific(A))))
2487  return BinaryOperator::CreateOr(A, B);
2488 
2489  if (Op1->hasOneUse() && match(A, m_Not(m_Specific(Op0)))) {
2490  Value *Not = Builder.CreateNot(B, B->getName() + ".not");
2491  return BinaryOperator::CreateOr(Not, Op0);
2492  }
2493  if (Op1->hasOneUse() && match(B, m_Not(m_Specific(Op0)))) {
2494  Value *Not = Builder.CreateNot(A, A->getName() + ".not");
2495  return BinaryOperator::CreateOr(Not, Op0);
2496  }
2497  }
2498 
2499  // A | ~(A | B) -> A | ~B
2500  // A | ~(A ^ B) -> A | ~B
2501  if (match(Op1, m_Not(m_Value(A))))
2502  if (BinaryOperator *B = dyn_cast<BinaryOperator>(A))
2503  if ((Op0 == B->getOperand(0) || Op0 == B->getOperand(1)) &&
2504  Op1->hasOneUse() && (B->getOpcode() == Instruction::Or ||
2505  B->getOpcode() == Instruction::Xor)) {
2506  Value *NotOp = Op0 == B->getOperand(0) ? B->getOperand(1) :
2507  B->getOperand(0);
2508  Value *Not = Builder.CreateNot(NotOp, NotOp->getName() + ".not");
2509  return BinaryOperator::CreateOr(Not, Op0);
2510  }
2511 
2512  if (SwappedForXor)
2513  std::swap(Op0, Op1);
2514 
2515  {
2516  ICmpInst *LHS = dyn_cast<ICmpInst>(Op0);
2517  ICmpInst *RHS = dyn_cast<ICmpInst>(Op1);
2518  if (LHS && RHS)
2519  if (Value *Res = foldOrOfICmps(LHS, RHS, I))
2520  return replaceInstUsesWith(I, Res);
2521 
2522  // TODO: Make this recursive; it's a little tricky because an arbitrary
2523  // number of 'or' instructions might have to be created.
2524  Value *X, *Y;
2525  if (LHS && match(Op1, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
2526  if (auto *Cmp = dyn_cast<ICmpInst>(X))
2527  if (Value *Res = foldOrOfICmps(LHS, Cmp, I))
2528  return replaceInstUsesWith(I, Builder.CreateOr(Res, Y));
2529  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
2530  if (Value *Res = foldOrOfICmps(LHS, Cmp, I))
2531  return replaceInstUsesWith(I, Builder.CreateOr(Res, X));
2532  }
2533  if (RHS && match(Op0, m_OneUse(m_Or(m_Value(X), m_Value(Y))))) {
2534  if (auto *Cmp = dyn_cast<ICmpInst>(X))
2535  if (Value *Res = foldOrOfICmps(Cmp, RHS, I))
2536  return replaceInstUsesWith(I, Builder.CreateOr(Res, Y));
2537  if (auto *Cmp = dyn_cast<ICmpInst>(Y))
2538  if (Value *Res = foldOrOfICmps(Cmp, RHS, I))
2539  return replaceInstUsesWith(I, Builder.CreateOr(Res, X));
2540  }
2541  }
2542 
2543  if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0)))
2544  if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
2545  if (Value *Res = foldLogicOfFCmps(LHS, RHS, false))
2546  return replaceInstUsesWith(I, Res);
2547 
2548  if (Instruction *FoldedFCmps = reassociateFCmps(I, Builder))
2549  return FoldedFCmps;
2550 
2551  if (Instruction *CastedOr = foldCastedBitwiseLogic(I))
2552  return CastedOr;
2553 
2554  // or(sext(A), B) / or(B, sext(A)) --> A ? -1 : B, where A is i1 or <N x i1>.
2555  if (match(Op0, m_OneUse(m_SExt(m_Value(A)))) &&
2556  A->getType()->isIntOrIntVectorTy(1))
2557  return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op1);
2558  if (match(Op1, m_OneUse(m_SExt(m_Value(A)))) &&
2559  A->getType()->isIntOrIntVectorTy(1))
2560  return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op0);
2561 
2562  // Note: If we've gotten to the point of visiting the outer OR, then the
2563  // inner one couldn't be simplified. If it was a constant, then it won't
2564  // be simplified by a later pass either, so we try swapping the inner/outer
2565  // ORs in the hopes that we'll be able to simplify it this way.
2566  // (X|C) | V --> (X|V) | C
2567  ConstantInt *CI;
2568  if (Op0->hasOneUse() && !isa<ConstantInt>(Op1) &&
2569  match(Op0, m_Or(m_Value(A), m_ConstantInt(CI)))) {
2570  Value *Inner = Builder.CreateOr(A, Op1);
2571  Inner->takeName(Op0);
2572  return BinaryOperator::CreateOr(Inner, CI);
2573  }
2574 
2575  // Change (or (bool?A:B),(bool?C:D)) --> (bool?(or A,C):(or B,D))
2576  // Since this OR statement hasn't been optimized further yet, we hope
2577  // that this transformation will allow the new ORs to be optimized.
2578  {
2579  Value *X = nullptr, *Y = nullptr;
2580  if (Op0->hasOneUse() && Op1->hasOneUse() &&
2581  match(Op0, m_Select(m_Value(X), m_Value(A), m_Value(B))) &&
2582  match(Op1, m_Select(m_Value(Y), m_Value(C), m_Value(D))) && X == Y) {
2583  Value *orTrue = Builder.CreateOr(A, C);
2584  Value *orFalse = Builder.CreateOr(B, D);
2585  return SelectInst::Create(X, orTrue, orFalse);
2586  }
2587  }
2588 
2589  return nullptr;
2590 }
2591 
2592 /// A ^ B can be specified using other logic ops in a variety of patterns. We
2593 /// can fold these early and efficiently by morphing an existing instruction.
2595  InstCombiner::BuilderTy &Builder) {
2596  assert(I.getOpcode() == Instruction::Xor);
2597  Value *Op0 = I.getOperand(0);
2598  Value *Op1 = I.getOperand(1);
2599  Value *A, *B;
2600 
2601  // There are 4 commuted variants for each of the basic patterns.
2602 
2603  // (A & B) ^ (A | B) -> A ^ B
2604  // (A & B) ^ (B | A) -> A ^ B
2605  // (A | B) ^ (A & B) -> A ^ B
2606  // (A | B) ^ (B & A) -> A ^ B
2607  if (match(&I, m_c_Xor(m_And(m_Value(A), m_Value(B)),
2608  m_c_Or(m_Deferred(A), m_Deferred(B))))) {
2609  I.setOperand(0, A);
2610  I.setOperand(1, B);
2611  return &I;
2612  }
2613 
2614  // (A | ~B) ^ (~A | B) -> A ^ B
2615  // (~B | A) ^ (~A | B) -> A ^ B
2616  // (~A | B) ^ (A | ~B) -> A ^ B
2617  // (B | ~A) ^ (A | ~B) -> A ^ B
2618  if (match(&I, m_Xor(m_c_Or(m_Value(A), m_Not(m_Value(B))),
2619  m_c_Or(m_Not(m_Deferred(A)), m_Deferred(B))))) {
2620  I.setOperand(0, A);
2621  I.setOperand(1, B);
2622  return &I;
2623  }
2624 
2625  // (A & ~B) ^ (~A & B) -> A ^ B
2626  // (~B & A) ^ (~A & B) -> A ^ B
2627  // (~A & B) ^ (A & ~B) -> A ^ B
2628  // (B & ~A) ^ (A & ~B) -> A ^ B
2629  if (match(&I, m_Xor(m_c_And(m_Value(A), m_Not(m_Value(B))),
2630  m_c_And(m_Not(m_Deferred(A)), m_Deferred(B))))) {
2631  I.setOperand(0, A);
2632  I.setOperand(1, B);
2633  return &I;
2634  }
2635 
2636  // For the remaining cases we need to get rid of one of the operands.
2637  if (!Op0->hasOneUse() && !Op1->hasOneUse())
2638  return nullptr;
2639 
2640  // (A | B) ^ ~(A & B) -> ~(A ^ B)
2641  // (A | B) ^ ~(B & A) -> ~(A ^ B)
2642  // (A & B) ^ ~(A | B) -> ~(A ^ B)
2643  // (A & B) ^ ~(B | A) -> ~(A ^ B)
2644  // Complexity sorting ensures the not will be on the right side.
2645  if ((match(Op0, m_Or(m_Value(A), m_Value(B))) &&
2646  match(Op1, m_Not(m_c_And(m_Specific(A), m_Specific(B))))) ||
2647  (match(Op0, m_And(m_Value(A), m_Value(B))) &&
2648  match(Op1, m_Not(m_c_Or(m_Specific(A), m_Specific(B))))))
2649  return BinaryOperator::CreateNot(Builder.CreateXor(A, B));
2650 
2651  return nullptr;
2652 }
2653 
2654 Value *InstCombiner::foldXorOfICmps(ICmpInst *LHS, ICmpInst *RHS,
2655  BinaryOperator &I) {
2656  assert(I.getOpcode() == Instruction::Xor && I.getOperand(0) == LHS &&
2657  I.getOperand(1) == RHS && "Should be 'xor' with these operands");
2658 
2659  if (predicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
2660  if (LHS->getOperand(0) == RHS->getOperand(1) &&
2661  LHS->getOperand(1) == RHS->getOperand(0))
2662  LHS->swapOperands();
2663  if (LHS->getOperand(0) == RHS->getOperand(0) &&
2664  LHS->getOperand(1) == RHS->getOperand(1)) {
2665  // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
2666  Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
2667  unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
2668  bool IsSigned = LHS->isSigned() || RHS->isSigned();
2669  return getNewICmpValue(Code, IsSigned, Op0, Op1, Builder);
2670  }
2671  }
2672 
2673  // TODO: This can be generalized to compares of non-signbits using
2674  // decomposeBitTestICmp(). It could be enhanced more by using (something like)
2675  // foldLogOpOfMaskedICmps().
2676  ICmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
2677  Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
2678  Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
2679  if ((LHS->hasOneUse() || RHS->hasOneUse()) &&
2680  LHS0->getType() == RHS0->getType() &&
2681  LHS0->getType()->isIntOrIntVectorTy()) {
2682  // (X > -1) ^ (Y > -1) --> (X ^ Y) < 0
2683  // (X < 0) ^ (Y < 0) --> (X ^ Y) < 0
2684  if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_AllOnes()) &&
2685  PredR == CmpInst::ICMP_SGT && match(RHS1, m_AllOnes())) ||
2686  (PredL == CmpInst::ICMP_SLT && match(LHS1, m_Zero()) &&
2687  PredR == CmpInst::ICMP_SLT && match(RHS1, m_Zero()))) {
2688  Value *Zero = ConstantInt::getNullValue(LHS0->getType());
2689  return Builder.CreateICmpSLT(Builder.CreateXor(LHS0, RHS0), Zero);
2690  }
2691  // (X > -1) ^ (Y < 0) --> (X ^ Y) > -1
2692  // (X < 0) ^ (Y > -1) --> (X ^ Y) > -1
2693  if ((PredL == CmpInst::ICMP_SGT && match(LHS1, m_AllOnes()) &&
2694  PredR == CmpInst::ICMP_SLT && match(RHS1, m_Zero())) ||
2695  (PredL == CmpInst::ICMP_SLT && match(LHS1, m_Zero()) &&
2696  PredR == CmpInst::ICMP_SGT && match(RHS1, m_AllOnes()))) {
2697  Value *MinusOne = ConstantInt::getAllOnesValue(LHS0->getType());
2698  return Builder.CreateICmpSGT(Builder.CreateXor(LHS0, RHS0), MinusOne);
2699  }
2700  }
2701 
2702  // Instead of trying to imitate the folds for and/or, decompose this 'xor'
2703  // into those logic ops. That is, try to turn this into an and-of-icmps
2704  // because we have many folds for that pattern.
2705  //
2706  // This is based on a truth table definition of xor:
2707  // X ^ Y --> (X | Y) & !(X & Y)
2708  if (Value *OrICmp = SimplifyBinOp(Instruction::Or, LHS, RHS, SQ)) {
2709  // TODO: If OrICmp is true, then the definition of xor simplifies to !(X&Y).
2710  // TODO: If OrICmp is false, the whole thing is false (InstSimplify?).
2711  if (Value *AndICmp = SimplifyBinOp(Instruction::And, LHS, RHS, SQ)) {
2712  // TODO: Independently handle cases where the 'and' side is a constant.
2713  ICmpInst *X = nullptr, *Y = nullptr;
2714  if (OrICmp == LHS && AndICmp == RHS) {
2715  // (LHS | RHS) & !(LHS & RHS) --> LHS & !RHS --> X & !Y
2716  X = LHS;
2717  Y = RHS;
2718  }
2719  if (OrICmp == RHS && AndICmp == LHS) {
2720  // !(LHS & RHS) & (LHS | RHS) --> !LHS & RHS --> !Y & X
2721  X = RHS;
2722  Y = LHS;
2723  }
2724  if (X && Y && (Y->hasOneUse() || canFreelyInvertAllUsersOf(Y, &I))) {
2725  // Invert the predicate of 'Y', thus inverting its output.
2726  Y->setPredicate(Y->getInversePredicate());
2727  // So, are there other uses of Y?
2728  if (!Y->hasOneUse()) {
2729  // We need to adapt other uses of Y though. Get a value that matches
2730  // the original value of Y before inversion. While this increases
2731  // immediate instruction count, we have just ensured that all the
2732  // users are freely-invertible, so that 'not' *will* get folded away.
2733  BuilderTy::InsertPointGuard Guard(Builder);
2734  // Set insertion point to right after the Y.
2735  Builder.SetInsertPoint(Y->getParent(), ++(Y->getIterator()));
2736  Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
2737  // Replace all uses of Y (excluding the one in NotY!) with NotY.
2738  Y->replaceUsesWithIf(NotY,
2739  [NotY](Use &U) { return U.getUser() != NotY; });
2740  }
2741  // All done.
2742  return Builder.CreateAnd(LHS, RHS);
2743  }
2744  }
2745  }
2746 
2747  return nullptr;
2748 }
2749 
2750 /// If we have a masked merge, in the canonical form of:
2751 /// (assuming that A only has one use.)
2752 /// | A | |B|
2753 /// ((x ^ y) & M) ^ y
2754 /// | D |
2755 /// * If M is inverted:
2756 /// | D |
2757 /// ((x ^ y) & ~M) ^ y
2758 /// We can canonicalize by swapping the final xor operand
2759 /// to eliminate the 'not' of the mask.
2760 /// ((x ^ y) & M) ^ x
2761 /// * If M is a constant, and D has one use, we transform to 'and' / 'or' ops
2762 /// because that shortens the dependency chain and improves analysis:
2763 /// (x & M) | (y & ~M)
2765  InstCombiner::BuilderTy &Builder) {
2766  Value *B, *X, *D;
2767  Value *M;
2768  if (!match(&I, m_c_Xor(m_Value(B),
2769  m_OneUse(m_c_And(
2771  m_Value(D)),
2772  m_Value(M))))))
2773  return nullptr;
2774 
2775  Value *NotM;
2776  if (match(M, m_Not(m_Value(NotM)))) {
2777  // De-invert the mask and swap the value in B part.
2778  Value *NewA = Builder.CreateAnd(D, NotM);
2779  return BinaryOperator::CreateXor(NewA, X);
2780  }
2781 
2782  Constant *C;
2783  if (D->hasOneUse() && match(M, m_Constant(C))) {
2784  // Unfold.
2785  Value *LHS = Builder.CreateAnd(X, C);
2786  Value *NotC = Builder.CreateNot(C);
2787  Value *RHS = Builder.CreateAnd(B, NotC);
2788  return BinaryOperator::CreateOr(LHS, RHS);
2789  }
2790 
2791  return nullptr;
2792 }
2793 
2794 // Transform
2795 // ~(x ^ y)
2796 // into:
2797 // (~x) ^ y
2798 // or into
2799 // x ^ (~y)
2801  InstCombiner::BuilderTy &Builder) {
2802  Value *X, *Y;
2803  // FIXME: one-use check is not needed in general, but currently we are unable
2804  // to fold 'not' into 'icmp', if that 'icmp' has multiple uses. (D35182)
2805  if (!match(&I, m_Not(m_OneUse(m_Xor(m_Value(X), m_Value(Y))))))
2806  return nullptr;
2807 
2808  // We only want to do the transform if it is free to do.
2809  if (isFreeToInvert(X, X->hasOneUse())) {
2810  // Ok, good.
2811  } else if (isFreeToInvert(Y, Y->hasOneUse())) {
2812  std::swap(X, Y);
2813  } else
2814  return nullptr;
2815 
2816  Value *NotX = Builder.CreateNot(X, X->getName() + ".not");
2817  return BinaryOperator::CreateXor(NotX, Y, I.getName() + ".demorgan");
2818 }
2819 
2820 // FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
2821 // here. We should standardize that construct where it is needed or choose some
2822 // other way to ensure that commutated variants of patterns are not missed.
2824  if (Value *V = SimplifyXorInst(I.getOperand(0), I.getOperand(1),
2825  SQ.getWithInstruction(&I)))
2826  return replaceInstUsesWith(I, V);
2827 
2828  if (SimplifyAssociativeOrCommutative(I))
2829  return &I;
2830 
2831  if (Instruction *X = foldVectorBinop(I))
2832  return X;
2833 
2834  if (Instruction *NewXor = foldXorToXor(I, Builder))
2835  return NewXor;
2836 
2837  // (A&B)^(A&C) -> A&(B^C) etc
2838  if (Value *V = SimplifyUsingDistributiveLaws(I))
2839  return replaceInstUsesWith(I, V);
2840 
2841  // See if we can simplify any instructions used by the instruction whose sole
2842  // purpose is to compute bits we don't care about.
2843  if (SimplifyDemandedInstructionBits(I))
2844  return &I;
2845 
2846  if (Value *V = SimplifyBSwap(I, Builder))
2847  return replaceInstUsesWith(I, V);
2848 
2849  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
2850 
2851  // Fold (X & M) ^ (Y & ~M) -> (X & M) | (Y & ~M)
2852  // This it a special case in haveNoCommonBitsSet, but the computeKnownBits
2853  // calls in there are unnecessary as SimplifyDemandedInstructionBits should
2854  // have already taken care of those cases.
2855  Value *M;
2856  if (match(&I, m_c_Xor(m_c_And(m_Not(m_Value(M)), m_Value()),
2857  m_c_And(m_Deferred(M), m_Value()))))
2858  return BinaryOperator::CreateOr(Op0, Op1);
2859 
2860  // Apply DeMorgan's Law for 'nand' / 'nor' logic with an inverted operand.
2861  Value *X, *Y;
2862 
2863  // We must eliminate the and/or (one-use) for these transforms to not increase
2864  // the instruction count.
2865  // ~(~X & Y) --> (X | ~Y)
2866  // ~(Y & ~X) --> (X | ~Y)
2867  if (match(&I, m_Not(m_OneUse(m_c_And(m_Not(m_Value(X)), m_Value(Y)))))) {
2868  Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
2869  return BinaryOperator::CreateOr(X, NotY);
2870  }
2871  // ~(~X | Y) --> (X & ~Y)
2872  // ~(Y | ~X) --> (X & ~Y)
2873  if (match(&I, m_Not(m_OneUse(m_c_Or(m_Not(m_Value(X)), m_Value(Y)))))) {
2874  Value *NotY = Builder.CreateNot(Y, Y->getName() + ".not");
2875  return BinaryOperator::CreateAnd(X, NotY);
2876  }
2877 
2878  if (Instruction *Xor = visitMaskedMerge(I, Builder))
2879  return Xor;
2880 
2881  // Is this a 'not' (~) fed by a binary operator?
2882  BinaryOperator *NotVal;
2883  if (match(&I, m_Not(m_BinOp(NotVal)))) {
2884  if (NotVal->getOpcode() == Instruction::And ||
2885  NotVal->getOpcode() == Instruction::Or) {
2886  // Apply DeMorgan's Law when inverts are free:
2887  // ~(X & Y) --> (~X | ~Y)
2888  // ~(X | Y) --> (~X & ~Y)
2889  if (isFreeToInvert(NotVal->getOperand(0),
2890  NotVal->getOperand(0)->hasOneUse()) &&
2891  isFreeToInvert(NotVal->getOperand(1),
2892  NotVal->getOperand(1)->hasOneUse())) {
2893  Value *NotX = Builder.CreateNot(NotVal->getOperand(0), "notlhs");
2894  Value *NotY = Builder.CreateNot(NotVal->getOperand(1), "notrhs");
2895  if (NotVal->getOpcode() == Instruction::And)
2896  return BinaryOperator::CreateOr(NotX, NotY);
2897  return BinaryOperator::CreateAnd(NotX, NotY);
2898  }
2899  }
2900 
2901  // ~(X - Y) --> ~X + Y
2902  if (match(NotVal, m_Sub(m_Value(X), m_Value(Y))))
2903  if (isa<Constant>(X) || NotVal->hasOneUse())
2904  return BinaryOperator::CreateAdd(Builder.CreateNot(X), Y);
2905 
2906  // ~(~X >>s Y) --> (X >>s Y)
2907  if (match(NotVal, m_AShr(m_Not(m_Value(X)), m_Value(Y))))
2908  return BinaryOperator::CreateAShr(X, Y);
2909 
2910  // If we are inverting a right-shifted constant, we may be able to eliminate
2911  // the 'not' by inverting the constant and using the opposite shift type.
2912  // Canonicalization rules ensure that only a negative constant uses 'ashr',
2913  // but we must check that in case that transform has not fired yet.
2914 
2915  // ~(C >>s Y) --> ~C >>u Y (when inverting the replicated sign bits)
2916  Constant *C;
2917  if (match(NotVal, m_AShr(m_Constant(C), m_Value(Y))) &&
2918  match(C, m_Negative()))
2919  return BinaryOperator::CreateLShr(ConstantExpr::getNot(C), Y);
2920 
2921  // ~(C >>u Y) --> ~C >>s Y (when inverting the replicated sign bits)
2922  if (match(NotVal, m_LShr(m_Constant(C), m_Value(Y))) &&
2923  match(C, m_NonNegative()))
2924  return BinaryOperator::CreateAShr(ConstantExpr::getNot(C), Y);
2925 
2926  // ~(X + C) --> -(C + 1) - X
2927  if (match(Op0, m_Add(m_Value(X), m_Constant(C))))
2928  return BinaryOperator::CreateSub(ConstantExpr::getNeg(AddOne(C)), X);
2929  }
2930 
2931  // Use DeMorgan and reassociation to eliminate a 'not' op.
2932  Constant *C1;
2933  if (match(Op1, m_Constant(C1))) {
2934  Constant *C2;
2935  if (match(Op0, m_OneUse(m_Or(m_Not(m_Value(X)), m_Constant(C2))))) {
2936  // (~X | C2) ^ C1 --> ((X & ~C2) ^ -1) ^ C1 --> (X & ~C2) ^ ~C1
2937  Value *And = Builder.CreateAnd(X, ConstantExpr::getNot(C2));
2938  return BinaryOperator::CreateXor(And, ConstantExpr::getNot(C1));
2939  }
2940  if (match(Op0, m_OneUse(m_And(m_Not(m_Value(X)), m_Constant(C2))))) {
2941  // (~X & C2) ^ C1 --> ((X | ~C2) ^ -1) ^ C1 --> (X | ~C2) ^ ~C1
2942  Value *Or = Builder.CreateOr(X, ConstantExpr::getNot(C2));
2943  return BinaryOperator::CreateXor(Or, ConstantExpr::getNot(C1));
2944  }
2945  }
2946 
2947  // not (cmp A, B) = !cmp A, B
2948  CmpInst::Predicate Pred;
2949  if (match(&I, m_Not(m_OneUse(m_Cmp(Pred, m_Value(), m_Value()))))) {
2950  cast<CmpInst>(Op0)->setPredicate(CmpInst::getInversePredicate(Pred));
2951  return replaceInstUsesWith(I, Op0);
2952  }
2953 
2954  {
2955  const APInt *RHSC;
2956  if (match(Op1, m_APInt(RHSC))) {
2957  Value *X;
2958  const APInt *C;
2959  if (RHSC->isSignMask() && match(Op0, m_Sub(m_APInt(C), m_Value(X)))) {
2960  // (C - X) ^ signmask -> (C + signmask - X)
2961  Constant *NewC = ConstantInt::get(I.getType(), *C + *RHSC);
2962  return BinaryOperator::CreateSub(NewC, X);
2963  }
2964  if (RHSC->isSignMask() && match(Op0, m_Add(m_Value(X), m_APInt(C)))) {
2965  // (X + C) ^ signmask -> (X + C + signmask)
2966  Constant *NewC = ConstantInt::get(I.getType(), *C + *RHSC);
2967  return BinaryOperator::CreateAdd(X, NewC);
2968  }
2969 
2970  // (X|C1)^C2 -> X^(C1^C2) iff X&~C1 == 0
2971  if (match(Op0, m_Or(m_Value(X), m_APInt(C))) &&
2972  MaskedValueIsZero(X, *C, 0, &I)) {
2973  Constant *NewC = ConstantInt::get(I.getType(), *C ^ *RHSC);
2974  Worklist.Add(cast<Instruction>(Op0));
2975  I.setOperand(0, X);
2976  I.setOperand(1, NewC);
2977  return &I;
2978  }
2979  }
2980  }
2981 
2982  if (ConstantInt *RHSC = dyn_cast<ConstantInt>(Op1)) {
2983  if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
2984  if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
2985  if (Op0I->getOpcode() == Instruction::LShr) {
2986  // ((X^C1) >> C2) ^ C3 -> (X>>C2) ^ ((C1>>C2)^C3)
2987  // E1 = "X ^ C1"
2988  BinaryOperator *E1;
2989  ConstantInt *C1;
2990  if (Op0I->hasOneUse() &&
2991  (E1 = dyn_cast<BinaryOperator>(Op0I->getOperand(0))) &&
2992  E1->getOpcode() == Instruction::Xor &&
2993  (C1 = dyn_cast<ConstantInt>(E1->getOperand(1)))) {
2994  // fold (C1 >> C2) ^ C3
2995  ConstantInt *C2 = Op0CI, *C3 = RHSC;
2996  APInt FoldConst = C1->getValue().lshr(C2->getValue());
2997  FoldConst ^= C3->getValue();
2998  // Prepare the two operands.
2999  Value *Opnd0 = Builder.CreateLShr(E1->getOperand(0), C2);
3000  Opnd0->takeName(Op0I);
3001  cast<Instruction>(Opnd0)->setDebugLoc(I.getDebugLoc());
3002  Value *FoldVal = ConstantInt::get(Opnd0->getType(), FoldConst);
3003 
3004  return BinaryOperator::CreateXor(Opnd0, FoldVal);
3005  }
3006  }
3007  }
3008  }
3009  }
3010 
3011  if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
3012  return FoldedLogic;
3013 
3014  // Y ^ (X | Y) --> X & ~Y
3015  // Y ^ (Y | X) --> X & ~Y
3016  if (match(Op1, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op0)))))
3017  return BinaryOperator::CreateAnd(X, Builder.CreateNot(Op0));
3018  // (X | Y) ^ Y --> X & ~Y
3019  // (Y | X) ^ Y --> X & ~Y
3020  if (match(Op0, m_OneUse(m_c_Or(m_Value(X), m_Specific(Op1)))))
3021  return BinaryOperator::CreateAnd(X, Builder.CreateNot(Op1));
3022 
3023  // Y ^ (X & Y) --> ~X & Y
3024  // Y ^ (Y & X) --> ~X & Y
3025  if (match(Op1, m_OneUse(m_c_And(m_Value(X), m_Specific(Op0)))))
3026  return BinaryOperator::CreateAnd(Op0, Builder.CreateNot(X));
3027  // (X & Y) ^ Y --> ~X & Y
3028  // (Y & X) ^ Y --> ~X & Y
3029  // Canonical form is (X & C) ^ C; don't touch that.
3030  // TODO: A 'not' op is better for analysis and codegen, but demanded bits must
3031  // be fixed to prefer that (otherwise we get infinite looping).
3032  if (!match(Op1, m_Constant()) &&
3033  match(Op0, m_OneUse(m_c_And(m_Value(X), m_Specific(Op1)))))
3034  return BinaryOperator::CreateAnd(Op1, Builder.CreateNot(X));
3035 
3036  Value *A, *B, *C;
3037  // (A ^ B) ^ (A | C) --> (~A & C) ^ B -- There are 4 commuted variants.
3038  if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_Value(A), m_Value(B))),
3039  m_OneUse(m_c_Or(m_Deferred(A), m_Value(C))))))
3040  return BinaryOperator::CreateXor(
3041  Builder.CreateAnd(Builder.CreateNot(A), C), B);
3042 
3043  // (A ^ B) ^ (B | C) --> (~B & C) ^ A -- There are 4 commuted variants.
3044  if (match(&I, m_c_Xor(m_OneUse(m_Xor(m_Value(A), m_Value(B))),
3045  m_OneUse(m_c_Or(m_Deferred(B), m_Value(C))))))
3046  return BinaryOperator::CreateXor(
3047  Builder.CreateAnd(Builder.CreateNot(B), C), A);
3048 
3049  // (A & B) ^ (A ^ B) -> (A | B)
3050  if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
3051  match(Op1, m_c_Xor(m_Specific(A), m_Specific(B))))
3052  return BinaryOperator::CreateOr(A, B);
3053  // (A ^ B) ^ (A & B) -> (A | B)
3054  if (match(Op0, m_Xor(m_Value(A), m_Value(B))) &&
3055  match(Op1, m_c_And(m_Specific(A), m_Specific(B))))
3056  return BinaryOperator::CreateOr(A, B);
3057 
3058  // (A & ~B) ^ ~A -> ~(A & B)
3059  // (~B & A) ^ ~A -> ~(A & B)
3060  if (match(Op0, m_c_And(m_Value(A), m_Not(m_Value(B)))) &&
3061  match(Op1, m_Not(m_Specific(A))))
3062  return BinaryOperator::CreateNot(Builder.CreateAnd(A, B));
3063 
3064  if (auto *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
3065  if (auto *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
3066  if (Value *V = foldXorOfICmps(LHS, RHS, I))
3067  return replaceInstUsesWith(I, V);
3068 
3069  if (Instruction *CastedXor = foldCastedBitwiseLogic(I))
3070  return CastedXor;
3071 
3072  // Canonicalize a shifty way to code absolute value to the common pattern.
3073  // There are 4 potential commuted variants. Move the 'ashr' candidate to Op1.
3074  // We're relying on the fact that we only do this transform when the shift has
3075  // exactly 2 uses and the add has exactly 1 use (otherwise, we might increase
3076  // instructions).
3077  if (Op0->hasNUses(2))
3078  std::swap(Op0, Op1);
3079 
3080  const APInt *ShAmt;
3081  Type *Ty = I.getType();
3082  if (match(Op1, m_AShr(m_Value(A), m_APInt(ShAmt))) &&
3083  Op1->hasNUses(2) && *ShAmt == Ty->getScalarSizeInBits() - 1 &&
3084  match(Op0, m_OneUse(m_c_Add(m_Specific(A), m_Specific(Op1))))) {
3085  // B = ashr i32 A, 31 ; smear the sign bit
3086  // xor (add A, B), B ; add -1 and flip bits if negative
3087  // --> (A < 0) ? -A : A
3088  Value *Cmp = Builder.CreateICmpSLT(A, ConstantInt::getNullValue(Ty));
3089  // Copy the nuw/nsw flags from the add to the negate.
3090  auto *Add = cast<BinaryOperator>(Op0);
3091  Value *Neg = Builder.CreateNeg(A, "", Add->hasNoUnsignedWrap(),
3092  Add->hasNoSignedWrap());
3093  return SelectInst::Create(Cmp, Neg, A);
3094  }
3095 
3096  // Eliminate a bitwise 'not' op of 'not' min/max by inverting the min/max:
3097  //
3098  // %notx = xor i32 %x, -1
3099  // %cmp1 = icmp sgt i32 %notx, %y
3100  // %smax = select i1 %cmp1, i32 %notx, i32 %y
3101  // %res = xor i32 %smax, -1
3102  // =>
3103  // %noty = xor i32 %y, -1
3104  // %cmp2 = icmp slt %x, %noty
3105  // %res = select i1 %cmp2, i32 %x, i32 %noty
3106  //
3107  // Same is applicable for smin/umax/umin.
3108  if (match(Op1, m_AllOnes()) && Op0->hasOneUse()) {
3109  Value *LHS, *RHS;
3110  SelectPatternFlavor SPF = matchSelectPattern(Op0, LHS, RHS).Flavor;
3112  // It's possible we get here before the not has been simplified, so make
3113  // sure the input to the not isn't freely invertible.
3114  if (match(LHS, m_Not(m_Value(X))) && !isFreeToInvert(X, X->hasOneUse())) {
3115  Value *NotY = Builder.CreateNot(RHS);
3116  return SelectInst::Create(
3117  Builder.CreateICmp(getInverseMinMaxPred(SPF), X, NotY), X, NotY);
3118  }
3119 
3120  // It's possible we get here before the not has been simplified, so make
3121  // sure the input to the not isn't freely invertible.
3122  if (match(RHS, m_Not(m_Value(Y))) && !isFreeToInvert(Y, Y->hasOneUse())) {
3123  Value *NotX = Builder.CreateNot(LHS);
3124  return SelectInst::Create(
3125  Builder.CreateICmp(getInverseMinMaxPred(SPF), NotX, Y), NotX, Y);
3126  }
3127 
3128  // If both sides are freely invertible, then we can get rid of the xor
3129  // completely.
3130  if (isFreeToInvert(LHS, !LHS->hasNUsesOrMore(3)) &&
3131  isFreeToInvert(RHS, !RHS->hasNUsesOrMore(3))) {
3132  Value *NotLHS = Builder.CreateNot(LHS);
3133  Value *NotRHS = Builder.CreateNot(RHS);
3134  return SelectInst::Create(
3135  Builder.CreateICmp(getInverseMinMaxPred(SPF), NotLHS, NotRHS),
3136  NotLHS, NotRHS);
3137  }
3138  }
3139  }
3140 
3141  if (Instruction *NewXor = sinkNotIntoXor(I, Builder))
3142  return NewXor;
3143 
3144  return nullptr;
3145 }
const NoneType None
Definition: None.h:23
BinaryOp_match< LHS, RHS, Instruction::And > m_And(const LHS &L, const RHS &R)
Definition: PatternMatch.h:831
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:365
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:2212
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
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:728
Instruction * visitOr(BinaryOperator &I)
is_zero m_Zero()
Match any null constant or a vector with all elements equal to 0.
Definition: PatternMatch.h:398
static BinaryOperator * CreateNot(Value *Op, const Twine &Name="", Instruction *InsertBefore=nullptr)
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2106
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:2118
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:783
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
bool slt(const APInt &RHS) const
Signed less than comparison.
Definition: APInt.h:1203
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:861
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
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 isFreeToInvert(Value *V, bool WillInvertAllUses)
Return true if the specified value is free to invert (apply ~ to).
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:386
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.
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:289
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:843
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
A Use represents the edge between a Value definition and its users.
Definition: Use.h:55
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:1682
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:716
static Constant * getZExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1696
User * getUser() const LLVM_READONLY
Returns the User that contains this Use.
Definition: Use.cpp:40
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:245
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:519
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:407
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:1057
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:359
Value * CreateFCmp(CmpInst::Predicate P, Value *LHS, Value *RHS, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2220
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:855
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:189
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:837
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:2309
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:331
specificval_ty m_Specific(const Value *V)
Match if we have a specific specified value.
Definition: PatternMatch.h:576
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:849
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:2102
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:2244
static Constant * getAllOnesValue(Type *Ty)
Definition: Constants.cpp:343
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:589
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:2121
CastClass_match< OpTy, Instruction::SExt > m_SExt(const OpTy &Op)
Matches SExt.
bool isMinValue(bool isSigned) const
This function will return true iff this constant represents the smallest value that may be represente...
Definition: Constants.h:229
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:353
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:1668
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:653
static ConstantInt * getSigned(IntegerType *Ty, int64_t V)
Return a ConstantInt with the specified value for the specified type.
Definition: Constants.cpp:667
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
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 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 bool canFreelyInvertAllUsersOf(Value *V, Value *IgnoredUser)
Given i1 V, can every user of V be freely adapted if V is changed to !V ?
static Instruction * foldAndToXor(BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static Constant * getNeg(Constant *C, bool HasNUW=false, bool HasNSW=false)
Definition: Constants.cpp:2231
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:331
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:2313
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:2237
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:73
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:377
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:143
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:432
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:2823
specific_intval m_SpecificInt(uint64_t V)
Match a specific integer value or vector with all elements equal to the value.
Definition: PatternMatch.h:653
cstfp_pred_ty< is_any_zero_fp > m_AnyZeroFP()
Match a floating-point negative zero or positive zero.
Definition: PatternMatch.h:510
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.
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:2317