LLVM  6.0.0svn
ConstantFolding.cpp
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1 //===-- ConstantFolding.cpp - Fold instructions into constants ------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines routines for folding instructions into constants.
11 //
12 // Also, to supplement the basic IR ConstantExpr simplifications,
13 // this file defines some additional folding routines that can make use of
14 // DataLayout information. These functions cannot go in IR due to library
15 // dependency issues.
16 //
17 //===----------------------------------------------------------------------===//
18 
20 #include "llvm/ADT/APFloat.h"
21 #include "llvm/ADT/APInt.h"
22 #include "llvm/ADT/ArrayRef.h"
23 #include "llvm/ADT/DenseMap.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/ADT/SmallVector.h"
26 #include "llvm/ADT/StringRef.h"
29 #include "llvm/Config/config.h"
30 #include "llvm/IR/Constant.h"
31 #include "llvm/IR/Constants.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/DerivedTypes.h"
34 #include "llvm/IR/Function.h"
35 #include "llvm/IR/GlobalValue.h"
36 #include "llvm/IR/GlobalVariable.h"
37 #include "llvm/IR/InstrTypes.h"
38 #include "llvm/IR/Instruction.h"
39 #include "llvm/IR/Instructions.h"
40 #include "llvm/IR/Operator.h"
41 #include "llvm/IR/Type.h"
42 #include "llvm/IR/Value.h"
43 #include "llvm/Support/Casting.h"
45 #include "llvm/Support/KnownBits.h"
47 #include <cassert>
48 #include <cerrno>
49 #include <cfenv>
50 #include <cmath>
51 #include <cstddef>
52 #include <cstdint>
53 
54 using namespace llvm;
55 
56 namespace {
57 
58 //===----------------------------------------------------------------------===//
59 // Constant Folding internal helper functions
60 //===----------------------------------------------------------------------===//
61 
62 static Constant *foldConstVectorToAPInt(APInt &Result, Type *DestTy,
63  Constant *C, Type *SrcEltTy,
64  unsigned NumSrcElts,
65  const DataLayout &DL) {
66  // Now that we know that the input value is a vector of integers, just shift
67  // and insert them into our result.
68  unsigned BitShift = DL.getTypeSizeInBits(SrcEltTy);
69  for (unsigned i = 0; i != NumSrcElts; ++i) {
70  Constant *Element;
71  if (DL.isLittleEndian())
72  Element = C->getAggregateElement(NumSrcElts - i - 1);
73  else
74  Element = C->getAggregateElement(i);
75 
76  if (Element && isa<UndefValue>(Element)) {
77  Result <<= BitShift;
78  continue;
79  }
80 
81  auto *ElementCI = dyn_cast_or_null<ConstantInt>(Element);
82  if (!ElementCI)
83  return ConstantExpr::getBitCast(C, DestTy);
84 
85  Result <<= BitShift;
86  Result |= ElementCI->getValue().zextOrSelf(Result.getBitWidth());
87  }
88 
89  return nullptr;
90 }
91 
92 /// Constant fold bitcast, symbolically evaluating it with DataLayout.
93 /// This always returns a non-null constant, but it may be a
94 /// ConstantExpr if unfoldable.
95 Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
96  // Catch the obvious splat cases.
97  if (C->isNullValue() && !DestTy->isX86_MMXTy())
98  return Constant::getNullValue(DestTy);
99  if (C->isAllOnesValue() && !DestTy->isX86_MMXTy() &&
100  !DestTy->isPtrOrPtrVectorTy()) // Don't get ones for ptr types!
101  return Constant::getAllOnesValue(DestTy);
102 
103  if (auto *VTy = dyn_cast<VectorType>(C->getType())) {
104  // Handle a vector->scalar integer/fp cast.
105  if (isa<IntegerType>(DestTy) || DestTy->isFloatingPointTy()) {
106  unsigned NumSrcElts = VTy->getNumElements();
107  Type *SrcEltTy = VTy->getElementType();
108 
109  // If the vector is a vector of floating point, convert it to vector of int
110  // to simplify things.
111  if (SrcEltTy->isFloatingPointTy()) {
112  unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
113  Type *SrcIVTy =
114  VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElts);
115  // Ask IR to do the conversion now that #elts line up.
116  C = ConstantExpr::getBitCast(C, SrcIVTy);
117  }
118 
119  APInt Result(DL.getTypeSizeInBits(DestTy), 0);
120  if (Constant *CE = foldConstVectorToAPInt(Result, DestTy, C,
121  SrcEltTy, NumSrcElts, DL))
122  return CE;
123 
124  if (isa<IntegerType>(DestTy))
125  return ConstantInt::get(DestTy, Result);
126 
127  APFloat FP(DestTy->getFltSemantics(), Result);
128  return ConstantFP::get(DestTy->getContext(), FP);
129  }
130  }
131 
132  // The code below only handles casts to vectors currently.
133  auto *DestVTy = dyn_cast<VectorType>(DestTy);
134  if (!DestVTy)
135  return ConstantExpr::getBitCast(C, DestTy);
136 
137  // If this is a scalar -> vector cast, convert the input into a <1 x scalar>
138  // vector so the code below can handle it uniformly.
139  if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
140  Constant *Ops = C; // don't take the address of C!
141  return FoldBitCast(ConstantVector::get(Ops), DestTy, DL);
142  }
143 
144  // If this is a bitcast from constant vector -> vector, fold it.
145  if (!isa<ConstantDataVector>(C) && !isa<ConstantVector>(C))
146  return ConstantExpr::getBitCast(C, DestTy);
147 
148  // If the element types match, IR can fold it.
149  unsigned NumDstElt = DestVTy->getNumElements();
150  unsigned NumSrcElt = C->getType()->getVectorNumElements();
151  if (NumDstElt == NumSrcElt)
152  return ConstantExpr::getBitCast(C, DestTy);
153 
154  Type *SrcEltTy = C->getType()->getVectorElementType();
155  Type *DstEltTy = DestVTy->getElementType();
156 
157  // Otherwise, we're changing the number of elements in a vector, which
158  // requires endianness information to do the right thing. For example,
159  // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
160  // folds to (little endian):
161  // <4 x i32> <i32 0, i32 0, i32 1, i32 0>
162  // and to (big endian):
163  // <4 x i32> <i32 0, i32 0, i32 0, i32 1>
164 
165  // First thing is first. We only want to think about integer here, so if
166  // we have something in FP form, recast it as integer.
167  if (DstEltTy->isFloatingPointTy()) {
168  // Fold to an vector of integers with same size as our FP type.
169  unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits();
170  Type *DestIVTy =
171  VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt);
172  // Recursively handle this integer conversion, if possible.
173  C = FoldBitCast(C, DestIVTy, DL);
174 
175  // Finally, IR can handle this now that #elts line up.
176  return ConstantExpr::getBitCast(C, DestTy);
177  }
178 
179  // Okay, we know the destination is integer, if the input is FP, convert
180  // it to integer first.
181  if (SrcEltTy->isFloatingPointTy()) {
182  unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
183  Type *SrcIVTy =
184  VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
185  // Ask IR to do the conversion now that #elts line up.
186  C = ConstantExpr::getBitCast(C, SrcIVTy);
187  // If IR wasn't able to fold it, bail out.
188  if (!isa<ConstantVector>(C) && // FIXME: Remove ConstantVector.
189  !isa<ConstantDataVector>(C))
190  return C;
191  }
192 
193  // Now we know that the input and output vectors are both integer vectors
194  // of the same size, and that their #elements is not the same. Do the
195  // conversion here, which depends on whether the input or output has
196  // more elements.
197  bool isLittleEndian = DL.isLittleEndian();
198 
200  if (NumDstElt < NumSrcElt) {
201  // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
202  Constant *Zero = Constant::getNullValue(DstEltTy);
203  unsigned Ratio = NumSrcElt/NumDstElt;
204  unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits();
205  unsigned SrcElt = 0;
206  for (unsigned i = 0; i != NumDstElt; ++i) {
207  // Build each element of the result.
208  Constant *Elt = Zero;
209  unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
210  for (unsigned j = 0; j != Ratio; ++j) {
211  Constant *Src = C->getAggregateElement(SrcElt++);
212  if (Src && isa<UndefValue>(Src))
214  else
215  Src = dyn_cast_or_null<ConstantInt>(Src);
216  if (!Src) // Reject constantexpr elements.
217  return ConstantExpr::getBitCast(C, DestTy);
218 
219  // Zero extend the element to the right size.
220  Src = ConstantExpr::getZExt(Src, Elt->getType());
221 
222  // Shift it to the right place, depending on endianness.
223  Src = ConstantExpr::getShl(Src,
224  ConstantInt::get(Src->getType(), ShiftAmt));
225  ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
226 
227  // Mix it in.
228  Elt = ConstantExpr::getOr(Elt, Src);
229  }
230  Result.push_back(Elt);
231  }
232  return ConstantVector::get(Result);
233  }
234 
235  // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
236  unsigned Ratio = NumDstElt/NumSrcElt;
237  unsigned DstBitSize = DL.getTypeSizeInBits(DstEltTy);
238 
239  // Loop over each source value, expanding into multiple results.
240  for (unsigned i = 0; i != NumSrcElt; ++i) {
241  auto *Element = C->getAggregateElement(i);
242 
243  if (!Element) // Reject constantexpr elements.
244  return ConstantExpr::getBitCast(C, DestTy);
245 
246  if (isa<UndefValue>(Element)) {
247  // Correctly Propagate undef values.
248  Result.append(Ratio, UndefValue::get(DstEltTy));
249  continue;
250  }
251 
252  auto *Src = dyn_cast<ConstantInt>(Element);
253  if (!Src)
254  return ConstantExpr::getBitCast(C, DestTy);
255 
256  unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
257  for (unsigned j = 0; j != Ratio; ++j) {
258  // Shift the piece of the value into the right place, depending on
259  // endianness.
260  Constant *Elt = ConstantExpr::getLShr(Src,
261  ConstantInt::get(Src->getType(), ShiftAmt));
262  ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
263 
264  // Truncate the element to an integer with the same pointer size and
265  // convert the element back to a pointer using a inttoptr.
266  if (DstEltTy->isPointerTy()) {
267  IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize);
268  Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy);
269  Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy));
270  continue;
271  }
272 
273  // Truncate and remember this piece.
274  Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
275  }
276  }
277 
278  return ConstantVector::get(Result);
279 }
280 
281 } // end anonymous namespace
282 
283 /// If this constant is a constant offset from a global, return the global and
284 /// the constant. Because of constantexprs, this function is recursive.
286  APInt &Offset, const DataLayout &DL) {
287  // Trivial case, constant is the global.
288  if ((GV = dyn_cast<GlobalValue>(C))) {
289  unsigned BitWidth = DL.getPointerTypeSizeInBits(GV->getType());
290  Offset = APInt(BitWidth, 0);
291  return true;
292  }
293 
294  // Otherwise, if this isn't a constant expr, bail out.
295  auto *CE = dyn_cast<ConstantExpr>(C);
296  if (!CE) return false;
297 
298  // Look through ptr->int and ptr->ptr casts.
299  if (CE->getOpcode() == Instruction::PtrToInt ||
300  CE->getOpcode() == Instruction::BitCast)
301  return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, DL);
302 
303  // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
304  auto *GEP = dyn_cast<GEPOperator>(CE);
305  if (!GEP)
306  return false;
307 
308  unsigned BitWidth = DL.getPointerTypeSizeInBits(GEP->getType());
309  APInt TmpOffset(BitWidth, 0);
310 
311  // If the base isn't a global+constant, we aren't either.
312  if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, DL))
313  return false;
314 
315  // Otherwise, add any offset that our operands provide.
316  if (!GEP->accumulateConstantOffset(DL, TmpOffset))
317  return false;
318 
319  Offset = TmpOffset;
320  return true;
321 }
322 
323 namespace {
324 
325 /// Recursive helper to read bits out of global. C is the constant being copied
326 /// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy
327 /// results into and BytesLeft is the number of bytes left in
328 /// the CurPtr buffer. DL is the DataLayout.
329 bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr,
330  unsigned BytesLeft, const DataLayout &DL) {
331  assert(ByteOffset <= DL.getTypeAllocSize(C->getType()) &&
332  "Out of range access");
333 
334  // If this element is zero or undefined, we can just return since *CurPtr is
335  // zero initialized.
336  if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
337  return true;
338 
339  if (auto *CI = dyn_cast<ConstantInt>(C)) {
340  if (CI->getBitWidth() > 64 ||
341  (CI->getBitWidth() & 7) != 0)
342  return false;
343 
344  uint64_t Val = CI->getZExtValue();
345  unsigned IntBytes = unsigned(CI->getBitWidth()/8);
346 
347  for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
348  int n = ByteOffset;
349  if (!DL.isLittleEndian())
350  n = IntBytes - n - 1;
351  CurPtr[i] = (unsigned char)(Val >> (n * 8));
352  ++ByteOffset;
353  }
354  return true;
355  }
356 
357  if (auto *CFP = dyn_cast<ConstantFP>(C)) {
358  if (CFP->getType()->isDoubleTy()) {
359  C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), DL);
360  return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
361  }
362  if (CFP->getType()->isFloatTy()){
363  C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), DL);
364  return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
365  }
366  if (CFP->getType()->isHalfTy()){
367  C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), DL);
368  return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
369  }
370  return false;
371  }
372 
373  if (auto *CS = dyn_cast<ConstantStruct>(C)) {
374  const StructLayout *SL = DL.getStructLayout(CS->getType());
375  unsigned Index = SL->getElementContainingOffset(ByteOffset);
376  uint64_t CurEltOffset = SL->getElementOffset(Index);
377  ByteOffset -= CurEltOffset;
378 
379  while (true) {
380  // If the element access is to the element itself and not to tail padding,
381  // read the bytes from the element.
382  uint64_t EltSize = DL.getTypeAllocSize(CS->getOperand(Index)->getType());
383 
384  if (ByteOffset < EltSize &&
385  !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
386  BytesLeft, DL))
387  return false;
388 
389  ++Index;
390 
391  // Check to see if we read from the last struct element, if so we're done.
392  if (Index == CS->getType()->getNumElements())
393  return true;
394 
395  // If we read all of the bytes we needed from this element we're done.
396  uint64_t NextEltOffset = SL->getElementOffset(Index);
397 
398  if (BytesLeft <= NextEltOffset - CurEltOffset - ByteOffset)
399  return true;
400 
401  // Move to the next element of the struct.
402  CurPtr += NextEltOffset - CurEltOffset - ByteOffset;
403  BytesLeft -= NextEltOffset - CurEltOffset - ByteOffset;
404  ByteOffset = 0;
405  CurEltOffset = NextEltOffset;
406  }
407  // not reached.
408  }
409 
410  if (isa<ConstantArray>(C) || isa<ConstantVector>(C) ||
411  isa<ConstantDataSequential>(C)) {
412  Type *EltTy = C->getType()->getSequentialElementType();
413  uint64_t EltSize = DL.getTypeAllocSize(EltTy);
414  uint64_t Index = ByteOffset / EltSize;
415  uint64_t Offset = ByteOffset - Index * EltSize;
416  uint64_t NumElts;
417  if (auto *AT = dyn_cast<ArrayType>(C->getType()))
418  NumElts = AT->getNumElements();
419  else
420  NumElts = C->getType()->getVectorNumElements();
421 
422  for (; Index != NumElts; ++Index) {
423  if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr,
424  BytesLeft, DL))
425  return false;
426 
427  uint64_t BytesWritten = EltSize - Offset;
428  assert(BytesWritten <= EltSize && "Not indexing into this element?");
429  if (BytesWritten >= BytesLeft)
430  return true;
431 
432  Offset = 0;
433  BytesLeft -= BytesWritten;
434  CurPtr += BytesWritten;
435  }
436  return true;
437  }
438 
439  if (auto *CE = dyn_cast<ConstantExpr>(C)) {
440  if (CE->getOpcode() == Instruction::IntToPtr &&
441  CE->getOperand(0)->getType() == DL.getIntPtrType(CE->getType())) {
442  return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
443  BytesLeft, DL);
444  }
445  }
446 
447  // Otherwise, unknown initializer type.
448  return false;
449 }
450 
451 Constant *FoldReinterpretLoadFromConstPtr(Constant *C, Type *LoadTy,
452  const DataLayout &DL) {
453  auto *PTy = cast<PointerType>(C->getType());
454  auto *IntType = dyn_cast<IntegerType>(LoadTy);
455 
456  // If this isn't an integer load we can't fold it directly.
457  if (!IntType) {
458  unsigned AS = PTy->getAddressSpace();
459 
460  // If this is a float/double load, we can try folding it as an int32/64 load
461  // and then bitcast the result. This can be useful for union cases. Note
462  // that address spaces don't matter here since we're not going to result in
463  // an actual new load.
464  Type *MapTy;
465  if (LoadTy->isHalfTy())
466  MapTy = Type::getInt16Ty(C->getContext());
467  else if (LoadTy->isFloatTy())
468  MapTy = Type::getInt32Ty(C->getContext());
469  else if (LoadTy->isDoubleTy())
470  MapTy = Type::getInt64Ty(C->getContext());
471  else if (LoadTy->isVectorTy()) {
472  MapTy = PointerType::getIntNTy(C->getContext(),
473  DL.getTypeAllocSizeInBits(LoadTy));
474  } else
475  return nullptr;
476 
477  C = FoldBitCast(C, MapTy->getPointerTo(AS), DL);
478  if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, MapTy, DL))
479  return FoldBitCast(Res, LoadTy, DL);
480  return nullptr;
481  }
482 
483  unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
484  if (BytesLoaded > 32 || BytesLoaded == 0)
485  return nullptr;
486 
487  GlobalValue *GVal;
488  APInt OffsetAI;
489  if (!IsConstantOffsetFromGlobal(C, GVal, OffsetAI, DL))
490  return nullptr;
491 
492  auto *GV = dyn_cast<GlobalVariable>(GVal);
493  if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
494  !GV->getInitializer()->getType()->isSized())
495  return nullptr;
496 
497  int64_t Offset = OffsetAI.getSExtValue();
498  int64_t InitializerSize = DL.getTypeAllocSize(GV->getInitializer()->getType());
499 
500  // If we're not accessing anything in this constant, the result is undefined.
501  if (Offset + BytesLoaded <= 0)
502  return UndefValue::get(IntType);
503 
504  // If we're not accessing anything in this constant, the result is undefined.
505  if (Offset >= InitializerSize)
506  return UndefValue::get(IntType);
507 
508  unsigned char RawBytes[32] = {0};
509  unsigned char *CurPtr = RawBytes;
510  unsigned BytesLeft = BytesLoaded;
511 
512  // If we're loading off the beginning of the global, some bytes may be valid.
513  if (Offset < 0) {
514  CurPtr += -Offset;
515  BytesLeft += Offset;
516  Offset = 0;
517  }
518 
519  if (!ReadDataFromGlobal(GV->getInitializer(), Offset, CurPtr, BytesLeft, DL))
520  return nullptr;
521 
522  APInt ResultVal = APInt(IntType->getBitWidth(), 0);
523  if (DL.isLittleEndian()) {
524  ResultVal = RawBytes[BytesLoaded - 1];
525  for (unsigned i = 1; i != BytesLoaded; ++i) {
526  ResultVal <<= 8;
527  ResultVal |= RawBytes[BytesLoaded - 1 - i];
528  }
529  } else {
530  ResultVal = RawBytes[0];
531  for (unsigned i = 1; i != BytesLoaded; ++i) {
532  ResultVal <<= 8;
533  ResultVal |= RawBytes[i];
534  }
535  }
536 
537  return ConstantInt::get(IntType->getContext(), ResultVal);
538 }
539 
540 Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE, Type *DestTy,
541  const DataLayout &DL) {
542  auto *SrcPtr = CE->getOperand(0);
543  auto *SrcPtrTy = dyn_cast<PointerType>(SrcPtr->getType());
544  if (!SrcPtrTy)
545  return nullptr;
546  Type *SrcTy = SrcPtrTy->getPointerElementType();
547 
548  Constant *C = ConstantFoldLoadFromConstPtr(SrcPtr, SrcTy, DL);
549  if (!C)
550  return nullptr;
551 
552  do {
553  Type *SrcTy = C->getType();
554 
555  // If the type sizes are the same and a cast is legal, just directly
556  // cast the constant.
557  if (DL.getTypeSizeInBits(DestTy) == DL.getTypeSizeInBits(SrcTy)) {
558  Instruction::CastOps Cast = Instruction::BitCast;
559  // If we are going from a pointer to int or vice versa, we spell the cast
560  // differently.
561  if (SrcTy->isIntegerTy() && DestTy->isPointerTy())
562  Cast = Instruction::IntToPtr;
563  else if (SrcTy->isPointerTy() && DestTy->isIntegerTy())
564  Cast = Instruction::PtrToInt;
565 
566  if (CastInst::castIsValid(Cast, C, DestTy))
567  return ConstantExpr::getCast(Cast, C, DestTy);
568  }
569 
570  // If this isn't an aggregate type, there is nothing we can do to drill down
571  // and find a bitcastable constant.
572  if (!SrcTy->isAggregateType())
573  return nullptr;
574 
575  // We're simulating a load through a pointer that was bitcast to point to
576  // a different type, so we can try to walk down through the initial
577  // elements of an aggregate to see if some part of th e aggregate is
578  // castable to implement the "load" semantic model.
579  C = C->getAggregateElement(0u);
580  } while (C);
581 
582  return nullptr;
583 }
584 
585 } // end anonymous namespace
586 
588  const DataLayout &DL) {
589  // First, try the easy cases:
590  if (auto *GV = dyn_cast<GlobalVariable>(C))
591  if (GV->isConstant() && GV->hasDefinitiveInitializer())
592  return GV->getInitializer();
593 
594  if (auto *GA = dyn_cast<GlobalAlias>(C))
595  if (GA->getAliasee() && !GA->isInterposable())
596  return ConstantFoldLoadFromConstPtr(GA->getAliasee(), Ty, DL);
597 
598  // If the loaded value isn't a constant expr, we can't handle it.
599  auto *CE = dyn_cast<ConstantExpr>(C);
600  if (!CE)
601  return nullptr;
602 
603  if (CE->getOpcode() == Instruction::GetElementPtr) {
604  if (auto *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
605  if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
606  if (Constant *V =
607  ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
608  return V;
609  }
610  }
611  }
612 
613  if (CE->getOpcode() == Instruction::BitCast)
614  if (Constant *LoadedC = ConstantFoldLoadThroughBitcast(CE, Ty, DL))
615  return LoadedC;
616 
617  // Instead of loading constant c string, use corresponding integer value
618  // directly if string length is small enough.
619  StringRef Str;
620  if (getConstantStringInfo(CE, Str) && !Str.empty()) {
621  size_t StrLen = Str.size();
622  unsigned NumBits = Ty->getPrimitiveSizeInBits();
623  // Replace load with immediate integer if the result is an integer or fp
624  // value.
625  if ((NumBits >> 3) == StrLen + 1 && (NumBits & 7) == 0 &&
626  (isa<IntegerType>(Ty) || Ty->isFloatingPointTy())) {
627  APInt StrVal(NumBits, 0);
628  APInt SingleChar(NumBits, 0);
629  if (DL.isLittleEndian()) {
630  for (unsigned char C : reverse(Str.bytes())) {
631  SingleChar = static_cast<uint64_t>(C);
632  StrVal = (StrVal << 8) | SingleChar;
633  }
634  } else {
635  for (unsigned char C : Str.bytes()) {
636  SingleChar = static_cast<uint64_t>(C);
637  StrVal = (StrVal << 8) | SingleChar;
638  }
639  // Append NULL at the end.
640  SingleChar = 0;
641  StrVal = (StrVal << 8) | SingleChar;
642  }
643 
644  Constant *Res = ConstantInt::get(CE->getContext(), StrVal);
645  if (Ty->isFloatingPointTy())
646  Res = ConstantExpr::getBitCast(Res, Ty);
647  return Res;
648  }
649  }
650 
651  // If this load comes from anywhere in a constant global, and if the global
652  // is all undef or zero, we know what it loads.
653  if (auto *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(CE, DL))) {
654  if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
655  if (GV->getInitializer()->isNullValue())
656  return Constant::getNullValue(Ty);
657  if (isa<UndefValue>(GV->getInitializer()))
658  return UndefValue::get(Ty);
659  }
660  }
661 
662  // Try hard to fold loads from bitcasted strange and non-type-safe things.
663  return FoldReinterpretLoadFromConstPtr(CE, Ty, DL);
664 }
665 
666 namespace {
667 
668 Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout &DL) {
669  if (LI->isVolatile()) return nullptr;
670 
671  if (auto *C = dyn_cast<Constant>(LI->getOperand(0)))
672  return ConstantFoldLoadFromConstPtr(C, LI->getType(), DL);
673 
674  return nullptr;
675 }
676 
677 /// One of Op0/Op1 is a constant expression.
678 /// Attempt to symbolically evaluate the result of a binary operator merging
679 /// these together. If target data info is available, it is provided as DL,
680 /// otherwise DL is null.
681 Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, Constant *Op1,
682  const DataLayout &DL) {
683  // SROA
684 
685  // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
686  // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
687  // bits.
688 
689  if (Opc == Instruction::And) {
690  KnownBits Known0 = computeKnownBits(Op0, DL);
691  KnownBits Known1 = computeKnownBits(Op1, DL);
692  if ((Known1.One | Known0.Zero).isAllOnesValue()) {
693  // All the bits of Op0 that the 'and' could be masking are already zero.
694  return Op0;
695  }
696  if ((Known0.One | Known1.Zero).isAllOnesValue()) {
697  // All the bits of Op1 that the 'and' could be masking are already zero.
698  return Op1;
699  }
700 
701  Known0.Zero |= Known1.Zero;
702  Known0.One &= Known1.One;
703  if (Known0.isConstant())
704  return ConstantInt::get(Op0->getType(), Known0.getConstant());
705  }
706 
707  // If the constant expr is something like &A[123] - &A[4].f, fold this into a
708  // constant. This happens frequently when iterating over a global array.
709  if (Opc == Instruction::Sub) {
710  GlobalValue *GV1, *GV2;
711  APInt Offs1, Offs2;
712 
713  if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, DL))
714  if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, DL) && GV1 == GV2) {
715  unsigned OpSize = DL.getTypeSizeInBits(Op0->getType());
716 
717  // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
718  // PtrToInt may change the bitwidth so we have convert to the right size
719  // first.
720  return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) -
721  Offs2.zextOrTrunc(OpSize));
722  }
723  }
724 
725  return nullptr;
726 }
727 
728 /// If array indices are not pointer-sized integers, explicitly cast them so
729 /// that they aren't implicitly casted by the getelementptr.
730 Constant *CastGEPIndices(Type *SrcElemTy, ArrayRef<Constant *> Ops,
731  Type *ResultTy, Optional<unsigned> InRangeIndex,
732  const DataLayout &DL, const TargetLibraryInfo *TLI) {
733  Type *IntPtrTy = DL.getIntPtrType(ResultTy);
734  Type *IntPtrScalarTy = IntPtrTy->getScalarType();
735 
736  bool Any = false;
738  for (unsigned i = 1, e = Ops.size(); i != e; ++i) {
739  if ((i == 1 ||
740  !isa<StructType>(GetElementPtrInst::getIndexedType(
741  SrcElemTy, Ops.slice(1, i - 1)))) &&
742  Ops[i]->getType()->getScalarType() != IntPtrScalarTy) {
743  Any = true;
744  Type *NewType = Ops[i]->getType()->isVectorTy()
745  ? IntPtrTy
746  : IntPtrTy->getScalarType();
748  true,
749  NewType,
750  true),
751  Ops[i], NewType));
752  } else
753  NewIdxs.push_back(Ops[i]);
754  }
755 
756  if (!Any)
757  return nullptr;
758 
760  SrcElemTy, Ops[0], NewIdxs, /*InBounds=*/false, InRangeIndex);
761  if (Constant *Folded = ConstantFoldConstant(C, DL, TLI))
762  C = Folded;
763 
764  return C;
765 }
766 
767 /// Strip the pointer casts, but preserve the address space information.
768 Constant* StripPtrCastKeepAS(Constant* Ptr, Type *&ElemTy) {
769  assert(Ptr->getType()->isPointerTy() && "Not a pointer type");
770  auto *OldPtrTy = cast<PointerType>(Ptr->getType());
771  Ptr = Ptr->stripPointerCasts();
772  auto *NewPtrTy = cast<PointerType>(Ptr->getType());
773 
774  ElemTy = NewPtrTy->getPointerElementType();
775 
776  // Preserve the address space number of the pointer.
777  if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) {
778  NewPtrTy = ElemTy->getPointerTo(OldPtrTy->getAddressSpace());
779  Ptr = ConstantExpr::getPointerCast(Ptr, NewPtrTy);
780  }
781  return Ptr;
782 }
783 
784 /// If we can symbolically evaluate the GEP constant expression, do so.
785 Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
787  const DataLayout &DL,
788  const TargetLibraryInfo *TLI) {
789  const GEPOperator *InnermostGEP = GEP;
790  bool InBounds = GEP->isInBounds();
791 
792  Type *SrcElemTy = GEP->getSourceElementType();
793  Type *ResElemTy = GEP->getResultElementType();
794  Type *ResTy = GEP->getType();
795  if (!SrcElemTy->isSized())
796  return nullptr;
797 
798  if (Constant *C = CastGEPIndices(SrcElemTy, Ops, ResTy,
799  GEP->getInRangeIndex(), DL, TLI))
800  return C;
801 
802  Constant *Ptr = Ops[0];
803  if (!Ptr->getType()->isPointerTy())
804  return nullptr;
805 
806  Type *IntPtrTy = DL.getIntPtrType(Ptr->getType());
807 
808  // If this is a constant expr gep that is effectively computing an
809  // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
810  for (unsigned i = 1, e = Ops.size(); i != e; ++i)
811  if (!isa<ConstantInt>(Ops[i])) {
812 
813  // If this is "gep i8* Ptr, (sub 0, V)", fold this as:
814  // "inttoptr (sub (ptrtoint Ptr), V)"
815  if (Ops.size() == 2 && ResElemTy->isIntegerTy(8)) {
816  auto *CE = dyn_cast<ConstantExpr>(Ops[1]);
817  assert((!CE || CE->getType() == IntPtrTy) &&
818  "CastGEPIndices didn't canonicalize index types!");
819  if (CE && CE->getOpcode() == Instruction::Sub &&
820  CE->getOperand(0)->isNullValue()) {
821  Constant *Res = ConstantExpr::getPtrToInt(Ptr, CE->getType());
822  Res = ConstantExpr::getSub(Res, CE->getOperand(1));
823  Res = ConstantExpr::getIntToPtr(Res, ResTy);
824  if (auto *FoldedRes = ConstantFoldConstant(Res, DL, TLI))
825  Res = FoldedRes;
826  return Res;
827  }
828  }
829  return nullptr;
830  }
831 
832  unsigned BitWidth = DL.getTypeSizeInBits(IntPtrTy);
833  APInt Offset =
834  APInt(BitWidth,
836  SrcElemTy,
837  makeArrayRef((Value * const *)Ops.data() + 1, Ops.size() - 1)));
838  Ptr = StripPtrCastKeepAS(Ptr, SrcElemTy);
839 
840  // If this is a GEP of a GEP, fold it all into a single GEP.
841  while (auto *GEP = dyn_cast<GEPOperator>(Ptr)) {
842  InnermostGEP = GEP;
843  InBounds &= GEP->isInBounds();
844 
845  SmallVector<Value *, 4> NestedOps(GEP->op_begin() + 1, GEP->op_end());
846 
847  // Do not try the incorporate the sub-GEP if some index is not a number.
848  bool AllConstantInt = true;
849  for (Value *NestedOp : NestedOps)
850  if (!isa<ConstantInt>(NestedOp)) {
851  AllConstantInt = false;
852  break;
853  }
854  if (!AllConstantInt)
855  break;
856 
857  Ptr = cast<Constant>(GEP->getOperand(0));
858  SrcElemTy = GEP->getSourceElementType();
859  Offset += APInt(BitWidth, DL.getIndexedOffsetInType(SrcElemTy, NestedOps));
860  Ptr = StripPtrCastKeepAS(Ptr, SrcElemTy);
861  }
862 
863  // If the base value for this address is a literal integer value, fold the
864  // getelementptr to the resulting integer value casted to the pointer type.
865  APInt BasePtr(BitWidth, 0);
866  if (auto *CE = dyn_cast<ConstantExpr>(Ptr)) {
867  if (CE->getOpcode() == Instruction::IntToPtr) {
868  if (auto *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
869  BasePtr = Base->getValue().zextOrTrunc(BitWidth);
870  }
871  }
872 
873  auto *PTy = cast<PointerType>(Ptr->getType());
874  if ((Ptr->isNullValue() || BasePtr != 0) &&
875  !DL.isNonIntegralPointerType(PTy)) {
876  Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr);
877  return ConstantExpr::getIntToPtr(C, ResTy);
878  }
879 
880  // Otherwise form a regular getelementptr. Recompute the indices so that
881  // we eliminate over-indexing of the notional static type array bounds.
882  // This makes it easy to determine if the getelementptr is "inbounds".
883  // Also, this helps GlobalOpt do SROA on GlobalVariables.
884  Type *Ty = PTy;
886 
887  do {
888  if (!Ty->isStructTy()) {
889  if (Ty->isPointerTy()) {
890  // The only pointer indexing we'll do is on the first index of the GEP.
891  if (!NewIdxs.empty())
892  break;
893 
894  Ty = SrcElemTy;
895 
896  // Only handle pointers to sized types, not pointers to functions.
897  if (!Ty->isSized())
898  return nullptr;
899  } else if (auto *ATy = dyn_cast<SequentialType>(Ty)) {
900  Ty = ATy->getElementType();
901  } else {
902  // We've reached some non-indexable type.
903  break;
904  }
905 
906  // Determine which element of the array the offset points into.
907  APInt ElemSize(BitWidth, DL.getTypeAllocSize(Ty));
908  if (ElemSize == 0) {
909  // The element size is 0. This may be [0 x Ty]*, so just use a zero
910  // index for this level and proceed to the next level to see if it can
911  // accommodate the offset.
912  NewIdxs.push_back(ConstantInt::get(IntPtrTy, 0));
913  } else {
914  // The element size is non-zero divide the offset by the element
915  // size (rounding down), to compute the index at this level.
916  bool Overflow;
917  APInt NewIdx = Offset.sdiv_ov(ElemSize, Overflow);
918  if (Overflow)
919  break;
920  Offset -= NewIdx * ElemSize;
921  NewIdxs.push_back(ConstantInt::get(IntPtrTy, NewIdx));
922  }
923  } else {
924  auto *STy = cast<StructType>(Ty);
925  // If we end up with an offset that isn't valid for this struct type, we
926  // can't re-form this GEP in a regular form, so bail out. The pointer
927  // operand likely went through casts that are necessary to make the GEP
928  // sensible.
929  const StructLayout &SL = *DL.getStructLayout(STy);
930  if (Offset.isNegative() || Offset.uge(SL.getSizeInBytes()))
931  break;
932 
933  // Determine which field of the struct the offset points into. The
934  // getZExtValue is fine as we've already ensured that the offset is
935  // within the range representable by the StructLayout API.
936  unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue());
938  ElIdx));
939  Offset -= APInt(BitWidth, SL.getElementOffset(ElIdx));
940  Ty = STy->getTypeAtIndex(ElIdx);
941  }
942  } while (Ty != ResElemTy);
943 
944  // If we haven't used up the entire offset by descending the static
945  // type, then the offset is pointing into the middle of an indivisible
946  // member, so we can't simplify it.
947  if (Offset != 0)
948  return nullptr;
949 
950  // Preserve the inrange index from the innermost GEP if possible. We must
951  // have calculated the same indices up to and including the inrange index.
952  Optional<unsigned> InRangeIndex;
953  if (Optional<unsigned> LastIRIndex = InnermostGEP->getInRangeIndex())
954  if (SrcElemTy == InnermostGEP->getSourceElementType() &&
955  NewIdxs.size() > *LastIRIndex) {
956  InRangeIndex = LastIRIndex;
957  for (unsigned I = 0; I <= *LastIRIndex; ++I)
958  if (NewIdxs[I] != InnermostGEP->getOperand(I + 1)) {
959  InRangeIndex = None;
960  break;
961  }
962  }
963 
964  // Create a GEP.
965  Constant *C = ConstantExpr::getGetElementPtr(SrcElemTy, Ptr, NewIdxs,
966  InBounds, InRangeIndex);
967  assert(C->getType()->getPointerElementType() == Ty &&
968  "Computed GetElementPtr has unexpected type!");
969 
970  // If we ended up indexing a member with a type that doesn't match
971  // the type of what the original indices indexed, add a cast.
972  if (Ty != ResElemTy)
973  C = FoldBitCast(C, ResTy, DL);
974 
975  return C;
976 }
977 
978 /// Attempt to constant fold an instruction with the
979 /// specified opcode and operands. If successful, the constant result is
980 /// returned, if not, null is returned. Note that this function can fail when
981 /// attempting to fold instructions like loads and stores, which have no
982 /// constant expression form.
983 ///
984 /// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/inrange
985 /// etc information, due to only being passed an opcode and operands. Constant
986 /// folding using this function strips this information.
987 ///
988 Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, unsigned Opcode,
990  const DataLayout &DL,
991  const TargetLibraryInfo *TLI) {
992  Type *DestTy = InstOrCE->getType();
993 
994  // Handle easy binops first.
995  if (Instruction::isBinaryOp(Opcode))
996  return ConstantFoldBinaryOpOperands(Opcode, Ops[0], Ops[1], DL);
997 
998  if (Instruction::isCast(Opcode))
999  return ConstantFoldCastOperand(Opcode, Ops[0], DestTy, DL);
1000 
1001  if (auto *GEP = dyn_cast<GEPOperator>(InstOrCE)) {
1002  if (Constant *C = SymbolicallyEvaluateGEP(GEP, Ops, DL, TLI))
1003  return C;
1004 
1006  Ops.slice(1), GEP->isInBounds(),
1007  GEP->getInRangeIndex());
1008  }
1009 
1010  if (auto *CE = dyn_cast<ConstantExpr>(InstOrCE))
1011  return CE->getWithOperands(Ops);
1012 
1013  switch (Opcode) {
1014  default: return nullptr;
1015  case Instruction::ICmp:
1016  case Instruction::FCmp: llvm_unreachable("Invalid for compares");
1017  case Instruction::Call:
1018  if (auto *F = dyn_cast<Function>(Ops.back())) {
1019  ImmutableCallSite CS(cast<CallInst>(InstOrCE));
1020  if (canConstantFoldCallTo(CS, F))
1021  return ConstantFoldCall(CS, F, Ops.slice(0, Ops.size() - 1), TLI);
1022  }
1023  return nullptr;
1024  case Instruction::Select:
1025  return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
1026  case Instruction::ExtractElement:
1027  return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
1028  case Instruction::InsertElement:
1029  return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
1030  case Instruction::ShuffleVector:
1031  return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
1032  }
1033 }
1034 
1035 } // end anonymous namespace
1036 
1037 //===----------------------------------------------------------------------===//
1038 // Constant Folding public APIs
1039 //===----------------------------------------------------------------------===//
1040 
1041 namespace {
1042 
1043 Constant *
1044 ConstantFoldConstantImpl(const Constant *C, const DataLayout &DL,
1045  const TargetLibraryInfo *TLI,
1047  if (!isa<ConstantVector>(C) && !isa<ConstantExpr>(C))
1048  return nullptr;
1049 
1051  for (const Use &NewU : C->operands()) {
1052  auto *NewC = cast<Constant>(&NewU);
1053  // Recursively fold the ConstantExpr's operands. If we have already folded
1054  // a ConstantExpr, we don't have to process it again.
1055  if (isa<ConstantVector>(NewC) || isa<ConstantExpr>(NewC)) {
1056  auto It = FoldedOps.find(NewC);
1057  if (It == FoldedOps.end()) {
1058  if (auto *FoldedC =
1059  ConstantFoldConstantImpl(NewC, DL, TLI, FoldedOps)) {
1060  FoldedOps.insert({NewC, FoldedC});
1061  NewC = FoldedC;
1062  } else {
1063  FoldedOps.insert({NewC, NewC});
1064  }
1065  } else {
1066  NewC = It->second;
1067  }
1068  }
1069  Ops.push_back(NewC);
1070  }
1071 
1072  if (auto *CE = dyn_cast<ConstantExpr>(C)) {
1073  if (CE->isCompare())
1074  return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1],
1075  DL, TLI);
1076 
1077  return ConstantFoldInstOperandsImpl(CE, CE->getOpcode(), Ops, DL, TLI);
1078  }
1079 
1080  assert(isa<ConstantVector>(C));
1081  return ConstantVector::get(Ops);
1082 }
1083 
1084 } // end anonymous namespace
1085 
1087  const TargetLibraryInfo *TLI) {
1088  // Handle PHI nodes quickly here...
1089  if (auto *PN = dyn_cast<PHINode>(I)) {
1090  Constant *CommonValue = nullptr;
1091 
1093  for (Value *Incoming : PN->incoming_values()) {
1094  // If the incoming value is undef then skip it. Note that while we could
1095  // skip the value if it is equal to the phi node itself we choose not to
1096  // because that would break the rule that constant folding only applies if
1097  // all operands are constants.
1098  if (isa<UndefValue>(Incoming))
1099  continue;
1100  // If the incoming value is not a constant, then give up.
1101  auto *C = dyn_cast<Constant>(Incoming);
1102  if (!C)
1103  return nullptr;
1104  // Fold the PHI's operands.
1105  if (auto *FoldedC = ConstantFoldConstantImpl(C, DL, TLI, FoldedOps))
1106  C = FoldedC;
1107  // If the incoming value is a different constant to
1108  // the one we saw previously, then give up.
1109  if (CommonValue && C != CommonValue)
1110  return nullptr;
1111  CommonValue = C;
1112  }
1113 
1114  // If we reach here, all incoming values are the same constant or undef.
1115  return CommonValue ? CommonValue : UndefValue::get(PN->getType());
1116  }
1117 
1118  // Scan the operand list, checking to see if they are all constants, if so,
1119  // hand off to ConstantFoldInstOperandsImpl.
1120  if (!all_of(I->operands(), [](Use &U) { return isa<Constant>(U); }))
1121  return nullptr;
1122 
1125  for (const Use &OpU : I->operands()) {
1126  auto *Op = cast<Constant>(&OpU);
1127  // Fold the Instruction's operands.
1128  if (auto *FoldedOp = ConstantFoldConstantImpl(Op, DL, TLI, FoldedOps))
1129  Op = FoldedOp;
1130 
1131  Ops.push_back(Op);
1132  }
1133 
1134  if (const auto *CI = dyn_cast<CmpInst>(I))
1135  return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
1136  DL, TLI);
1137 
1138  if (const auto *LI = dyn_cast<LoadInst>(I))
1139  return ConstantFoldLoadInst(LI, DL);
1140 
1141  if (auto *IVI = dyn_cast<InsertValueInst>(I)) {
1143  cast<Constant>(IVI->getAggregateOperand()),
1144  cast<Constant>(IVI->getInsertedValueOperand()),
1145  IVI->getIndices());
1146  }
1147 
1148  if (auto *EVI = dyn_cast<ExtractValueInst>(I)) {
1150  cast<Constant>(EVI->getAggregateOperand()),
1151  EVI->getIndices());
1152  }
1153 
1154  return ConstantFoldInstOperands(I, Ops, DL, TLI);
1155 }
1156 
1158  const TargetLibraryInfo *TLI) {
1160  return ConstantFoldConstantImpl(C, DL, TLI, FoldedOps);
1161 }
1162 
1165  const DataLayout &DL,
1166  const TargetLibraryInfo *TLI) {
1167  return ConstantFoldInstOperandsImpl(I, I->getOpcode(), Ops, DL, TLI);
1168 }
1169 
1171  Constant *Ops0, Constant *Ops1,
1172  const DataLayout &DL,
1173  const TargetLibraryInfo *TLI) {
1174  // fold: icmp (inttoptr x), null -> icmp x, 0
1175  // fold: icmp null, (inttoptr x) -> icmp 0, x
1176  // fold: icmp (ptrtoint x), 0 -> icmp x, null
1177  // fold: icmp 0, (ptrtoint x) -> icmp null, x
1178  // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y
1179  // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y
1180  //
1181  // FIXME: The following comment is out of data and the DataLayout is here now.
1182  // ConstantExpr::getCompare cannot do this, because it doesn't have DL
1183  // around to know if bit truncation is happening.
1184  if (auto *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
1185  if (Ops1->isNullValue()) {
1186  if (CE0->getOpcode() == Instruction::IntToPtr) {
1187  Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
1188  // Convert the integer value to the right size to ensure we get the
1189  // proper extension or truncation.
1190  Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
1191  IntPtrTy, false);
1192  Constant *Null = Constant::getNullValue(C->getType());
1193  return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI);
1194  }
1195 
1196  // Only do this transformation if the int is intptrty in size, otherwise
1197  // there is a truncation or extension that we aren't modeling.
1198  if (CE0->getOpcode() == Instruction::PtrToInt) {
1199  Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
1200  if (CE0->getType() == IntPtrTy) {
1201  Constant *C = CE0->getOperand(0);
1202  Constant *Null = Constant::getNullValue(C->getType());
1203  return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI);
1204  }
1205  }
1206  }
1207 
1208  if (auto *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
1209  if (CE0->getOpcode() == CE1->getOpcode()) {
1210  if (CE0->getOpcode() == Instruction::IntToPtr) {
1211  Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
1212 
1213  // Convert the integer value to the right size to ensure we get the
1214  // proper extension or truncation.
1215  Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0),
1216  IntPtrTy, false);
1217  Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0),
1218  IntPtrTy, false);
1219  return ConstantFoldCompareInstOperands(Predicate, C0, C1, DL, TLI);
1220  }
1221 
1222  // Only do this transformation if the int is intptrty in size, otherwise
1223  // there is a truncation or extension that we aren't modeling.
1224  if (CE0->getOpcode() == Instruction::PtrToInt) {
1225  Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
1226  if (CE0->getType() == IntPtrTy &&
1227  CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()) {
1229  Predicate, CE0->getOperand(0), CE1->getOperand(0), DL, TLI);
1230  }
1231  }
1232  }
1233  }
1234 
1235  // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
1236  // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
1237  if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
1238  CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
1240  Predicate, CE0->getOperand(0), Ops1, DL, TLI);
1242  Predicate, CE0->getOperand(1), Ops1, DL, TLI);
1243  unsigned OpC =
1244  Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
1245  return ConstantFoldBinaryOpOperands(OpC, LHS, RHS, DL);
1246  }
1247  } else if (isa<ConstantExpr>(Ops1)) {
1248  // If RHS is a constant expression, but the left side isn't, swap the
1249  // operands and try again.
1250  Predicate = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)Predicate);
1251  return ConstantFoldCompareInstOperands(Predicate, Ops1, Ops0, DL, TLI);
1252  }
1253 
1254  return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
1255 }
1256 
1258  Constant *RHS,
1259  const DataLayout &DL) {
1261  if (isa<ConstantExpr>(LHS) || isa<ConstantExpr>(RHS))
1262  if (Constant *C = SymbolicallyEvaluateBinop(Opcode, LHS, RHS, DL))
1263  return C;
1264 
1265  return ConstantExpr::get(Opcode, LHS, RHS);
1266 }
1267 
1269  Type *DestTy, const DataLayout &DL) {
1270  assert(Instruction::isCast(Opcode));
1271  switch (Opcode) {
1272  default:
1273  llvm_unreachable("Missing case");
1274  case Instruction::PtrToInt:
1275  // If the input is a inttoptr, eliminate the pair. This requires knowing
1276  // the width of a pointer, so it can't be done in ConstantExpr::getCast.
1277  if (auto *CE = dyn_cast<ConstantExpr>(C)) {
1278  if (CE->getOpcode() == Instruction::IntToPtr) {
1279  Constant *Input = CE->getOperand(0);
1280  unsigned InWidth = Input->getType()->getScalarSizeInBits();
1281  unsigned PtrWidth = DL.getPointerTypeSizeInBits(CE->getType());
1282  if (PtrWidth < InWidth) {
1283  Constant *Mask =
1284  ConstantInt::get(CE->getContext(),
1285  APInt::getLowBitsSet(InWidth, PtrWidth));
1286  Input = ConstantExpr::getAnd(Input, Mask);
1287  }
1288  // Do a zext or trunc to get to the dest size.
1289  return ConstantExpr::getIntegerCast(Input, DestTy, false);
1290  }
1291  }
1292  return ConstantExpr::getCast(Opcode, C, DestTy);
1293  case Instruction::IntToPtr:
1294  // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
1295  // the int size is >= the ptr size and the address spaces are the same.
1296  // This requires knowing the width of a pointer, so it can't be done in
1297  // ConstantExpr::getCast.
1298  if (auto *CE = dyn_cast<ConstantExpr>(C)) {
1299  if (CE->getOpcode() == Instruction::PtrToInt) {
1300  Constant *SrcPtr = CE->getOperand(0);
1301  unsigned SrcPtrSize = DL.getPointerTypeSizeInBits(SrcPtr->getType());
1302  unsigned MidIntSize = CE->getType()->getScalarSizeInBits();
1303 
1304  if (MidIntSize >= SrcPtrSize) {
1305  unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
1306  if (SrcAS == DestTy->getPointerAddressSpace())
1307  return FoldBitCast(CE->getOperand(0), DestTy, DL);
1308  }
1309  }
1310  }
1311 
1312  return ConstantExpr::getCast(Opcode, C, DestTy);
1313  case Instruction::Trunc:
1314  case Instruction::ZExt:
1315  case Instruction::SExt:
1316  case Instruction::FPTrunc:
1317  case Instruction::FPExt:
1318  case Instruction::UIToFP:
1319  case Instruction::SIToFP:
1320  case Instruction::FPToUI:
1321  case Instruction::FPToSI:
1322  case Instruction::AddrSpaceCast:
1323  return ConstantExpr::getCast(Opcode, C, DestTy);
1324  case Instruction::BitCast:
1325  return FoldBitCast(C, DestTy, DL);
1326  }
1327 }
1328 
1330  ConstantExpr *CE) {
1331  if (!CE->getOperand(1)->isNullValue())
1332  return nullptr; // Do not allow stepping over the value!
1333 
1334  // Loop over all of the operands, tracking down which value we are
1335  // addressing.
1336  for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i) {
1337  C = C->getAggregateElement(CE->getOperand(i));
1338  if (!C)
1339  return nullptr;
1340  }
1341  return C;
1342 }
1343 
1344 Constant *
1346  ArrayRef<Constant *> Indices) {
1347  // Loop over all of the operands, tracking down which value we are
1348  // addressing.
1349  for (Constant *Index : Indices) {
1350  C = C->getAggregateElement(Index);
1351  if (!C)
1352  return nullptr;
1353  }
1354  return C;
1355 }
1356 
1357 //===----------------------------------------------------------------------===//
1358 // Constant Folding for Calls
1359 //
1360 
1362  if (CS.isNoBuiltin())
1363  return false;
1364  switch (F->getIntrinsicID()) {
1365  case Intrinsic::fabs:
1366  case Intrinsic::minnum:
1367  case Intrinsic::maxnum:
1368  case Intrinsic::log:
1369  case Intrinsic::log2:
1370  case Intrinsic::log10:
1371  case Intrinsic::exp:
1372  case Intrinsic::exp2:
1373  case Intrinsic::floor:
1374  case Intrinsic::ceil:
1375  case Intrinsic::sqrt:
1376  case Intrinsic::sin:
1377  case Intrinsic::cos:
1378  case Intrinsic::trunc:
1379  case Intrinsic::rint:
1380  case Intrinsic::nearbyint:
1381  case Intrinsic::pow:
1382  case Intrinsic::powi:
1383  case Intrinsic::bswap:
1384  case Intrinsic::ctpop:
1385  case Intrinsic::ctlz:
1386  case Intrinsic::cttz:
1387  case Intrinsic::fma:
1388  case Intrinsic::fmuladd:
1389  case Intrinsic::copysign:
1390  case Intrinsic::round:
1391  case Intrinsic::masked_load:
1392  case Intrinsic::sadd_with_overflow:
1393  case Intrinsic::uadd_with_overflow:
1394  case Intrinsic::ssub_with_overflow:
1395  case Intrinsic::usub_with_overflow:
1396  case Intrinsic::smul_with_overflow:
1397  case Intrinsic::umul_with_overflow:
1398  case Intrinsic::convert_from_fp16:
1399  case Intrinsic::convert_to_fp16:
1400  case Intrinsic::bitreverse:
1401  case Intrinsic::x86_sse_cvtss2si:
1402  case Intrinsic::x86_sse_cvtss2si64:
1403  case Intrinsic::x86_sse_cvttss2si:
1404  case Intrinsic::x86_sse_cvttss2si64:
1405  case Intrinsic::x86_sse2_cvtsd2si:
1406  case Intrinsic::x86_sse2_cvtsd2si64:
1407  case Intrinsic::x86_sse2_cvttsd2si:
1408  case Intrinsic::x86_sse2_cvttsd2si64:
1409  return true;
1410  default:
1411  return false;
1412  case Intrinsic::not_intrinsic: break;
1413  }
1414 
1415  if (!F->hasName())
1416  return false;
1417  StringRef Name = F->getName();
1418 
1419  // In these cases, the check of the length is required. We don't want to
1420  // return true for a name like "cos\0blah" which strcmp would return equal to
1421  // "cos", but has length 8.
1422  switch (Name[0]) {
1423  default:
1424  return false;
1425  case 'a':
1426  return Name == "acos" || Name == "asin" || Name == "atan" ||
1427  Name == "atan2" || Name == "acosf" || Name == "asinf" ||
1428  Name == "atanf" || Name == "atan2f";
1429  case 'c':
1430  return Name == "ceil" || Name == "cos" || Name == "cosh" ||
1431  Name == "ceilf" || Name == "cosf" || Name == "coshf";
1432  case 'e':
1433  return Name == "exp" || Name == "exp2" || Name == "expf" || Name == "exp2f";
1434  case 'f':
1435  return Name == "fabs" || Name == "floor" || Name == "fmod" ||
1436  Name == "fabsf" || Name == "floorf" || Name == "fmodf";
1437  case 'l':
1438  return Name == "log" || Name == "log10" || Name == "logf" ||
1439  Name == "log10f";
1440  case 'p':
1441  return Name == "pow" || Name == "powf";
1442  case 'r':
1443  return Name == "round" || Name == "roundf";
1444  case 's':
1445  return Name == "sin" || Name == "sinh" || Name == "sqrt" ||
1446  Name == "sinf" || Name == "sinhf" || Name == "sqrtf";
1447  case 't':
1448  return Name == "tan" || Name == "tanh" || Name == "tanf" || Name == "tanhf";
1449  case '_':
1450 
1451  // Check for various function names that get used for the math functions
1452  // when the header files are preprocessed with the macro
1453  // __FINITE_MATH_ONLY__ enabled.
1454  // The '12' here is the length of the shortest name that can match.
1455  // We need to check the size before looking at Name[1] and Name[2]
1456  // so we may as well check a limit that will eliminate mismatches.
1457  if (Name.size() < 12 || Name[1] != '_')
1458  return false;
1459  switch (Name[2]) {
1460  default:
1461  return false;
1462  case 'a':
1463  return Name == "__acos_finite" || Name == "__acosf_finite" ||
1464  Name == "__asin_finite" || Name == "__asinf_finite" ||
1465  Name == "__atan2_finite" || Name == "__atan2f_finite";
1466  case 'c':
1467  return Name == "__cosh_finite" || Name == "__coshf_finite";
1468  case 'e':
1469  return Name == "__exp_finite" || Name == "__expf_finite" ||
1470  Name == "__exp2_finite" || Name == "__exp2f_finite";
1471  case 'l':
1472  return Name == "__log_finite" || Name == "__logf_finite" ||
1473  Name == "__log10_finite" || Name == "__log10f_finite";
1474  case 'p':
1475  return Name == "__pow_finite" || Name == "__powf_finite";
1476  case 's':
1477  return Name == "__sinh_finite" || Name == "__sinhf_finite";
1478  }
1479  }
1480 }
1481 
1482 namespace {
1483 
1484 Constant *GetConstantFoldFPValue(double V, Type *Ty) {
1485  if (Ty->isHalfTy()) {
1486  APFloat APF(V);
1487  bool unused;
1489  return ConstantFP::get(Ty->getContext(), APF);
1490  }
1491  if (Ty->isFloatTy())
1492  return ConstantFP::get(Ty->getContext(), APFloat((float)V));
1493  if (Ty->isDoubleTy())
1494  return ConstantFP::get(Ty->getContext(), APFloat(V));
1495  llvm_unreachable("Can only constant fold half/float/double");
1496 }
1497 
1498 /// Clear the floating-point exception state.
1499 inline void llvm_fenv_clearexcept() {
1500 #if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT
1501  feclearexcept(FE_ALL_EXCEPT);
1502 #endif
1503  errno = 0;
1504 }
1505 
1506 /// Test if a floating-point exception was raised.
1507 inline bool llvm_fenv_testexcept() {
1508  int errno_val = errno;
1509  if (errno_val == ERANGE || errno_val == EDOM)
1510  return true;
1511 #if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT
1512  if (fetestexcept(FE_ALL_EXCEPT & ~FE_INEXACT))
1513  return true;
1514 #endif
1515  return false;
1516 }
1517 
1518 Constant *ConstantFoldFP(double (*NativeFP)(double), double V, Type *Ty) {
1519  llvm_fenv_clearexcept();
1520  V = NativeFP(V);
1521  if (llvm_fenv_testexcept()) {
1522  llvm_fenv_clearexcept();
1523  return nullptr;
1524  }
1525 
1526  return GetConstantFoldFPValue(V, Ty);
1527 }
1528 
1529 Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), double V,
1530  double W, Type *Ty) {
1531  llvm_fenv_clearexcept();
1532  V = NativeFP(V, W);
1533  if (llvm_fenv_testexcept()) {
1534  llvm_fenv_clearexcept();
1535  return nullptr;
1536  }
1537 
1538  return GetConstantFoldFPValue(V, Ty);
1539 }
1540 
1541 /// Attempt to fold an SSE floating point to integer conversion of a constant
1542 /// floating point. If roundTowardZero is false, the default IEEE rounding is
1543 /// used (toward nearest, ties to even). This matches the behavior of the
1544 /// non-truncating SSE instructions in the default rounding mode. The desired
1545 /// integer type Ty is used to select how many bits are available for the
1546 /// result. Returns null if the conversion cannot be performed, otherwise
1547 /// returns the Constant value resulting from the conversion.
1548 Constant *ConstantFoldSSEConvertToInt(const APFloat &Val, bool roundTowardZero,
1549  Type *Ty) {
1550  // All of these conversion intrinsics form an integer of at most 64bits.
1551  unsigned ResultWidth = Ty->getIntegerBitWidth();
1552  assert(ResultWidth <= 64 &&
1553  "Can only constant fold conversions to 64 and 32 bit ints");
1554 
1555  uint64_t UIntVal;
1556  bool isExact = false;
1560  Val.convertToInteger(makeMutableArrayRef(UIntVal), ResultWidth,
1561  /*isSigned=*/true, mode, &isExact);
1562  if (status != APFloat::opOK &&
1563  (!roundTowardZero || status != APFloat::opInexact))
1564  return nullptr;
1565  return ConstantInt::get(Ty, UIntVal, /*isSigned=*/true);
1566 }
1567 
1568 double getValueAsDouble(ConstantFP *Op) {
1569  Type *Ty = Op->getType();
1570 
1571  if (Ty->isFloatTy())
1572  return Op->getValueAPF().convertToFloat();
1573 
1574  if (Ty->isDoubleTy())
1575  return Op->getValueAPF().convertToDouble();
1576 
1577  bool unused;
1578  APFloat APF = Op->getValueAPF();
1580  return APF.convertToDouble();
1581 }
1582 
1583 Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, Type *Ty,
1584  ArrayRef<Constant *> Operands,
1585  const TargetLibraryInfo *TLI) {
1586  if (Operands.size() == 1) {
1587  if (isa<UndefValue>(Operands[0])) {
1588  // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN
1589  if (IntrinsicID == Intrinsic::cos)
1590  return Constant::getNullValue(Ty);
1591  if (IntrinsicID == Intrinsic::bswap ||
1592  IntrinsicID == Intrinsic::bitreverse)
1593  return Operands[0];
1594  }
1595  if (auto *Op = dyn_cast<ConstantFP>(Operands[0])) {
1596  if (IntrinsicID == Intrinsic::convert_to_fp16) {
1597  APFloat Val(Op->getValueAPF());
1598 
1599  bool lost = false;
1601 
1602  return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt());
1603  }
1604 
1605  if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
1606  return nullptr;
1607 
1608  if (IntrinsicID == Intrinsic::round) {
1609  APFloat V = Op->getValueAPF();
1611  return ConstantFP::get(Ty->getContext(), V);
1612  }
1613 
1614  if (IntrinsicID == Intrinsic::floor) {
1615  APFloat V = Op->getValueAPF();
1617  return ConstantFP::get(Ty->getContext(), V);
1618  }
1619 
1620  if (IntrinsicID == Intrinsic::ceil) {
1621  APFloat V = Op->getValueAPF();
1623  return ConstantFP::get(Ty->getContext(), V);
1624  }
1625 
1626  if (IntrinsicID == Intrinsic::trunc) {
1627  APFloat V = Op->getValueAPF();
1629  return ConstantFP::get(Ty->getContext(), V);
1630  }
1631 
1632  if (IntrinsicID == Intrinsic::rint) {
1633  APFloat V = Op->getValueAPF();
1635  return ConstantFP::get(Ty->getContext(), V);
1636  }
1637 
1638  if (IntrinsicID == Intrinsic::nearbyint) {
1639  APFloat V = Op->getValueAPF();
1641  return ConstantFP::get(Ty->getContext(), V);
1642  }
1643 
1644  /// We only fold functions with finite arguments. Folding NaN and inf is
1645  /// likely to be aborted with an exception anyway, and some host libms
1646  /// have known errors raising exceptions.
1647  if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity())
1648  return nullptr;
1649 
1650  /// Currently APFloat versions of these functions do not exist, so we use
1651  /// the host native double versions. Float versions are not called
1652  /// directly but for all these it is true (float)(f((double)arg)) ==
1653  /// f(arg). Long double not supported yet.
1654  double V = getValueAsDouble(Op);
1655 
1656  switch (IntrinsicID) {
1657  default: break;
1658  case Intrinsic::fabs:
1659  return ConstantFoldFP(fabs, V, Ty);
1660  case Intrinsic::log2:
1661  return ConstantFoldFP(Log2, V, Ty);
1662  case Intrinsic::log:
1663  return ConstantFoldFP(log, V, Ty);
1664  case Intrinsic::log10:
1665  return ConstantFoldFP(log10, V, Ty);
1666  case Intrinsic::exp:
1667  return ConstantFoldFP(exp, V, Ty);
1668  case Intrinsic::exp2:
1669  return ConstantFoldFP(exp2, V, Ty);
1670  case Intrinsic::sin:
1671  return ConstantFoldFP(sin, V, Ty);
1672  case Intrinsic::cos:
1673  return ConstantFoldFP(cos, V, Ty);
1674  case Intrinsic::sqrt:
1675  return ConstantFoldFP(sqrt, V, Ty);
1676  }
1677 
1678  if (!TLI)
1679  return nullptr;
1680 
1681  char NameKeyChar = Name[0];
1682  if (Name[0] == '_' && Name.size() > 2 && Name[1] == '_')
1683  NameKeyChar = Name[2];
1684 
1685  switch (NameKeyChar) {
1686  case 'a':
1687  if ((Name == "acos" && TLI->has(LibFunc_acos)) ||
1688  (Name == "acosf" && TLI->has(LibFunc_acosf)) ||
1689  (Name == "__acos_finite" && TLI->has(LibFunc_acos_finite)) ||
1690  (Name == "__acosf_finite" && TLI->has(LibFunc_acosf_finite)))
1691  return ConstantFoldFP(acos, V, Ty);
1692  else if ((Name == "asin" && TLI->has(LibFunc_asin)) ||
1693  (Name == "asinf" && TLI->has(LibFunc_asinf)) ||
1694  (Name == "__asin_finite" && TLI->has(LibFunc_asin_finite)) ||
1695  (Name == "__asinf_finite" && TLI->has(LibFunc_asinf_finite)))
1696  return ConstantFoldFP(asin, V, Ty);
1697  else if ((Name == "atan" && TLI->has(LibFunc_atan)) ||
1698  (Name == "atanf" && TLI->has(LibFunc_atanf)))
1699  return ConstantFoldFP(atan, V, Ty);
1700  break;
1701  case 'c':
1702  if ((Name == "ceil" && TLI->has(LibFunc_ceil)) ||
1703  (Name == "ceilf" && TLI->has(LibFunc_ceilf)))
1704  return ConstantFoldFP(ceil, V, Ty);
1705  else if ((Name == "cos" && TLI->has(LibFunc_cos)) ||
1706  (Name == "cosf" && TLI->has(LibFunc_cosf)))
1707  return ConstantFoldFP(cos, V, Ty);
1708  else if ((Name == "cosh" && TLI->has(LibFunc_cosh)) ||
1709  (Name == "coshf" && TLI->has(LibFunc_coshf)) ||
1710  (Name == "__cosh_finite" && TLI->has(LibFunc_cosh_finite)) ||
1711  (Name == "__coshf_finite" && TLI->has(LibFunc_coshf_finite)))
1712  return ConstantFoldFP(cosh, V, Ty);
1713  break;
1714  case 'e':
1715  if ((Name == "exp" && TLI->has(LibFunc_exp)) ||
1716  (Name == "expf" && TLI->has(LibFunc_expf)) ||
1717  (Name == "__exp_finite" && TLI->has(LibFunc_exp_finite)) ||
1718  (Name == "__expf_finite" && TLI->has(LibFunc_expf_finite)))
1719  return ConstantFoldFP(exp, V, Ty);
1720  if ((Name == "exp2" && TLI->has(LibFunc_exp2)) ||
1721  (Name == "exp2f" && TLI->has(LibFunc_exp2f)) ||
1722  (Name == "__exp2_finite" && TLI->has(LibFunc_exp2_finite)) ||
1723  (Name == "__exp2f_finite" && TLI->has(LibFunc_exp2f_finite)))
1724  // Constant fold exp2(x) as pow(2,x) in case the host doesn't have a
1725  // C99 library.
1726  return ConstantFoldBinaryFP(pow, 2.0, V, Ty);
1727  break;
1728  case 'f':
1729  if ((Name == "fabs" && TLI->has(LibFunc_fabs)) ||
1730  (Name == "fabsf" && TLI->has(LibFunc_fabsf)))
1731  return ConstantFoldFP(fabs, V, Ty);
1732  else if ((Name == "floor" && TLI->has(LibFunc_floor)) ||
1733  (Name == "floorf" && TLI->has(LibFunc_floorf)))
1734  return ConstantFoldFP(floor, V, Ty);
1735  break;
1736  case 'l':
1737  if ((Name == "log" && V > 0 && TLI->has(LibFunc_log)) ||
1738  (Name == "logf" && V > 0 && TLI->has(LibFunc_logf)) ||
1739  (Name == "__log_finite" && V > 0 &&
1740  TLI->has(LibFunc_log_finite)) ||
1741  (Name == "__logf_finite" && V > 0 &&
1742  TLI->has(LibFunc_logf_finite)))
1743  return ConstantFoldFP(log, V, Ty);
1744  else if ((Name == "log10" && V > 0 && TLI->has(LibFunc_log10)) ||
1745  (Name == "log10f" && V > 0 && TLI->has(LibFunc_log10f)) ||
1746  (Name == "__log10_finite" && V > 0 &&
1747  TLI->has(LibFunc_log10_finite)) ||
1748  (Name == "__log10f_finite" && V > 0 &&
1749  TLI->has(LibFunc_log10f_finite)))
1750  return ConstantFoldFP(log10, V, Ty);
1751  break;
1752  case 'r':
1753  if ((Name == "round" && TLI->has(LibFunc_round)) ||
1754  (Name == "roundf" && TLI->has(LibFunc_roundf)))
1755  return ConstantFoldFP(round, V, Ty);
1756  break;
1757  case 's':
1758  if ((Name == "sin" && TLI->has(LibFunc_sin)) ||
1759  (Name == "sinf" && TLI->has(LibFunc_sinf)))
1760  return ConstantFoldFP(sin, V, Ty);
1761  else if ((Name == "sinh" && TLI->has(LibFunc_sinh)) ||
1762  (Name == "sinhf" && TLI->has(LibFunc_sinhf)) ||
1763  (Name == "__sinh_finite" && TLI->has(LibFunc_sinh_finite)) ||
1764  (Name == "__sinhf_finite" && TLI->has(LibFunc_sinhf_finite)))
1765  return ConstantFoldFP(sinh, V, Ty);
1766  else if ((Name == "sqrt" && V >= 0 && TLI->has(LibFunc_sqrt)) ||
1767  (Name == "sqrtf" && V >= 0 && TLI->has(LibFunc_sqrtf)))
1768  return ConstantFoldFP(sqrt, V, Ty);
1769  break;
1770  case 't':
1771  if ((Name == "tan" && TLI->has(LibFunc_tan)) ||
1772  (Name == "tanf" && TLI->has(LibFunc_tanf)))
1773  return ConstantFoldFP(tan, V, Ty);
1774  else if ((Name == "tanh" && TLI->has(LibFunc_tanh)) ||
1775  (Name == "tanhf" && TLI->has(LibFunc_tanhf)))
1776  return ConstantFoldFP(tanh, V, Ty);
1777  break;
1778  default:
1779  break;
1780  }
1781  return nullptr;
1782  }
1783 
1784  if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) {
1785  switch (IntrinsicID) {
1786  case Intrinsic::bswap:
1787  return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap());
1788  case Intrinsic::ctpop:
1789  return ConstantInt::get(Ty, Op->getValue().countPopulation());
1790  case Intrinsic::bitreverse:
1791  return ConstantInt::get(Ty->getContext(), Op->getValue().reverseBits());
1792  case Intrinsic::convert_from_fp16: {
1793  APFloat Val(APFloat::IEEEhalf(), Op->getValue());
1794 
1795  bool lost = false;
1798 
1799  // Conversion is always precise.
1800  (void)status;
1801  assert(status == APFloat::opOK && !lost &&
1802  "Precision lost during fp16 constfolding");
1803 
1804  return ConstantFP::get(Ty->getContext(), Val);
1805  }
1806  default:
1807  return nullptr;
1808  }
1809  }
1810 
1811  // Support ConstantVector in case we have an Undef in the top.
1812  if (isa<ConstantVector>(Operands[0]) ||
1813  isa<ConstantDataVector>(Operands[0])) {
1814  auto *Op = cast<Constant>(Operands[0]);
1815  switch (IntrinsicID) {
1816  default: break;
1817  case Intrinsic::x86_sse_cvtss2si:
1818  case Intrinsic::x86_sse_cvtss2si64:
1819  case Intrinsic::x86_sse2_cvtsd2si:
1820  case Intrinsic::x86_sse2_cvtsd2si64:
1821  if (ConstantFP *FPOp =
1822  dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
1823  return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
1824  /*roundTowardZero=*/false, Ty);
1825  break;
1826  case Intrinsic::x86_sse_cvttss2si:
1827  case Intrinsic::x86_sse_cvttss2si64:
1828  case Intrinsic::x86_sse2_cvttsd2si:
1829  case Intrinsic::x86_sse2_cvttsd2si64:
1830  if (ConstantFP *FPOp =
1831  dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
1832  return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
1833  /*roundTowardZero=*/true, Ty);
1834  break;
1835  }
1836  }
1837 
1838  return nullptr;
1839  }
1840 
1841  if (Operands.size() == 2) {
1842  if (auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
1843  if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
1844  return nullptr;
1845  double Op1V = getValueAsDouble(Op1);
1846 
1847  if (auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
1848  if (Op2->getType() != Op1->getType())
1849  return nullptr;
1850 
1851  double Op2V = getValueAsDouble(Op2);
1852  if (IntrinsicID == Intrinsic::pow) {
1853  return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
1854  }
1855  if (IntrinsicID == Intrinsic::copysign) {
1856  APFloat V1 = Op1->getValueAPF();
1857  const APFloat &V2 = Op2->getValueAPF();
1858  V1.copySign(V2);
1859  return ConstantFP::get(Ty->getContext(), V1);
1860  }
1861 
1862  if (IntrinsicID == Intrinsic::minnum) {
1863  const APFloat &C1 = Op1->getValueAPF();
1864  const APFloat &C2 = Op2->getValueAPF();
1865  return ConstantFP::get(Ty->getContext(), minnum(C1, C2));
1866  }
1867 
1868  if (IntrinsicID == Intrinsic::maxnum) {
1869  const APFloat &C1 = Op1->getValueAPF();
1870  const APFloat &C2 = Op2->getValueAPF();
1871  return ConstantFP::get(Ty->getContext(), maxnum(C1, C2));
1872  }
1873 
1874  if (!TLI)
1875  return nullptr;
1876  if ((Name == "pow" && TLI->has(LibFunc_pow)) ||
1877  (Name == "powf" && TLI->has(LibFunc_powf)) ||
1878  (Name == "__pow_finite" && TLI->has(LibFunc_pow_finite)) ||
1879  (Name == "__powf_finite" && TLI->has(LibFunc_powf_finite)))
1880  return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
1881  if ((Name == "fmod" && TLI->has(LibFunc_fmod)) ||
1882  (Name == "fmodf" && TLI->has(LibFunc_fmodf)))
1883  return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty);
1884  if ((Name == "atan2" && TLI->has(LibFunc_atan2)) ||
1885  (Name == "atan2f" && TLI->has(LibFunc_atan2f)) ||
1886  (Name == "__atan2_finite" && TLI->has(LibFunc_atan2_finite)) ||
1887  (Name == "__atan2f_finite" && TLI->has(LibFunc_atan2f_finite)))
1888  return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
1889  } else if (auto *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
1890  if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy())
1891  return ConstantFP::get(Ty->getContext(),
1892  APFloat((float)std::pow((float)Op1V,
1893  (int)Op2C->getZExtValue())));
1894  if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy())
1895  return ConstantFP::get(Ty->getContext(),
1896  APFloat((float)std::pow((float)Op1V,
1897  (int)Op2C->getZExtValue())));
1898  if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy())
1899  return ConstantFP::get(Ty->getContext(),
1900  APFloat((double)std::pow((double)Op1V,
1901  (int)Op2C->getZExtValue())));
1902  }
1903  return nullptr;
1904  }
1905 
1906  if (auto *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
1907  if (auto *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
1908  switch (IntrinsicID) {
1909  default: break;
1910  case Intrinsic::sadd_with_overflow:
1911  case Intrinsic::uadd_with_overflow:
1912  case Intrinsic::ssub_with_overflow:
1913  case Intrinsic::usub_with_overflow:
1914  case Intrinsic::smul_with_overflow:
1915  case Intrinsic::umul_with_overflow: {
1916  APInt Res;
1917  bool Overflow;
1918  switch (IntrinsicID) {
1919  default: llvm_unreachable("Invalid case");
1920  case Intrinsic::sadd_with_overflow:
1921  Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
1922  break;
1923  case Intrinsic::uadd_with_overflow:
1924  Res = Op1->getValue().uadd_ov(Op2->getValue(), Overflow);
1925  break;
1926  case Intrinsic::ssub_with_overflow:
1927  Res = Op1->getValue().ssub_ov(Op2->getValue(), Overflow);
1928  break;
1929  case Intrinsic::usub_with_overflow:
1930  Res = Op1->getValue().usub_ov(Op2->getValue(), Overflow);
1931  break;
1932  case Intrinsic::smul_with_overflow:
1933  Res = Op1->getValue().smul_ov(Op2->getValue(), Overflow);
1934  break;
1935  case Intrinsic::umul_with_overflow:
1936  Res = Op1->getValue().umul_ov(Op2->getValue(), Overflow);
1937  break;
1938  }
1939  Constant *Ops[] = {
1940  ConstantInt::get(Ty->getContext(), Res),
1941  ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
1942  };
1943  return ConstantStruct::get(cast<StructType>(Ty), Ops);
1944  }
1945  case Intrinsic::cttz:
1946  if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef.
1947  return UndefValue::get(Ty);
1948  return ConstantInt::get(Ty, Op1->getValue().countTrailingZeros());
1949  case Intrinsic::ctlz:
1950  if (Op2->isOne() && Op1->isZero()) // ctlz(0, 1) is undef.
1951  return UndefValue::get(Ty);
1952  return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros());
1953  }
1954  }
1955 
1956  return nullptr;
1957  }
1958  return nullptr;
1959  }
1960 
1961  if (Operands.size() != 3)
1962  return nullptr;
1963 
1964  if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
1965  if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
1966  if (const auto *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
1967  switch (IntrinsicID) {
1968  default: break;
1969  case Intrinsic::fma:
1970  case Intrinsic::fmuladd: {
1971  APFloat V = Op1->getValueAPF();
1972  APFloat::opStatus s = V.fusedMultiplyAdd(Op2->getValueAPF(),
1973  Op3->getValueAPF(),
1975  if (s != APFloat::opInvalidOp)
1976  return ConstantFP::get(Ty->getContext(), V);
1977 
1978  return nullptr;
1979  }
1980  }
1981  }
1982  }
1983  }
1984 
1985  return nullptr;
1986 }
1987 
1988 Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
1989  VectorType *VTy, ArrayRef<Constant *> Operands,
1990  const DataLayout &DL,
1991  const TargetLibraryInfo *TLI) {
1993  SmallVector<Constant *, 4> Lane(Operands.size());
1994  Type *Ty = VTy->getElementType();
1995 
1996  if (IntrinsicID == Intrinsic::masked_load) {
1997  auto *SrcPtr = Operands[0];
1998  auto *Mask = Operands[2];
1999  auto *Passthru = Operands[3];
2000 
2001  Constant *VecData = ConstantFoldLoadFromConstPtr(SrcPtr, VTy, DL);
2002 
2003  SmallVector<Constant *, 32> NewElements;
2004  for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
2005  auto *MaskElt = Mask->getAggregateElement(I);
2006  if (!MaskElt)
2007  break;
2008  auto *PassthruElt = Passthru->getAggregateElement(I);
2009  auto *VecElt = VecData ? VecData->getAggregateElement(I) : nullptr;
2010  if (isa<UndefValue>(MaskElt)) {
2011  if (PassthruElt)
2012  NewElements.push_back(PassthruElt);
2013  else if (VecElt)
2014  NewElements.push_back(VecElt);
2015  else
2016  return nullptr;
2017  }
2018  if (MaskElt->isNullValue()) {
2019  if (!PassthruElt)
2020  return nullptr;
2021  NewElements.push_back(PassthruElt);
2022  } else if (MaskElt->isOneValue()) {
2023  if (!VecElt)
2024  return nullptr;
2025  NewElements.push_back(VecElt);
2026  } else {
2027  return nullptr;
2028  }
2029  }
2030  if (NewElements.size() != VTy->getNumElements())
2031  return nullptr;
2032  return ConstantVector::get(NewElements);
2033  }
2034 
2035  for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
2036  // Gather a column of constants.
2037  for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
2038  // These intrinsics use a scalar type for their second argument.
2039  if (J == 1 &&
2040  (IntrinsicID == Intrinsic::cttz || IntrinsicID == Intrinsic::ctlz ||
2041  IntrinsicID == Intrinsic::powi)) {
2042  Lane[J] = Operands[J];
2043  continue;
2044  }
2045 
2046  Constant *Agg = Operands[J]->getAggregateElement(I);
2047  if (!Agg)
2048  return nullptr;
2049 
2050  Lane[J] = Agg;
2051  }
2052 
2053  // Use the regular scalar folding to simplify this column.
2054  Constant *Folded = ConstantFoldScalarCall(Name, IntrinsicID, Ty, Lane, TLI);
2055  if (!Folded)
2056  return nullptr;
2057  Result[I] = Folded;
2058  }
2059 
2060  return ConstantVector::get(Result);
2061 }
2062 
2063 } // end anonymous namespace
2064 
2065 Constant *
2067  ArrayRef<Constant *> Operands,
2068  const TargetLibraryInfo *TLI) {
2069  if (CS.isNoBuiltin())
2070  return nullptr;
2071  if (!F->hasName())
2072  return nullptr;
2073  StringRef Name = F->getName();
2074 
2075  Type *Ty = F->getReturnType();
2076 
2077  if (auto *VTy = dyn_cast<VectorType>(Ty))
2078  return ConstantFoldVectorCall(Name, F->getIntrinsicID(), VTy, Operands,
2079  F->getParent()->getDataLayout(), TLI);
2080 
2081  return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI);
2082 }
2083 
2085  // FIXME: Refactor this code; this duplicates logic in LibCallsShrinkWrap
2086  // (and to some extent ConstantFoldScalarCall).
2087  if (CS.isNoBuiltin())
2088  return false;
2089  Function *F = CS.getCalledFunction();
2090  if (!F)
2091  return false;
2092 
2093  LibFunc Func;
2094  if (!TLI || !TLI->getLibFunc(*F, Func))
2095  return false;
2096 
2097  if (CS.getNumArgOperands() == 1) {
2098  if (ConstantFP *OpC = dyn_cast<ConstantFP>(CS.getArgOperand(0))) {
2099  const APFloat &Op = OpC->getValueAPF();
2100  switch (Func) {
2101  case LibFunc_logl:
2102  case LibFunc_log:
2103  case LibFunc_logf:
2104  case LibFunc_log2l:
2105  case LibFunc_log2:
2106  case LibFunc_log2f:
2107  case LibFunc_log10l:
2108  case LibFunc_log10:
2109  case LibFunc_log10f:
2110  return Op.isNaN() || (!Op.isZero() && !Op.isNegative());
2111 
2112  case LibFunc_expl:
2113  case LibFunc_exp:
2114  case LibFunc_expf:
2115  // FIXME: These boundaries are slightly conservative.
2116  if (OpC->getType()->isDoubleTy())
2117  return Op.compare(APFloat(-745.0)) != APFloat::cmpLessThan &&
2118  Op.compare(APFloat(709.0)) != APFloat::cmpGreaterThan;
2119  if (OpC->getType()->isFloatTy())
2120  return Op.compare(APFloat(-103.0f)) != APFloat::cmpLessThan &&
2121  Op.compare(APFloat(88.0f)) != APFloat::cmpGreaterThan;
2122  break;
2123 
2124  case LibFunc_exp2l:
2125  case LibFunc_exp2:
2126  case LibFunc_exp2f:
2127  // FIXME: These boundaries are slightly conservative.
2128  if (OpC->getType()->isDoubleTy())
2129  return Op.compare(APFloat(-1074.0)) != APFloat::cmpLessThan &&
2130  Op.compare(APFloat(1023.0)) != APFloat::cmpGreaterThan;
2131  if (OpC->getType()->isFloatTy())
2132  return Op.compare(APFloat(-149.0f)) != APFloat::cmpLessThan &&
2133  Op.compare(APFloat(127.0f)) != APFloat::cmpGreaterThan;
2134  break;
2135 
2136  case LibFunc_sinl:
2137  case LibFunc_sin:
2138  case LibFunc_sinf:
2139  case LibFunc_cosl:
2140  case LibFunc_cos:
2141  case LibFunc_cosf:
2142  return !Op.isInfinity();
2143 
2144  case LibFunc_tanl:
2145  case LibFunc_tan:
2146  case LibFunc_tanf: {
2147  // FIXME: Stop using the host math library.
2148  // FIXME: The computation isn't done in the right precision.
2149  Type *Ty = OpC->getType();
2150  if (Ty->isDoubleTy() || Ty->isFloatTy() || Ty->isHalfTy()) {
2151  double OpV = getValueAsDouble(OpC);
2152  return ConstantFoldFP(tan, OpV, Ty) != nullptr;
2153  }
2154  break;
2155  }
2156 
2157  case LibFunc_asinl:
2158  case LibFunc_asin:
2159  case LibFunc_asinf:
2160  case LibFunc_acosl:
2161  case LibFunc_acos:
2162  case LibFunc_acosf:
2163  return Op.compare(APFloat(Op.getSemantics(), "-1")) !=
2165  Op.compare(APFloat(Op.getSemantics(), "1")) !=
2167 
2168  case LibFunc_sinh:
2169  case LibFunc_cosh:
2170  case LibFunc_sinhf:
2171  case LibFunc_coshf:
2172  case LibFunc_sinhl:
2173  case LibFunc_coshl:
2174  // FIXME: These boundaries are slightly conservative.
2175  if (OpC->getType()->isDoubleTy())
2176  return Op.compare(APFloat(-710.0)) != APFloat::cmpLessThan &&
2177  Op.compare(APFloat(710.0)) != APFloat::cmpGreaterThan;
2178  if (OpC->getType()->isFloatTy())
2179  return Op.compare(APFloat(-89.0f)) != APFloat::cmpLessThan &&
2180  Op.compare(APFloat(89.0f)) != APFloat::cmpGreaterThan;
2181  break;
2182 
2183  case LibFunc_sqrtl:
2184  case LibFunc_sqrt:
2185  case LibFunc_sqrtf:
2186  return Op.isNaN() || Op.isZero() || !Op.isNegative();
2187 
2188  // FIXME: Add more functions: sqrt_finite, atanh, expm1, log1p,
2189  // maybe others?
2190  default:
2191  break;
2192  }
2193  }
2194  }
2195 
2196  if (CS.getNumArgOperands() == 2) {
2197  ConstantFP *Op0C = dyn_cast<ConstantFP>(CS.getArgOperand(0));
2198  ConstantFP *Op1C = dyn_cast<ConstantFP>(CS.getArgOperand(1));
2199  if (Op0C && Op1C) {
2200  const APFloat &Op0 = Op0C->getValueAPF();
2201  const APFloat &Op1 = Op1C->getValueAPF();
2202 
2203  switch (Func) {
2204  case LibFunc_powl:
2205  case LibFunc_pow:
2206  case LibFunc_powf: {
2207  // FIXME: Stop using the host math library.
2208  // FIXME: The computation isn't done in the right precision.
2209  Type *Ty = Op0C->getType();
2210  if (Ty->isDoubleTy() || Ty->isFloatTy() || Ty->isHalfTy()) {
2211  if (Ty == Op1C->getType()) {
2212  double Op0V = getValueAsDouble(Op0C);
2213  double Op1V = getValueAsDouble(Op1C);
2214  return ConstantFoldBinaryFP(pow, Op0V, Op1V, Ty) != nullptr;
2215  }
2216  }
2217  break;
2218  }
2219 
2220  case LibFunc_fmodl:
2221  case LibFunc_fmod:
2222  case LibFunc_fmodf:
2223  return Op0.isNaN() || Op1.isNaN() ||
2224  (!Op0.isInfinity() && !Op1.isZero());
2225 
2226  default:
2227  break;
2228  }
2229  }
2230  }
2231 
2232  return false;
2233 }
Constant * ConstantFoldCastOperand(unsigned Opcode, Constant *C, Type *DestTy, const DataLayout &DL)
Attempt to constant fold a cast with the specified operand.
opStatus roundToIntegral(roundingMode RM)
Definition: APFloat.h:1008
Type * getVectorElementType() const
Definition: Type.h:368
const NoneType None
Definition: None.h:24
uint64_t CallInst * C
static Constant * FoldBitCast(Constant *V, Type *DestTy)
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:109
bool isZero() const
Definition: APFloat.h:1128
bool isAllOnesValue() const
Return true if this is the value that would be returned by getAllOnesValue.
Definition: Constants.cpp:101
static IntegerType * getInt1Ty(LLVMContext &C)
Definition: Type.cpp:173
uint64_t getZExtValue() const
Get zero extended value.
Definition: APInt.h:1542
const T & back() const
back - Get the last element.
Definition: ArrayRef.h:158
MutableArrayRef< T > makeMutableArrayRef(T &OneElt)
Construct a MutableArrayRef from a single element.
Definition: ArrayRef.h:503
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
Constant * ConstantFoldLoadThroughGEPConstantExpr(Constant *C, ConstantExpr *CE)
ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a getelementptr constantexpr, return the constant value being addressed by the constant expression, or null if something is funny and we can&#39;t decide.
static Constant * getGetElementPtr(Type *Ty, Constant *C, ArrayRef< Constant *> IdxList, bool InBounds=false, Optional< unsigned > InRangeIndex=None, Type *OnlyIfReducedTy=nullptr)
Getelementptr form.
Definition: Constants.h:1115
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
const StructLayout * getStructLayout(StructType *Ty) const
Returns a StructLayout object, indicating the alignment of the struct, its size, and the offsets of i...
Definition: DataLayout.cpp:562
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE size_t size() const
size - Get the string size.
Definition: StringRef.h:138
Optional< unsigned > getInRangeIndex() const
Returns the offset of the index with an inrange attachment, or None if none.
Definition: Operator.h:410
static APInt getLowBitsSet(unsigned numBits, unsigned loBitsSet)
Get a value with low bits set.
Definition: APInt.h:641
static uint64_t round(uint64_t Acc, uint64_t Input)
Definition: xxhash.cpp:57
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1665
float convertToFloat() const
Definition: APFloat.h:1098
static Constant * getExtractElement(Constant *Vec, Constant *Idx, Type *OnlyIfReducedTy=nullptr)
Definition: Constants.cpp:1980
bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, APInt &Offset, const DataLayout &DL)
If this constant is a constant offset from a global, return the global and the constant.
LLVMContext & getContext() const
All values hold a context through their type.
Definition: Value.cpp:697
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:818
const fltSemantics & getSemantics() const
Definition: APFloat.h:1140
unsigned getPointerAddressSpace() const
Get the address space of this pointer or pointer vector type.
Definition: DerivedTypes.h:503
An instruction for reading from memory.
Definition: Instructions.h:164
static IntegerType * getInt64Ty(LLVMContext &C)
Definition: Type.cpp:177
APInt zextOrTrunc(unsigned width) const
Zero extend or truncate to width.
Definition: APInt.cpp:883
static Constant * getCompare(unsigned short pred, Constant *C1, Constant *C2, bool OnlyIfReduced=false)
Return an ICmp or FCmp comparison operator constant expression.
Definition: Constants.cpp:1832
Hexagon Common GEP
static Constant * getSub(Constant *C1, Constant *C2, bool HasNUW=false, bool HasNSW=false)
Definition: Constants.cpp:2126
bool isVectorTy() const
True if this is an instance of VectorType.
Definition: Type.h:227
static IntegerType * getInt16Ty(LLVMContext &C)
Definition: Type.cpp:175
op_iterator op_begin()
Definition: User.h:214
unsigned getElementContainingOffset(uint64_t Offset) const
Given a valid byte offset into the structure, returns the structure index that contains it...
Definition: DataLayout.cpp:84
unsigned getBitWidth() const
Return the number of bits in the APInt.
Definition: APInt.h:1488
static Constant * getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx, Type *OnlyIfReducedTy=nullptr)
Definition: Constants.cpp:2002
LLVMContext & getContext() const
Return the LLVMContext in which this type was uniqued.
Definition: Type.h:130
static Constant * getNullValue(Type *Ty)
Constructor to create a &#39;0&#39; constant of arbitrary type.
Definition: Constants.cpp:207
amode Optimize addressing mode
opStatus convertToInteger(MutableArrayRef< integerPart > Input, unsigned int Width, bool IsSigned, roundingMode RM, bool *IsExact) const
Definition: APFloat.h:1069
Used to lazily calculate structure layout information for a target machine, based on the DataLayout s...
Definition: DataLayout.h:493
bool isVolatile() const
Return true if this is a load from a volatile memory location.
Definition: Instructions.h:217
static Constant * getIntegerCast(Constant *C, Type *Ty, bool isSigned)
Create a ZExt, Bitcast or Trunc for integer -> integer casts.
Definition: Constants.cpp:1518
static bool castIsValid(Instruction::CastOps op, Value *S, Type *DstTy)
This method can be used to determine if a cast from S to DstTy using Opcode op is valid or not...
Type * getPointerElementType() const
Definition: Type.h:373
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:361
unsigned getPointerTypeSizeInBits(Type *) const
Layout pointer size, in bits, based on the type.
Definition: DataLayout.cpp:614
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:451
bool isFloatingPointTy() const
Return true if this is one of the six floating-point types.
Definition: Type.h:162
roundingMode
IEEE-754R 4.3: Rounding-direction attributes.
Definition: APFloat.h:174
APInt zextOrSelf(unsigned width) const
Zero extend or truncate to width.
Definition: APInt.cpp:899
A Use represents the edge between a Value definition and its users.
Definition: Use.h:56
static Constant * getLShr(Constant *C1, Constant *C2, bool isExact=false)
Definition: Constants.cpp:2193
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
Definition: Type.cpp:639
bool isIntegerTy() const
True if this is an instance of IntegerType.
Definition: Type.h:197
Windows NT (Windows on ARM)
iterator_range< const unsigned char * > bytes() const
Definition: StringRef.h:116
uint64_t getNumElements() const
Definition: DerivedTypes.h:359
This file implements a class to represent arbitrary precision integral constant values and operations...
auto reverse(ContainerTy &&C, typename std::enable_if< has_rbegin< ContainerTy >::value >::type *=nullptr) -> decltype(make_range(C.rbegin(), C.rend()))
Definition: STLExtras.h:250
Constant * ConstantFoldConstant(const Constant *C, const DataLayout &DL, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldConstant - Attempt to fold the constant using the specified DataLayout.
static Constant * get(unsigned Opcode, Constant *C1, Constant *C2, unsigned Flags=0, Type *OnlyIfReducedTy=nullptr)
get - Return a binary or shift operator constant expression, folding if possible. ...
Definition: Constants.cpp:1711
static Constant * getZExt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1570
bool isNullValue() const
Return true if this is the value that would be returned by getNullValue.
Definition: Constants.cpp:86
A constant value that is initialized with an expression using other constant values.
Definition: Constants.h:862
int64_t getSExtValue() const
Get sign extended value.
Definition: APInt.h:1554
bool isInfinity() const
Definition: APFloat.h:1129
#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
opStatus convert(const fltSemantics &ToSemantics, roundingMode RM, bool *losesInfo)
Definition: APFloat.cpp:4441
ValTy * getArgOperand(unsigned i) const
Definition: CallSite.h:294
bool isNoBuiltin() const
Return true if the call should not be treated as a call to a builtin.
Definition: CallSite.h:425
bool isInBounds() const
Test whether this is an inbounds GEP, as defined by LangRef.html.
Definition: Operator.h:404
bool has(LibFunc F) const
Tests whether a library function is available.
static Constant * getSelect(Constant *C, Constant *V1, Constant *V2, Type *OnlyIfReducedTy=nullptr)
Select constant expr.
Definition: Constants.cpp:1854
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:133
bool isMathLibCallNoop(CallSite CS, const TargetLibraryInfo *TLI)
Check whether the given call has no side-effects.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
bool isLittleEndian() const
Layout endianness...
Definition: DataLayout.h:216
unsigned getOpcode() const
Returns a member of one of the enums like Instruction::Add.
Definition: Instruction.h:121
static const fltSemantics & IEEEdouble() LLVM_READNONE
Definition: APFloat.cpp:122
const char * Name
Value * getOperand(unsigned i) const
Definition: User.h:154
Class to represent pointers.
Definition: DerivedTypes.h:467
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:277
Type * getScalarType() const
If this is a vector type, return the element type, otherwise return &#39;this&#39;.
Definition: Type.h:301
static Constant * getBitCast(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1678
bool isFloatTy() const
Return true if this is &#39;float&#39;, a 32-bit IEEE fp type.
Definition: Type.h:147
IntegerType * getIntPtrType(LLVMContext &C, unsigned AddressSpace=0) const
Returns an integer type with size at least as big as that of a pointer in the given address space...
Definition: DataLayout.cpp:702
static Constant * getInsertValue(Constant *Agg, Constant *Val, ArrayRef< unsigned > Idxs, Type *OnlyIfReducedTy=nullptr)
Definition: Constants.cpp:2048
bool isNegative() const
Determine sign of this APInt.
Definition: APInt.h:357
Type * getReturnType() const
Returns the type of the ret val.
Definition: Function.h:142
bool isNegative() const
Definition: APFloat.h:1132
bool hasName() const
Definition: Value.h:251
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
std::error_code status(const Twine &path, file_status &result, bool follow=true)
Get file status as if by POSIX stat().
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
bool isNaN() const
Definition: APFloat.h:1130
This is an important base class in LLVM.
Definition: Constant.h:42
const APInt & getConstant() const
Returns the value when all bits have a known value.
Definition: KnownBits.h:57
This file contains the declarations for the subclasses of Constant, which represent the different fla...
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:221
static Constant * getAnd(Constant *C1, Constant *C2)
Definition: Constants.cpp:2174
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:264
APInt ssub_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1886
Constant * ConstantFoldInstruction(Instruction *I, const DataLayout &DL, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldInstruction - Try to constant fold the specified instruction.
double convertToDouble() const
Definition: APFloat.h:1097
static Constant * getShuffleVector(Constant *V1, Constant *V2, Constant *Mask, Type *OnlyIfReducedTy=nullptr)
Definition: Constants.cpp:2025
op_iterator op_end()
Definition: User.h:216
This file declares a class to represent arbitrary precision floating point values and provide a varie...
bool isHalfTy() const
Return true if this is &#39;half&#39;, a 16-bit IEEE fp type.
Definition: Type.h:144
bool isConstant() const
Returns true if we know the value of all bits.
Definition: KnownBits.h:50
Predicate
This enumeration lists the possible predicates for CmpInst subclasses.
Definition: InstrTypes.h:860
bool isBinaryOp() const
Definition: Instruction.h:125
static Constant * get(StructType *T, ArrayRef< Constant *> V)
Definition: Constants.cpp:949
op_range operands()
Definition: User.h:222
bool isX86_MMXTy() const
Return true if this is X86 MMX.
Definition: Type.h:182
Class to represent integer types.
Definition: DerivedTypes.h:40
Constant * ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty, const DataLayout &DL)
ConstantFoldLoadFromConstPtr - Return the value that a load from C would produce if it is constant an...
static Constant * getAllOnesValue(Type *Ty)
Get the all ones value.
Definition: Constants.cpp:261
static UndefValue * get(Type *T)
Static factory methods - Return an &#39;undef&#39; object of the specified type.
Definition: Constants.cpp:1320
const Constant * stripPointerCasts() const
Definition: Constant.h:153
const AMDGPUAS & AS
unsigned getNumArgOperands() const
Definition: CallSite.h:290
bool isCast() const
Definition: Instruction.h:127
Constant * ConstantFoldLoadThroughGEPIndices(Constant *C, ArrayRef< Constant *> Indices)
ConstantFoldLoadThroughGEPIndices - Given a constant and getelementptr indices (with an implied zero ...
static wasm::ValType getType(const TargetRegisterClass *RC)
APInt uadd_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1880
Constant * ConstantFoldCompareInstOperands(unsigned Predicate, Constant *LHS, Constant *RHS, const DataLayout &DL, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldCompareInstOperands - Attempt to constant fold a compare instruction (icmp/fcmp) with the...
Value * GetUnderlyingObject(Value *V, const DataLayout &DL, unsigned MaxLookup=6)
This method strips off any GEP address adjustments and pointer casts from the specified value...
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void copySign(const APFloat &RHS)
Definition: APFloat.h:1055
LLVM_READONLY APFloat maxnum(const APFloat &A, const APFloat &B)
Implements IEEE maxNum semantics.
Definition: APFloat.h:1223
const T * data() const
Definition: ArrayRef.h:146
const APFloat & getValueAPF() const
Definition: Constants.h:294
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:1492
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
Type * getSequentialElementType() const
Definition: Type.h:355
unsigned getNumOperands() const
Definition: User.h:176
#define E
Definition: LargeTest.cpp:27
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
static const fltSemantics & IEEEhalf() LLVM_READNONE
Definition: APFloat.cpp:116
unsigned getScalarSizeInBits() const LLVM_READONLY
If this is a vector type, return the getPrimitiveSizeInBits value for the element type...
Definition: Type.cpp:130
double Log2(double Value)
Return the log base 2 of the specified value.
Definition: MathExtras.h:520
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:864
Provides information about what library functions are available for the current target.
Predicate
Predicate - These are "(BI << 5) | BO" for various predicates.
Definition: PPCPredicates.h:27
bool isAggregateType() const
Return true if the type is an aggregate type.
Definition: Type.h:255
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:180
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 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
bool uge(const APInt &RHS) const
Unsigned greater or equal comparison.
Definition: APInt.h:1272
Intrinsic::ID getIntrinsicID() const LLVM_READONLY
getIntrinsicID - This method returns the ID number of the specified function, or Intrinsic::not_intri...
Definition: Function.h:167
unsigned getVectorNumElements() const
Definition: DerivedTypes.h:462
Class to represent vector types.
Definition: DerivedTypes.h:393
Class for arbitrary precision integers.
Definition: APInt.h:69
static Constant * getCast(unsigned ops, Constant *C, Type *Ty, bool OnlyIfReduced=false)
Convenience function for getting a Cast operation.
Definition: Constants.cpp:1435
Type * getResultElementType() const
Definition: Operator.cpp:29
bool getLibFunc(StringRef funcName, LibFunc &F) const
Searches for a particular function name.
ArrayRef< T > slice(size_t N, size_t M) const
slice(n, m) - Chop off the first N elements of the array, and keep M elements in the array...
Definition: ArrayRef.h:179
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:398
bool isNonIntegralPointerType(PointerType *PT) const
Definition: DataLayout.h:332
uint64_t getTypeSizeInBits(Type *Ty) const
Size examples:
Definition: DataLayout.h:532
uint64_t getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:405
opStatus
IEEE-754R 7: Default exception handling.
Definition: APFloat.h:185
uint64_t getElementOffset(unsigned Idx) const
Definition: DataLayout.h:515
static Type * getIndexedType(Type *Ty, ArrayRef< Value *> IdxList)
Returns the type of the element that would be loaded with a load instruction with the specified param...
static IntegerType * getInt32Ty(LLVMContext &C)
Definition: Type.cpp:176
unsigned getIntegerBitWidth() const
Definition: DerivedTypes.h:97
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:61
StringRef getName() const
Return a constant reference to the value&#39;s name.
Definition: Value.cpp:218
Establish a view to a call site for examination.
Definition: CallSite.h:687
APInt smul_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1905
static Instruction::CastOps getCastOpcode(const Value *Val, bool SrcIsSigned, Type *Ty, bool DstIsSigned)
Returns the opcode necessary to cast Val into Ty using usual casting rules.
static Constant * getPtrToInt(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:1652
#define I(x, y, z)
Definition: MD5.cpp:58
static Constant * getOr(Constant *C1, Constant *C2)
Definition: Constants.cpp:2178
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
Constant * ConstantFoldInstOperands(Instruction *I, ArrayRef< Constant *> Ops, const DataLayout &DL, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldInstOperands - Attempt to constant fold an instruction with the specified operands...
static Constant * getShl(Constant *C1, Constant *C2, bool HasNUW=false, bool HasNSW=false)
Definition: Constants.cpp:2186
static volatile int Zero
APInt umul_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1915
bool getConstantStringInfo(const Value *V, StringRef &Str, uint64_t Offset=0, bool TrimAtNul=true)
This function computes the length of a null-terminated C string pointed to by V.
FunTy * getCalledFunction() const
Return the function being called if this is a direct call, otherwise return null (if it&#39;s an indirect...
Definition: CallSite.h:104
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
opStatus fusedMultiplyAdd(const APFloat &Multiplicand, const APFloat &Addend, roundingMode RM)
Definition: APFloat.h:995
APInt sadd_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1873
unsigned getPrimitiveSizeInBits() const LLVM_READONLY
Return the basic size of this type if it is a primitive type.
Definition: Type.cpp:115
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:545
LLVM Value Representation.
Definition: Value.h:73
static VectorType * get(Type *ElementType, unsigned NumElements)
This static method is the primary way to construct an VectorType.
Definition: Type.cpp:593
bool canConstantFoldCallTo(ImmutableCallSite CS, const Function *F)
canConstantFoldCallTo - Return true if its even possible to fold a call to the specified function...
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
uint64_t getTypeAllocSizeInBits(Type *Ty) const
Returns the offset in bits between successive objects of the specified type, including alignment padd...
Definition: DataLayout.h:415
Type * getElementType() const
Definition: DerivedTypes.h:360
static Constant * getExtractValue(Constant *Agg, ArrayRef< unsigned > Idxs, Type *OnlyIfReducedTy=nullptr)
Definition: Constants.cpp:2072
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Predicate getSwappedPredicate() const
For example, EQ->EQ, SLE->SGE, ULT->UGT, OEQ->OEQ, ULE->UGE, OLT->OGT, etc.
Definition: InstrTypes.h:974
Type * getSourceElementType() const
Definition: Operator.cpp:23
APInt bitcastToAPInt() const
Definition: APFloat.h:1094
int * Ptr
bool isDoubleTy() const
Return true if this is &#39;double&#39;, a 64-bit IEEE fp type.
Definition: Type.h:150
Constant * ConstantFoldCall(ImmutableCallSite CS, Function *F, ArrayRef< Constant *> Operands, const TargetLibraryInfo *TLI=nullptr)
ConstantFoldCall - Attempt to constant fold a call to the specified function with the specified argum...
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...
static Constant * get(ArrayRef< Constant *> V)
Definition: Constants.cpp:984
LLVM_READONLY APFloat minnum(const APFloat &A, const APFloat &B)
Implements IEEE minNum semantics.
Definition: APFloat.h:1212
int64_t getIndexedOffsetInType(Type *ElemTy, ArrayRef< Value *> Indices) const
Returns the offset from the beginning of the type for the specified indices.
Definition: DataLayout.cpp:729
PointerType * getType() const
Global values are always pointers.
Definition: GlobalValue.h:260
bool isNullValue() const
Determine if all bits are clear.
Definition: APInt.h:399
bool isStructTy() const
True if this is an instance of StructType.
Definition: Type.h:215
cmpResult compare(const APFloat &RHS) const
Definition: APFloat.h:1102
APInt sdiv_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1899
const fltSemantics & getFltSemantics() const
Definition: Type.h:169
APInt usub_ov(const APInt &RHS, bool &Overflow) const
Definition: APInt.cpp:1893
Constant * ConstantFoldBinaryOpOperands(unsigned Opcode, Constant *LHS, Constant *RHS, const DataLayout &DL)
Attempt to constant fold a binary operation with the specified operands.