LLVM  6.0.0svn
InstCombineCasts.cpp
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1 //===- InstCombineCasts.cpp -----------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the visit functions for cast operations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "InstCombineInternal.h"
15 #include "llvm/ADT/SetVector.h"
18 #include "llvm/IR/DataLayout.h"
19 #include "llvm/IR/PatternMatch.h"
20 #include "llvm/Support/KnownBits.h"
21 using namespace llvm;
22 using namespace PatternMatch;
23 
24 #define DEBUG_TYPE "instcombine"
25 
26 /// Analyze 'Val', seeing if it is a simple linear expression.
27 /// If so, decompose it, returning some value X, such that Val is
28 /// X*Scale+Offset.
29 ///
30 static Value *decomposeSimpleLinearExpr(Value *Val, unsigned &Scale,
31  uint64_t &Offset) {
32  if (ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
33  Offset = CI->getZExtValue();
34  Scale = 0;
35  return ConstantInt::get(Val->getType(), 0);
36  }
37 
38  if (BinaryOperator *I = dyn_cast<BinaryOperator>(Val)) {
39  // Cannot look past anything that might overflow.
41  if (OBI && !OBI->hasNoUnsignedWrap() && !OBI->hasNoSignedWrap()) {
42  Scale = 1;
43  Offset = 0;
44  return Val;
45  }
46 
47  if (ConstantInt *RHS = dyn_cast<ConstantInt>(I->getOperand(1))) {
48  if (I->getOpcode() == Instruction::Shl) {
49  // This is a value scaled by '1 << the shift amt'.
50  Scale = UINT64_C(1) << RHS->getZExtValue();
51  Offset = 0;
52  return I->getOperand(0);
53  }
54 
55  if (I->getOpcode() == Instruction::Mul) {
56  // This value is scaled by 'RHS'.
57  Scale = RHS->getZExtValue();
58  Offset = 0;
59  return I->getOperand(0);
60  }
61 
62  if (I->getOpcode() == Instruction::Add) {
63  // We have X+C. Check to see if we really have (X*C2)+C1,
64  // where C1 is divisible by C2.
65  unsigned SubScale;
66  Value *SubVal =
67  decomposeSimpleLinearExpr(I->getOperand(0), SubScale, Offset);
68  Offset += RHS->getZExtValue();
69  Scale = SubScale;
70  return SubVal;
71  }
72  }
73  }
74 
75  // Otherwise, we can't look past this.
76  Scale = 1;
77  Offset = 0;
78  return Val;
79 }
80 
81 /// If we find a cast of an allocation instruction, try to eliminate the cast by
82 /// moving the type information into the alloc.
83 Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI,
84  AllocaInst &AI) {
85  PointerType *PTy = cast<PointerType>(CI.getType());
86 
87  BuilderTy AllocaBuilder(Builder);
88  AllocaBuilder.SetInsertPoint(&AI);
89 
90  // Get the type really allocated and the type casted to.
91  Type *AllocElTy = AI.getAllocatedType();
92  Type *CastElTy = PTy->getElementType();
93  if (!AllocElTy->isSized() || !CastElTy->isSized()) return nullptr;
94 
95  unsigned AllocElTyAlign = DL.getABITypeAlignment(AllocElTy);
96  unsigned CastElTyAlign = DL.getABITypeAlignment(CastElTy);
97  if (CastElTyAlign < AllocElTyAlign) return nullptr;
98 
99  // If the allocation has multiple uses, only promote it if we are strictly
100  // increasing the alignment of the resultant allocation. If we keep it the
101  // same, we open the door to infinite loops of various kinds.
102  if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return nullptr;
103 
104  uint64_t AllocElTySize = DL.getTypeAllocSize(AllocElTy);
105  uint64_t CastElTySize = DL.getTypeAllocSize(CastElTy);
106  if (CastElTySize == 0 || AllocElTySize == 0) return nullptr;
107 
108  // If the allocation has multiple uses, only promote it if we're not
109  // shrinking the amount of memory being allocated.
110  uint64_t AllocElTyStoreSize = DL.getTypeStoreSize(AllocElTy);
111  uint64_t CastElTyStoreSize = DL.getTypeStoreSize(CastElTy);
112  if (!AI.hasOneUse() && CastElTyStoreSize < AllocElTyStoreSize) return nullptr;
113 
114  // See if we can satisfy the modulus by pulling a scale out of the array
115  // size argument.
116  unsigned ArraySizeScale;
117  uint64_t ArrayOffset;
118  Value *NumElements = // See if the array size is a decomposable linear expr.
119  decomposeSimpleLinearExpr(AI.getOperand(0), ArraySizeScale, ArrayOffset);
120 
121  // If we can now satisfy the modulus, by using a non-1 scale, we really can
122  // do the xform.
123  if ((AllocElTySize*ArraySizeScale) % CastElTySize != 0 ||
124  (AllocElTySize*ArrayOffset ) % CastElTySize != 0) return nullptr;
125 
126  unsigned Scale = (AllocElTySize*ArraySizeScale)/CastElTySize;
127  Value *Amt = nullptr;
128  if (Scale == 1) {
129  Amt = NumElements;
130  } else {
131  Amt = ConstantInt::get(AI.getArraySize()->getType(), Scale);
132  // Insert before the alloca, not before the cast.
133  Amt = AllocaBuilder.CreateMul(Amt, NumElements);
134  }
135 
136  if (uint64_t Offset = (AllocElTySize*ArrayOffset)/CastElTySize) {
138  Offset, true);
139  Amt = AllocaBuilder.CreateAdd(Amt, Off);
140  }
141 
142  AllocaInst *New = AllocaBuilder.CreateAlloca(CastElTy, Amt);
143  New->setAlignment(AI.getAlignment());
144  New->takeName(&AI);
146 
147  // If the allocation has multiple real uses, insert a cast and change all
148  // things that used it to use the new cast. This will also hack on CI, but it
149  // will die soon.
150  if (!AI.hasOneUse()) {
151  // New is the allocation instruction, pointer typed. AI is the original
152  // allocation instruction, also pointer typed. Thus, cast to use is BitCast.
153  Value *NewCast = AllocaBuilder.CreateBitCast(New, AI.getType(), "tmpcast");
154  replaceInstUsesWith(AI, NewCast);
155  }
156  return replaceInstUsesWith(CI, New);
157 }
158 
159 /// Given an expression that CanEvaluateTruncated or CanEvaluateSExtd returns
160 /// true for, actually insert the code to evaluate the expression.
161 Value *InstCombiner::EvaluateInDifferentType(Value *V, Type *Ty,
162  bool isSigned) {
163  if (Constant *C = dyn_cast<Constant>(V)) {
164  C = ConstantExpr::getIntegerCast(C, Ty, isSigned /*Sext or ZExt*/);
165  // If we got a constantexpr back, try to simplify it with DL info.
166  if (Constant *FoldedC = ConstantFoldConstant(C, DL, &TLI))
167  C = FoldedC;
168  return C;
169  }
170 
171  // Otherwise, it must be an instruction.
172  Instruction *I = cast<Instruction>(V);
173  Instruction *Res = nullptr;
174  unsigned Opc = I->getOpcode();
175  switch (Opc) {
176  case Instruction::Add:
177  case Instruction::Sub:
178  case Instruction::Mul:
179  case Instruction::And:
180  case Instruction::Or:
181  case Instruction::Xor:
182  case Instruction::AShr:
183  case Instruction::LShr:
184  case Instruction::Shl:
185  case Instruction::UDiv:
186  case Instruction::URem: {
187  Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
188  Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
189  Res = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
190  break;
191  }
192  case Instruction::Trunc:
193  case Instruction::ZExt:
194  case Instruction::SExt:
195  // If the source type of the cast is the type we're trying for then we can
196  // just return the source. There's no need to insert it because it is not
197  // new.
198  if (I->getOperand(0)->getType() == Ty)
199  return I->getOperand(0);
200 
201  // Otherwise, must be the same type of cast, so just reinsert a new one.
202  // This also handles the case of zext(trunc(x)) -> zext(x).
203  Res = CastInst::CreateIntegerCast(I->getOperand(0), Ty,
204  Opc == Instruction::SExt);
205  break;
206  case Instruction::Select: {
207  Value *True = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
208  Value *False = EvaluateInDifferentType(I->getOperand(2), Ty, isSigned);
209  Res = SelectInst::Create(I->getOperand(0), True, False);
210  break;
211  }
212  case Instruction::PHI: {
213  PHINode *OPN = cast<PHINode>(I);
214  PHINode *NPN = PHINode::Create(Ty, OPN->getNumIncomingValues());
215  for (unsigned i = 0, e = OPN->getNumIncomingValues(); i != e; ++i) {
216  Value *V =
217  EvaluateInDifferentType(OPN->getIncomingValue(i), Ty, isSigned);
218  NPN->addIncoming(V, OPN->getIncomingBlock(i));
219  }
220  Res = NPN;
221  break;
222  }
223  default:
224  // TODO: Can handle more cases here.
225  llvm_unreachable("Unreachable!");
226  }
227 
228  Res->takeName(I);
229  return InsertNewInstWith(Res, *I);
230 }
231 
232 Instruction::CastOps InstCombiner::isEliminableCastPair(const CastInst *CI1,
233  const CastInst *CI2) {
234  Type *SrcTy = CI1->getSrcTy();
235  Type *MidTy = CI1->getDestTy();
236  Type *DstTy = CI2->getDestTy();
237 
240  Type *SrcIntPtrTy =
241  SrcTy->isPtrOrPtrVectorTy() ? DL.getIntPtrType(SrcTy) : nullptr;
242  Type *MidIntPtrTy =
243  MidTy->isPtrOrPtrVectorTy() ? DL.getIntPtrType(MidTy) : nullptr;
244  Type *DstIntPtrTy =
245  DstTy->isPtrOrPtrVectorTy() ? DL.getIntPtrType(DstTy) : nullptr;
246  unsigned Res = CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy,
247  DstTy, SrcIntPtrTy, MidIntPtrTy,
248  DstIntPtrTy);
249 
250  // We don't want to form an inttoptr or ptrtoint that converts to an integer
251  // type that differs from the pointer size.
252  if ((Res == Instruction::IntToPtr && SrcTy != DstIntPtrTy) ||
253  (Res == Instruction::PtrToInt && DstTy != SrcIntPtrTy))
254  Res = 0;
255 
256  return Instruction::CastOps(Res);
257 }
258 
259 /// @brief Implement the transforms common to all CastInst visitors.
261  Value *Src = CI.getOperand(0);
262 
263  // Try to eliminate a cast of a cast.
264  if (auto *CSrc = dyn_cast<CastInst>(Src)) { // A->B->C cast
265  if (Instruction::CastOps NewOpc = isEliminableCastPair(CSrc, &CI)) {
266  // The first cast (CSrc) is eliminable so we need to fix up or replace
267  // the second cast (CI). CSrc will then have a good chance of being dead.
268  return CastInst::Create(NewOpc, CSrc->getOperand(0), CI.getType());
269  }
270  }
271 
272  // If we are casting a select, then fold the cast into the select.
273  if (auto *SI = dyn_cast<SelectInst>(Src))
274  if (Instruction *NV = FoldOpIntoSelect(CI, SI))
275  return NV;
276 
277  // If we are casting a PHI, then fold the cast into the PHI.
278  if (auto *PN = dyn_cast<PHINode>(Src)) {
279  // Don't do this if it would create a PHI node with an illegal type from a
280  // legal type.
281  if (!Src->getType()->isIntegerTy() || !CI.getType()->isIntegerTy() ||
282  shouldChangeType(CI.getType(), Src->getType()))
283  if (Instruction *NV = foldOpIntoPhi(CI, PN))
284  return NV;
285  }
286 
287  return nullptr;
288 }
289 
290 /// Return true if we can evaluate the specified expression tree as type Ty
291 /// instead of its larger type, and arrive with the same value.
292 /// This is used by code that tries to eliminate truncates.
293 ///
294 /// Ty will always be a type smaller than V. We should return true if trunc(V)
295 /// can be computed by computing V in the smaller type. If V is an instruction,
296 /// then trunc(inst(x,y)) can be computed as inst(trunc(x),trunc(y)), which only
297 /// makes sense if x and y can be efficiently truncated.
298 ///
299 /// This function works on both vectors and scalars.
300 ///
301 static bool canEvaluateTruncated(Value *V, Type *Ty, InstCombiner &IC,
302  Instruction *CxtI) {
303  // We can always evaluate constants in another type.
304  if (isa<Constant>(V))
305  return true;
306 
308  if (!I) return false;
309 
310  Type *OrigTy = V->getType();
311 
312  // If this is an extension from the dest type, we can eliminate it, even if it
313  // has multiple uses.
314  if ((isa<ZExtInst>(I) || isa<SExtInst>(I)) &&
315  I->getOperand(0)->getType() == Ty)
316  return true;
317 
318  // We can't extend or shrink something that has multiple uses: doing so would
319  // require duplicating the instruction in general, which isn't profitable.
320  if (!I->hasOneUse()) return false;
321 
322  unsigned Opc = I->getOpcode();
323  switch (Opc) {
324  case Instruction::Add:
325  case Instruction::Sub:
326  case Instruction::Mul:
327  case Instruction::And:
328  case Instruction::Or:
329  case Instruction::Xor:
330  // These operators can all arbitrarily be extended or truncated.
331  return canEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI) &&
332  canEvaluateTruncated(I->getOperand(1), Ty, IC, CxtI);
333 
334  case Instruction::UDiv:
335  case Instruction::URem: {
336  // UDiv and URem can be truncated if all the truncated bits are zero.
337  uint32_t OrigBitWidth = OrigTy->getScalarSizeInBits();
338  uint32_t BitWidth = Ty->getScalarSizeInBits();
339  if (BitWidth < OrigBitWidth) {
340  APInt Mask = APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth);
341  if (IC.MaskedValueIsZero(I->getOperand(0), Mask, 0, CxtI) &&
342  IC.MaskedValueIsZero(I->getOperand(1), Mask, 0, CxtI)) {
343  return canEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI) &&
344  canEvaluateTruncated(I->getOperand(1), Ty, IC, CxtI);
345  }
346  }
347  break;
348  }
349  case Instruction::Shl:
350  // If we are truncating the result of this SHL, and if it's a shift of a
351  // constant amount, we can always perform a SHL in a smaller type.
352  if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
353  uint32_t BitWidth = Ty->getScalarSizeInBits();
354  if (CI->getLimitedValue(BitWidth) < BitWidth)
355  return canEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI);
356  }
357  break;
358  case Instruction::LShr:
359  // If this is a truncate of a logical shr, we can truncate it to a smaller
360  // lshr iff we know that the bits we would otherwise be shifting in are
361  // already zeros.
362  if (ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1))) {
363  uint32_t OrigBitWidth = OrigTy->getScalarSizeInBits();
364  uint32_t BitWidth = Ty->getScalarSizeInBits();
365  if (IC.MaskedValueIsZero(I->getOperand(0),
366  APInt::getHighBitsSet(OrigBitWidth, OrigBitWidth-BitWidth), 0, CxtI) &&
367  CI->getLimitedValue(BitWidth) < BitWidth) {
368  return canEvaluateTruncated(I->getOperand(0), Ty, IC, CxtI);
369  }
370  }
371  break;
372  case Instruction::Trunc:
373  // trunc(trunc(x)) -> trunc(x)
374  return true;
375  case Instruction::ZExt:
376  case Instruction::SExt:
377  // trunc(ext(x)) -> ext(x) if the source type is smaller than the new dest
378  // trunc(ext(x)) -> trunc(x) if the source type is larger than the new dest
379  return true;
380  case Instruction::Select: {
381  SelectInst *SI = cast<SelectInst>(I);
382  return canEvaluateTruncated(SI->getTrueValue(), Ty, IC, CxtI) &&
383  canEvaluateTruncated(SI->getFalseValue(), Ty, IC, CxtI);
384  }
385  case Instruction::PHI: {
386  // We can change a phi if we can change all operands. Note that we never
387  // get into trouble with cyclic PHIs here because we only consider
388  // instructions with a single use.
389  PHINode *PN = cast<PHINode>(I);
390  for (Value *IncValue : PN->incoming_values())
391  if (!canEvaluateTruncated(IncValue, Ty, IC, CxtI))
392  return false;
393  return true;
394  }
395  default:
396  // TODO: Can handle more cases here.
397  break;
398  }
399 
400  return false;
401 }
402 
403 /// Given a vector that is bitcast to an integer, optionally logically
404 /// right-shifted, and truncated, convert it to an extractelement.
405 /// Example (big endian):
406 /// trunc (lshr (bitcast <4 x i32> %X to i128), 32) to i32
407 /// --->
408 /// extractelement <4 x i32> %X, 1
410  Value *TruncOp = Trunc.getOperand(0);
411  Type *DestType = Trunc.getType();
412  if (!TruncOp->hasOneUse() || !isa<IntegerType>(DestType))
413  return nullptr;
414 
415  Value *VecInput = nullptr;
416  ConstantInt *ShiftVal = nullptr;
417  if (!match(TruncOp, m_CombineOr(m_BitCast(m_Value(VecInput)),
418  m_LShr(m_BitCast(m_Value(VecInput)),
419  m_ConstantInt(ShiftVal)))) ||
420  !isa<VectorType>(VecInput->getType()))
421  return nullptr;
422 
423  VectorType *VecType = cast<VectorType>(VecInput->getType());
424  unsigned VecWidth = VecType->getPrimitiveSizeInBits();
425  unsigned DestWidth = DestType->getPrimitiveSizeInBits();
426  unsigned ShiftAmount = ShiftVal ? ShiftVal->getZExtValue() : 0;
427 
428  if ((VecWidth % DestWidth != 0) || (ShiftAmount % DestWidth != 0))
429  return nullptr;
430 
431  // If the element type of the vector doesn't match the result type,
432  // bitcast it to a vector type that we can extract from.
433  unsigned NumVecElts = VecWidth / DestWidth;
434  if (VecType->getElementType() != DestType) {
435  VecType = VectorType::get(DestType, NumVecElts);
436  VecInput = IC.Builder.CreateBitCast(VecInput, VecType, "bc");
437  }
438 
439  unsigned Elt = ShiftAmount / DestWidth;
440  if (IC.getDataLayout().isBigEndian())
441  Elt = NumVecElts - 1 - Elt;
442 
443  return ExtractElementInst::Create(VecInput, IC.Builder.getInt32(Elt));
444 }
445 
446 /// Try to narrow the width of bitwise logic instructions with constants.
447 Instruction *InstCombiner::shrinkBitwiseLogic(TruncInst &Trunc) {
448  Type *SrcTy = Trunc.getSrcTy();
449  Type *DestTy = Trunc.getType();
450  if (isa<IntegerType>(SrcTy) && !shouldChangeType(SrcTy, DestTy))
451  return nullptr;
452 
453  BinaryOperator *LogicOp;
454  Constant *C;
455  if (!match(Trunc.getOperand(0), m_OneUse(m_BinOp(LogicOp))) ||
456  !LogicOp->isBitwiseLogicOp() ||
457  !match(LogicOp->getOperand(1), m_Constant(C)))
458  return nullptr;
459 
460  // trunc (logic X, C) --> logic (trunc X, C')
461  Constant *NarrowC = ConstantExpr::getTrunc(C, DestTy);
462  Value *NarrowOp0 = Builder.CreateTrunc(LogicOp->getOperand(0), DestTy);
463  return BinaryOperator::Create(LogicOp->getOpcode(), NarrowOp0, NarrowC);
464 }
465 
466 /// Try to narrow the width of a splat shuffle. This could be generalized to any
467 /// shuffle with a constant operand, but we limit the transform to avoid
468 /// creating a shuffle type that targets may not be able to lower effectively.
470  InstCombiner::BuilderTy &Builder) {
471  auto *Shuf = dyn_cast<ShuffleVectorInst>(Trunc.getOperand(0));
472  if (Shuf && Shuf->hasOneUse() && isa<UndefValue>(Shuf->getOperand(1)) &&
473  Shuf->getMask()->getSplatValue() &&
474  Shuf->getType() == Shuf->getOperand(0)->getType()) {
475  // trunc (shuf X, Undef, SplatMask) --> shuf (trunc X), Undef, SplatMask
476  Constant *NarrowUndef = UndefValue::get(Trunc.getType());
477  Value *NarrowOp = Builder.CreateTrunc(Shuf->getOperand(0), Trunc.getType());
478  return new ShuffleVectorInst(NarrowOp, NarrowUndef, Shuf->getMask());
479  }
480 
481  return nullptr;
482 }
483 
484 /// Try to narrow the width of an insert element. This could be generalized for
485 /// any vector constant, but we limit the transform to insertion into undef to
486 /// avoid potential backend problems from unsupported insertion widths. This
487 /// could also be extended to handle the case of inserting a scalar constant
488 /// into a vector variable.
490  InstCombiner::BuilderTy &Builder) {
491  Instruction::CastOps Opcode = Trunc.getOpcode();
492  assert((Opcode == Instruction::Trunc || Opcode == Instruction::FPTrunc) &&
493  "Unexpected instruction for shrinking");
494 
495  auto *InsElt = dyn_cast<InsertElementInst>(Trunc.getOperand(0));
496  if (!InsElt || !InsElt->hasOneUse())
497  return nullptr;
498 
499  Type *DestTy = Trunc.getType();
500  Type *DestScalarTy = DestTy->getScalarType();
501  Value *VecOp = InsElt->getOperand(0);
502  Value *ScalarOp = InsElt->getOperand(1);
503  Value *Index = InsElt->getOperand(2);
504 
505  if (isa<UndefValue>(VecOp)) {
506  // trunc (inselt undef, X, Index) --> inselt undef, (trunc X), Index
507  // fptrunc (inselt undef, X, Index) --> inselt undef, (fptrunc X), Index
508  UndefValue *NarrowUndef = UndefValue::get(DestTy);
509  Value *NarrowOp = Builder.CreateCast(Opcode, ScalarOp, DestScalarTy);
510  return InsertElementInst::Create(NarrowUndef, NarrowOp, Index);
511  }
512 
513  return nullptr;
514 }
515 
517  if (Instruction *Result = commonCastTransforms(CI))
518  return Result;
519 
520  // Test if the trunc is the user of a select which is part of a
521  // minimum or maximum operation. If so, don't do any more simplification.
522  // Even simplifying demanded bits can break the canonical form of a
523  // min/max.
524  Value *LHS, *RHS;
525  if (SelectInst *SI = dyn_cast<SelectInst>(CI.getOperand(0)))
526  if (matchSelectPattern(SI, LHS, RHS).Flavor != SPF_UNKNOWN)
527  return nullptr;
528 
529  // See if we can simplify any instructions used by the input whose sole
530  // purpose is to compute bits we don't care about.
531  if (SimplifyDemandedInstructionBits(CI))
532  return &CI;
533 
534  Value *Src = CI.getOperand(0);
535  Type *DestTy = CI.getType(), *SrcTy = Src->getType();
536 
537  // Attempt to truncate the entire input expression tree to the destination
538  // type. Only do this if the dest type is a simple type, don't convert the
539  // expression tree to something weird like i93 unless the source is also
540  // strange.
541  if ((DestTy->isVectorTy() || shouldChangeType(SrcTy, DestTy)) &&
542  canEvaluateTruncated(Src, DestTy, *this, &CI)) {
543 
544  // If this cast is a truncate, evaluting in a different type always
545  // eliminates the cast, so it is always a win.
546  DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
547  " to avoid cast: " << CI << '\n');
548  Value *Res = EvaluateInDifferentType(Src, DestTy, false);
549  assert(Res->getType() == DestTy);
550  return replaceInstUsesWith(CI, Res);
551  }
552 
553  // Canonicalize trunc x to i1 -> (icmp ne (and x, 1), 0), likewise for vector.
554  if (DestTy->getScalarSizeInBits() == 1) {
555  Constant *One = ConstantInt::get(SrcTy, 1);
556  Src = Builder.CreateAnd(Src, One);
558  return new ICmpInst(ICmpInst::ICMP_NE, Src, Zero);
559  }
560 
561  // FIXME: Maybe combine the next two transforms to handle the no cast case
562  // more efficiently. Support vector types. Cleanup code by using m_OneUse.
563 
564  // Transform trunc(lshr (zext A), Cst) to eliminate one type conversion.
565  Value *A = nullptr; ConstantInt *Cst = nullptr;
566  if (Src->hasOneUse() &&
567  match(Src, m_LShr(m_ZExt(m_Value(A)), m_ConstantInt(Cst)))) {
568  // We have three types to worry about here, the type of A, the source of
569  // the truncate (MidSize), and the destination of the truncate. We know that
570  // ASize < MidSize and MidSize > ResultSize, but don't know the relation
571  // between ASize and ResultSize.
572  unsigned ASize = A->getType()->getPrimitiveSizeInBits();
573 
574  // If the shift amount is larger than the size of A, then the result is
575  // known to be zero because all the input bits got shifted out.
576  if (Cst->getZExtValue() >= ASize)
577  return replaceInstUsesWith(CI, Constant::getNullValue(DestTy));
578 
579  // Since we're doing an lshr and a zero extend, and know that the shift
580  // amount is smaller than ASize, it is always safe to do the shift in A's
581  // type, then zero extend or truncate to the result.
582  Value *Shift = Builder.CreateLShr(A, Cst->getZExtValue());
583  Shift->takeName(Src);
584  return CastInst::CreateIntegerCast(Shift, DestTy, false);
585  }
586 
587  // FIXME: We should canonicalize to zext/trunc and remove this transform.
588  // Transform trunc(lshr (sext A), Cst) to ashr A, Cst to eliminate type
589  // conversion.
590  // It works because bits coming from sign extension have the same value as
591  // the sign bit of the original value; performing ashr instead of lshr
592  // generates bits of the same value as the sign bit.
593  if (Src->hasOneUse() &&
594  match(Src, m_LShr(m_SExt(m_Value(A)), m_ConstantInt(Cst)))) {
595  Value *SExt = cast<Instruction>(Src)->getOperand(0);
596  const unsigned SExtSize = SExt->getType()->getPrimitiveSizeInBits();
597  const unsigned ASize = A->getType()->getPrimitiveSizeInBits();
598  const unsigned CISize = CI.getType()->getPrimitiveSizeInBits();
599  const unsigned MaxAmt = SExtSize - std::max(CISize, ASize);
600  unsigned ShiftAmt = Cst->getZExtValue();
601 
602  // This optimization can be only performed when zero bits generated by
603  // the original lshr aren't pulled into the value after truncation, so we
604  // can only shift by values no larger than the number of extension bits.
605  // FIXME: Instead of bailing when the shift is too large, use and to clear
606  // the extra bits.
607  if (ShiftAmt <= MaxAmt) {
608  if (CISize == ASize)
609  return BinaryOperator::CreateAShr(A, ConstantInt::get(CI.getType(),
610  std::min(ShiftAmt, ASize - 1)));
611  if (SExt->hasOneUse()) {
612  Value *Shift = Builder.CreateAShr(A, std::min(ShiftAmt, ASize - 1));
613  Shift->takeName(Src);
614  return CastInst::CreateIntegerCast(Shift, CI.getType(), true);
615  }
616  }
617  }
618 
619  if (Instruction *I = shrinkBitwiseLogic(CI))
620  return I;
621 
622  if (Instruction *I = shrinkSplatShuffle(CI, Builder))
623  return I;
624 
625  if (Instruction *I = shrinkInsertElt(CI, Builder))
626  return I;
627 
628  if (Src->hasOneUse() && isa<IntegerType>(SrcTy) &&
629  shouldChangeType(SrcTy, DestTy)) {
630  // Transform "trunc (shl X, cst)" -> "shl (trunc X), cst" so long as the
631  // dest type is native and cst < dest size.
632  if (match(Src, m_Shl(m_Value(A), m_ConstantInt(Cst))) &&
633  !match(A, m_Shr(m_Value(), m_Constant()))) {
634  // Skip shifts of shift by constants. It undoes a combine in
635  // FoldShiftByConstant and is the extend in reg pattern.
636  const unsigned DestSize = DestTy->getScalarSizeInBits();
637  if (Cst->getValue().ult(DestSize)) {
638  Value *NewTrunc = Builder.CreateTrunc(A, DestTy, A->getName() + ".tr");
639 
640  return BinaryOperator::Create(
641  Instruction::Shl, NewTrunc,
642  ConstantInt::get(DestTy, Cst->getValue().trunc(DestSize)));
643  }
644  }
645  }
646 
647  if (Instruction *I = foldVecTruncToExtElt(CI, *this))
648  return I;
649 
650  return nullptr;
651 }
652 
653 Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, ZExtInst &CI,
654  bool DoTransform) {
655  // If we are just checking for a icmp eq of a single bit and zext'ing it
656  // to an integer, then shift the bit to the appropriate place and then
657  // cast to integer to avoid the comparison.
658  if (ConstantInt *Op1C = dyn_cast<ConstantInt>(ICI->getOperand(1))) {
659  const APInt &Op1CV = Op1C->getValue();
660 
661  // zext (x <s 0) to i32 --> x>>u31 true if signbit set.
662  // zext (x >s -1) to i32 --> (x>>u31)^1 true if signbit clear.
663  if ((ICI->getPredicate() == ICmpInst::ICMP_SLT && Op1CV.isNullValue()) ||
664  (ICI->getPredicate() == ICmpInst::ICMP_SGT && Op1CV.isAllOnesValue())) {
665  if (!DoTransform) return ICI;
666 
667  Value *In = ICI->getOperand(0);
668  Value *Sh = ConstantInt::get(In->getType(),
669  In->getType()->getScalarSizeInBits() - 1);
670  In = Builder.CreateLShr(In, Sh, In->getName() + ".lobit");
671  if (In->getType() != CI.getType())
672  In = Builder.CreateIntCast(In, CI.getType(), false /*ZExt*/);
673 
674  if (ICI->getPredicate() == ICmpInst::ICMP_SGT) {
675  Constant *One = ConstantInt::get(In->getType(), 1);
676  In = Builder.CreateXor(In, One, In->getName() + ".not");
677  }
678 
679  return replaceInstUsesWith(CI, In);
680  }
681 
682  // zext (X == 0) to i32 --> X^1 iff X has only the low bit set.
683  // zext (X == 0) to i32 --> (X>>1)^1 iff X has only the 2nd bit set.
684  // zext (X == 1) to i32 --> X iff X has only the low bit set.
685  // zext (X == 2) to i32 --> X>>1 iff X has only the 2nd bit set.
686  // zext (X != 0) to i32 --> X iff X has only the low bit set.
687  // zext (X != 0) to i32 --> X>>1 iff X has only the 2nd bit set.
688  // zext (X != 1) to i32 --> X^1 iff X has only the low bit set.
689  // zext (X != 2) to i32 --> (X>>1)^1 iff X has only the 2nd bit set.
690  if ((Op1CV.isNullValue() || Op1CV.isPowerOf2()) &&
691  // This only works for EQ and NE
692  ICI->isEquality()) {
693  // If Op1C some other power of two, convert:
694  KnownBits Known = computeKnownBits(ICI->getOperand(0), 0, &CI);
695 
696  APInt KnownZeroMask(~Known.Zero);
697  if (KnownZeroMask.isPowerOf2()) { // Exactly 1 possible 1?
698  if (!DoTransform) return ICI;
699 
700  bool isNE = ICI->getPredicate() == ICmpInst::ICMP_NE;
701  if (!Op1CV.isNullValue() && (Op1CV != KnownZeroMask)) {
702  // (X&4) == 2 --> false
703  // (X&4) != 2 --> true
705  isNE);
706  Res = ConstantExpr::getZExt(Res, CI.getType());
707  return replaceInstUsesWith(CI, Res);
708  }
709 
710  uint32_t ShAmt = KnownZeroMask.logBase2();
711  Value *In = ICI->getOperand(0);
712  if (ShAmt) {
713  // Perform a logical shr by shiftamt.
714  // Insert the shift to put the result in the low bit.
715  In = Builder.CreateLShr(In, ConstantInt::get(In->getType(), ShAmt),
716  In->getName() + ".lobit");
717  }
718 
719  if (!Op1CV.isNullValue() == isNE) { // Toggle the low bit.
720  Constant *One = ConstantInt::get(In->getType(), 1);
721  In = Builder.CreateXor(In, One);
722  }
723 
724  if (CI.getType() == In->getType())
725  return replaceInstUsesWith(CI, In);
726 
727  Value *IntCast = Builder.CreateIntCast(In, CI.getType(), false);
728  return replaceInstUsesWith(CI, IntCast);
729  }
730  }
731  }
732 
733  // icmp ne A, B is equal to xor A, B when A and B only really have one bit.
734  // It is also profitable to transform icmp eq into not(xor(A, B)) because that
735  // may lead to additional simplifications.
736  if (ICI->isEquality() && CI.getType() == ICI->getOperand(0)->getType()) {
737  if (IntegerType *ITy = dyn_cast<IntegerType>(CI.getType())) {
738  Value *LHS = ICI->getOperand(0);
739  Value *RHS = ICI->getOperand(1);
740 
741  KnownBits KnownLHS = computeKnownBits(LHS, 0, &CI);
742  KnownBits KnownRHS = computeKnownBits(RHS, 0, &CI);
743 
744  if (KnownLHS.Zero == KnownRHS.Zero && KnownLHS.One == KnownRHS.One) {
745  APInt KnownBits = KnownLHS.Zero | KnownLHS.One;
746  APInt UnknownBit = ~KnownBits;
747  if (UnknownBit.countPopulation() == 1) {
748  if (!DoTransform) return ICI;
749 
750  Value *Result = Builder.CreateXor(LHS, RHS);
751 
752  // Mask off any bits that are set and won't be shifted away.
753  if (KnownLHS.One.uge(UnknownBit))
754  Result = Builder.CreateAnd(Result,
755  ConstantInt::get(ITy, UnknownBit));
756 
757  // Shift the bit we're testing down to the lsb.
758  Result = Builder.CreateLShr(
759  Result, ConstantInt::get(ITy, UnknownBit.countTrailingZeros()));
760 
761  if (ICI->getPredicate() == ICmpInst::ICMP_EQ)
762  Result = Builder.CreateXor(Result, ConstantInt::get(ITy, 1));
763  Result->takeName(ICI);
764  return replaceInstUsesWith(CI, Result);
765  }
766  }
767  }
768  }
769 
770  return nullptr;
771 }
772 
773 /// Determine if the specified value can be computed in the specified wider type
774 /// and produce the same low bits. If not, return false.
775 ///
776 /// If this function returns true, it can also return a non-zero number of bits
777 /// (in BitsToClear) which indicates that the value it computes is correct for
778 /// the zero extend, but that the additional BitsToClear bits need to be zero'd
779 /// out. For example, to promote something like:
780 ///
781 /// %B = trunc i64 %A to i32
782 /// %C = lshr i32 %B, 8
783 /// %E = zext i32 %C to i64
784 ///
785 /// CanEvaluateZExtd for the 'lshr' will return true, and BitsToClear will be
786 /// set to 8 to indicate that the promoted value needs to have bits 24-31
787 /// cleared in addition to bits 32-63. Since an 'and' will be generated to
788 /// clear the top bits anyway, doing this has no extra cost.
789 ///
790 /// This function works on both vectors and scalars.
791 static bool canEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear,
792  InstCombiner &IC, Instruction *CxtI) {
793  BitsToClear = 0;
794  if (isa<Constant>(V))
795  return true;
796 
798  if (!I) return false;
799 
800  // If the input is a truncate from the destination type, we can trivially
801  // eliminate it.
802  if (isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty)
803  return true;
804 
805  // We can't extend or shrink something that has multiple uses: doing so would
806  // require duplicating the instruction in general, which isn't profitable.
807  if (!I->hasOneUse()) return false;
808 
809  unsigned Opc = I->getOpcode(), Tmp;
810  switch (Opc) {
811  case Instruction::ZExt: // zext(zext(x)) -> zext(x).
812  case Instruction::SExt: // zext(sext(x)) -> sext(x).
813  case Instruction::Trunc: // zext(trunc(x)) -> trunc(x) or zext(x)
814  return true;
815  case Instruction::And:
816  case Instruction::Or:
817  case Instruction::Xor:
818  case Instruction::Add:
819  case Instruction::Sub:
820  case Instruction::Mul:
821  if (!canEvaluateZExtd(I->getOperand(0), Ty, BitsToClear, IC, CxtI) ||
822  !canEvaluateZExtd(I->getOperand(1), Ty, Tmp, IC, CxtI))
823  return false;
824  // These can all be promoted if neither operand has 'bits to clear'.
825  if (BitsToClear == 0 && Tmp == 0)
826  return true;
827 
828  // If the operation is an AND/OR/XOR and the bits to clear are zero in the
829  // other side, BitsToClear is ok.
830  if (Tmp == 0 && I->isBitwiseLogicOp()) {
831  // We use MaskedValueIsZero here for generality, but the case we care
832  // about the most is constant RHS.
833  unsigned VSize = V->getType()->getScalarSizeInBits();
834  if (IC.MaskedValueIsZero(I->getOperand(1),
835  APInt::getHighBitsSet(VSize, BitsToClear),
836  0, CxtI))
837  return true;
838  }
839 
840  // Otherwise, we don't know how to analyze this BitsToClear case yet.
841  return false;
842 
843  case Instruction::Shl:
844  // We can promote shl(x, cst) if we can promote x. Since shl overwrites the
845  // upper bits we can reduce BitsToClear by the shift amount.
846  if (ConstantInt *Amt = dyn_cast<ConstantInt>(I->getOperand(1))) {
847  if (!canEvaluateZExtd(I->getOperand(0), Ty, BitsToClear, IC, CxtI))
848  return false;
849  uint64_t ShiftAmt = Amt->getZExtValue();
850  BitsToClear = ShiftAmt < BitsToClear ? BitsToClear - ShiftAmt : 0;
851  return true;
852  }
853  return false;
854  case Instruction::LShr:
855  // We can promote lshr(x, cst) if we can promote x. This requires the
856  // ultimate 'and' to clear out the high zero bits we're clearing out though.
857  if (ConstantInt *Amt = dyn_cast<ConstantInt>(I->getOperand(1))) {
858  if (!canEvaluateZExtd(I->getOperand(0), Ty, BitsToClear, IC, CxtI))
859  return false;
860  BitsToClear += Amt->getZExtValue();
861  if (BitsToClear > V->getType()->getScalarSizeInBits())
862  BitsToClear = V->getType()->getScalarSizeInBits();
863  return true;
864  }
865  // Cannot promote variable LSHR.
866  return false;
867  case Instruction::Select:
868  if (!canEvaluateZExtd(I->getOperand(1), Ty, Tmp, IC, CxtI) ||
869  !canEvaluateZExtd(I->getOperand(2), Ty, BitsToClear, IC, CxtI) ||
870  // TODO: If important, we could handle the case when the BitsToClear are
871  // known zero in the disagreeing side.
872  Tmp != BitsToClear)
873  return false;
874  return true;
875 
876  case Instruction::PHI: {
877  // We can change a phi if we can change all operands. Note that we never
878  // get into trouble with cyclic PHIs here because we only consider
879  // instructions with a single use.
880  PHINode *PN = cast<PHINode>(I);
881  if (!canEvaluateZExtd(PN->getIncomingValue(0), Ty, BitsToClear, IC, CxtI))
882  return false;
883  for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
884  if (!canEvaluateZExtd(PN->getIncomingValue(i), Ty, Tmp, IC, CxtI) ||
885  // TODO: If important, we could handle the case when the BitsToClear
886  // are known zero in the disagreeing input.
887  Tmp != BitsToClear)
888  return false;
889  return true;
890  }
891  default:
892  // TODO: Can handle more cases here.
893  return false;
894  }
895 }
896 
898  // If this zero extend is only used by a truncate, let the truncate be
899  // eliminated before we try to optimize this zext.
900  if (CI.hasOneUse() && isa<TruncInst>(CI.user_back()))
901  return nullptr;
902 
903  // If one of the common conversion will work, do it.
904  if (Instruction *Result = commonCastTransforms(CI))
905  return Result;
906 
907  Value *Src = CI.getOperand(0);
908  Type *SrcTy = Src->getType(), *DestTy = CI.getType();
909 
910  // Attempt to extend the entire input expression tree to the destination
911  // type. Only do this if the dest type is a simple type, don't convert the
912  // expression tree to something weird like i93 unless the source is also
913  // strange.
914  unsigned BitsToClear;
915  if ((DestTy->isVectorTy() || shouldChangeType(SrcTy, DestTy)) &&
916  canEvaluateZExtd(Src, DestTy, BitsToClear, *this, &CI)) {
917  assert(BitsToClear <= SrcTy->getScalarSizeInBits() &&
918  "Can't clear more bits than in SrcTy");
919 
920  // Okay, we can transform this! Insert the new expression now.
921  DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
922  " to avoid zero extend: " << CI << '\n');
923  Value *Res = EvaluateInDifferentType(Src, DestTy, false);
924  assert(Res->getType() == DestTy);
925 
926  uint32_t SrcBitsKept = SrcTy->getScalarSizeInBits()-BitsToClear;
927  uint32_t DestBitSize = DestTy->getScalarSizeInBits();
928 
929  // If the high bits are already filled with zeros, just replace this
930  // cast with the result.
931  if (MaskedValueIsZero(Res,
932  APInt::getHighBitsSet(DestBitSize,
933  DestBitSize-SrcBitsKept),
934  0, &CI))
935  return replaceInstUsesWith(CI, Res);
936 
937  // We need to emit an AND to clear the high bits.
939  APInt::getLowBitsSet(DestBitSize, SrcBitsKept));
940  return BinaryOperator::CreateAnd(Res, C);
941  }
942 
943  // If this is a TRUNC followed by a ZEXT then we are dealing with integral
944  // types and if the sizes are just right we can convert this into a logical
945  // 'and' which will be much cheaper than the pair of casts.
946  if (TruncInst *CSrc = dyn_cast<TruncInst>(Src)) { // A->B->C cast
947  // TODO: Subsume this into EvaluateInDifferentType.
948 
949  // Get the sizes of the types involved. We know that the intermediate type
950  // will be smaller than A or C, but don't know the relation between A and C.
951  Value *A = CSrc->getOperand(0);
952  unsigned SrcSize = A->getType()->getScalarSizeInBits();
953  unsigned MidSize = CSrc->getType()->getScalarSizeInBits();
954  unsigned DstSize = CI.getType()->getScalarSizeInBits();
955  // If we're actually extending zero bits, then if
956  // SrcSize < DstSize: zext(a & mask)
957  // SrcSize == DstSize: a & mask
958  // SrcSize > DstSize: trunc(a) & mask
959  if (SrcSize < DstSize) {
960  APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
961  Constant *AndConst = ConstantInt::get(A->getType(), AndValue);
962  Value *And = Builder.CreateAnd(A, AndConst, CSrc->getName() + ".mask");
963  return new ZExtInst(And, CI.getType());
964  }
965 
966  if (SrcSize == DstSize) {
967  APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
968  return BinaryOperator::CreateAnd(A, ConstantInt::get(A->getType(),
969  AndValue));
970  }
971  if (SrcSize > DstSize) {
972  Value *Trunc = Builder.CreateTrunc(A, CI.getType());
973  APInt AndValue(APInt::getLowBitsSet(DstSize, MidSize));
974  return BinaryOperator::CreateAnd(Trunc,
975  ConstantInt::get(Trunc->getType(),
976  AndValue));
977  }
978  }
979 
980  if (ICmpInst *ICI = dyn_cast<ICmpInst>(Src))
981  return transformZExtICmp(ICI, CI);
982 
983  BinaryOperator *SrcI = dyn_cast<BinaryOperator>(Src);
984  if (SrcI && SrcI->getOpcode() == Instruction::Or) {
985  // zext (or icmp, icmp) -> or (zext icmp), (zext icmp) if at least one
986  // of the (zext icmp) can be eliminated. If so, immediately perform the
987  // according elimination.
988  ICmpInst *LHS = dyn_cast<ICmpInst>(SrcI->getOperand(0));
989  ICmpInst *RHS = dyn_cast<ICmpInst>(SrcI->getOperand(1));
990  if (LHS && RHS && LHS->hasOneUse() && RHS->hasOneUse() &&
991  (transformZExtICmp(LHS, CI, false) ||
992  transformZExtICmp(RHS, CI, false))) {
993  // zext (or icmp, icmp) -> or (zext icmp), (zext icmp)
994  Value *LCast = Builder.CreateZExt(LHS, CI.getType(), LHS->getName());
995  Value *RCast = Builder.CreateZExt(RHS, CI.getType(), RHS->getName());
996  BinaryOperator *Or = BinaryOperator::Create(Instruction::Or, LCast, RCast);
997 
998  // Perform the elimination.
999  if (auto *LZExt = dyn_cast<ZExtInst>(LCast))
1000  transformZExtICmp(LHS, *LZExt);
1001  if (auto *RZExt = dyn_cast<ZExtInst>(RCast))
1002  transformZExtICmp(RHS, *RZExt);
1003 
1004  return Or;
1005  }
1006  }
1007 
1008  // zext(trunc(X) & C) -> (X & zext(C)).
1009  Constant *C;
1010  Value *X;
1011  if (SrcI &&
1012  match(SrcI, m_OneUse(m_And(m_Trunc(m_Value(X)), m_Constant(C)))) &&
1013  X->getType() == CI.getType())
1014  return BinaryOperator::CreateAnd(X, ConstantExpr::getZExt(C, CI.getType()));
1015 
1016  // zext((trunc(X) & C) ^ C) -> ((X & zext(C)) ^ zext(C)).
1017  Value *And;
1018  if (SrcI && match(SrcI, m_OneUse(m_Xor(m_Value(And), m_Constant(C)))) &&
1019  match(And, m_OneUse(m_And(m_Trunc(m_Value(X)), m_Specific(C)))) &&
1020  X->getType() == CI.getType()) {
1021  Constant *ZC = ConstantExpr::getZExt(C, CI.getType());
1022  return BinaryOperator::CreateXor(Builder.CreateAnd(X, ZC), ZC);
1023  }
1024 
1025  return nullptr;
1026 }
1027 
1028 /// Transform (sext icmp) to bitwise / integer operations to eliminate the icmp.
1029 Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
1030  Value *Op0 = ICI->getOperand(0), *Op1 = ICI->getOperand(1);
1031  ICmpInst::Predicate Pred = ICI->getPredicate();
1032 
1033  // Don't bother if Op1 isn't of vector or integer type.
1034  if (!Op1->getType()->isIntOrIntVectorTy())
1035  return nullptr;
1036 
1037  if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
1038  // (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if negative
1039  // (x >s -1) ? -1 : 0 -> not (ashr x, 31) -> all ones if positive
1040  if ((Pred == ICmpInst::ICMP_SLT && Op1C->isNullValue()) ||
1041  (Pred == ICmpInst::ICMP_SGT && Op1C->isAllOnesValue())) {
1042 
1043  Value *Sh = ConstantInt::get(Op0->getType(),
1044  Op0->getType()->getScalarSizeInBits()-1);
1045  Value *In = Builder.CreateAShr(Op0, Sh, Op0->getName() + ".lobit");
1046  if (In->getType() != CI.getType())
1047  In = Builder.CreateIntCast(In, CI.getType(), true /*SExt*/);
1048 
1049  if (Pred == ICmpInst::ICMP_SGT)
1050  In = Builder.CreateNot(In, In->getName() + ".not");
1051  return replaceInstUsesWith(CI, In);
1052  }
1053  }
1054 
1055  if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
1056  // If we know that only one bit of the LHS of the icmp can be set and we
1057  // have an equality comparison with zero or a power of 2, we can transform
1058  // the icmp and sext into bitwise/integer operations.
1059  if (ICI->hasOneUse() &&
1060  ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){
1061  KnownBits Known = computeKnownBits(Op0, 0, &CI);
1062 
1063  APInt KnownZeroMask(~Known.Zero);
1064  if (KnownZeroMask.isPowerOf2()) {
1065  Value *In = ICI->getOperand(0);
1066 
1067  // If the icmp tests for a known zero bit we can constant fold it.
1068  if (!Op1C->isZero() && Op1C->getValue() != KnownZeroMask) {
1069  Value *V = Pred == ICmpInst::ICMP_NE ?
1072  return replaceInstUsesWith(CI, V);
1073  }
1074 
1075  if (!Op1C->isZero() == (Pred == ICmpInst::ICMP_NE)) {
1076  // sext ((x & 2^n) == 0) -> (x >> n) - 1
1077  // sext ((x & 2^n) != 2^n) -> (x >> n) - 1
1078  unsigned ShiftAmt = KnownZeroMask.countTrailingZeros();
1079  // Perform a right shift to place the desired bit in the LSB.
1080  if (ShiftAmt)
1081  In = Builder.CreateLShr(In,
1082  ConstantInt::get(In->getType(), ShiftAmt));
1083 
1084  // At this point "In" is either 1 or 0. Subtract 1 to turn
1085  // {1, 0} -> {0, -1}.
1086  In = Builder.CreateAdd(In,
1088  "sext");
1089  } else {
1090  // sext ((x & 2^n) != 0) -> (x << bitwidth-n) a>> bitwidth-1
1091  // sext ((x & 2^n) == 2^n) -> (x << bitwidth-n) a>> bitwidth-1
1092  unsigned ShiftAmt = KnownZeroMask.countLeadingZeros();
1093  // Perform a left shift to place the desired bit in the MSB.
1094  if (ShiftAmt)
1095  In = Builder.CreateShl(In,
1096  ConstantInt::get(In->getType(), ShiftAmt));
1097 
1098  // Distribute the bit over the whole bit width.
1099  In = Builder.CreateAShr(In, ConstantInt::get(In->getType(),
1100  KnownZeroMask.getBitWidth() - 1), "sext");
1101  }
1102 
1103  if (CI.getType() == In->getType())
1104  return replaceInstUsesWith(CI, In);
1105  return CastInst::CreateIntegerCast(In, CI.getType(), true/*SExt*/);
1106  }
1107  }
1108  }
1109 
1110  return nullptr;
1111 }
1112 
1113 /// Return true if we can take the specified value and return it as type Ty
1114 /// without inserting any new casts and without changing the value of the common
1115 /// low bits. This is used by code that tries to promote integer operations to
1116 /// a wider types will allow us to eliminate the extension.
1117 ///
1118 /// This function works on both vectors and scalars.
1119 ///
1120 static bool canEvaluateSExtd(Value *V, Type *Ty) {
1122  "Can't sign extend type to a smaller type");
1123  // If this is a constant, it can be trivially promoted.
1124  if (isa<Constant>(V))
1125  return true;
1126 
1128  if (!I) return false;
1129 
1130  // If this is a truncate from the dest type, we can trivially eliminate it.
1131  if (isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty)
1132  return true;
1133 
1134  // We can't extend or shrink something that has multiple uses: doing so would
1135  // require duplicating the instruction in general, which isn't profitable.
1136  if (!I->hasOneUse()) return false;
1137 
1138  switch (I->getOpcode()) {
1139  case Instruction::SExt: // sext(sext(x)) -> sext(x)
1140  case Instruction::ZExt: // sext(zext(x)) -> zext(x)
1141  case Instruction::Trunc: // sext(trunc(x)) -> trunc(x) or sext(x)
1142  return true;
1143  case Instruction::And:
1144  case Instruction::Or:
1145  case Instruction::Xor:
1146  case Instruction::Add:
1147  case Instruction::Sub:
1148  case Instruction::Mul:
1149  // These operators can all arbitrarily be extended if their inputs can.
1150  return canEvaluateSExtd(I->getOperand(0), Ty) &&
1151  canEvaluateSExtd(I->getOperand(1), Ty);
1152 
1153  //case Instruction::Shl: TODO
1154  //case Instruction::LShr: TODO
1155 
1156  case Instruction::Select:
1157  return canEvaluateSExtd(I->getOperand(1), Ty) &&
1158  canEvaluateSExtd(I->getOperand(2), Ty);
1159 
1160  case Instruction::PHI: {
1161  // We can change a phi if we can change all operands. Note that we never
1162  // get into trouble with cyclic PHIs here because we only consider
1163  // instructions with a single use.
1164  PHINode *PN = cast<PHINode>(I);
1165  for (Value *IncValue : PN->incoming_values())
1166  if (!canEvaluateSExtd(IncValue, Ty)) return false;
1167  return true;
1168  }
1169  default:
1170  // TODO: Can handle more cases here.
1171  break;
1172  }
1173 
1174  return false;
1175 }
1176 
1178  // If this sign extend is only used by a truncate, let the truncate be
1179  // eliminated before we try to optimize this sext.
1180  if (CI.hasOneUse() && isa<TruncInst>(CI.user_back()))
1181  return nullptr;
1182 
1183  if (Instruction *I = commonCastTransforms(CI))
1184  return I;
1185 
1186  Value *Src = CI.getOperand(0);
1187  Type *SrcTy = Src->getType(), *DestTy = CI.getType();
1188 
1189  // If we know that the value being extended is positive, we can use a zext
1190  // instead.
1191  KnownBits Known = computeKnownBits(Src, 0, &CI);
1192  if (Known.isNonNegative()) {
1193  Value *ZExt = Builder.CreateZExt(Src, DestTy);
1194  return replaceInstUsesWith(CI, ZExt);
1195  }
1196 
1197  // Attempt to extend the entire input expression tree to the destination
1198  // type. Only do this if the dest type is a simple type, don't convert the
1199  // expression tree to something weird like i93 unless the source is also
1200  // strange.
1201  if ((DestTy->isVectorTy() || shouldChangeType(SrcTy, DestTy)) &&
1202  canEvaluateSExtd(Src, DestTy)) {
1203  // Okay, we can transform this! Insert the new expression now.
1204  DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
1205  " to avoid sign extend: " << CI << '\n');
1206  Value *Res = EvaluateInDifferentType(Src, DestTy, true);
1207  assert(Res->getType() == DestTy);
1208 
1209  uint32_t SrcBitSize = SrcTy->getScalarSizeInBits();
1210  uint32_t DestBitSize = DestTy->getScalarSizeInBits();
1211 
1212  // If the high bits are already filled with sign bit, just replace this
1213  // cast with the result.
1214  if (ComputeNumSignBits(Res, 0, &CI) > DestBitSize - SrcBitSize)
1215  return replaceInstUsesWith(CI, Res);
1216 
1217  // We need to emit a shl + ashr to do the sign extend.
1218  Value *ShAmt = ConstantInt::get(DestTy, DestBitSize-SrcBitSize);
1219  return BinaryOperator::CreateAShr(Builder.CreateShl(Res, ShAmt, "sext"),
1220  ShAmt);
1221  }
1222 
1223  // If the input is a trunc from the destination type, then turn sext(trunc(x))
1224  // into shifts.
1225  Value *X;
1226  if (match(Src, m_OneUse(m_Trunc(m_Value(X)))) && X->getType() == DestTy) {
1227  // sext(trunc(X)) --> ashr(shl(X, C), C)
1228  unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
1229  unsigned DestBitSize = DestTy->getScalarSizeInBits();
1230  Constant *ShAmt = ConstantInt::get(DestTy, DestBitSize - SrcBitSize);
1231  return BinaryOperator::CreateAShr(Builder.CreateShl(X, ShAmt), ShAmt);
1232  }
1233 
1234  if (ICmpInst *ICI = dyn_cast<ICmpInst>(Src))
1235  return transformSExtICmp(ICI, CI);
1236 
1237  // If the input is a shl/ashr pair of a same constant, then this is a sign
1238  // extension from a smaller value. If we could trust arbitrary bitwidth
1239  // integers, we could turn this into a truncate to the smaller bit and then
1240  // use a sext for the whole extension. Since we don't, look deeper and check
1241  // for a truncate. If the source and dest are the same type, eliminate the
1242  // trunc and extend and just do shifts. For example, turn:
1243  // %a = trunc i32 %i to i8
1244  // %b = shl i8 %a, 6
1245  // %c = ashr i8 %b, 6
1246  // %d = sext i8 %c to i32
1247  // into:
1248  // %a = shl i32 %i, 30
1249  // %d = ashr i32 %a, 30
1250  Value *A = nullptr;
1251  // TODO: Eventually this could be subsumed by EvaluateInDifferentType.
1252  ConstantInt *BA = nullptr, *CA = nullptr;
1253  if (match(Src, m_AShr(m_Shl(m_Trunc(m_Value(A)), m_ConstantInt(BA)),
1254  m_ConstantInt(CA))) &&
1255  BA == CA && A->getType() == CI.getType()) {
1256  unsigned MidSize = Src->getType()->getScalarSizeInBits();
1257  unsigned SrcDstSize = CI.getType()->getScalarSizeInBits();
1258  unsigned ShAmt = CA->getZExtValue()+SrcDstSize-MidSize;
1259  Constant *ShAmtV = ConstantInt::get(CI.getType(), ShAmt);
1260  A = Builder.CreateShl(A, ShAmtV, CI.getName());
1261  return BinaryOperator::CreateAShr(A, ShAmtV);
1262  }
1263 
1264  return nullptr;
1265 }
1266 
1267 
1268 /// Return a Constant* for the specified floating-point constant if it fits
1269 /// in the specified FP type without changing its value.
1270 static Constant *fitsInFPType(ConstantFP *CFP, const fltSemantics &Sem) {
1271  bool losesInfo;
1272  APFloat F = CFP->getValueAPF();
1273  (void)F.convert(Sem, APFloat::rmNearestTiesToEven, &losesInfo);
1274  if (!losesInfo)
1275  return ConstantFP::get(CFP->getContext(), F);
1276  return nullptr;
1277 }
1278 
1279 /// Look through floating-point extensions until we get the source value.
1281  while (auto *FPExt = dyn_cast<FPExtInst>(V))
1282  V = FPExt->getOperand(0);
1283 
1284  // If this value is a constant, return the constant in the smallest FP type
1285  // that can accurately represent it. This allows us to turn
1286  // (float)((double)X+2.0) into x+2.0f.
1287  if (auto *CFP = dyn_cast<ConstantFP>(V)) {
1288  if (CFP->getType() == Type::getPPC_FP128Ty(V->getContext()))
1289  return V; // No constant folding of this.
1290  // See if the value can be truncated to half and then reextended.
1291  if (Value *V = fitsInFPType(CFP, APFloat::IEEEhalf()))
1292  return V;
1293  // See if the value can be truncated to float and then reextended.
1294  if (Value *V = fitsInFPType(CFP, APFloat::IEEEsingle()))
1295  return V;
1296  if (CFP->getType()->isDoubleTy())
1297  return V; // Won't shrink.
1298  if (Value *V = fitsInFPType(CFP, APFloat::IEEEdouble()))
1299  return V;
1300  // Don't try to shrink to various long double types.
1301  }
1302 
1303  return V;
1304 }
1305 
1307  if (Instruction *I = commonCastTransforms(CI))
1308  return I;
1309  // If we have fptrunc(OpI (fpextend x), (fpextend y)), we would like to
1310  // simplify this expression to avoid one or more of the trunc/extend
1311  // operations if we can do so without changing the numerical results.
1312  //
1313  // The exact manner in which the widths of the operands interact to limit
1314  // what we can and cannot do safely varies from operation to operation, and
1315  // is explained below in the various case statements.
1317  if (OpI && OpI->hasOneUse()) {
1318  Value *LHSOrig = lookThroughFPExtensions(OpI->getOperand(0));
1319  Value *RHSOrig = lookThroughFPExtensions(OpI->getOperand(1));
1320  unsigned OpWidth = OpI->getType()->getFPMantissaWidth();
1321  unsigned LHSWidth = LHSOrig->getType()->getFPMantissaWidth();
1322  unsigned RHSWidth = RHSOrig->getType()->getFPMantissaWidth();
1323  unsigned SrcWidth = std::max(LHSWidth, RHSWidth);
1324  unsigned DstWidth = CI.getType()->getFPMantissaWidth();
1325  switch (OpI->getOpcode()) {
1326  default: break;
1327  case Instruction::FAdd:
1328  case Instruction::FSub:
1329  // For addition and subtraction, the infinitely precise result can
1330  // essentially be arbitrarily wide; proving that double rounding
1331  // will not occur because the result of OpI is exact (as we will for
1332  // FMul, for example) is hopeless. However, we *can* nonetheless
1333  // frequently know that double rounding cannot occur (or that it is
1334  // innocuous) by taking advantage of the specific structure of
1335  // infinitely-precise results that admit double rounding.
1336  //
1337  // Specifically, if OpWidth >= 2*DstWdith+1 and DstWidth is sufficient
1338  // to represent both sources, we can guarantee that the double
1339  // rounding is innocuous (See p50 of Figueroa's 2000 PhD thesis,
1340  // "A Rigorous Framework for Fully Supporting the IEEE Standard ..."
1341  // for proof of this fact).
1342  //
1343  // Note: Figueroa does not consider the case where DstFormat !=
1344  // SrcFormat. It's possible (likely even!) that this analysis
1345  // could be tightened for those cases, but they are rare (the main
1346  // case of interest here is (float)((double)float + float)).
1347  if (OpWidth >= 2*DstWidth+1 && DstWidth >= SrcWidth) {
1348  if (LHSOrig->getType() != CI.getType())
1349  LHSOrig = Builder.CreateFPExt(LHSOrig, CI.getType());
1350  if (RHSOrig->getType() != CI.getType())
1351  RHSOrig = Builder.CreateFPExt(RHSOrig, CI.getType());
1352  Instruction *RI =
1353  BinaryOperator::Create(OpI->getOpcode(), LHSOrig, RHSOrig);
1354  RI->copyFastMathFlags(OpI);
1355  return RI;
1356  }
1357  break;
1358  case Instruction::FMul:
1359  // For multiplication, the infinitely precise result has at most
1360  // LHSWidth + RHSWidth significant bits; if OpWidth is sufficient
1361  // that such a value can be exactly represented, then no double
1362  // rounding can possibly occur; we can safely perform the operation
1363  // in the destination format if it can represent both sources.
1364  if (OpWidth >= LHSWidth + RHSWidth && DstWidth >= SrcWidth) {
1365  if (LHSOrig->getType() != CI.getType())
1366  LHSOrig = Builder.CreateFPExt(LHSOrig, CI.getType());
1367  if (RHSOrig->getType() != CI.getType())
1368  RHSOrig = Builder.CreateFPExt(RHSOrig, CI.getType());
1369  Instruction *RI =
1370  BinaryOperator::CreateFMul(LHSOrig, RHSOrig);
1371  RI->copyFastMathFlags(OpI);
1372  return RI;
1373  }
1374  break;
1375  case Instruction::FDiv:
1376  // For division, we use again use the bound from Figueroa's
1377  // dissertation. I am entirely certain that this bound can be
1378  // tightened in the unbalanced operand case by an analysis based on
1379  // the diophantine rational approximation bound, but the well-known
1380  // condition used here is a good conservative first pass.
1381  // TODO: Tighten bound via rigorous analysis of the unbalanced case.
1382  if (OpWidth >= 2*DstWidth && DstWidth >= SrcWidth) {
1383  if (LHSOrig->getType() != CI.getType())
1384  LHSOrig = Builder.CreateFPExt(LHSOrig, CI.getType());
1385  if (RHSOrig->getType() != CI.getType())
1386  RHSOrig = Builder.CreateFPExt(RHSOrig, CI.getType());
1387  Instruction *RI =
1388  BinaryOperator::CreateFDiv(LHSOrig, RHSOrig);
1389  RI->copyFastMathFlags(OpI);
1390  return RI;
1391  }
1392  break;
1393  case Instruction::FRem:
1394  // Remainder is straightforward. Remainder is always exact, so the
1395  // type of OpI doesn't enter into things at all. We simply evaluate
1396  // in whichever source type is larger, then convert to the
1397  // destination type.
1398  if (SrcWidth == OpWidth)
1399  break;
1400  if (LHSWidth < SrcWidth)
1401  LHSOrig = Builder.CreateFPExt(LHSOrig, RHSOrig->getType());
1402  else if (RHSWidth <= SrcWidth)
1403  RHSOrig = Builder.CreateFPExt(RHSOrig, LHSOrig->getType());
1404  if (LHSOrig != OpI->getOperand(0) || RHSOrig != OpI->getOperand(1)) {
1405  Value *ExactResult = Builder.CreateFRem(LHSOrig, RHSOrig);
1406  if (Instruction *RI = dyn_cast<Instruction>(ExactResult))
1407  RI->copyFastMathFlags(OpI);
1408  return CastInst::CreateFPCast(ExactResult, CI.getType());
1409  }
1410  }
1411 
1412  // (fptrunc (fneg x)) -> (fneg (fptrunc x))
1413  if (BinaryOperator::isFNeg(OpI)) {
1414  Value *InnerTrunc = Builder.CreateFPTrunc(OpI->getOperand(1),
1415  CI.getType());
1416  Instruction *RI = BinaryOperator::CreateFNeg(InnerTrunc);
1417  RI->copyFastMathFlags(OpI);
1418  return RI;
1419  }
1420  }
1421 
1422  // (fptrunc (select cond, R1, Cst)) -->
1423  // (select cond, (fptrunc R1), (fptrunc Cst))
1424  //
1425  // - but only if this isn't part of a min/max operation, else we'll
1426  // ruin min/max canonical form which is to have the select and
1427  // compare's operands be of the same type with no casts to look through.
1428  Value *LHS, *RHS;
1430  if (SI &&
1431  (isa<ConstantFP>(SI->getOperand(1)) ||
1432  isa<ConstantFP>(SI->getOperand(2))) &&
1433  matchSelectPattern(SI, LHS, RHS).Flavor == SPF_UNKNOWN) {
1434  Value *LHSTrunc = Builder.CreateFPTrunc(SI->getOperand(1), CI.getType());
1435  Value *RHSTrunc = Builder.CreateFPTrunc(SI->getOperand(2), CI.getType());
1436  return SelectInst::Create(SI->getOperand(0), LHSTrunc, RHSTrunc);
1437  }
1438 
1440  if (II) {
1441  switch (II->getIntrinsicID()) {
1442  default: break;
1443  case Intrinsic::fabs:
1444  case Intrinsic::ceil:
1445  case Intrinsic::floor:
1446  case Intrinsic::rint:
1447  case Intrinsic::round:
1448  case Intrinsic::nearbyint:
1449  case Intrinsic::trunc: {
1450  Value *Src = II->getArgOperand(0);
1451  if (!Src->hasOneUse())
1452  break;
1453 
1454  // Except for fabs, this transformation requires the input of the unary FP
1455  // operation to be itself an fpext from the type to which we're
1456  // truncating.
1457  if (II->getIntrinsicID() != Intrinsic::fabs) {
1458  FPExtInst *FPExtSrc = dyn_cast<FPExtInst>(Src);
1459  if (!FPExtSrc || FPExtSrc->getOperand(0)->getType() != CI.getType())
1460  break;
1461  }
1462 
1463  // Do unary FP operation on smaller type.
1464  // (fptrunc (fabs x)) -> (fabs (fptrunc x))
1465  Value *InnerTrunc = Builder.CreateFPTrunc(Src, CI.getType());
1466  Type *IntrinsicType[] = { CI.getType() };
1467  Function *Overload = Intrinsic::getDeclaration(
1468  CI.getModule(), II->getIntrinsicID(), IntrinsicType);
1469 
1471  II->getOperandBundlesAsDefs(OpBundles);
1472 
1473  Value *Args[] = { InnerTrunc };
1474  CallInst *NewCI = CallInst::Create(Overload, Args,
1475  OpBundles, II->getName());
1476  NewCI->copyFastMathFlags(II);
1477  return NewCI;
1478  }
1479  }
1480  }
1481 
1482  if (Instruction *I = shrinkInsertElt(CI, Builder))
1483  return I;
1484 
1485  return nullptr;
1486 }
1487 
1489  return commonCastTransforms(CI);
1490 }
1491 
1492 // fpto{s/u}i({u/s}itofp(X)) --> X or zext(X) or sext(X) or trunc(X)
1493 // This is safe if the intermediate type has enough bits in its mantissa to
1494 // accurately represent all values of X. For example, this won't work with
1495 // i64 -> float -> i64.
1497  if (!isa<UIToFPInst>(FI.getOperand(0)) && !isa<SIToFPInst>(FI.getOperand(0)))
1498  return nullptr;
1499  Instruction *OpI = cast<Instruction>(FI.getOperand(0));
1500 
1501  Value *SrcI = OpI->getOperand(0);
1502  Type *FITy = FI.getType();
1503  Type *OpITy = OpI->getType();
1504  Type *SrcTy = SrcI->getType();
1505  bool IsInputSigned = isa<SIToFPInst>(OpI);
1506  bool IsOutputSigned = isa<FPToSIInst>(FI);
1507 
1508  // We can safely assume the conversion won't overflow the output range,
1509  // because (for example) (uint8_t)18293.f is undefined behavior.
1510 
1511  // Since we can assume the conversion won't overflow, our decision as to
1512  // whether the input will fit in the float should depend on the minimum
1513  // of the input range and output range.
1514 
1515  // This means this is also safe for a signed input and unsigned output, since
1516  // a negative input would lead to undefined behavior.
1517  int InputSize = (int)SrcTy->getScalarSizeInBits() - IsInputSigned;
1518  int OutputSize = (int)FITy->getScalarSizeInBits() - IsOutputSigned;
1519  int ActualSize = std::min(InputSize, OutputSize);
1520 
1521  if (ActualSize <= OpITy->getFPMantissaWidth()) {
1522  if (FITy->getScalarSizeInBits() > SrcTy->getScalarSizeInBits()) {
1523  if (IsInputSigned && IsOutputSigned)
1524  return new SExtInst(SrcI, FITy);
1525  return new ZExtInst(SrcI, FITy);
1526  }
1527  if (FITy->getScalarSizeInBits() < SrcTy->getScalarSizeInBits())
1528  return new TruncInst(SrcI, FITy);
1529  if (SrcTy == FITy)
1530  return replaceInstUsesWith(FI, SrcI);
1531  return new BitCastInst(SrcI, FITy);
1532  }
1533  return nullptr;
1534 }
1535 
1537  Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
1538  if (!OpI)
1539  return commonCastTransforms(FI);
1540 
1541  if (Instruction *I = FoldItoFPtoI(FI))
1542  return I;
1543 
1544  return commonCastTransforms(FI);
1545 }
1546 
1548  Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
1549  if (!OpI)
1550  return commonCastTransforms(FI);
1551 
1552  if (Instruction *I = FoldItoFPtoI(FI))
1553  return I;
1554 
1555  return commonCastTransforms(FI);
1556 }
1557 
1559  return commonCastTransforms(CI);
1560 }
1561 
1563  return commonCastTransforms(CI);
1564 }
1565 
1567  // If the source integer type is not the intptr_t type for this target, do a
1568  // trunc or zext to the intptr_t type, then inttoptr of it. This allows the
1569  // cast to be exposed to other transforms.
1570  unsigned AS = CI.getAddressSpace();
1571  if (CI.getOperand(0)->getType()->getScalarSizeInBits() !=
1572  DL.getPointerSizeInBits(AS)) {
1573  Type *Ty = DL.getIntPtrType(CI.getContext(), AS);
1574  if (CI.getType()->isVectorTy()) // Handle vectors of pointers.
1575  Ty = VectorType::get(Ty, CI.getType()->getVectorNumElements());
1576 
1577  Value *P = Builder.CreateZExtOrTrunc(CI.getOperand(0), Ty);
1578  return new IntToPtrInst(P, CI.getType());
1579  }
1580 
1581  if (Instruction *I = commonCastTransforms(CI))
1582  return I;
1583 
1584  return nullptr;
1585 }
1586 
1587 /// @brief Implement the transforms for cast of pointer (bitcast/ptrtoint)
1589  Value *Src = CI.getOperand(0);
1590 
1591  if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Src)) {
1592  // If casting the result of a getelementptr instruction with no offset, turn
1593  // this into a cast of the original pointer!
1594  if (GEP->hasAllZeroIndices() &&
1595  // If CI is an addrspacecast and GEP changes the poiner type, merging
1596  // GEP into CI would undo canonicalizing addrspacecast with different
1597  // pointer types, causing infinite loops.
1598  (!isa<AddrSpaceCastInst>(CI) ||
1599  GEP->getType() == GEP->getPointerOperandType())) {
1600  // Changing the cast operand is usually not a good idea but it is safe
1601  // here because the pointer operand is being replaced with another
1602  // pointer operand so the opcode doesn't need to change.
1603  Worklist.Add(GEP);
1604  CI.setOperand(0, GEP->getOperand(0));
1605  return &CI;
1606  }
1607  }
1608 
1609  return commonCastTransforms(CI);
1610 }
1611 
1613  // If the destination integer type is not the intptr_t type for this target,
1614  // do a ptrtoint to intptr_t then do a trunc or zext. This allows the cast
1615  // to be exposed to other transforms.
1616 
1617  Type *Ty = CI.getType();
1618  unsigned AS = CI.getPointerAddressSpace();
1619 
1620  if (Ty->getScalarSizeInBits() == DL.getPointerSizeInBits(AS))
1621  return commonPointerCastTransforms(CI);
1622 
1623  Type *PtrTy = DL.getIntPtrType(CI.getContext(), AS);
1624  if (Ty->isVectorTy()) // Handle vectors of pointers.
1625  PtrTy = VectorType::get(PtrTy, Ty->getVectorNumElements());
1626 
1627  Value *P = Builder.CreatePtrToInt(CI.getOperand(0), PtrTy);
1628  return CastInst::CreateIntegerCast(P, Ty, /*isSigned=*/false);
1629 }
1630 
1631 /// This input value (which is known to have vector type) is being zero extended
1632 /// or truncated to the specified vector type.
1633 /// Try to replace it with a shuffle (and vector/vector bitcast) if possible.
1634 ///
1635 /// The source and destination vector types may have different element types.
1637  InstCombiner &IC) {
1638  // We can only do this optimization if the output is a multiple of the input
1639  // element size, or the input is a multiple of the output element size.
1640  // Convert the input type to have the same element type as the output.
1641  VectorType *SrcTy = cast<VectorType>(InVal->getType());
1642 
1643  if (SrcTy->getElementType() != DestTy->getElementType()) {
1644  // The input types don't need to be identical, but for now they must be the
1645  // same size. There is no specific reason we couldn't handle things like
1646  // <4 x i16> -> <4 x i32> by bitcasting to <2 x i32> but haven't gotten
1647  // there yet.
1648  if (SrcTy->getElementType()->getPrimitiveSizeInBits() !=
1650  return nullptr;
1651 
1652  SrcTy = VectorType::get(DestTy->getElementType(), SrcTy->getNumElements());
1653  InVal = IC.Builder.CreateBitCast(InVal, SrcTy);
1654  }
1655 
1656  // Now that the element types match, get the shuffle mask and RHS of the
1657  // shuffle to use, which depends on whether we're increasing or decreasing the
1658  // size of the input.
1659  SmallVector<uint32_t, 16> ShuffleMask;
1660  Value *V2;
1661 
1662  if (SrcTy->getNumElements() > DestTy->getNumElements()) {
1663  // If we're shrinking the number of elements, just shuffle in the low
1664  // elements from the input and use undef as the second shuffle input.
1665  V2 = UndefValue::get(SrcTy);
1666  for (unsigned i = 0, e = DestTy->getNumElements(); i != e; ++i)
1667  ShuffleMask.push_back(i);
1668 
1669  } else {
1670  // If we're increasing the number of elements, shuffle in all of the
1671  // elements from InVal and fill the rest of the result elements with zeros
1672  // from a constant zero.
1673  V2 = Constant::getNullValue(SrcTy);
1674  unsigned SrcElts = SrcTy->getNumElements();
1675  for (unsigned i = 0, e = SrcElts; i != e; ++i)
1676  ShuffleMask.push_back(i);
1677 
1678  // The excess elements reference the first element of the zero input.
1679  for (unsigned i = 0, e = DestTy->getNumElements()-SrcElts; i != e; ++i)
1680  ShuffleMask.push_back(SrcElts);
1681  }
1682 
1683  return new ShuffleVectorInst(InVal, V2,
1685  ShuffleMask));
1686 }
1687 
1688 static bool isMultipleOfTypeSize(unsigned Value, Type *Ty) {
1689  return Value % Ty->getPrimitiveSizeInBits() == 0;
1690 }
1691 
1692 static unsigned getTypeSizeIndex(unsigned Value, Type *Ty) {
1693  return Value / Ty->getPrimitiveSizeInBits();
1694 }
1695 
1696 /// V is a value which is inserted into a vector of VecEltTy.
1697 /// Look through the value to see if we can decompose it into
1698 /// insertions into the vector. See the example in the comment for
1699 /// OptimizeIntegerToVectorInsertions for the pattern this handles.
1700 /// The type of V is always a non-zero multiple of VecEltTy's size.
1701 /// Shift is the number of bits between the lsb of V and the lsb of
1702 /// the vector.
1703 ///
1704 /// This returns false if the pattern can't be matched or true if it can,
1705 /// filling in Elements with the elements found here.
1706 static bool collectInsertionElements(Value *V, unsigned Shift,
1707  SmallVectorImpl<Value *> &Elements,
1708  Type *VecEltTy, bool isBigEndian) {
1709  assert(isMultipleOfTypeSize(Shift, VecEltTy) &&
1710  "Shift should be a multiple of the element type size");
1711 
1712  // Undef values never contribute useful bits to the result.
1713  if (isa<UndefValue>(V)) return true;
1714 
1715  // If we got down to a value of the right type, we win, try inserting into the
1716  // right element.
1717  if (V->getType() == VecEltTy) {
1718  // Inserting null doesn't actually insert any elements.
1719  if (Constant *C = dyn_cast<Constant>(V))
1720  if (C->isNullValue())
1721  return true;
1722 
1723  unsigned ElementIndex = getTypeSizeIndex(Shift, VecEltTy);
1724  if (isBigEndian)
1725  ElementIndex = Elements.size() - ElementIndex - 1;
1726 
1727  // Fail if multiple elements are inserted into this slot.
1728  if (Elements[ElementIndex])
1729  return false;
1730 
1731  Elements[ElementIndex] = V;
1732  return true;
1733  }
1734 
1735  if (Constant *C = dyn_cast<Constant>(V)) {
1736  // Figure out the # elements this provides, and bitcast it or slice it up
1737  // as required.
1738  unsigned NumElts = getTypeSizeIndex(C->getType()->getPrimitiveSizeInBits(),
1739  VecEltTy);
1740  // If the constant is the size of a vector element, we just need to bitcast
1741  // it to the right type so it gets properly inserted.
1742  if (NumElts == 1)
1744  Shift, Elements, VecEltTy, isBigEndian);
1745 
1746  // Okay, this is a constant that covers multiple elements. Slice it up into
1747  // pieces and insert each element-sized piece into the vector.
1748  if (!isa<IntegerType>(C->getType()))
1751  unsigned ElementSize = VecEltTy->getPrimitiveSizeInBits();
1752  Type *ElementIntTy = IntegerType::get(C->getContext(), ElementSize);
1753 
1754  for (unsigned i = 0; i != NumElts; ++i) {
1755  unsigned ShiftI = Shift+i*ElementSize;
1757  ShiftI));
1758  Piece = ConstantExpr::getTrunc(Piece, ElementIntTy);
1759  if (!collectInsertionElements(Piece, ShiftI, Elements, VecEltTy,
1760  isBigEndian))
1761  return false;
1762  }
1763  return true;
1764  }
1765 
1766  if (!V->hasOneUse()) return false;
1767 
1769  if (!I) return false;
1770  switch (I->getOpcode()) {
1771  default: return false; // Unhandled case.
1772  case Instruction::BitCast:
1773  return collectInsertionElements(I->getOperand(0), Shift, Elements, VecEltTy,
1774  isBigEndian);
1775  case Instruction::ZExt:
1776  if (!isMultipleOfTypeSize(
1778  VecEltTy))
1779  return false;
1780  return collectInsertionElements(I->getOperand(0), Shift, Elements, VecEltTy,
1781  isBigEndian);
1782  case Instruction::Or:
1783  return collectInsertionElements(I->getOperand(0), Shift, Elements, VecEltTy,
1784  isBigEndian) &&
1785  collectInsertionElements(I->getOperand(1), Shift, Elements, VecEltTy,
1786  isBigEndian);
1787  case Instruction::Shl: {
1788  // Must be shifting by a constant that is a multiple of the element size.
1790  if (!CI) return false;
1791  Shift += CI->getZExtValue();
1792  if (!isMultipleOfTypeSize(Shift, VecEltTy)) return false;
1793  return collectInsertionElements(I->getOperand(0), Shift, Elements, VecEltTy,
1794  isBigEndian);
1795  }
1796 
1797  }
1798 }
1799 
1800 
1801 /// If the input is an 'or' instruction, we may be doing shifts and ors to
1802 /// assemble the elements of the vector manually.
1803 /// Try to rip the code out and replace it with insertelements. This is to
1804 /// optimize code like this:
1805 ///
1806 /// %tmp37 = bitcast float %inc to i32
1807 /// %tmp38 = zext i32 %tmp37 to i64
1808 /// %tmp31 = bitcast float %inc5 to i32
1809 /// %tmp32 = zext i32 %tmp31 to i64
1810 /// %tmp33 = shl i64 %tmp32, 32
1811 /// %ins35 = or i64 %tmp33, %tmp38
1812 /// %tmp43 = bitcast i64 %ins35 to <2 x float>
1813 ///
1814 /// Into two insertelements that do "buildvector{%inc, %inc5}".
1816  InstCombiner &IC) {
1817  VectorType *DestVecTy = cast<VectorType>(CI.getType());
1818  Value *IntInput = CI.getOperand(0);
1819 
1820  SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
1821  if (!collectInsertionElements(IntInput, 0, Elements,
1822  DestVecTy->getElementType(),
1823  IC.getDataLayout().isBigEndian()))
1824  return nullptr;
1825 
1826  // If we succeeded, we know that all of the element are specified by Elements
1827  // or are zero if Elements has a null entry. Recast this as a set of
1828  // insertions.
1829  Value *Result = Constant::getNullValue(CI.getType());
1830  for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
1831  if (!Elements[i]) continue; // Unset element.
1832 
1833  Result = IC.Builder.CreateInsertElement(Result, Elements[i],
1834  IC.Builder.getInt32(i));
1835  }
1836 
1837  return Result;
1838 }
1839 
1840 /// Canonicalize scalar bitcasts of extracted elements into a bitcast of the
1841 /// vector followed by extract element. The backend tends to handle bitcasts of
1842 /// vectors better than bitcasts of scalars because vector registers are
1843 /// usually not type-specific like scalar integer or scalar floating-point.
1845  InstCombiner &IC) {
1846  // TODO: Create and use a pattern matcher for ExtractElementInst.
1847  auto *ExtElt = dyn_cast<ExtractElementInst>(BitCast.getOperand(0));
1848  if (!ExtElt || !ExtElt->hasOneUse())
1849  return nullptr;
1850 
1851  // The bitcast must be to a vectorizable type, otherwise we can't make a new
1852  // type to extract from.
1853  Type *DestType = BitCast.getType();
1854  if (!VectorType::isValidElementType(DestType))
1855  return nullptr;
1856 
1857  unsigned NumElts = ExtElt->getVectorOperandType()->getNumElements();
1858  auto *NewVecType = VectorType::get(DestType, NumElts);
1859  auto *NewBC = IC.Builder.CreateBitCast(ExtElt->getVectorOperand(),
1860  NewVecType, "bc");
1861  return ExtractElementInst::Create(NewBC, ExtElt->getIndexOperand());
1862 }
1863 
1864 /// Change the type of a bitwise logic operation if we can eliminate a bitcast.
1866  InstCombiner::BuilderTy &Builder) {
1867  Type *DestTy = BitCast.getType();
1868  BinaryOperator *BO;
1869  if (!DestTy->isIntOrIntVectorTy() ||
1870  !match(BitCast.getOperand(0), m_OneUse(m_BinOp(BO))) ||
1871  !BO->isBitwiseLogicOp())
1872  return nullptr;
1873 
1874  // FIXME: This transform is restricted to vector types to avoid backend
1875  // problems caused by creating potentially illegal operations. If a fix-up is
1876  // added to handle that situation, we can remove this check.
1877  if (!DestTy->isVectorTy() || !BO->getType()->isVectorTy())
1878  return nullptr;
1879 
1880  Value *X;
1881  if (match(BO->getOperand(0), m_OneUse(m_BitCast(m_Value(X)))) &&
1882  X->getType() == DestTy && !isa<Constant>(X)) {
1883  // bitcast(logic(bitcast(X), Y)) --> logic'(X, bitcast(Y))
1884  Value *CastedOp1 = Builder.CreateBitCast(BO->getOperand(1), DestTy);
1885  return BinaryOperator::Create(BO->getOpcode(), X, CastedOp1);
1886  }
1887 
1888  if (match(BO->getOperand(1), m_OneUse(m_BitCast(m_Value(X)))) &&
1889  X->getType() == DestTy && !isa<Constant>(X)) {
1890  // bitcast(logic(Y, bitcast(X))) --> logic'(bitcast(Y), X)
1891  Value *CastedOp0 = Builder.CreateBitCast(BO->getOperand(0), DestTy);
1892  return BinaryOperator::Create(BO->getOpcode(), CastedOp0, X);
1893  }
1894 
1895  // Canonicalize vector bitcasts to come before vector bitwise logic with a
1896  // constant. This eases recognition of special constants for later ops.
1897  // Example:
1898  // icmp u/s (a ^ signmask), (b ^ signmask) --> icmp s/u a, b
1899  Constant *C;
1900  if (match(BO->getOperand(1), m_Constant(C))) {
1901  // bitcast (logic X, C) --> logic (bitcast X, C')
1902  Value *CastedOp0 = Builder.CreateBitCast(BO->getOperand(0), DestTy);
1903  Value *CastedC = ConstantExpr::getBitCast(C, DestTy);
1904  return BinaryOperator::Create(BO->getOpcode(), CastedOp0, CastedC);
1905  }
1906 
1907  return nullptr;
1908 }
1909 
1910 /// Change the type of a select if we can eliminate a bitcast.
1912  InstCombiner::BuilderTy &Builder) {
1913  Value *Cond, *TVal, *FVal;
1914  if (!match(BitCast.getOperand(0),
1915  m_OneUse(m_Select(m_Value(Cond), m_Value(TVal), m_Value(FVal)))))
1916  return nullptr;
1917 
1918  // A vector select must maintain the same number of elements in its operands.
1919  Type *CondTy = Cond->getType();
1920  Type *DestTy = BitCast.getType();
1921  if (CondTy->isVectorTy()) {
1922  if (!DestTy->isVectorTy())
1923  return nullptr;
1924  if (DestTy->getVectorNumElements() != CondTy->getVectorNumElements())
1925  return nullptr;
1926  }
1927 
1928  // FIXME: This transform is restricted from changing the select between
1929  // scalars and vectors to avoid backend problems caused by creating
1930  // potentially illegal operations. If a fix-up is added to handle that
1931  // situation, we can remove this check.
1932  if (DestTy->isVectorTy() != TVal->getType()->isVectorTy())
1933  return nullptr;
1934 
1935  auto *Sel = cast<Instruction>(BitCast.getOperand(0));
1936  Value *X;
1937  if (match(TVal, m_OneUse(m_BitCast(m_Value(X)))) && X->getType() == DestTy &&
1938  !isa<Constant>(X)) {
1939  // bitcast(select(Cond, bitcast(X), Y)) --> select'(Cond, X, bitcast(Y))
1940  Value *CastedVal = Builder.CreateBitCast(FVal, DestTy);
1941  return SelectInst::Create(Cond, X, CastedVal, "", nullptr, Sel);
1942  }
1943 
1944  if (match(FVal, m_OneUse(m_BitCast(m_Value(X)))) && X->getType() == DestTy &&
1945  !isa<Constant>(X)) {
1946  // bitcast(select(Cond, Y, bitcast(X))) --> select'(Cond, bitcast(Y), X)
1947  Value *CastedVal = Builder.CreateBitCast(TVal, DestTy);
1948  return SelectInst::Create(Cond, CastedVal, X, "", nullptr, Sel);
1949  }
1950 
1951  return nullptr;
1952 }
1953 
1954 /// Check if all users of CI are StoreInsts.
1955 static bool hasStoreUsersOnly(CastInst &CI) {
1956  for (User *U : CI.users()) {
1957  if (!isa<StoreInst>(U))
1958  return false;
1959  }
1960  return true;
1961 }
1962 
1963 /// This function handles following case
1964 ///
1965 /// A -> B cast
1966 /// PHI
1967 /// B -> A cast
1968 ///
1969 /// All the related PHI nodes can be replaced by new PHI nodes with type A.
1970 /// The uses of \p CI can be changed to the new PHI node corresponding to \p PN.
1971 Instruction *InstCombiner::optimizeBitCastFromPhi(CastInst &CI, PHINode *PN) {
1972  // BitCast used by Store can be handled in InstCombineLoadStoreAlloca.cpp.
1973  if (hasStoreUsersOnly(CI))
1974  return nullptr;
1975 
1976  Value *Src = CI.getOperand(0);
1977  Type *SrcTy = Src->getType(); // Type B
1978  Type *DestTy = CI.getType(); // Type A
1979 
1980  SmallVector<PHINode *, 4> PhiWorklist;
1981  SmallSetVector<PHINode *, 4> OldPhiNodes;
1982 
1983  // Find all of the A->B casts and PHI nodes.
1984  // We need to inpect all related PHI nodes, but PHIs can be cyclic, so
1985  // OldPhiNodes is used to track all known PHI nodes, before adding a new
1986  // PHI to PhiWorklist, it is checked against and added to OldPhiNodes first.
1987  PhiWorklist.push_back(PN);
1988  OldPhiNodes.insert(PN);
1989  while (!PhiWorklist.empty()) {
1990  auto *OldPN = PhiWorklist.pop_back_val();
1991  for (Value *IncValue : OldPN->incoming_values()) {
1992  if (isa<Constant>(IncValue))
1993  continue;
1994 
1995  if (auto *LI = dyn_cast<LoadInst>(IncValue)) {
1996  // If there is a sequence of one or more load instructions, each loaded
1997  // value is used as address of later load instruction, bitcast is
1998  // necessary to change the value type, don't optimize it. For
1999  // simplicity we give up if the load address comes from another load.
2000  Value *Addr = LI->getOperand(0);
2001  if (Addr == &CI || isa<LoadInst>(Addr))
2002  return nullptr;
2003  if (LI->hasOneUse() && LI->isSimple())
2004  continue;
2005  // If a LoadInst has more than one use, changing the type of loaded
2006  // value may create another bitcast.
2007  return nullptr;
2008  }
2009 
2010  if (auto *PNode = dyn_cast<PHINode>(IncValue)) {
2011  if (OldPhiNodes.insert(PNode))
2012  PhiWorklist.push_back(PNode);
2013  continue;
2014  }
2015 
2016  auto *BCI = dyn_cast<BitCastInst>(IncValue);
2017  // We can't handle other instructions.
2018  if (!BCI)
2019  return nullptr;
2020 
2021  // Verify it's a A->B cast.
2022  Type *TyA = BCI->getOperand(0)->getType();
2023  Type *TyB = BCI->getType();
2024  if (TyA != DestTy || TyB != SrcTy)
2025  return nullptr;
2026  }
2027  }
2028 
2029  // For each old PHI node, create a corresponding new PHI node with a type A.
2031  for (auto *OldPN : OldPhiNodes) {
2032  Builder.SetInsertPoint(OldPN);
2033  PHINode *NewPN = Builder.CreatePHI(DestTy, OldPN->getNumOperands());
2034  NewPNodes[OldPN] = NewPN;
2035  }
2036 
2037  // Fill in the operands of new PHI nodes.
2038  for (auto *OldPN : OldPhiNodes) {
2039  PHINode *NewPN = NewPNodes[OldPN];
2040  for (unsigned j = 0, e = OldPN->getNumOperands(); j != e; ++j) {
2041  Value *V = OldPN->getOperand(j);
2042  Value *NewV = nullptr;
2043  if (auto *C = dyn_cast<Constant>(V)) {
2044  NewV = ConstantExpr::getBitCast(C, DestTy);
2045  } else if (auto *LI = dyn_cast<LoadInst>(V)) {
2046  Builder.SetInsertPoint(LI->getNextNode());
2047  NewV = Builder.CreateBitCast(LI, DestTy);
2048  Worklist.Add(LI);
2049  } else if (auto *BCI = dyn_cast<BitCastInst>(V)) {
2050  NewV = BCI->getOperand(0);
2051  } else if (auto *PrevPN = dyn_cast<PHINode>(V)) {
2052  NewV = NewPNodes[PrevPN];
2053  }
2054  assert(NewV);
2055  NewPN->addIncoming(NewV, OldPN->getIncomingBlock(j));
2056  }
2057  }
2058 
2059  // If there is a store with type B, change it to type A.
2060  for (User *U : PN->users()) {
2061  auto *SI = dyn_cast<StoreInst>(U);
2062  if (SI && SI->isSimple() && SI->getOperand(0) == PN) {
2063  Builder.SetInsertPoint(SI);
2064  auto *NewBC =
2065  cast<BitCastInst>(Builder.CreateBitCast(NewPNodes[PN], SrcTy));
2066  SI->setOperand(0, NewBC);
2067  Worklist.Add(SI);
2068  assert(hasStoreUsersOnly(*NewBC));
2069  }
2070  }
2071 
2072  return replaceInstUsesWith(CI, NewPNodes[PN]);
2073 }
2074 
2076  // If the operands are integer typed then apply the integer transforms,
2077  // otherwise just apply the common ones.
2078  Value *Src = CI.getOperand(0);
2079  Type *SrcTy = Src->getType();
2080  Type *DestTy = CI.getType();
2081 
2082  // Get rid of casts from one type to the same type. These are useless and can
2083  // be replaced by the operand.
2084  if (DestTy == Src->getType())
2085  return replaceInstUsesWith(CI, Src);
2086 
2087  if (PointerType *DstPTy = dyn_cast<PointerType>(DestTy)) {
2088  PointerType *SrcPTy = cast<PointerType>(SrcTy);
2089  Type *DstElTy = DstPTy->getElementType();
2090  Type *SrcElTy = SrcPTy->getElementType();
2091 
2092  // If we are casting a alloca to a pointer to a type of the same
2093  // size, rewrite the allocation instruction to allocate the "right" type.
2094  // There is no need to modify malloc calls because it is their bitcast that
2095  // needs to be cleaned up.
2096  if (AllocaInst *AI = dyn_cast<AllocaInst>(Src))
2097  if (Instruction *V = PromoteCastOfAllocation(CI, *AI))
2098  return V;
2099 
2100  // When the type pointed to is not sized the cast cannot be
2101  // turned into a gep.
2102  Type *PointeeType =
2103  cast<PointerType>(Src->getType()->getScalarType())->getElementType();
2104  if (!PointeeType->isSized())
2105  return nullptr;
2106 
2107  // If the source and destination are pointers, and this cast is equivalent
2108  // to a getelementptr X, 0, 0, 0... turn it into the appropriate gep.
2109  // This can enhance SROA and other transforms that want type-safe pointers.
2110  unsigned NumZeros = 0;
2111  while (SrcElTy != DstElTy &&
2112  isa<CompositeType>(SrcElTy) && !SrcElTy->isPointerTy() &&
2113  SrcElTy->getNumContainedTypes() /* not "{}" */) {
2114  SrcElTy = cast<CompositeType>(SrcElTy)->getTypeAtIndex(0U);
2115  ++NumZeros;
2116  }
2117 
2118  // If we found a path from the src to dest, create the getelementptr now.
2119  if (SrcElTy == DstElTy) {
2120  SmallVector<Value *, 8> Idxs(NumZeros + 1, Builder.getInt32(0));
2121  return GetElementPtrInst::CreateInBounds(Src, Idxs);
2122  }
2123  }
2124 
2125  if (VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
2126  if (DestVTy->getNumElements() == 1 && !SrcTy->isVectorTy()) {
2127  Value *Elem = Builder.CreateBitCast(Src, DestVTy->getElementType());
2128  return InsertElementInst::Create(UndefValue::get(DestTy), Elem,
2130  // FIXME: Canonicalize bitcast(insertelement) -> insertelement(bitcast)
2131  }
2132 
2133  if (isa<IntegerType>(SrcTy)) {
2134  // If this is a cast from an integer to vector, check to see if the input
2135  // is a trunc or zext of a bitcast from vector. If so, we can replace all
2136  // the casts with a shuffle and (potentially) a bitcast.
2137  if (isa<TruncInst>(Src) || isa<ZExtInst>(Src)) {
2138  CastInst *SrcCast = cast<CastInst>(Src);
2139  if (BitCastInst *BCIn = dyn_cast<BitCastInst>(SrcCast->getOperand(0)))
2140  if (isa<VectorType>(BCIn->getOperand(0)->getType()))
2141  if (Instruction *I = optimizeVectorResize(BCIn->getOperand(0),
2142  cast<VectorType>(DestTy), *this))
2143  return I;
2144  }
2145 
2146  // If the input is an 'or' instruction, we may be doing shifts and ors to
2147  // assemble the elements of the vector manually. Try to rip the code out
2148  // and replace it with insertelements.
2149  if (Value *V = optimizeIntegerToVectorInsertions(CI, *this))
2150  return replaceInstUsesWith(CI, V);
2151  }
2152  }
2153 
2154  if (VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
2155  if (SrcVTy->getNumElements() == 1) {
2156  // If our destination is not a vector, then make this a straight
2157  // scalar-scalar cast.
2158  if (!DestTy->isVectorTy()) {
2159  Value *Elem =
2160  Builder.CreateExtractElement(Src,
2162  return CastInst::Create(Instruction::BitCast, Elem, DestTy);
2163  }
2164 
2165  // Otherwise, see if our source is an insert. If so, then use the scalar
2166  // component directly.
2167  if (InsertElementInst *IEI =
2168  dyn_cast<InsertElementInst>(CI.getOperand(0)))
2169  return CastInst::Create(Instruction::BitCast, IEI->getOperand(1),
2170  DestTy);
2171  }
2172  }
2173 
2174  if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(Src)) {
2175  // Okay, we have (bitcast (shuffle ..)). Check to see if this is
2176  // a bitcast to a vector with the same # elts.
2177  if (SVI->hasOneUse() && DestTy->isVectorTy() &&
2178  DestTy->getVectorNumElements() == SVI->getType()->getNumElements() &&
2179  SVI->getType()->getNumElements() ==
2180  SVI->getOperand(0)->getType()->getVectorNumElements()) {
2181  BitCastInst *Tmp;
2182  // If either of the operands is a cast from CI.getType(), then
2183  // evaluating the shuffle in the casted destination's type will allow
2184  // us to eliminate at least one cast.
2185  if (((Tmp = dyn_cast<BitCastInst>(SVI->getOperand(0))) &&
2186  Tmp->getOperand(0)->getType() == DestTy) ||
2187  ((Tmp = dyn_cast<BitCastInst>(SVI->getOperand(1))) &&
2188  Tmp->getOperand(0)->getType() == DestTy)) {
2189  Value *LHS = Builder.CreateBitCast(SVI->getOperand(0), DestTy);
2190  Value *RHS = Builder.CreateBitCast(SVI->getOperand(1), DestTy);
2191  // Return a new shuffle vector. Use the same element ID's, as we
2192  // know the vector types match #elts.
2193  return new ShuffleVectorInst(LHS, RHS, SVI->getOperand(2));
2194  }
2195  }
2196  }
2197 
2198  // Handle the A->B->A cast, and there is an intervening PHI node.
2199  if (PHINode *PN = dyn_cast<PHINode>(Src))
2200  if (Instruction *I = optimizeBitCastFromPhi(CI, PN))
2201  return I;
2202 
2203  if (Instruction *I = canonicalizeBitCastExtElt(CI, *this))
2204  return I;
2205 
2206  if (Instruction *I = foldBitCastBitwiseLogic(CI, Builder))
2207  return I;
2208 
2209  if (Instruction *I = foldBitCastSelect(CI, Builder))
2210  return I;
2211 
2212  if (SrcTy->isPointerTy())
2213  return commonPointerCastTransforms(CI);
2214  return commonCastTransforms(CI);
2215 }
2216 
2218  // If the destination pointer element type is not the same as the source's
2219  // first do a bitcast to the destination type, and then the addrspacecast.
2220  // This allows the cast to be exposed to other transforms.
2221  Value *Src = CI.getOperand(0);
2222  PointerType *SrcTy = cast<PointerType>(Src->getType()->getScalarType());
2223  PointerType *DestTy = cast<PointerType>(CI.getType()->getScalarType());
2224 
2225  Type *DestElemTy = DestTy->getElementType();
2226  if (SrcTy->getElementType() != DestElemTy) {
2227  Type *MidTy = PointerType::get(DestElemTy, SrcTy->getAddressSpace());
2228  if (VectorType *VT = dyn_cast<VectorType>(CI.getType())) {
2229  // Handle vectors of pointers.
2230  MidTy = VectorType::get(MidTy, VT->getNumElements());
2231  }
2232 
2233  Value *NewBitCast = Builder.CreateBitCast(Src, MidTy);
2234  return new AddrSpaceCastInst(NewBitCast, CI.getType());
2235  }
2236 
2237  return commonPointerCastTransforms(CI);
2238 }
BinaryOp_match< LHS, RHS, Instruction::And > m_And(const LHS &L, const RHS &R)
Definition: PatternMatch.h:550
uint64_t CallInst * C
BinOpPred_match< LHS, RHS, is_right_shift_op > m_Shr(const LHS &L, const RHS &R)
Matches logical shift operations.
Definition: PatternMatch.h:734
void push_back(const T &Elt)
Definition: SmallVector.h:212
void copyFastMathFlags(FastMathFlags FMF)
Convenience function for transferring all fast-math flag values to this instruction, which must be an operator which supports these flags.
class_match< Value > m_Value()
Match an arbitrary value and ignore it.
Definition: PatternMatch.h:72
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
Type * getSrcTy() const
Return the source type, as a convenience.
Definition: InstrTypes.h:825
static IntegerType * getInt1Ty(LLVMContext &C)
Definition: Type.cpp:173
void addIncoming(Value *V, BasicBlock *BB)
Add an incoming value to the end of the PHI list.
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
DiagnosticInfoOptimizationBase::Argument NV
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
BinaryOps getOpcode() const
Definition: InstrTypes.h:523
Instruction * visitBitCast(BitCastInst &CI)
bool isSized(SmallPtrSetImpl< Type *> *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:262
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:136
void setAlignment(unsigned Align)
This class represents zero extension of integer types.
Instruction * commonCastTransforms(CastInst &CI)
Implement the transforms common to all CastInst visitors.
This class represents a function call, abstracting a target machine&#39;s calling convention.
static APInt getLowBitsSet(unsigned numBits, unsigned loBitsSet)
Get a value with low bits set.
Definition: APInt.h:641
class_match< Constant > m_Constant()
Match an arbitrary Constant and ignore it.
Definition: PatternMatch.h:91
static PointerType * get(Type *ElementType, unsigned AddressSpace)
This constructs a pointer to an object of the specified type in a numbered address space...
Definition: Type.cpp:617
static uint64_t round(uint64_t Acc, uint64_t Input)
Definition: xxhash.cpp:57
const Value * getTrueValue() const
BinaryOp_match< LHS, RHS, Instruction::AShr > m_AShr(const LHS &L, const RHS &R)
Definition: PatternMatch.h:580
This instruction constructs a fixed permutation of two input vectors.
static SelectInst * Create(Value *C, Value *S1, Value *S2, const Twine &NameStr="", Instruction *InsertBefore=nullptr, Instruction *MDFrom=nullptr)
LLVMContext & getContext() const
All values hold a context through their type.
Definition: Value.cpp:697
static bool isEquality(Predicate P)
Return true if this predicate is either EQ or NE.
APInt trunc(unsigned width) const
Truncate to new width.
Definition: APInt.cpp:818
static Value * lookThroughFPExtensions(Value *V)
Look through floating-point extensions until we get the source value.
static CallInst * Create(Value *Func, ArrayRef< Value *> Args, ArrayRef< OperandBundleDef > Bundles=None, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
This class represents a sign extension of integer types.
Hexagon Common GEP
bool isVectorTy() const
True if this is an instance of VectorType.
Definition: Type.h:227
static bool isBitwiseLogicOp(unsigned Opcode)
Determine if the Opcode is and/or/xor.
Definition: Instruction.h:156
Instruction * visitUIToFP(CastInst &CI)
unsigned getBitWidth() const
Return the number of bits in the APInt.
Definition: APInt.h:1488
static Constant * getNullValue(Type *Ty)
Constructor to create a &#39;0&#39; constant of arbitrary type.
Definition: Constants.cpp:207
Instruction * visitFPExt(CastInst &CI)
Instruction * FoldItoFPtoI(Instruction &FI)
unsigned countTrailingZeros() const
Count the number of trailing zero bits.
Definition: APInt.h:1611
bool match(Val *V, const Pattern &P)
Definition: PatternMatch.h:49
static InsertElementInst * Create(Value *Vec, Value *NewElt, Value *Idx, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Instruction * visitFPToUI(FPToUIInst &FI)
This class represents a conversion between pointers from one address space to another.
static Constant * getIntegerCast(Constant *C, Type *Ty, bool isSigned)
Create a ZExt, Bitcast or Trunc for integer -> integer casts.
Definition: Constants.cpp:1518
BinaryOp_match< LHS, RHS, Instruction::Xor > m_Xor(const LHS &L, const RHS &R)
Definition: PatternMatch.h:562
This class represents the LLVM &#39;select&#39; instruction.
unsigned getAlignment() const
Return the alignment of the memory that is being allocated by the instruction.
Definition: Instructions.h:109
static bool hasStoreUsersOnly(CastInst &CI)
Check if all users of CI are StoreInsts.
This is the base class for all instructions that perform data casts.
Definition: InstrTypes.h:560
PointerType * getType() const
Overload to return most specific pointer type.
Definition: Instructions.h:97
&#39;undef&#39; values are things that do not have specified contents.
Definition: Constants.h:1247
static Constant * getLShr(Constant *C1, Constant *C2, bool isExact=false)
Definition: Constants.cpp:2193
static bool canEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear, InstCombiner &IC, Instruction *CxtI)
Determine if the specified value can be computed in the specified wider type and produce the same low...
CastClass_match< OpTy, Instruction::Trunc > m_Trunc(const OpTy &Op)
Matches Trunc.
Definition: PatternMatch.h:888
bool isIntegerTy() const
True if this is an instance of IntegerType.
Definition: Type.h:197
The core instruction combiner logic.
static bool canEvaluateTruncated(Value *V, Type *Ty, InstCombiner &IC, Instruction *CxtI)
Return true if we can evaluate the specified expression tree as type Ty instead of its larger type...
static Instruction * canonicalizeBitCastExtElt(BitCastInst &BitCast, InstCombiner &IC)
Canonicalize scalar bitcasts of extracted elements into a bitcast of the vector followed by extract e...
Instruction * visitIntToPtr(IntToPtrInst &CI)
static Instruction * optimizeVectorResize(Value *InVal, VectorType *DestTy, InstCombiner &IC)
This input value (which is known to have vector type) is being zero extended or truncated to the spec...
Instruction * visitAddrSpaceCast(AddrSpaceCastInst &CI)
uint64_t getNumElements() const
Definition: DerivedTypes.h:359
static Type * getPPC_FP128Ty(LLVMContext &C)
Definition: Type.cpp:170
static unsigned getTypeSizeIndex(unsigned Value, Type *Ty)
This class represents a cast from a pointer to an integer.
unsigned getPointerAddressSpace() const
Returns the address space of the pointer operand.
Constant * ConstantFoldConstant(const Constant *C, const DataLayout &DL, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldConstant - Attempt to fold the constant using the specified DataLayout.
static Constant * getZExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1570
Value * CreateBitCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1444
static bool isMultipleOfTypeSize(unsigned Value, Type *Ty)
Instruction::CastOps getOpcode() const
Return the opcode of this CastInst.
Definition: InstrTypes.h:820
#define F(x, y, z)
Definition: MD5.cpp:55
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:245
bool insert(const value_type &X)
Insert a new element into the SetVector.
Definition: SetVector.h:142
opStatus convert(const fltSemantics &ToSemantics, roundingMode RM, bool *losesInfo)
Definition: APFloat.cpp:4441
match_combine_or< LTy, RTy > m_CombineOr(const LTy &L, const RTy &R)
Combine two pattern matchers matching L || R.
Definition: PatternMatch.h:125
CastClass_match< OpTy, Instruction::ZExt > m_ZExt(const OpTy &Op)
Matches ZExt.
Definition: PatternMatch.h:900
bool isUsedWithInAlloca() const
Return true if this alloca is used as an inalloca argument to a call.
Definition: Instructions.h:121
static bool isValidElementType(Type *ElemTy)
Return true if the specified type is valid as a element type.
Definition: Type.cpp:608
static bool collectInsertionElements(Value *V, unsigned Shift, SmallVectorImpl< Value *> &Elements, Type *VecEltTy, bool isBigEndian)
V is a value which is inserted into a vector of VecEltTy.
This class represents a no-op cast from one type to another.
class_match< ConstantInt > m_ConstantInt()
Match an arbitrary ConstantInt and ignore it.
Definition: PatternMatch.h:83
const APInt & getValue() const
Return the constant as an APInt value reference.
Definition: Constants.h:138
unsigned getOpcode() const
Returns a member of one of the enums like Instruction::Add.
Definition: Instruction.h:121
An instruction for storing to memory.
Definition: Instructions.h:306
bool isIntOrIntVectorTy() const
Return true if this is an integer type or a vector of integer types.
Definition: Type.h:203
int getFPMantissaWidth() const
Return the width of the mantissa of this type.
Definition: Type.cpp:134
This class represents a cast from floating point to signed integer.
SelectClass_match< Cond, LHS, RHS > m_Select(const Cond &C, const LHS &L, const RHS &R)
Definition: PatternMatch.h:845
static Value * optimizeIntegerToVectorInsertions(BitCastInst &CI, InstCombiner &IC)
If the input is an &#39;or&#39; instruction, we may be doing shifts and ors to assemble the elements of the v...
static const fltSemantics & IEEEdouble() LLVM_READNONE
Definition: APFloat.cpp:122
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:290
static Instruction * foldBitCastSelect(BitCastInst &BitCast, InstCombiner::BuilderTy &Builder)
Change the type of a select if we can eliminate a bitcast.
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:975
This class represents a truncation of integer types.
Value * getOperand(unsigned i) const
Definition: User.h:154
Class to represent pointers.
Definition: DerivedTypes.h:467
SelectPatternResult matchSelectPattern(Value *V, Value *&LHS, Value *&RHS, Instruction::CastOps *CastOp=nullptr)
Pattern match integer [SU]MIN, [SU]MAX and ABS idioms, returning the kind and providing the out param...
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return &#39;this&#39;.
Definition: Type.h:301
const DataLayout & getDataLayout() const
static APInt getHighBitsSet(unsigned numBits, unsigned hiBitsSet)
Get a value with high bits set.
Definition: APInt.h:629
static Constant * getBitCast(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1678
an instruction for type-safe pointer arithmetic to access elements of arrays and structs ...
Definition: Instructions.h:837
OneUse_match< T > m_OneUse(const T &SubPattern)
Definition: PatternMatch.h:63
#define P(N)
BinaryOp_match< LHS, RHS, Instruction::LShr > m_LShr(const LHS &L, const RHS &R)
Definition: PatternMatch.h:574
static Instruction * foldBitCastBitwiseLogic(BitCastInst &BitCast, InstCombiner::BuilderTy &Builder)
Change the type of a bitwise logic operation if we can eliminate a bitcast.
This instruction inserts a single (scalar) element into a VectorType value.
bool isAllOnesValue() const
Determine if all bits are set.
Definition: APInt.h:389
uint64_t getZExtValue() const
Return the constant as a 64-bit unsigned integer value after it has been zero extended as appropriate...
Definition: Constants.h:149
unsigned countPopulation() const
Count the number of bits set.
Definition: APInt.h:1637
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
bool ult(const APInt &RHS) const
Unsigned less than comparison.
Definition: APInt.h:1164
CastClass_match< OpTy, Instruction::BitCast > m_BitCast(const OpTy &Op)
Matches BitCast.
Definition: PatternMatch.h:876
This is an important base class in LLVM.
Definition: Constant.h:42
unsigned getNumContainedTypes() const
Return the number of types in the derived type.
Definition: Type.h:336
constexpr char Args[]
Key for Kernel::Metadata::mArgs.
void setUsedWithInAlloca(bool V)
Specify whether this alloca is used to represent the arguments to a call.
Definition: Instructions.h:126
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:221
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)
Return true if &#39;V & Mask&#39; is known to be zero.
#define A
Definition: LargeTest.cpp:12
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:264
specificval_ty m_Specific(const Value *V)
Match if we have a specific specified value.
Definition: PatternMatch.h:358
BinaryOp_match< LHS, RHS, Instruction::Shl > m_Shl(const LHS &L, const RHS &R)
Definition: PatternMatch.h:568
static Value * decomposeSimpleLinearExpr(Value *Val, unsigned &Scale, uint64_t &Offset)
Analyze &#39;Val&#39;, seeing if it is a simple linear expression.
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:860
Utility class for integer arithmetic operators which may exhibit overflow - Add, Sub, and Mul.
Definition: Operator.h:67
unsigned getAddressSpace() const
Return the address space of the Pointer type.
Definition: DerivedTypes.h:495
class_match< BinaryOperator > m_BinOp()
Match an arbitrary binary operation and ignore it.
Definition: PatternMatch.h:75
unsigned getAddressSpace() const
Returns the address space of this instruction&#39;s pointer type.
Class to represent integer types.
Definition: DerivedTypes.h:40
This class represents a cast from an integer to a pointer.
static Constant * getAllOnesValue(Type *Ty)
Get the all ones value.
Definition: Constants.cpp:261
Instruction * visitFPToSI(FPToSIInst &FI)
static UndefValue * get(Type *T)
Static factory methods - Return an &#39;undef&#39; object of the specified type.
Definition: Constants.cpp:1320
const AMDGPUAS & AS
const Value * getArraySize() const
Get the number of elements allocated.
Definition: Instructions.h:93
Value * getIncomingValue(unsigned i) const
Return incoming value number x.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Value * CreateTrunc(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1380
Type * getAllocatedType() const
Return the type that is being allocated by the instruction.
Definition: Instructions.h:102
signed greater than
Definition: InstrTypes.h:887
const APFloat & getValueAPF() const
Definition: Constants.h:294
CastClass_match< OpTy, Instruction::SExt > m_SExt(const OpTy &Op)
Matches SExt.
Definition: PatternMatch.h:894
static BinaryOperator * CreateFNeg(Value *Op, const Twine &Name="", Instruction *InsertBefore=nullptr)
bool isPtrOrPtrVectorTy() const
Return true if this is a pointer type or a vector of pointer types.
Definition: Type.h:224
static IntegerType * get(LLVMContext &C, unsigned NumBits)
This static method is the primary way of constructing an IntegerType.
Definition: Type.cpp:240
static const fltSemantics & IEEEsingle() LLVM_READNONE
Definition: APFloat.cpp:119
static CastInst * CreateIntegerCast(Value *S, Type *Ty, bool isSigned, const Twine &Name="", Instruction *InsertBefore=nullptr)
Create a ZExt, BitCast, or Trunc for int -> int casts.
A SetVector that performs no allocations if smaller than a certain size.
Definition: SetVector.h:298
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
static const fltSemantics & IEEEhalf() LLVM_READNONE
Definition: APFloat.cpp:116
SelectPatternFlavor Flavor
unsigned ComputeNumSignBits(const Value *Op, const DataLayout &DL, unsigned Depth=0, AssumptionCache *AC=nullptr, const Instruction *CxtI=nullptr, const DominatorTree *DT=nullptr)
Return the number of times the sign bit of the register is replicated into the other bits...
static Instruction * shrinkInsertElt(CastInst &Trunc, InstCombiner::BuilderTy &Builder)
Try to narrow the width of an insert element.
unsigned getScalarSizeInBits() const LLVM_READONLY
If this is a vector type, return the getPrimitiveSizeInBits value for the element type...
Definition: Type.cpp:130
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:864
Instruction * user_back()
Specialize the methods defined in Value, as we know that an instruction can only be used by other ins...
Definition: Instruction.h:63
Value * CreateInsertElement(Value *Vec, Value *NewElt, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:1722
static Instruction * shrinkSplatShuffle(TruncInst &Trunc, InstCombiner::BuilderTy &Builder)
Try to narrow the width of a splat shuffle.
Instruction * visitSExt(SExtInst &CI)
signed less than
Definition: InstrTypes.h:889
This class represents a cast from floating point to unsigned integer.
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:385
Instruction * visitZExt(ZExtInst &CI)
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:308
static CastInst * CreateFPCast(Value *S, Type *Ty, const Twine &Name="", Instruction *InsertBefore=nullptr)
Create an FPExt, BitCast, or FPTrunc for fp -> fp casts.
static unsigned isEliminableCastPair(Instruction::CastOps firstOpcode, Instruction::CastOps secondOpcode, Type *SrcTy, Type *MidTy, Type *DstTy, Type *SrcIntPtrTy, Type *MidIntPtrTy, Type *DstIntPtrTy)
Determine how a pair of casts can be eliminated, if they can be at all.
static Constant * getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1542
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:560
static PHINode * Create(Type *Ty, unsigned NumReservedValues, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Constructors - NumReservedValues is a hint for the number of incoming edges that this phi node will h...
static Constant * get(Type *Ty, double V)
This returns a ConstantFP, or a vector containing a splat of a ConstantFP, for the specified value in...
Definition: Constants.cpp:623
Type * getDestTy() const
Return the destination type, as a convenience.
Definition: InstrTypes.h:827
unsigned getNumIncomingValues() const
Return the number of incoming edges.
bool uge(const APInt &RHS) const
Unsigned greater or equal comparison.
Definition: APInt.h:1272
void setOperand(unsigned i, Value *Val)
Definition: User.h:159
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
unsigned getVectorNumElements() const
Definition: DerivedTypes.h:462
Class to represent vector types.
Definition: DerivedTypes.h:393
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
Definition: Instruction.cpp:57
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:457
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.
iterator_range< user_iterator > users()
Definition: Value.h:395
bool hasNoSignedWrap() const
Test whether this operation is known to never undergo signed overflow, aka the nsw property...
Definition: Operator.h:96
const Value * getFalseValue() const
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 ...
Predicate getPredicate() const
Return the predicate for this instruction.
Definition: InstrTypes.h:934
Instruction * visitTrunc(TruncInst &CI)
static IntegerType * getInt32Ty(LLVMContext &C)
Definition: Type.cpp:176
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:61
Instruction * visitSIToFP(CastInst &CI)
static bool isFNeg(const Value *V, bool IgnoreZeroSign=false)
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:218
BasicBlock * getIncomingBlock(unsigned i) const
Return incoming basic block number i.
#define I(x, y, z)
Definition: MD5.cpp:58
static Instruction * foldVecTruncToExtElt(TruncInst &Trunc, InstCombiner &IC)
Given a vector that is bitcast to an integer, optionally logically right-shifted, and truncated...
static Constant * fitsInFPType(ConstantFP *CFP, const fltSemantics &Sem)
Return a Constant* for the specified floating-point constant if it fits in the specified FP type with...
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:323
This instruction extracts a single (scalar) element from a VectorType value.
static volatile int Zero
Value * CreateCast(Instruction::CastOps Op, Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1476
static GetElementPtrInst * CreateInBounds(Value *Ptr, ArrayRef< Value *> IdxList, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
Create an "inbounds" getelementptr.
Definition: Instructions.h:897
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This class represents a truncation of floating point types.
unsigned getPrimitiveSizeInBits() const LLVM_READONLY
Return the basic size of this type if it is a primitive type.
Definition: Type.cpp:115
LLVM Value Representation.
Definition: Value.h:73
This file provides internal interfaces used to implement the InstCombine.
static VectorType * get(Type *ElementType, unsigned NumElements)
This static method is the primary way to construct an VectorType.
Definition: Type.cpp:593
static bool canEvaluateSExtd(Value *V, Type *Ty)
Return true if we can take the specified value and return it as type Ty without inserting any new cas...
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:81
Instruction * commonPointerCastTransforms(CastInst &CI)
Implement the transforms for cast of pointer (bitcast/ptrtoint)
#define DEBUG(X)
Definition: Debug.h:118
Type * getElementType() const
Definition: DerivedTypes.h:360
bool hasOneUse() const
Return true if there is exactly one user of this value.
Definition: Value.h:408
bool isNonNegative() const
Returns true if this value is known to be non-negative.
Definition: KnownBits.h:99
unsigned countLeadingZeros() const
The APInt version of the countLeadingZeros functions in MathExtras.h.
Definition: APInt.h:1575
bool isBigEndian() const
Definition: DataLayout.h:217
static Constant * get(LLVMContext &Context, ArrayRef< uint8_t > Elts)
get() constructors - Return a constant with vector type with an element count and element type matchi...
Definition: Constants.cpp:2467
Instruction * visitPtrToInt(PtrToIntInst &CI)
static ExtractElementInst * Create(Value *Vec, Value *Idx, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
op_range incoming_values()
This class represents an extension of floating point types.
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)
Determine which bits of V are known to be either zero or one and return them in the KnownZero/KnownOn...
Type * getElementType() const
Definition: DerivedTypes.h:486
bool isNullValue() const
Determine if all bits are clear.
Definition: APInt.h:399
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:44
an instruction to allocate memory on the stack
Definition: Instructions.h:60
Instruction * visitFPTrunc(FPTruncInst &CI)
bool hasNoUnsignedWrap() const
Test whether this operation is known to never undergo unsigned overflow, aka the nuw property...
Definition: Operator.h:90