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1 : //===- ConstantFold.cpp - LLVM constant folder ----------------------------===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 : //
10 : // This file implements folding of constants for LLVM. This implements the
11 : // (internal) ConstantFold.h interface, which is used by the
12 : // ConstantExpr::get* methods to automatically fold constants when possible.
13 : //
14 : // The current constant folding implementation is implemented in two pieces: the
15 : // pieces that don't need DataLayout, and the pieces that do. This is to avoid
16 : // a dependence in IR on Target.
17 : //
18 : //===----------------------------------------------------------------------===//
19 :
20 : #include "ConstantFold.h"
21 : #include "llvm/ADT/APSInt.h"
22 : #include "llvm/ADT/SmallVector.h"
23 : #include "llvm/IR/Constants.h"
24 : #include "llvm/IR/DerivedTypes.h"
25 : #include "llvm/IR/Function.h"
26 : #include "llvm/IR/GetElementPtrTypeIterator.h"
27 : #include "llvm/IR/GlobalAlias.h"
28 : #include "llvm/IR/GlobalVariable.h"
29 : #include "llvm/IR/Instructions.h"
30 : #include "llvm/IR/Operator.h"
31 : #include "llvm/IR/PatternMatch.h"
32 : #include "llvm/Support/ErrorHandling.h"
33 : #include "llvm/Support/ManagedStatic.h"
34 : #include "llvm/Support/MathExtras.h"
35 : using namespace llvm;
36 : using namespace llvm::PatternMatch;
37 :
38 : //===----------------------------------------------------------------------===//
39 : // ConstantFold*Instruction Implementations
40 : //===----------------------------------------------------------------------===//
41 :
42 : /// Convert the specified vector Constant node to the specified vector type.
43 : /// At this point, we know that the elements of the input vector constant are
44 : /// all simple integer or FP values.
45 195 : static Constant *BitCastConstantVector(Constant *CV, VectorType *DstTy) {
46 :
47 195 : if (CV->isAllOnesValue()) return Constant::getAllOnesValue(DstTy);
48 106 : if (CV->isNullValue()) return Constant::getNullValue(DstTy);
49 :
50 : // If this cast changes element count then we can't handle it here:
51 : // doing so requires endianness information. This should be handled by
52 : // Analysis/ConstantFolding.cpp
53 106 : unsigned NumElts = DstTy->getNumElements();
54 212 : if (NumElts != CV->getType()->getVectorNumElements())
55 : return nullptr;
56 :
57 2 : Type *DstEltTy = DstTy->getElementType();
58 :
59 : SmallVector<Constant*, 16> Result;
60 2 : Type *Ty = IntegerType::get(CV->getContext(), 32);
61 6 : for (unsigned i = 0; i != NumElts; ++i) {
62 : Constant *C =
63 4 : ConstantExpr::getExtractElement(CV, ConstantInt::get(Ty, i));
64 4 : C = ConstantExpr::getBitCast(C, DstEltTy);
65 4 : Result.push_back(C);
66 : }
67 :
68 2 : return ConstantVector::get(Result);
69 : }
70 :
71 : /// This function determines which opcode to use to fold two constant cast
72 : /// expressions together. It uses CastInst::isEliminableCastPair to determine
73 : /// the opcode. Consequently its just a wrapper around that function.
74 : /// Determine if it is valid to fold a cast of a cast
75 : static unsigned
76 696714 : foldConstantCastPair(
77 : unsigned opc, ///< opcode of the second cast constant expression
78 : ConstantExpr *Op, ///< the first cast constant expression
79 : Type *DstTy ///< destination type of the first cast
80 : ) {
81 : assert(Op && Op->isCast() && "Can't fold cast of cast without a cast!");
82 : assert(DstTy && DstTy->isFirstClassType() && "Invalid cast destination type");
83 : assert(CastInst::isCast(opc) && "Invalid cast opcode");
84 :
85 : // The types and opcodes for the two Cast constant expressions
86 696714 : Type *SrcTy = Op->getOperand(0)->getType();
87 696714 : Type *MidTy = Op->getType();
88 : Instruction::CastOps firstOp = Instruction::CastOps(Op->getOpcode());
89 : Instruction::CastOps secondOp = Instruction::CastOps(opc);
90 :
91 : // Assume that pointers are never more than 64 bits wide, and only use this
92 : // for the middle type. Otherwise we could end up folding away illegal
93 : // bitcasts between address spaces with different sizes.
94 696714 : IntegerType *FakeIntPtrTy = Type::getInt64Ty(DstTy->getContext());
95 :
96 : // Let CastInst::isEliminableCastPair do the heavy lifting.
97 696714 : return CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy, DstTy,
98 696714 : nullptr, FakeIntPtrTy, nullptr);
99 : }
100 :
101 2317173 : static Constant *FoldBitCast(Constant *V, Type *DestTy) {
102 2317173 : Type *SrcTy = V->getType();
103 2317173 : if (SrcTy == DestTy)
104 : return V; // no-op cast
105 :
106 : // Check to see if we are casting a pointer to an aggregate to a pointer to
107 : // the first element. If so, return the appropriate GEP instruction.
108 : if (PointerType *PTy = dyn_cast<PointerType>(V->getType()))
109 : if (PointerType *DPTy = dyn_cast<PointerType>(DestTy))
110 : if (PTy->getAddressSpace() == DPTy->getAddressSpace()
111 2312819 : && PTy->getElementType()->isSized()) {
112 : SmallVector<Value*, 8> IdxList;
113 : Value *Zero =
114 2140702 : Constant::getNullValue(Type::getInt32Ty(DPTy->getContext()));
115 2140702 : IdxList.push_back(Zero);
116 2140702 : Type *ElTy = PTy->getElementType();
117 4121303 : while (ElTy != DPTy->getElementType()) {
118 : if (StructType *STy = dyn_cast<StructType>(ElTy)) {
119 92516 : if (STy->getNumElements() == 0) break;
120 92470 : ElTy = STy->getElementType(0);
121 92470 : IdxList.push_back(Zero);
122 : } else if (SequentialType *STy =
123 : dyn_cast<SequentialType>(ElTy)) {
124 1888131 : ElTy = STy->getElementType();
125 1888131 : IdxList.push_back(Zero);
126 : } else {
127 : break;
128 : }
129 : }
130 :
131 2140702 : if (ElTy == DPTy->getElementType())
132 : // This GEP is inbounds because all indices are zero.
133 88781 : return ConstantExpr::getInBoundsGetElementPtr(PTy->getElementType(),
134 : V, IdxList);
135 : }
136 :
137 : // Handle casts from one vector constant to another. We know that the src
138 : // and dest type have the same size (otherwise its an illegal cast).
139 : if (VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
140 320 : if (VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
141 : assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
142 : "Not cast between same sized vectors!");
143 : SrcTy = nullptr;
144 : // First, check for null. Undef is already handled.
145 195 : if (isa<ConstantAggregateZero>(V))
146 0 : return Constant::getNullValue(DestTy);
147 :
148 : // Handle ConstantVector and ConstantAggregateVector.
149 195 : return BitCastConstantVector(V, DestPTy);
150 : }
151 :
152 : // Canonicalize scalar-to-vector bitcasts into vector-to-vector bitcasts
153 : // This allows for other simplifications (although some of them
154 : // can only be handled by Analysis/ConstantFolding.cpp).
155 125 : if (isa<ConstantInt>(V) || isa<ConstantFP>(V))
156 96 : return ConstantExpr::getBitCast(ConstantVector::get(V), DestPTy);
157 : }
158 :
159 : // Finally, implement bitcast folding now. The code below doesn't handle
160 : // bitcast right.
161 4456202 : if (isa<ConstantPointerNull>(V)) // ptr->ptr cast.
162 0 : return ConstantPointerNull::get(cast<PointerType>(DestTy));
163 :
164 : // Handle integral constant input.
165 : if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
166 611 : if (DestTy->isIntegerTy())
167 : // Integral -> Integral. This is a no-op because the bit widths must
168 : // be the same. Consequently, we just fold to V.
169 : return V;
170 :
171 : // See note below regarding the PPC_FP128 restriction.
172 607 : if (DestTy->isFloatingPointTy() && !DestTy->isPPC_FP128Ty())
173 607 : return ConstantFP::get(DestTy->getContext(),
174 1214 : APFloat(DestTy->getFltSemantics(),
175 : CI->getValue()));
176 :
177 : // Otherwise, can't fold this (vector?)
178 : return nullptr;
179 : }
180 :
181 : // Handle ConstantFP input: FP -> Integral.
182 : if (ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
183 : // PPC_FP128 is really the sum of two consecutive doubles, where the first
184 : // double is always stored first in memory, regardless of the target
185 : // endianness. The memory layout of i128, however, depends on the target
186 : // endianness, and so we can't fold this without target endianness
187 : // information. This should instead be handled by
188 : // Analysis/ConstantFolding.cpp
189 6472 : if (FP->getType()->isPPC_FP128Ty())
190 : return nullptr;
191 :
192 : // Make sure dest type is compatible with the folded integer constant.
193 3227 : if (!DestTy->isIntegerTy())
194 : return nullptr;
195 :
196 3222 : return ConstantInt::get(FP->getContext(),
197 6444 : FP->getValueAPF().bitcastToAPInt());
198 : }
199 :
200 : return nullptr;
201 : }
202 :
203 :
204 : /// V is an integer constant which only has a subset of its bytes used.
205 : /// The bytes used are indicated by ByteStart (which is the first byte used,
206 : /// counting from the least significant byte) and ByteSize, which is the number
207 : /// of bytes used.
208 : ///
209 : /// This function analyzes the specified constant to see if the specified byte
210 : /// range can be returned as a simplified constant. If so, the constant is
211 : /// returned, otherwise null is returned.
212 1265 : static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart,
213 : unsigned ByteSize) {
214 : assert(C->getType()->isIntegerTy() &&
215 : (cast<IntegerType>(C->getType())->getBitWidth() & 7) == 0 &&
216 : "Non-byte sized integer input");
217 2530 : unsigned CSize = cast<IntegerType>(C->getType())->getBitWidth()/8;
218 : assert(ByteSize && "Must be accessing some piece");
219 : assert(ByteStart+ByteSize <= CSize && "Extracting invalid piece from input");
220 : assert(ByteSize != CSize && "Should not extract everything");
221 :
222 : // Constant Integers are simple.
223 : if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
224 : APInt V = CI->getValue();
225 18 : if (ByteStart)
226 13 : V.lshrInPlace(ByteStart*8);
227 18 : V = V.trunc(ByteSize*8);
228 18 : return ConstantInt::get(CI->getContext(), V);
229 : }
230 :
231 : // In the input is a constant expr, we might be able to recursively simplify.
232 : // If not, we definitely can't do anything.
233 : ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
234 : if (!CE) return nullptr;
235 :
236 1247 : switch (CE->getOpcode()) {
237 : default: return nullptr;
238 : case Instruction::Or: {
239 14 : Constant *RHS = ExtractConstantBytes(CE->getOperand(1), ByteStart,ByteSize);
240 14 : if (!RHS)
241 : return nullptr;
242 :
243 : // X | -1 -> -1.
244 : if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS))
245 12 : if (RHSC->isMinusOne())
246 : return RHSC;
247 :
248 14 : Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize);
249 14 : if (!LHS)
250 : return nullptr;
251 7 : return ConstantExpr::getOr(LHS, RHS);
252 : }
253 : case Instruction::And: {
254 11 : Constant *RHS = ExtractConstantBytes(CE->getOperand(1), ByteStart,ByteSize);
255 11 : if (!RHS)
256 : return nullptr;
257 :
258 : // X & 0 -> 0.
259 11 : if (RHS->isNullValue())
260 : return RHS;
261 :
262 7 : Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize);
263 7 : if (!LHS)
264 : return nullptr;
265 3 : return ConstantExpr::getAnd(LHS, RHS);
266 : }
267 : case Instruction::LShr: {
268 : ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1));
269 : if (!Amt)
270 : return nullptr;
271 36 : unsigned ShAmt = Amt->getZExtValue();
272 : // Cannot analyze non-byte shifts.
273 36 : if ((ShAmt & 7) != 0)
274 : return nullptr;
275 36 : ShAmt >>= 3;
276 :
277 : // If the extract is known to be all zeros, return zero.
278 36 : if (ByteStart >= CSize-ShAmt)
279 0 : return Constant::getNullValue(IntegerType::get(CE->getContext(),
280 0 : ByteSize*8));
281 : // If the extract is known to be fully in the input, extract it.
282 36 : if (ByteStart+ByteSize+ShAmt <= CSize)
283 36 : return ExtractConstantBytes(CE->getOperand(0), ByteStart+ShAmt, ByteSize);
284 :
285 : // TODO: Handle the 'partially zero' case.
286 : return nullptr;
287 : }
288 :
289 : case Instruction::Shl: {
290 : ConstantInt *Amt = dyn_cast<ConstantInt>(CE->getOperand(1));
291 : if (!Amt)
292 : return nullptr;
293 20 : unsigned ShAmt = Amt->getZExtValue();
294 : // Cannot analyze non-byte shifts.
295 20 : if ((ShAmt & 7) != 0)
296 : return nullptr;
297 16 : ShAmt >>= 3;
298 :
299 : // If the extract is known to be all zeros, return zero.
300 16 : if (ByteStart+ByteSize <= ShAmt)
301 5 : return Constant::getNullValue(IntegerType::get(CE->getContext(),
302 5 : ByteSize*8));
303 : // If the extract is known to be fully in the input, extract it.
304 11 : if (ByteStart >= ShAmt)
305 5 : return ExtractConstantBytes(CE->getOperand(0), ByteStart-ShAmt, ByteSize);
306 :
307 : // TODO: Handle the 'partially zero' case.
308 : return nullptr;
309 : }
310 :
311 : case Instruction::ZExt: {
312 : unsigned SrcBitSize =
313 12 : cast<IntegerType>(CE->getOperand(0)->getType())->getBitWidth();
314 :
315 : // If extracting something that is completely zero, return 0.
316 12 : if (ByteStart*8 >= SrcBitSize)
317 6 : return Constant::getNullValue(IntegerType::get(CE->getContext(),
318 6 : ByteSize*8));
319 :
320 : // If exactly extracting the input, return it.
321 6 : if (ByteStart == 0 && ByteSize*8 == SrcBitSize)
322 : return CE->getOperand(0);
323 :
324 : // If extracting something completely in the input, if the input is a
325 : // multiple of 8 bits, recurse.
326 1 : if ((SrcBitSize&7) == 0 && (ByteStart+ByteSize)*8 <= SrcBitSize)
327 0 : return ExtractConstantBytes(CE->getOperand(0), ByteStart, ByteSize);
328 :
329 : // Otherwise, if extracting a subset of the input, which is not multiple of
330 : // 8 bits, do a shift and trunc to get the bits.
331 1 : if ((ByteStart+ByteSize)*8 < SrcBitSize) {
332 : assert((SrcBitSize&7) && "Shouldn't get byte sized case here");
333 : Constant *Res = CE->getOperand(0);
334 0 : if (ByteStart)
335 0 : Res = ConstantExpr::getLShr(Res,
336 : ConstantInt::get(Res->getType(), ByteStart*8));
337 0 : return ConstantExpr::getTrunc(Res, IntegerType::get(C->getContext(),
338 0 : ByteSize*8));
339 : }
340 :
341 : // TODO: Handle the 'partially zero' case.
342 : return nullptr;
343 : }
344 : }
345 : }
346 :
347 : /// Return a ConstantExpr with type DestTy for sizeof on Ty, with any known
348 : /// factors factored out. If Folded is false, return null if no factoring was
349 : /// possible, to avoid endlessly bouncing an unfoldable expression back into the
350 : /// top-level folder.
351 1211 : static Constant *getFoldedSizeOf(Type *Ty, Type *DestTy, bool Folded) {
352 : if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
353 21 : Constant *N = ConstantInt::get(DestTy, ATy->getNumElements());
354 21 : Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true);
355 21 : return ConstantExpr::getNUWMul(E, N);
356 : }
357 :
358 : if (StructType *STy = dyn_cast<StructType>(Ty))
359 112 : if (!STy->isPacked()) {
360 112 : unsigned NumElems = STy->getNumElements();
361 : // An empty struct has size zero.
362 112 : if (NumElems == 0)
363 0 : return ConstantExpr::getNullValue(DestTy);
364 : // Check for a struct with all members having the same size.
365 : Constant *MemberSize =
366 224 : getFoldedSizeOf(STy->getElementType(0), DestTy, true);
367 : bool AllSame = true;
368 125 : for (unsigned i = 1; i != NumElems; ++i)
369 32 : if (MemberSize !=
370 64 : getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
371 : AllSame = false;
372 : break;
373 : }
374 112 : if (AllSame) {
375 93 : Constant *N = ConstantInt::get(DestTy, NumElems);
376 93 : return ConstantExpr::getNUWMul(MemberSize, N);
377 : }
378 : }
379 :
380 : // Pointer size doesn't depend on the pointee type, so canonicalize them
381 : // to an arbitrary pointee.
382 : if (PointerType *PTy = dyn_cast<PointerType>(Ty))
383 48 : if (!PTy->getElementType()->isIntegerTy(1))
384 : return
385 15 : getFoldedSizeOf(PointerType::get(IntegerType::get(PTy->getContext(), 1),
386 : PTy->getAddressSpace()),
387 15 : DestTy, true);
388 :
389 : // If there's no interesting folding happening, bail so that we don't create
390 : // a constant that looks like it needs folding but really doesn't.
391 1082 : if (!Folded)
392 : return nullptr;
393 :
394 : // Base case: Get a regular sizeof expression.
395 197 : Constant *C = ConstantExpr::getSizeOf(Ty);
396 197 : C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
397 : DestTy, false),
398 : C, DestTy);
399 197 : return C;
400 : }
401 :
402 : /// Return a ConstantExpr with type DestTy for alignof on Ty, with any known
403 : /// factors factored out. If Folded is false, return null if no factoring was
404 : /// possible, to avoid endlessly bouncing an unfoldable expression back into the
405 : /// top-level folder.
406 106 : static Constant *getFoldedAlignOf(Type *Ty, Type *DestTy, bool Folded) {
407 : // The alignment of an array is equal to the alignment of the
408 : // array element. Note that this is not always true for vectors.
409 : if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
410 10 : Constant *C = ConstantExpr::getAlignOf(ATy->getElementType());
411 10 : C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
412 : DestTy,
413 : false),
414 : C, DestTy);
415 10 : return C;
416 : }
417 :
418 : if (StructType *STy = dyn_cast<StructType>(Ty)) {
419 : // Packed structs always have an alignment of 1.
420 20 : if (STy->isPacked())
421 10 : return ConstantInt::get(DestTy, 1);
422 :
423 : // Otherwise, struct alignment is the maximum alignment of any member.
424 : // Without target data, we can't compare much, but we can check to see
425 : // if all the members have the same alignment.
426 10 : unsigned NumElems = STy->getNumElements();
427 : // An empty struct has minimal alignment.
428 10 : if (NumElems == 0)
429 0 : return ConstantInt::get(DestTy, 1);
430 : // Check for a struct with all members having the same alignment.
431 : Constant *MemberAlign =
432 20 : getFoldedAlignOf(STy->getElementType(0), DestTy, true);
433 : bool AllSame = true;
434 20 : for (unsigned i = 1; i != NumElems; ++i)
435 20 : if (MemberAlign != getFoldedAlignOf(STy->getElementType(i), DestTy, true)) {
436 : AllSame = false;
437 : break;
438 : }
439 10 : if (AllSame)
440 : return MemberAlign;
441 : }
442 :
443 : // Pointer alignment doesn't depend on the pointee type, so canonicalize them
444 : // to an arbitrary pointee.
445 : if (PointerType *PTy = dyn_cast<PointerType>(Ty))
446 24 : if (!PTy->getElementType()->isIntegerTy(1))
447 : return
448 8 : getFoldedAlignOf(PointerType::get(IntegerType::get(PTy->getContext(),
449 : 1),
450 : PTy->getAddressSpace()),
451 8 : DestTy, true);
452 :
453 : // If there's no interesting folding happening, bail so that we don't create
454 : // a constant that looks like it needs folding but really doesn't.
455 68 : if (!Folded)
456 : return nullptr;
457 :
458 : // Base case: Get a regular alignof expression.
459 28 : Constant *C = ConstantExpr::getAlignOf(Ty);
460 28 : C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
461 : DestTy, false),
462 : C, DestTy);
463 28 : return C;
464 : }
465 :
466 : /// Return a ConstantExpr with type DestTy for offsetof on Ty and FieldNo, with
467 : /// any known factors factored out. If Folded is false, return null if no
468 : /// factoring was possible, to avoid endlessly bouncing an unfoldable expression
469 : /// back into the top-level folder.
470 35 : static Constant *getFoldedOffsetOf(Type *Ty, Constant *FieldNo, Type *DestTy,
471 : bool Folded) {
472 : if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
473 10 : Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo, false,
474 : DestTy, false),
475 : FieldNo, DestTy);
476 10 : Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true);
477 10 : return ConstantExpr::getNUWMul(E, N);
478 : }
479 :
480 : if (StructType *STy = dyn_cast<StructType>(Ty))
481 25 : if (!STy->isPacked()) {
482 25 : unsigned NumElems = STy->getNumElements();
483 : // An empty struct has no members.
484 25 : if (NumElems == 0)
485 : return nullptr;
486 : // Check for a struct with all members having the same size.
487 : Constant *MemberSize =
488 50 : getFoldedSizeOf(STy->getElementType(0), DestTy, true);
489 : bool AllSame = true;
490 55 : for (unsigned i = 1; i != NumElems; ++i)
491 45 : if (MemberSize !=
492 90 : getFoldedSizeOf(STy->getElementType(i), DestTy, true)) {
493 : AllSame = false;
494 : break;
495 : }
496 25 : if (AllSame) {
497 10 : Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo,
498 : false,
499 : DestTy,
500 : false),
501 : FieldNo, DestTy);
502 10 : return ConstantExpr::getNUWMul(MemberSize, N);
503 : }
504 : }
505 :
506 : // If there's no interesting folding happening, bail so that we don't create
507 : // a constant that looks like it needs folding but really doesn't.
508 15 : if (!Folded)
509 : return nullptr;
510 :
511 : // Base case: Get a regular offsetof expression.
512 0 : Constant *C = ConstantExpr::getOffsetOf(Ty, FieldNo);
513 0 : C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
514 : DestTy, false),
515 : C, DestTy);
516 0 : return C;
517 : }
518 :
519 4750386 : Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
520 : Type *DestTy) {
521 4750386 : if (isa<UndefValue>(V)) {
522 : // zext(undef) = 0, because the top bits will be zero.
523 : // sext(undef) = 0, because the top bits will all be the same.
524 : // [us]itofp(undef) = 0, because the result value is bounded.
525 8816 : if (opc == Instruction::ZExt || opc == Instruction::SExt ||
526 4408 : opc == Instruction::UIToFP || opc == Instruction::SIToFP)
527 4050 : return Constant::getNullValue(DestTy);
528 358 : return UndefValue::get(DestTy);
529 : }
530 :
531 4745978 : if (V->isNullValue() && !DestTy->isX86_MMXTy() &&
532 : opc != Instruction::AddrSpaceCast)
533 606474 : return Constant::getNullValue(DestTy);
534 :
535 : // If the cast operand is a constant expression, there's a few things we can
536 : // do to try to simplify it.
537 : if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
538 1075218 : if (CE->isCast()) {
539 : // Try hard to fold cast of cast because they are often eliminable.
540 696714 : if (unsigned newOpc = foldConstantCastPair(opc, CE, DestTy))
541 695382 : return ConstantExpr::getCast(newOpc, CE->getOperand(0), DestTy);
542 750005 : } else if (CE->getOpcode() == Instruction::GetElementPtr &&
543 : // Do not fold addrspacecast (gep 0, .., 0). It might make the
544 : // addrspacecast uncanonicalized.
545 371417 : opc != Instruction::AddrSpaceCast &&
546 : // Do not fold bitcast (gep) with inrange index, as this loses
547 : // information.
548 750005 : !cast<GEPOperator>(CE)->getInRangeIndex().hasValue() &&
549 : // Do not fold if the gep type is a vector, as bitcasting
550 : // operand 0 of a vector gep will result in a bitcast between
551 : // different sizes.
552 316662 : !CE->getType()->isVectorTy()) {
553 : // If all of the indexes in the GEP are null values, there is no pointer
554 : // adjustment going on. We might as well cast the source pointer.
555 : bool isAllNull = true;
556 828163 : for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
557 623714 : if (!CE->getOperand(i)->isNullValue()) {
558 : isAllNull = false;
559 : break;
560 : }
561 316658 : if (isAllNull)
562 : // This is casting one pointer type to another, always BitCast
563 204449 : return ConstantExpr::getPointerCast(CE->getOperand(0), DestTy);
564 : }
565 : }
566 :
567 : // If the cast operand is a constant vector, perform the cast by
568 : // operating on each element. In the cast of bitcasts, the element
569 : // count may be mismatched; don't attempt to handle that here.
570 3239673 : if ((isa<ConstantVector>(V) || isa<ConstantDataVector>(V)) &&
571 3241564 : DestTy->isVectorTy() &&
572 1891 : DestTy->getVectorNumElements() == V->getType()->getVectorNumElements()) {
573 : SmallVector<Constant*, 16> res;
574 : VectorType *DestVecTy = cast<VectorType>(DestTy);
575 1701 : Type *DstEltTy = DestVecTy->getElementType();
576 1701 : Type *Ty = IntegerType::get(V->getContext(), 32);
577 6924 : for (unsigned i = 0, e = V->getType()->getVectorNumElements(); i != e; ++i) {
578 : Constant *C =
579 5223 : ConstantExpr::getExtractElement(V, ConstantInt::get(Ty, i));
580 5223 : res.push_back(ConstantExpr::getCast(opc, C, DstEltTy));
581 : }
582 1701 : return ConstantVector::get(res);
583 : }
584 :
585 : // We actually have to do a cast now. Perform the cast according to the
586 : // opcode specified.
587 3237972 : switch (opc) {
588 0 : default:
589 0 : llvm_unreachable("Failed to cast constant expression");
590 3839 : case Instruction::FPTrunc:
591 : case Instruction::FPExt:
592 : if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
593 : bool ignored;
594 : APFloat Val = FPC->getValueAPF();
595 7536 : Val.convert(DestTy->isHalfTy() ? APFloat::IEEEhalf() :
596 1994 : DestTy->isFloatTy() ? APFloat::IEEEsingle() :
597 1213 : DestTy->isDoubleTy() ? APFloat::IEEEdouble() :
598 491 : DestTy->isX86_FP80Ty() ? APFloat::x87DoubleExtended() :
599 1 : DestTy->isFP128Ty() ? APFloat::IEEEquad() :
600 0 : DestTy->isPPC_FP128Ty() ? APFloat::PPCDoubleDouble() :
601 0 : APFloat::Bogus(),
602 : APFloat::rmNearestTiesToEven, &ignored);
603 3837 : return ConstantFP::get(V->getContext(), Val);
604 : }
605 : return nullptr; // Can't fold.
606 80 : case Instruction::FPToUI:
607 : case Instruction::FPToSI:
608 : if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
609 : const APFloat &V = FPC->getValueAPF();
610 : bool ignored;
611 : uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
612 80 : APSInt IntVal(DestBitWidth, opc == Instruction::FPToUI);
613 80 : if (APFloat::opInvalidOp ==
614 80 : V.convertToInteger(IntVal, APFloat::rmTowardZero, &ignored)) {
615 : // Undefined behavior invoked - the destination type can't represent
616 : // the input constant.
617 18 : return UndefValue::get(DestTy);
618 : }
619 62 : return ConstantInt::get(FPC->getContext(), IntVal);
620 : }
621 : return nullptr; // Can't fold.
622 26065 : case Instruction::IntToPtr: //always treated as unsigned
623 26065 : if (V->isNullValue()) // Is it an integral null value?
624 0 : return ConstantPointerNull::get(cast<PointerType>(DestTy));
625 : return nullptr; // Other pointer types cannot be casted
626 19748 : case Instruction::PtrToInt: // always treated as unsigned
627 : // Is it a null pointer value?
628 19748 : if (V->isNullValue())
629 0 : return ConstantInt::get(DestTy, 0);
630 : // If this is a sizeof-like expression, pull out multiplications by
631 : // known factors to expose them to subsequent folding. If it's an
632 : // alignof-like expression, factor out known factors.
633 : if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
634 12692 : if (CE->getOpcode() == Instruction::GetElementPtr &&
635 6257 : CE->getOperand(0)->isNullValue()) {
636 : // FIXME: Looks like getFoldedSizeOf(), getFoldedOffsetOf() and
637 : // getFoldedAlignOf() don't handle the case when DestTy is a vector of
638 : // pointers yet. We end up in asserts in CastInst::getCastOpcode (see
639 : // test/Analysis/ConstantFolding/cast-vector.ll). I've only seen this
640 : // happen in one "real" C-code test case, so it does not seem to be an
641 : // important optimization to handle vectors here. For now, simply bail
642 : // out.
643 1066 : if (DestTy->isVectorTy())
644 : return nullptr;
645 : GEPOperator *GEPO = cast<GEPOperator>(CE);
646 1064 : Type *Ty = GEPO->getSourceElementType();
647 1064 : if (CE->getNumOperands() == 2) {
648 : // Handle a sizeof-like expression.
649 : Constant *Idx = CE->getOperand(1);
650 1902 : bool isOne = isa<ConstantInt>(Idx) && cast<ConstantInt>(Idx)->isOne();
651 951 : if (Constant *C = getFoldedSizeOf(Ty, DestTy, !isOne)) {
652 66 : Idx = ConstantExpr::getCast(CastInst::getCastOpcode(Idx, true,
653 : DestTy, false),
654 : Idx, DestTy);
655 66 : return ConstantExpr::getMul(C, Idx);
656 : }
657 226 : } else if (CE->getNumOperands() == 3 &&
658 113 : CE->getOperand(1)->isNullValue()) {
659 : // Handle an alignof-like expression.
660 : if (StructType *STy = dyn_cast<StructType>(Ty))
661 103 : if (!STy->isPacked()) {
662 : ConstantInt *CI = cast<ConstantInt>(CE->getOperand(2));
663 80 : if (CI->isOne() &&
664 182 : STy->getNumElements() == 2 &&
665 158 : STy->getElementType(0)->isIntegerTy(1)) {
666 156 : return getFoldedAlignOf(STy->getElementType(1), DestTy, false);
667 : }
668 : }
669 : // Handle an offsetof-like expression.
670 35 : if (Ty->isStructTy() || Ty->isArrayTy()) {
671 35 : if (Constant *C = getFoldedOffsetOf(Ty, CE->getOperand(2),
672 : DestTy, false))
673 20 : return C;
674 : }
675 : }
676 : }
677 : // Other pointer types cannot be casted
678 : return nullptr;
679 6901 : case Instruction::UIToFP:
680 : case Instruction::SIToFP:
681 : if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
682 : const APInt &api = CI->getValue();
683 : APFloat apf(DestTy->getFltSemantics(),
684 6888 : APInt::getNullValue(DestTy->getPrimitiveSizeInBits()));
685 6888 : apf.convertFromAPInt(api, opc==Instruction::SIToFP,
686 : APFloat::rmNearestTiesToEven);
687 6888 : return ConstantFP::get(V->getContext(), apf);
688 : }
689 : return nullptr;
690 175674 : case Instruction::ZExt:
691 : if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
692 : uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
693 174252 : return ConstantInt::get(V->getContext(),
694 348504 : CI->getValue().zext(BitWidth));
695 : }
696 : return nullptr;
697 433686 : case Instruction::SExt:
698 : if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
699 : uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
700 433662 : return ConstantInt::get(V->getContext(),
701 867324 : CI->getValue().sext(BitWidth));
702 : }
703 : return nullptr;
704 252705 : case Instruction::Trunc: {
705 505410 : if (V->getType()->isVectorTy())
706 : return nullptr;
707 :
708 : uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
709 : if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
710 251516 : return ConstantInt::get(V->getContext(),
711 503032 : CI->getValue().trunc(DestBitWidth));
712 : }
713 :
714 : // The input must be a constantexpr. See if we can simplify this based on
715 : // the bytes we are demanding. Only do this if the source and dest are an
716 : // even multiple of a byte.
717 1186 : if ((DestBitWidth & 7) == 0 &&
718 : (cast<IntegerType>(V->getType())->getBitWidth() & 7) == 0)
719 1178 : if (Constant *Res = ExtractConstantBytes(V, 0, DestBitWidth / 8))
720 13 : return Res;
721 :
722 : return nullptr;
723 : }
724 2317173 : case Instruction::BitCast:
725 2317173 : return FoldBitCast(V, DestTy);
726 : case Instruction::AddrSpaceCast:
727 : return nullptr;
728 : }
729 : }
730 :
731 1293 : Constant *llvm::ConstantFoldSelectInstruction(Constant *Cond,
732 : Constant *V1, Constant *V2) {
733 : // Check for i1 and vector true/false conditions.
734 1293 : if (Cond->isNullValue()) return V2;
735 798 : if (Cond->isAllOnesValue()) return V1;
736 :
737 : // If the condition is a vector constant, fold the result elementwise.
738 : if (ConstantVector *CondV = dyn_cast<ConstantVector>(Cond)) {
739 : SmallVector<Constant*, 16> Result;
740 77 : Type *Ty = IntegerType::get(CondV->getContext(), 32);
741 587 : for (unsigned i = 0, e = V1->getType()->getVectorNumElements(); i != e;++i){
742 : Constant *V;
743 511 : Constant *V1Element = ConstantExpr::getExtractElement(V1,
744 : ConstantInt::get(Ty, i));
745 511 : Constant *V2Element = ConstantExpr::getExtractElement(V2,
746 : ConstantInt::get(Ty, i));
747 511 : Constant *Cond = dyn_cast<Constant>(CondV->getOperand(i));
748 511 : if (V1Element == V2Element) {
749 78 : V = V1Element;
750 433 : } else if (isa<UndefValue>(Cond)) {
751 10 : V = isa<UndefValue>(V1Element) ? V1Element : V2Element;
752 : } else {
753 427 : if (!isa<ConstantInt>(Cond)) break;
754 728 : V = Cond->isNullValue() ? V2Element : V1Element;
755 : }
756 510 : Result.push_back(V);
757 : }
758 :
759 : // If we were able to build the vector, return it.
760 231 : if (Result.size() == V1->getType()->getVectorNumElements())
761 76 : return ConstantVector::get(Result);
762 : }
763 :
764 138 : if (isa<UndefValue>(Cond)) {
765 28 : if (isa<UndefValue>(V1)) return V1;
766 16 : return V2;
767 : }
768 110 : if (isa<UndefValue>(V1)) return V2;
769 110 : if (isa<UndefValue>(V2)) return V1;
770 109 : if (V1 == V2) return V1;
771 :
772 63 : if (ConstantExpr *TrueVal = dyn_cast<ConstantExpr>(V1)) {
773 63 : if (TrueVal->getOpcode() == Instruction::Select)
774 1 : if (TrueVal->getOperand(0) == Cond)
775 1 : return ConstantExpr::getSelect(Cond, TrueVal->getOperand(1), V2);
776 : }
777 18 : if (ConstantExpr *FalseVal = dyn_cast<ConstantExpr>(V2)) {
778 18 : if (FalseVal->getOpcode() == Instruction::Select)
779 0 : if (FalseVal->getOperand(0) == Cond)
780 0 : return ConstantExpr::getSelect(Cond, V1, FalseVal->getOperand(2));
781 : }
782 :
783 : return nullptr;
784 : }
785 :
786 363399 : Constant *llvm::ConstantFoldExtractElementInstruction(Constant *Val,
787 : Constant *Idx) {
788 363399 : if (isa<UndefValue>(Val)) // ee(undef, x) -> undef
789 236962 : return UndefValue::get(Val->getType()->getVectorElementType());
790 244918 : if (Val->isNullValue()) // ee(zero, x) -> zero
791 7320 : return Constant::getNullValue(Val->getType()->getVectorElementType());
792 : // ee({w,x,y,z}, undef) -> undef
793 241258 : if (isa<UndefValue>(Idx))
794 2 : return UndefValue::get(Val->getType()->getVectorElementType());
795 :
796 : if (ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx)) {
797 : // ee({w,x,y,z}, wrong_value) -> undef
798 482514 : if (CIdx->uge(Val->getType()->getVectorNumElements()))
799 6 : return UndefValue::get(Val->getType()->getVectorElementType());
800 241254 : return Val->getAggregateElement(CIdx->getZExtValue());
801 : }
802 : return nullptr;
803 : }
804 :
805 201412 : Constant *llvm::ConstantFoldInsertElementInstruction(Constant *Val,
806 : Constant *Elt,
807 : Constant *Idx) {
808 201412 : if (isa<UndefValue>(Idx))
809 1 : return UndefValue::get(Val->getType());
810 :
811 : ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx);
812 : if (!CIdx) return nullptr;
813 :
814 201411 : unsigned NumElts = Val->getType()->getVectorNumElements();
815 201411 : if (CIdx->uge(NumElts))
816 3 : return UndefValue::get(Val->getType());
817 :
818 : SmallVector<Constant*, 16> Result;
819 : Result.reserve(NumElts);
820 201408 : auto *Ty = Type::getInt32Ty(Val->getContext());
821 : uint64_t IdxVal = CIdx->getZExtValue();
822 710678 : for (unsigned i = 0; i != NumElts; ++i) {
823 509270 : if (i == IdxVal) {
824 201408 : Result.push_back(Elt);
825 201408 : continue;
826 : }
827 :
828 307862 : Constant *C = ConstantExpr::getExtractElement(Val, ConstantInt::get(Ty, i));
829 307862 : Result.push_back(C);
830 : }
831 :
832 201408 : return ConstantVector::get(Result);
833 : }
834 :
835 3527 : Constant *llvm::ConstantFoldShuffleVectorInstruction(Constant *V1,
836 : Constant *V2,
837 : Constant *Mask) {
838 3527 : unsigned MaskNumElts = Mask->getType()->getVectorNumElements();
839 3527 : Type *EltTy = V1->getType()->getVectorElementType();
840 :
841 : // Undefined shuffle mask -> undefined value.
842 3527 : if (isa<UndefValue>(Mask))
843 13 : return UndefValue::get(VectorType::get(EltTy, MaskNumElts));
844 :
845 : // Don't break the bitcode reader hack.
846 3514 : if (isa<ConstantExpr>(Mask)) return nullptr;
847 :
848 : unsigned SrcNumElts = V1->getType()->getVectorNumElements();
849 :
850 : // Loop over the shuffle mask, evaluating each element.
851 : SmallVector<Constant*, 32> Result;
852 23596 : for (unsigned i = 0; i != MaskNumElts; ++i) {
853 20082 : int Elt = ShuffleVectorInst::getMaskValue(Mask, i);
854 20082 : if (Elt == -1) {
855 297 : Result.push_back(UndefValue::get(EltTy));
856 297 : continue;
857 : }
858 : Constant *InElt;
859 19785 : if (unsigned(Elt) >= SrcNumElts*2)
860 0 : InElt = UndefValue::get(EltTy);
861 19785 : else if (unsigned(Elt) >= SrcNumElts) {
862 698 : Type *Ty = IntegerType::get(V2->getContext(), 32);
863 698 : InElt =
864 698 : ConstantExpr::getExtractElement(V2,
865 698 : ConstantInt::get(Ty, Elt - SrcNumElts));
866 : } else {
867 19087 : Type *Ty = IntegerType::get(V1->getContext(), 32);
868 19087 : InElt = ConstantExpr::getExtractElement(V1, ConstantInt::get(Ty, Elt));
869 : }
870 19785 : Result.push_back(InElt);
871 : }
872 :
873 3514 : return ConstantVector::get(Result);
874 : }
875 :
876 335371 : Constant *llvm::ConstantFoldExtractValueInstruction(Constant *Agg,
877 : ArrayRef<unsigned> Idxs) {
878 : // Base case: no indices, so return the entire value.
879 335371 : if (Idxs.empty())
880 : return Agg;
881 :
882 167694 : if (Constant *C = Agg->getAggregateElement(Idxs[0]))
883 167689 : return ConstantFoldExtractValueInstruction(C, Idxs.slice(1));
884 :
885 : return nullptr;
886 : }
887 :
888 808 : Constant *llvm::ConstantFoldInsertValueInstruction(Constant *Agg,
889 : Constant *Val,
890 : ArrayRef<unsigned> Idxs) {
891 : // Base case: no indices, so replace the entire value.
892 808 : if (Idxs.empty())
893 : return Val;
894 :
895 : unsigned NumElts;
896 466 : if (StructType *ST = dyn_cast<StructType>(Agg->getType()))
897 306 : NumElts = ST->getNumElements();
898 : else
899 160 : NumElts = cast<SequentialType>(Agg->getType())->getNumElements();
900 :
901 : SmallVector<Constant*, 32> Result;
902 5726 : for (unsigned i = 0; i != NumElts; ++i) {
903 5261 : Constant *C = Agg->getAggregateElement(i);
904 5261 : if (!C) return nullptr;
905 :
906 5260 : if (Idxs[0] == i)
907 465 : C = ConstantFoldInsertValueInstruction(C, Val, Idxs.slice(1));
908 :
909 5260 : Result.push_back(C);
910 : }
911 :
912 465 : if (StructType *ST = dyn_cast<StructType>(Agg->getType()))
913 305 : return ConstantStruct::get(ST, Result);
914 : if (ArrayType *AT = dyn_cast<ArrayType>(Agg->getType()))
915 160 : return ConstantArray::get(AT, Result);
916 0 : return ConstantVector::get(Result);
917 : }
918 :
919 1024098 : Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, Constant *C1,
920 : Constant *C2) {
921 : assert(Instruction::isBinaryOp(Opcode) && "Non-binary instruction detected");
922 :
923 : // Handle scalar UndefValue. Vectors are always evaluated per element.
924 2048196 : bool HasScalarUndef = !C1->getType()->isVectorTy() &&
925 1019693 : (isa<UndefValue>(C1) || isa<UndefValue>(C2));
926 : if (HasScalarUndef) {
927 1127 : switch (static_cast<Instruction::BinaryOps>(Opcode)) {
928 56 : case Instruction::Xor:
929 56 : if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
930 : // Handle undef ^ undef -> 0 special case. This is a common
931 : // idiom (misuse).
932 19 : return Constant::getNullValue(C1->getType());
933 : LLVM_FALLTHROUGH;
934 : case Instruction::Add:
935 : case Instruction::Sub:
936 214 : return UndefValue::get(C1->getType());
937 302 : case Instruction::And:
938 302 : if (isa<UndefValue>(C1) && isa<UndefValue>(C2)) // undef & undef -> undef
939 : return C1;
940 293 : return Constant::getNullValue(C1->getType()); // undef & X -> 0
941 13 : case Instruction::Mul: {
942 : // undef * undef -> undef
943 13 : if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
944 : return C1;
945 : const APInt *CV;
946 : // X * undef -> undef if X is odd
947 11 : if (match(C1, m_APInt(CV)) || match(C2, m_APInt(CV)))
948 22 : if ((*CV)[0])
949 5 : return UndefValue::get(C1->getType());
950 :
951 : // X * undef -> 0 otherwise
952 6 : return Constant::getNullValue(C1->getType());
953 : }
954 8 : case Instruction::SDiv:
955 : case Instruction::UDiv:
956 : // X / undef -> undef
957 8 : if (isa<UndefValue>(C2))
958 : return C2;
959 : // undef / 0 -> undef
960 : // undef / 1 -> undef
961 11 : if (match(C2, m_Zero()) || match(C2, m_One()))
962 3 : return C1;
963 : // undef / X -> 0 otherwise
964 3 : return Constant::getNullValue(C1->getType());
965 : case Instruction::URem:
966 : case Instruction::SRem:
967 : // X % undef -> undef
968 12 : if (match(C2, m_Undef()))
969 : return C2;
970 : // undef % 0 -> undef
971 12 : if (match(C2, m_Zero()))
972 : return C1;
973 : // undef % X -> 0 otherwise
974 12 : return Constant::getNullValue(C1->getType());
975 25 : case Instruction::Or: // X | undef -> -1
976 25 : if (isa<UndefValue>(C1) && isa<UndefValue>(C2)) // undef | undef -> undef
977 : return C1;
978 12 : return Constant::getAllOnesValue(C1->getType()); // undef | X -> ~0
979 31 : case Instruction::LShr:
980 : // X >>l undef -> undef
981 31 : if (isa<UndefValue>(C2))
982 : return C2;
983 : // undef >>l 0 -> undef
984 28 : if (match(C2, m_Zero()))
985 : return C1;
986 : // undef >>l X -> 0
987 27 : return Constant::getNullValue(C1->getType());
988 33 : case Instruction::AShr:
989 : // X >>a undef -> undef
990 33 : if (isa<UndefValue>(C2))
991 : return C2;
992 : // undef >>a 0 -> undef
993 31 : if (match(C2, m_Zero()))
994 : return C1;
995 : // TODO: undef >>a X -> undef if the shift is exact
996 : // undef >>a X -> 0
997 30 : return Constant::getNullValue(C1->getType());
998 67 : case Instruction::Shl:
999 : // X << undef -> undef
1000 67 : if (isa<UndefValue>(C2))
1001 : return C2;
1002 : // undef << 0 -> undef
1003 60 : if (match(C2, m_Zero()))
1004 : return C1;
1005 : // undef << X -> 0
1006 58 : return Constant::getNullValue(C1->getType());
1007 403 : case Instruction::FAdd:
1008 : case Instruction::FSub:
1009 : case Instruction::FMul:
1010 : case Instruction::FDiv:
1011 : case Instruction::FRem:
1012 : // [any flop] undef, undef -> undef
1013 403 : if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
1014 : return C1;
1015 : // [any flop] C, undef -> NaN
1016 : // [any flop] undef, C -> NaN
1017 : // We could potentially specialize NaN/Inf constants vs. 'normal'
1018 : // constants (possibly differently depending on opcode and operand). This
1019 : // would allow returning undef sometimes. But it is always safe to fold to
1020 : // NaN because we can choose the undef operand as NaN, and any FP opcode
1021 : // with a NaN operand will propagate NaN.
1022 318 : return ConstantFP::getNaN(C1->getType());
1023 : case Instruction::BinaryOpsEnd:
1024 : llvm_unreachable("Invalid BinaryOp");
1025 : }
1026 : }
1027 :
1028 : // Neither constant should be UndefValue, unless these are vector constants.
1029 : assert(!HasScalarUndef && "Unexpected UndefValue");
1030 :
1031 : // Handle simplifications when the RHS is a constant int.
1032 : if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
1033 1011118 : switch (Opcode) {
1034 : case Instruction::Add:
1035 203321 : if (CI2->isZero()) return C1; // X + 0 == X
1036 : break;
1037 : case Instruction::Sub:
1038 584953 : if (CI2->isZero()) return C1; // X - 0 == X
1039 : break;
1040 : case Instruction::Mul:
1041 22578 : if (CI2->isZero()) return C2; // X * 0 == 0
1042 22128 : if (CI2->isOne())
1043 : return C1; // X * 1 == X
1044 : break;
1045 : case Instruction::UDiv:
1046 : case Instruction::SDiv:
1047 44785 : if (CI2->isOne())
1048 : return C1; // X / 1 == X
1049 24264 : if (CI2->isZero())
1050 6 : return UndefValue::get(CI2->getType()); // X / 0 == undef
1051 : break;
1052 : case Instruction::URem:
1053 : case Instruction::SRem:
1054 995 : if (CI2->isOne())
1055 14 : return Constant::getNullValue(CI2->getType()); // X % 1 == 0
1056 981 : if (CI2->isZero())
1057 3 : return UndefValue::get(CI2->getType()); // X % 0 == undef
1058 : break;
1059 : case Instruction::And:
1060 16102 : if (CI2->isZero()) return C2; // X & 0 == 0
1061 16006 : if (CI2->isMinusOne())
1062 : return C1; // X & -1 == X
1063 :
1064 : if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
1065 : // (zext i32 to i64) & 4294967295 -> (zext i32 to i64)
1066 3170 : if (CE1->getOpcode() == Instruction::ZExt) {
1067 : unsigned DstWidth = CI2->getType()->getBitWidth();
1068 : unsigned SrcWidth =
1069 3 : CE1->getOperand(0)->getType()->getPrimitiveSizeInBits();
1070 3 : APInt PossiblySetBits(APInt::getLowBitsSet(DstWidth, SrcWidth));
1071 3 : if ((PossiblySetBits & CI2->getValue()) == PossiblySetBits)
1072 : return C1;
1073 : }
1074 :
1075 : // If and'ing the address of a global with a constant, fold it.
1076 3170 : if (CE1->getOpcode() == Instruction::PtrToInt &&
1077 : isa<GlobalValue>(CE1->getOperand(0))) {
1078 : GlobalValue *GV = cast<GlobalValue>(CE1->getOperand(0));
1079 :
1080 : // Functions are at least 4-byte aligned.
1081 169 : unsigned GVAlign = GV->getAlignment();
1082 169 : if (isa<Function>(GV))
1083 191 : GVAlign = std::max(GVAlign, 4U);
1084 :
1085 169 : if (GVAlign > 1) {
1086 144 : unsigned DstWidth = CI2->getType()->getBitWidth();
1087 144 : unsigned SrcWidth = std::min(DstWidth, Log2_32(GVAlign));
1088 144 : APInt BitsNotSet(APInt::getLowBitsSet(DstWidth, SrcWidth));
1089 :
1090 : // If checking bits we know are clear, return zero.
1091 144 : if ((CI2->getValue() & BitsNotSet) == CI2->getValue())
1092 115 : return Constant::getNullValue(CI2->getType());
1093 : }
1094 : }
1095 : }
1096 : break;
1097 : case Instruction::Or:
1098 14668 : if (CI2->isZero()) return C1; // X | 0 == X
1099 14044 : if (CI2->isMinusOne())
1100 : return C2; // X | -1 == -1
1101 : break;
1102 : case Instruction::Xor:
1103 101079 : if (CI2->isZero()) return C1; // X ^ 0 == X
1104 :
1105 : if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
1106 : switch (CE1->getOpcode()) {
1107 : default: break;
1108 29 : case Instruction::ICmp:
1109 : case Instruction::FCmp:
1110 : // cmp pred ^ true -> cmp !pred
1111 : assert(CI2->isOne());
1112 29 : CmpInst::Predicate pred = (CmpInst::Predicate)CE1->getPredicate();
1113 29 : pred = CmpInst::getInversePredicate(pred);
1114 29 : return ConstantExpr::getCompare(pred, CE1->getOperand(0),
1115 29 : CE1->getOperand(1));
1116 : }
1117 : }
1118 : break;
1119 1491 : case Instruction::AShr:
1120 : // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
1121 : if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
1122 47 : if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
1123 0 : return ConstantExpr::getLShr(C1, C2);
1124 : break;
1125 : }
1126 11853 : } else if (isa<ConstantInt>(C1)) {
1127 : // If C1 is a ConstantInt and C2 is not, swap the operands.
1128 : if (Instruction::isCommutative(Opcode))
1129 1003 : return ConstantExpr::get(Opcode, C2, C1);
1130 : }
1131 :
1132 : if (ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
1133 : if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
1134 : const APInt &C1V = CI1->getValue();
1135 : const APInt &C2V = CI2->getValue();
1136 737703 : switch (Opcode) {
1137 : default:
1138 : break;
1139 : case Instruction::Add:
1140 395166 : return ConstantInt::get(CI1->getContext(), C1V + C2V);
1141 : case Instruction::Sub:
1142 709942 : return ConstantInt::get(CI1->getContext(), C1V - C2V);
1143 10249 : case Instruction::Mul:
1144 20498 : return ConstantInt::get(CI1->getContext(), C1V * C2V);
1145 21671 : case Instruction::UDiv:
1146 : assert(!CI2->isZero() && "Div by zero handled above");
1147 43342 : return ConstantInt::get(CI1->getContext(), C1V.udiv(C2V));
1148 : case Instruction::SDiv:
1149 : assert(!CI2->isZero() && "Div by zero handled above");
1150 2285 : if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
1151 1 : return UndefValue::get(CI1->getType()); // MIN_INT / -1 -> undef
1152 4568 : return ConstantInt::get(CI1->getContext(), C1V.sdiv(C2V));
1153 767 : case Instruction::URem:
1154 : assert(!CI2->isZero() && "Div by zero handled above");
1155 1534 : return ConstantInt::get(CI1->getContext(), C1V.urem(C2V));
1156 : case Instruction::SRem:
1157 : assert(!CI2->isZero() && "Div by zero handled above");
1158 191 : if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
1159 1 : return UndefValue::get(CI1->getType()); // MIN_INT % -1 -> undef
1160 380 : return ConstantInt::get(CI1->getContext(), C1V.srem(C2V));
1161 : case Instruction::And:
1162 25584 : return ConstantInt::get(CI1->getContext(), C1V & C2V);
1163 : case Instruction::Or:
1164 27880 : return ConstantInt::get(CI1->getContext(), C1V | C2V);
1165 : case Instruction::Xor:
1166 201740 : return ConstantInt::get(CI1->getContext(), C1V ^ C2V);
1167 17403 : case Instruction::Shl:
1168 17403 : if (C2V.ult(C1V.getBitWidth()))
1169 34728 : return ConstantInt::get(CI1->getContext(), C1V.shl(C2V));
1170 39 : return UndefValue::get(C1->getType()); // too big shift is undef
1171 3537 : case Instruction::LShr:
1172 3537 : if (C2V.ult(C1V.getBitWidth()))
1173 6974 : return ConstantInt::get(CI1->getContext(), C1V.lshr(C2V));
1174 50 : return UndefValue::get(C1->getType()); // too big shift is undef
1175 1444 : case Instruction::AShr:
1176 1444 : if (C2V.ult(C1V.getBitWidth()))
1177 2868 : return ConstantInt::get(CI1->getContext(), C1V.ashr(C2V));
1178 10 : return UndefValue::get(C1->getType()); // too big shift is undef
1179 : }
1180 : }
1181 :
1182 : switch (Opcode) {
1183 : case Instruction::SDiv:
1184 : case Instruction::UDiv:
1185 : case Instruction::URem:
1186 : case Instruction::SRem:
1187 : case Instruction::LShr:
1188 : case Instruction::AShr:
1189 : case Instruction::Shl:
1190 64 : if (CI1->isZero()) return C1;
1191 : break;
1192 : default:
1193 : break;
1194 : }
1195 : } else if (ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
1196 : if (ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
1197 : const APFloat &C1V = CFP1->getValueAPF();
1198 : const APFloat &C2V = CFP2->getValueAPF();
1199 : APFloat C3V = C1V; // copy for modification
1200 1686 : switch (Opcode) {
1201 : default:
1202 : break;
1203 416 : case Instruction::FAdd:
1204 416 : (void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
1205 416 : return ConstantFP::get(C1->getContext(), C3V);
1206 746 : case Instruction::FSub:
1207 746 : (void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
1208 746 : return ConstantFP::get(C1->getContext(), C3V);
1209 284 : case Instruction::FMul:
1210 284 : (void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
1211 284 : return ConstantFP::get(C1->getContext(), C3V);
1212 179 : case Instruction::FDiv:
1213 179 : (void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
1214 179 : return ConstantFP::get(C1->getContext(), C3V);
1215 61 : case Instruction::FRem:
1216 61 : (void)C3V.mod(C2V);
1217 61 : return ConstantFP::get(C1->getContext(), C3V);
1218 : }
1219 : }
1220 15673 : } else if (VectorType *VTy = dyn_cast<VectorType>(C1->getType())) {
1221 : // Fold each element and create a vector constant from those constants.
1222 : SmallVector<Constant*, 16> Result;
1223 3608 : Type *Ty = IntegerType::get(VTy->getContext(), 32);
1224 17793 : for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
1225 14190 : Constant *ExtractIdx = ConstantInt::get(Ty, i);
1226 14190 : Constant *LHS = ConstantExpr::getExtractElement(C1, ExtractIdx);
1227 14190 : Constant *RHS = ConstantExpr::getExtractElement(C2, ExtractIdx);
1228 :
1229 : // If any element of a divisor vector is zero, the whole op is undef.
1230 35 : if (Instruction::isIntDivRem(Opcode) && RHS->isNullValue())
1231 5 : return UndefValue::get(VTy);
1232 :
1233 14185 : Result.push_back(ConstantExpr::get(Opcode, LHS, RHS));
1234 : }
1235 :
1236 3603 : return ConstantVector::get(Result);
1237 : }
1238 :
1239 : if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
1240 : // There are many possible foldings we could do here. We should probably
1241 : // at least fold add of a pointer with an integer into the appropriate
1242 : // getelementptr. This will improve alias analysis a bit.
1243 :
1244 : // Given ((a + b) + c), if (b + c) folds to something interesting, return
1245 : // (a + (b + c)).
1246 10012 : if (Instruction::isAssociative(Opcode) && CE1->getOpcode() == Opcode) {
1247 62 : Constant *T = ConstantExpr::get(Opcode, CE1->getOperand(1), C2);
1248 62 : if (!isa<ConstantExpr>(T) || cast<ConstantExpr>(T)->getOpcode() != Opcode)
1249 47 : return ConstantExpr::get(Opcode, CE1->getOperand(0), T);
1250 : }
1251 149 : } else if (isa<ConstantExpr>(C2)) {
1252 : // If C2 is a constant expr and C1 isn't, flop them around and fold the
1253 : // other way if possible.
1254 : if (Instruction::isCommutative(Opcode))
1255 0 : return ConstantFoldBinaryInstruction(Opcode, C2, C1);
1256 : }
1257 :
1258 : // i1 can be simplified in many cases.
1259 12167 : if (C1->getType()->isIntegerTy(1)) {
1260 700 : switch (Opcode) {
1261 2 : case Instruction::Add:
1262 : case Instruction::Sub:
1263 2 : return ConstantExpr::getXor(C1, C2);
1264 1 : case Instruction::Mul:
1265 1 : return ConstantExpr::getAnd(C1, C2);
1266 0 : case Instruction::Shl:
1267 : case Instruction::LShr:
1268 : case Instruction::AShr:
1269 : // We can assume that C2 == 0. If it were one the result would be
1270 : // undefined because the shift value is as large as the bitwidth.
1271 0 : return C1;
1272 2 : case Instruction::SDiv:
1273 : case Instruction::UDiv:
1274 : // We can assume that C2 == 1. If it were zero the result would be
1275 : // undefined through division by zero.
1276 2 : return C1;
1277 2 : case Instruction::URem:
1278 : case Instruction::SRem:
1279 : // We can assume that C2 == 1. If it were zero the result would be
1280 : // undefined through division by zero.
1281 2 : return ConstantInt::getFalse(C1->getContext());
1282 : default:
1283 : break;
1284 : }
1285 : }
1286 :
1287 : // We don't know how to fold this.
1288 : return nullptr;
1289 : }
1290 :
1291 : /// This type is zero-sized if it's an array or structure of zero-sized types.
1292 : /// The only leaf zero-sized type is an empty structure.
1293 515 : static bool isMaybeZeroSizedType(Type *Ty) {
1294 : if (StructType *STy = dyn_cast<StructType>(Ty)) {
1295 212 : if (STy->isOpaque()) return true; // Can't say.
1296 :
1297 : // If all of elements have zero size, this does too.
1298 212 : for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
1299 424 : if (!isMaybeZeroSizedType(STy->getElementType(i))) return false;
1300 : return true;
1301 :
1302 : } else if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
1303 53 : return isMaybeZeroSizedType(ATy->getElementType());
1304 : }
1305 : return false;
1306 : }
1307 :
1308 : /// Compare the two constants as though they were getelementptr indices.
1309 : /// This allows coercion of the types to be the same thing.
1310 : ///
1311 : /// If the two constants are the "same" (after coercion), return 0. If the
1312 : /// first is less than the second, return -1, if the second is less than the
1313 : /// first, return 1. If the constants are not integral, return -2.
1314 : ///
1315 561 : static int IdxCompare(Constant *C1, Constant *C2, Type *ElTy) {
1316 561 : if (C1 == C2) return 0;
1317 :
1318 : // Ok, we found a different index. If they are not ConstantInt, we can't do
1319 : // anything with them.
1320 305 : if (!isa<ConstantInt>(C1) || !isa<ConstantInt>(C2))
1321 : return -2; // don't know!
1322 :
1323 : // We cannot compare the indices if they don't fit in an int64_t.
1324 304 : if (cast<ConstantInt>(C1)->getValue().getActiveBits() > 64 ||
1325 : cast<ConstantInt>(C2)->getValue().getActiveBits() > 64)
1326 : return -2; // don't know!
1327 :
1328 : // Ok, we have two differing integer indices. Sign extend them to be the same
1329 : // type.
1330 : int64_t C1Val = cast<ConstantInt>(C1)->getSExtValue();
1331 : int64_t C2Val = cast<ConstantInt>(C2)->getSExtValue();
1332 :
1333 304 : if (C1Val == C2Val) return 0; // They are equal
1334 :
1335 : // If the type being indexed over is really just a zero sized type, there is
1336 : // no pointer difference being made here.
1337 303 : if (isMaybeZeroSizedType(ElTy))
1338 : return -2; // dunno.
1339 :
1340 : // If they are really different, now that they are the same type, then we
1341 : // found a difference!
1342 303 : if (C1Val < C2Val)
1343 : return -1;
1344 : else
1345 34 : return 1;
1346 : }
1347 :
1348 : /// This function determines if there is anything we can decide about the two
1349 : /// constants provided. This doesn't need to handle simple things like
1350 : /// ConstantFP comparisons, but should instead handle ConstantExprs.
1351 : /// If we can determine that the two constants have a particular relation to
1352 : /// each other, we should return the corresponding FCmpInst predicate,
1353 : /// otherwise return FCmpInst::BAD_FCMP_PREDICATE. This is used below in
1354 : /// ConstantFoldCompareInstruction.
1355 : ///
1356 : /// To simplify this code we canonicalize the relation so that the first
1357 : /// operand is always the most "complex" of the two. We consider ConstantFP
1358 : /// to be the simplest, and ConstantExprs to be the most complex.
1359 4 : static FCmpInst::Predicate evaluateFCmpRelation(Constant *V1, Constant *V2) {
1360 : assert(V1->getType() == V2->getType() &&
1361 : "Cannot compare values of different types!");
1362 :
1363 : // Handle degenerate case quickly
1364 4 : if (V1 == V2) return FCmpInst::FCMP_OEQ;
1365 :
1366 4 : if (!isa<ConstantExpr>(V1)) {
1367 0 : if (!isa<ConstantExpr>(V2)) {
1368 : // Simple case, use the standard constant folder.
1369 : ConstantInt *R = nullptr;
1370 0 : R = dyn_cast<ConstantInt>(
1371 : ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ, V1, V2));
1372 0 : if (R && !R->isZero())
1373 : return FCmpInst::FCMP_OEQ;
1374 0 : R = dyn_cast<ConstantInt>(
1375 : ConstantExpr::getFCmp(FCmpInst::FCMP_OLT, V1, V2));
1376 0 : if (R && !R->isZero())
1377 : return FCmpInst::FCMP_OLT;
1378 0 : R = dyn_cast<ConstantInt>(
1379 : ConstantExpr::getFCmp(FCmpInst::FCMP_OGT, V1, V2));
1380 0 : if (R && !R->isZero())
1381 0 : return FCmpInst::FCMP_OGT;
1382 :
1383 : // Nothing more we can do
1384 : return FCmpInst::BAD_FCMP_PREDICATE;
1385 : }
1386 :
1387 : // If the first operand is simple and second is ConstantExpr, swap operands.
1388 0 : FCmpInst::Predicate SwappedRelation = evaluateFCmpRelation(V2, V1);
1389 0 : if (SwappedRelation != FCmpInst::BAD_FCMP_PREDICATE)
1390 0 : return FCmpInst::getSwappedPredicate(SwappedRelation);
1391 : } else {
1392 : // Ok, the LHS is known to be a constantexpr. The RHS can be any of a
1393 : // constantexpr or a simple constant.
1394 : ConstantExpr *CE1 = cast<ConstantExpr>(V1);
1395 : switch (CE1->getOpcode()) {
1396 : case Instruction::FPTrunc:
1397 : case Instruction::FPExt:
1398 : case Instruction::UIToFP:
1399 : case Instruction::SIToFP:
1400 : // We might be able to do something with these but we don't right now.
1401 : break;
1402 : default:
1403 : break;
1404 : }
1405 : }
1406 : // There are MANY other foldings that we could perform here. They will
1407 : // probably be added on demand, as they seem needed.
1408 : return FCmpInst::BAD_FCMP_PREDICATE;
1409 : }
1410 :
1411 104 : static ICmpInst::Predicate areGlobalsPotentiallyEqual(const GlobalValue *GV1,
1412 : const GlobalValue *GV2) {
1413 : auto isGlobalUnsafeForEquality = [](const GlobalValue *GV) {
1414 : if (GV->hasExternalWeakLinkage() || GV->hasWeakAnyLinkage())
1415 : return true;
1416 : if (const auto *GVar = dyn_cast<GlobalVariable>(GV)) {
1417 : Type *Ty = GVar->getValueType();
1418 : // A global with opaque type might end up being zero sized.
1419 : if (!Ty->isSized())
1420 : return true;
1421 : // A global with an empty type might lie at the address of any other
1422 : // global.
1423 : if (Ty->isEmptyTy())
1424 : return true;
1425 : }
1426 : return false;
1427 : };
1428 : // Don't try to decide equality of aliases.
1429 104 : if (!isa<GlobalAlias>(GV1) && !isa<GlobalAlias>(GV2))
1430 104 : if (!isGlobalUnsafeForEquality(GV1) && !isGlobalUnsafeForEquality(GV2))
1431 51 : return ICmpInst::ICMP_NE;
1432 : return ICmpInst::BAD_ICMP_PREDICATE;
1433 : }
1434 :
1435 : /// This function determines if there is anything we can decide about the two
1436 : /// constants provided. This doesn't need to handle simple things like integer
1437 : /// comparisons, but should instead handle ConstantExprs and GlobalValues.
1438 : /// If we can determine that the two constants have a particular relation to
1439 : /// each other, we should return the corresponding ICmp predicate, otherwise
1440 : /// return ICmpInst::BAD_ICMP_PREDICATE.
1441 : ///
1442 : /// To simplify this code we canonicalize the relation so that the first
1443 : /// operand is always the most "complex" of the two. We consider simple
1444 : /// constants (like ConstantInt) to be the simplest, followed by
1445 : /// GlobalValues, followed by ConstantExpr's (the most complex).
1446 : ///
1447 25996 : static ICmpInst::Predicate evaluateICmpRelation(Constant *V1, Constant *V2,
1448 : bool isSigned) {
1449 : assert(V1->getType() == V2->getType() &&
1450 : "Cannot compare different types of values!");
1451 25996 : if (V1 == V2) return ICmpInst::ICMP_EQ;
1452 :
1453 11939 : if (!isa<ConstantExpr>(V1) && !isa<GlobalValue>(V1) &&
1454 : !isa<BlockAddress>(V1)) {
1455 12 : if (!isa<GlobalValue>(V2) && !isa<ConstantExpr>(V2) &&
1456 : !isa<BlockAddress>(V2)) {
1457 : // We distilled this down to a simple case, use the standard constant
1458 : // folder.
1459 : ConstantInt *R = nullptr;
1460 : ICmpInst::Predicate pred = ICmpInst::ICMP_EQ;
1461 1 : R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
1462 0 : if (R && !R->isZero())
1463 : return pred;
1464 1 : pred = isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
1465 1 : R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
1466 0 : if (R && !R->isZero())
1467 : return pred;
1468 1 : pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
1469 1 : R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, V1, V2));
1470 0 : if (R && !R->isZero())
1471 0 : return pred;
1472 :
1473 : // If we couldn't figure it out, bail.
1474 : return ICmpInst::BAD_ICMP_PREDICATE;
1475 : }
1476 :
1477 : // If the first operand is simple, swap operands.
1478 : ICmpInst::Predicate SwappedRelation =
1479 15 : evaluateICmpRelation(V2, V1, isSigned);
1480 15 : if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
1481 0 : return ICmpInst::getSwappedPredicate(SwappedRelation);
1482 :
1483 : } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(V1)) {
1484 692 : if (isa<ConstantExpr>(V2)) { // Swap as necessary.
1485 : ICmpInst::Predicate SwappedRelation =
1486 4 : evaluateICmpRelation(V2, V1, isSigned);
1487 4 : if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
1488 4 : return ICmpInst::getSwappedPredicate(SwappedRelation);
1489 : return ICmpInst::BAD_ICMP_PREDICATE;
1490 : }
1491 :
1492 : // Now we know that the RHS is a GlobalValue, BlockAddress or simple
1493 : // constant (which, since the types must match, means that it's a
1494 : // ConstantPointerNull).
1495 : if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2)) {
1496 91 : return areGlobalsPotentiallyEqual(GV, GV2);
1497 597 : } else if (isa<BlockAddress>(V2)) {
1498 : return ICmpInst::ICMP_NE; // Globals never equal labels.
1499 : } else {
1500 : assert(isa<ConstantPointerNull>(V2) && "Canonicalization guarantee!");
1501 : // GlobalVals can never be null unless they have external weak linkage.
1502 : // We don't try to evaluate aliases here.
1503 : // NOTE: We should not be doing this constant folding if null pointer
1504 : // is considered valid for the function. But currently there is no way to
1505 : // query it from the Constant type.
1506 812 : if (!GV->hasExternalWeakLinkage() && !isa<GlobalAlias>(GV) &&
1507 215 : !NullPointerIsDefined(nullptr /* F */,
1508 : GV->getType()->getAddressSpace()))
1509 167 : return ICmpInst::ICMP_NE;
1510 : }
1511 : } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(V1)) {
1512 1 : if (isa<ConstantExpr>(V2)) { // Swap as necessary.
1513 : ICmpInst::Predicate SwappedRelation =
1514 0 : evaluateICmpRelation(V2, V1, isSigned);
1515 0 : if (SwappedRelation != ICmpInst::BAD_ICMP_PREDICATE)
1516 0 : return ICmpInst::getSwappedPredicate(SwappedRelation);
1517 : return ICmpInst::BAD_ICMP_PREDICATE;
1518 : }
1519 :
1520 : // Now we know that the RHS is a GlobalValue, BlockAddress or simple
1521 : // constant (which, since the types must match, means that it is a
1522 : // ConstantPointerNull).
1523 : if (const BlockAddress *BA2 = dyn_cast<BlockAddress>(V2)) {
1524 : // Block address in another function can't equal this one, but block
1525 : // addresses in the current function might be the same if blocks are
1526 : // empty.
1527 0 : if (BA2->getFunction() != BA->getFunction())
1528 0 : return ICmpInst::ICMP_NE;
1529 : } else {
1530 : // Block addresses aren't null, don't equal the address of globals.
1531 : assert((isa<ConstantPointerNull>(V2) || isa<GlobalValue>(V2)) &&
1532 : "Canonicalization guarantee!");
1533 : return ICmpInst::ICMP_NE;
1534 : }
1535 : } else {
1536 : // Ok, the LHS is known to be a constantexpr. The RHS can be any of a
1537 : // constantexpr, a global, block address, or a simple constant.
1538 : ConstantExpr *CE1 = cast<ConstantExpr>(V1);
1539 : Constant *CE1Op0 = CE1->getOperand(0);
1540 :
1541 : switch (CE1->getOpcode()) {
1542 : case Instruction::Trunc:
1543 : case Instruction::FPTrunc:
1544 : case Instruction::FPExt:
1545 : case Instruction::FPToUI:
1546 : case Instruction::FPToSI:
1547 : break; // We can't evaluate floating point casts or truncations.
1548 :
1549 1493 : case Instruction::UIToFP:
1550 : case Instruction::SIToFP:
1551 : case Instruction::BitCast:
1552 : case Instruction::ZExt:
1553 : case Instruction::SExt:
1554 : // We can't evaluate floating point casts or truncations.
1555 1493 : if (CE1Op0->getType()->isFloatingPointTy())
1556 : break;
1557 :
1558 : // If the cast is not actually changing bits, and the second operand is a
1559 : // null pointer, do the comparison with the pre-casted value.
1560 1493 : if (V2->isNullValue() && CE1->getType()->isIntOrPtrTy()) {
1561 1401 : if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
1562 1401 : if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
1563 1401 : return evaluateICmpRelation(CE1Op0,
1564 : Constant::getNullValue(CE1Op0->getType()),
1565 1401 : isSigned);
1566 : }
1567 : break;
1568 :
1569 : case Instruction::GetElementPtr: {
1570 : GEPOperator *CE1GEP = cast<GEPOperator>(CE1);
1571 : // Ok, since this is a getelementptr, we know that the constant has a
1572 : // pointer type. Check the various cases.
1573 7692 : if (isa<ConstantPointerNull>(V2)) {
1574 : // If we are comparing a GEP to a null pointer, check to see if the base
1575 : // of the GEP equals the null pointer.
1576 : if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0)) {
1577 7034 : if (GV->hasExternalWeakLinkage())
1578 : // Weak linkage GVals could be zero or not. We're comparing that
1579 : // to null pointer so its greater-or-equal
1580 0 : return isSigned ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE;
1581 : else
1582 : // If its not weak linkage, the GVal must have a non-zero address
1583 : // so the result is greater-than
1584 14068 : return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
1585 172 : } else if (isa<ConstantPointerNull>(CE1Op0)) {
1586 : // If we are indexing from a null pointer, check to see if we have any
1587 : // non-zero indices.
1588 2 : for (unsigned i = 1, e = CE1->getNumOperands(); i != e; ++i)
1589 2 : if (!CE1->getOperand(i)->isNullValue())
1590 : // Offsetting from null, must not be equal.
1591 2 : return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
1592 : // Only zero indexes from null, must still be zero.
1593 : return ICmpInst::ICMP_EQ;
1594 : }
1595 : // Otherwise, we can't really say if the first operand is null or not.
1596 : } else if (const GlobalValue *GV2 = dyn_cast<GlobalValue>(V2)) {
1597 132 : if (isa<ConstantPointerNull>(CE1Op0)) {
1598 0 : if (GV2->hasExternalWeakLinkage())
1599 : // Weak linkage GVals could be zero or not. We're comparing it to
1600 : // a null pointer, so its less-or-equal
1601 0 : return isSigned ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE;
1602 : else
1603 : // If its not weak linkage, the GVal must have a non-zero address
1604 : // so the result is less-than
1605 0 : return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
1606 : } else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CE1Op0)) {
1607 132 : if (GV == GV2) {
1608 : // If this is a getelementptr of the same global, then it must be
1609 : // different. Because the types must match, the getelementptr could
1610 : // only have at most one index, and because we fold getelementptr's
1611 : // with a single zero index, it must be nonzero.
1612 : assert(CE1->getNumOperands() == 2 &&
1613 : !CE1->getOperand(1)->isNullValue() &&
1614 : "Surprising getelementptr!");
1615 8 : return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
1616 : } else {
1617 127 : if (CE1GEP->hasAllZeroIndices())
1618 9 : return areGlobalsPotentiallyEqual(GV, GV2);
1619 : return ICmpInst::BAD_ICMP_PREDICATE;
1620 : }
1621 : }
1622 : } else {
1623 : ConstantExpr *CE2 = cast<ConstantExpr>(V2);
1624 : Constant *CE2Op0 = CE2->getOperand(0);
1625 :
1626 : // There are MANY other foldings that we could perform here. They will
1627 : // probably be added on demand, as they seem needed.
1628 : switch (CE2->getOpcode()) {
1629 : default: break;
1630 351 : case Instruction::GetElementPtr:
1631 : // By far the most common case to handle is when the base pointers are
1632 : // obviously to the same global.
1633 : if (isa<GlobalValue>(CE1Op0) && isa<GlobalValue>(CE2Op0)) {
1634 : // Don't know relative ordering, but check for inequality.
1635 332 : if (CE1Op0 != CE2Op0) {
1636 : GEPOperator *CE2GEP = cast<GEPOperator>(CE2);
1637 28 : if (CE1GEP->hasAllZeroIndices() && CE2GEP->hasAllZeroIndices())
1638 4 : return areGlobalsPotentiallyEqual(cast<GlobalValue>(CE1Op0),
1639 4 : cast<GlobalValue>(CE2Op0));
1640 : return ICmpInst::BAD_ICMP_PREDICATE;
1641 : }
1642 : // Ok, we know that both getelementptr instructions are based on the
1643 : // same global. From this, we can precisely determine the relative
1644 : // ordering of the resultant pointers.
1645 : unsigned i = 1;
1646 :
1647 : // The logic below assumes that the result of the comparison
1648 : // can be determined by finding the first index that differs.
1649 : // This doesn't work if there is over-indexing in any
1650 : // subsequent indices, so check for that case first.
1651 608 : if (!CE1->isGEPWithNoNotionalOverIndexing() ||
1652 304 : !CE2->isGEPWithNoNotionalOverIndexing())
1653 0 : return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
1654 :
1655 : // Compare all of the operands the GEP's have in common.
1656 304 : gep_type_iterator GTI = gep_type_begin(CE1);
1657 561 : for (;i != CE1->getNumOperands() && i != CE2->getNumOperands();
1658 257 : ++i, ++GTI)
1659 1122 : switch (IdxCompare(CE1->getOperand(i),
1660 : CE2->getOperand(i), GTI.getIndexedType())) {
1661 536 : case -1: return isSigned ? ICmpInst::ICMP_SLT:ICmpInst::ICMP_ULT;
1662 68 : case 1: return isSigned ? ICmpInst::ICMP_SGT:ICmpInst::ICMP_UGT;
1663 : case -2: return ICmpInst::BAD_ICMP_PREDICATE;
1664 : }
1665 :
1666 : // Ok, we ran out of things they have in common. If any leftovers
1667 : // are non-zero then we have a difference, otherwise we are equal.
1668 0 : for (; i < CE1->getNumOperands(); ++i)
1669 0 : if (!CE1->getOperand(i)->isNullValue()) {
1670 0 : if (isa<ConstantInt>(CE1->getOperand(i)))
1671 0 : return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
1672 : else
1673 : return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
1674 : }
1675 :
1676 0 : for (; i < CE2->getNumOperands(); ++i)
1677 0 : if (!CE2->getOperand(i)->isNullValue()) {
1678 0 : if (isa<ConstantInt>(CE2->getOperand(i)))
1679 0 : return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
1680 : else
1681 : return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
1682 : }
1683 : return ICmpInst::ICMP_EQ;
1684 : }
1685 : }
1686 : }
1687 : break;
1688 : }
1689 : default:
1690 : break;
1691 : }
1692 : }
1693 :
1694 : return ICmpInst::BAD_ICMP_PREDICATE;
1695 : }
1696 :
1697 106121 : Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
1698 : Constant *C1, Constant *C2) {
1699 : Type *ResultTy;
1700 106121 : if (VectorType *VT = dyn_cast<VectorType>(C1->getType()))
1701 85 : ResultTy = VectorType::get(Type::getInt1Ty(C1->getContext()),
1702 85 : VT->getNumElements());
1703 : else
1704 106036 : ResultTy = Type::getInt1Ty(C1->getContext());
1705 :
1706 : // Fold FCMP_FALSE/FCMP_TRUE unconditionally.
1707 106121 : if (pred == FCmpInst::FCMP_FALSE)
1708 0 : return Constant::getNullValue(ResultTy);
1709 :
1710 106121 : if (pred == FCmpInst::FCMP_TRUE)
1711 0 : return Constant::getAllOnesValue(ResultTy);
1712 :
1713 : // Handle some degenerate cases first
1714 106121 : if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
1715 366 : CmpInst::Predicate Predicate = CmpInst::Predicate(pred);
1716 : bool isIntegerPredicate = ICmpInst::isIntPredicate(Predicate);
1717 : // For EQ and NE, we can always pick a value for the undef to make the
1718 : // predicate pass or fail, so we can return undef.
1719 : // Also, if both operands are undef, we can return undef for int comparison.
1720 366 : if (ICmpInst::isEquality(Predicate) || (isIntegerPredicate && C1 == C2))
1721 225 : return UndefValue::get(ResultTy);
1722 :
1723 : // Otherwise, for integer compare, pick the same value as the non-undef
1724 : // operand, and fold it to true or false.
1725 141 : if (isIntegerPredicate)
1726 73 : return ConstantInt::get(ResultTy, CmpInst::isTrueWhenEqual(Predicate));
1727 :
1728 : // Choosing NaN for the undef will always make unordered comparison succeed
1729 : // and ordered comparison fails.
1730 68 : return ConstantInt::get(ResultTy, CmpInst::isUnordered(Predicate));
1731 : }
1732 :
1733 : // icmp eq/ne(null,GV) -> false/true
1734 105755 : if (C1->isNullValue()) {
1735 : if (const GlobalValue *GV = dyn_cast<GlobalValue>(C2))
1736 : // Don't try to evaluate aliases. External weak GV can be null.
1737 8 : if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage() &&
1738 4 : !NullPointerIsDefined(nullptr /* F */,
1739 : GV->getType()->getAddressSpace())) {
1740 0 : if (pred == ICmpInst::ICMP_EQ)
1741 0 : return ConstantInt::getFalse(C1->getContext());
1742 0 : else if (pred == ICmpInst::ICMP_NE)
1743 0 : return ConstantInt::getTrue(C1->getContext());
1744 : }
1745 : // icmp eq/ne(GV,null) -> false/true
1746 70508 : } else if (C2->isNullValue()) {
1747 : if (const GlobalValue *GV = dyn_cast<GlobalValue>(C1))
1748 : // Don't try to evaluate aliases. External weak GV can be null.
1749 238 : if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage() &&
1750 88 : !NullPointerIsDefined(nullptr /* F */,
1751 : GV->getType()->getAddressSpace())) {
1752 44 : if (pred == ICmpInst::ICMP_EQ)
1753 27 : return ConstantInt::getFalse(C1->getContext());
1754 17 : else if (pred == ICmpInst::ICMP_NE)
1755 13 : return ConstantInt::getTrue(C1->getContext());
1756 : }
1757 : }
1758 :
1759 : // If the comparison is a comparison between two i1's, simplify it.
1760 105715 : if (C1->getType()->isIntegerTy(1)) {
1761 146 : switch(pred) {
1762 86 : case ICmpInst::ICMP_EQ:
1763 86 : if (isa<ConstantInt>(C2))
1764 86 : return ConstantExpr::getXor(C1, ConstantExpr::getNot(C2));
1765 0 : return ConstantExpr::getXor(ConstantExpr::getNot(C1), C2);
1766 16 : case ICmpInst::ICMP_NE:
1767 16 : return ConstantExpr::getXor(C1, C2);
1768 : default:
1769 : break;
1770 : }
1771 : }
1772 :
1773 105613 : if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2)) {
1774 : const APInt &V1 = cast<ConstantInt>(C1)->getValue();
1775 : const APInt &V2 = cast<ConstantInt>(C2)->getValue();
1776 80564 : switch (pred) {
1777 0 : default: llvm_unreachable("Invalid ICmp Predicate");
1778 33589 : case ICmpInst::ICMP_EQ: return ConstantInt::get(ResultTy, V1 == V2);
1779 5668 : case ICmpInst::ICMP_NE: return ConstantInt::get(ResultTy, V1 != V2);
1780 1478 : case ICmpInst::ICMP_SLT: return ConstantInt::get(ResultTy, V1.slt(V2));
1781 10411 : case ICmpInst::ICMP_SGT: return ConstantInt::get(ResultTy, V1.sgt(V2));
1782 972 : case ICmpInst::ICMP_SLE: return ConstantInt::get(ResultTy, V1.sle(V2));
1783 645 : case ICmpInst::ICMP_SGE: return ConstantInt::get(ResultTy, V1.sge(V2));
1784 20182 : case ICmpInst::ICMP_ULT: return ConstantInt::get(ResultTy, V1.ult(V2));
1785 5539 : case ICmpInst::ICMP_UGT: return ConstantInt::get(ResultTy, V1.ugt(V2));
1786 1318 : case ICmpInst::ICMP_ULE: return ConstantInt::get(ResultTy, V1.ule(V2));
1787 762 : case ICmpInst::ICMP_UGE: return ConstantInt::get(ResultTy, V1.uge(V2));
1788 : }
1789 25049 : } else if (isa<ConstantFP>(C1) && isa<ConstantFP>(C2)) {
1790 : const APFloat &C1V = cast<ConstantFP>(C1)->getValueAPF();
1791 : const APFloat &C2V = cast<ConstantFP>(C2)->getValueAPF();
1792 397 : APFloat::cmpResult R = C1V.compare(C2V);
1793 397 : switch (pred) {
1794 0 : default: llvm_unreachable("Invalid FCmp Predicate");
1795 0 : case FCmpInst::FCMP_FALSE: return Constant::getNullValue(ResultTy);
1796 0 : case FCmpInst::FCMP_TRUE: return Constant::getAllOnesValue(ResultTy);
1797 8 : case FCmpInst::FCMP_UNO:
1798 8 : return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered);
1799 1 : case FCmpInst::FCMP_ORD:
1800 1 : return ConstantInt::get(ResultTy, R!=APFloat::cmpUnordered);
1801 7 : case FCmpInst::FCMP_UEQ:
1802 14 : return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
1803 7 : R==APFloat::cmpEqual);
1804 42 : case FCmpInst::FCMP_OEQ:
1805 42 : return ConstantInt::get(ResultTy, R==APFloat::cmpEqual);
1806 88 : case FCmpInst::FCMP_UNE:
1807 88 : return ConstantInt::get(ResultTy, R!=APFloat::cmpEqual);
1808 3 : case FCmpInst::FCMP_ONE:
1809 6 : return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan ||
1810 3 : R==APFloat::cmpGreaterThan);
1811 10 : case FCmpInst::FCMP_ULT:
1812 20 : return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
1813 10 : R==APFloat::cmpLessThan);
1814 117 : case FCmpInst::FCMP_OLT:
1815 117 : return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan);
1816 21 : case FCmpInst::FCMP_UGT:
1817 21 : return ConstantInt::get(ResultTy, R==APFloat::cmpUnordered ||
1818 21 : R==APFloat::cmpGreaterThan);
1819 20 : case FCmpInst::FCMP_OGT:
1820 20 : return ConstantInt::get(ResultTy, R==APFloat::cmpGreaterThan);
1821 0 : case FCmpInst::FCMP_ULE:
1822 0 : return ConstantInt::get(ResultTy, R!=APFloat::cmpGreaterThan);
1823 15 : case FCmpInst::FCMP_OLE:
1824 15 : return ConstantInt::get(ResultTy, R==APFloat::cmpLessThan ||
1825 15 : R==APFloat::cmpEqual);
1826 30 : case FCmpInst::FCMP_UGE:
1827 30 : return ConstantInt::get(ResultTy, R!=APFloat::cmpLessThan);
1828 35 : case FCmpInst::FCMP_OGE:
1829 35 : return ConstantInt::get(ResultTy, R==APFloat::cmpGreaterThan ||
1830 35 : R==APFloat::cmpEqual);
1831 : }
1832 49304 : } else if (C1->getType()->isVectorTy()) {
1833 : // If we can constant fold the comparison of each element, constant fold
1834 : // the whole vector comparison.
1835 : SmallVector<Constant*, 4> ResElts;
1836 72 : Type *Ty = IntegerType::get(C1->getContext(), 32);
1837 : // Compare the elements, producing an i1 result or constant expr.
1838 428 : for (unsigned i = 0, e = C1->getType()->getVectorNumElements(); i != e;++i){
1839 : Constant *C1E =
1840 356 : ConstantExpr::getExtractElement(C1, ConstantInt::get(Ty, i));
1841 : Constant *C2E =
1842 356 : ConstantExpr::getExtractElement(C2, ConstantInt::get(Ty, i));
1843 :
1844 356 : ResElts.push_back(ConstantExpr::getCompare(pred, C1E, C2E));
1845 : }
1846 :
1847 72 : return ConstantVector::get(ResElts);
1848 : }
1849 :
1850 4 : if (C1->getType()->isFloatingPointTy() &&
1851 : // Only call evaluateFCmpRelation if we have a constant expr to avoid
1852 : // infinite recursive loop
1853 0 : (isa<ConstantExpr>(C1) || isa<ConstantExpr>(C2))) {
1854 : int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
1855 4 : switch (evaluateFCmpRelation(C1, C2)) {
1856 0 : default: llvm_unreachable("Unknown relation!");
1857 : case FCmpInst::FCMP_UNO:
1858 : case FCmpInst::FCMP_ORD:
1859 : case FCmpInst::FCMP_UEQ:
1860 : case FCmpInst::FCMP_UNE:
1861 : case FCmpInst::FCMP_ULT:
1862 : case FCmpInst::FCMP_UGT:
1863 : case FCmpInst::FCMP_ULE:
1864 : case FCmpInst::FCMP_UGE:
1865 : case FCmpInst::FCMP_TRUE:
1866 : case FCmpInst::FCMP_FALSE:
1867 : case FCmpInst::BAD_FCMP_PREDICATE:
1868 : break; // Couldn't determine anything about these constants.
1869 0 : case FCmpInst::FCMP_OEQ: // We know that C1 == C2
1870 0 : Result = (pred == FCmpInst::FCMP_UEQ || pred == FCmpInst::FCMP_OEQ ||
1871 0 : pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE ||
1872 0 : pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
1873 0 : break;
1874 0 : case FCmpInst::FCMP_OLT: // We know that C1 < C2
1875 0 : Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
1876 0 : pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT ||
1877 0 : pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE);
1878 0 : break;
1879 0 : case FCmpInst::FCMP_OGT: // We know that C1 > C2
1880 0 : Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
1881 0 : pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT ||
1882 0 : pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
1883 0 : break;
1884 0 : case FCmpInst::FCMP_OLE: // We know that C1 <= C2
1885 : // We can only partially decide this relation.
1886 0 : if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
1887 : Result = 0;
1888 0 : else if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
1889 : Result = 1;
1890 : break;
1891 0 : case FCmpInst::FCMP_OGE: // We known that C1 >= C2
1892 : // We can only partially decide this relation.
1893 0 : if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
1894 : Result = 0;
1895 0 : else if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
1896 : Result = 1;
1897 : break;
1898 0 : case FCmpInst::FCMP_ONE: // We know that C1 != C2
1899 : // We can only partially decide this relation.
1900 0 : if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ)
1901 : Result = 0;
1902 0 : else if (pred == FCmpInst::FCMP_ONE || pred == FCmpInst::FCMP_UNE)
1903 : Result = 1;
1904 : break;
1905 : }
1906 :
1907 : // If we evaluated the result, return it now.
1908 : if (Result != -1)
1909 0 : return ConstantInt::get(ResultTy, Result);
1910 :
1911 : } else {
1912 : // Evaluate the relation between the two constants, per the predicate.
1913 : int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
1914 24576 : switch (evaluateICmpRelation(C1, C2,
1915 24576 : CmpInst::isSigned((CmpInst::Predicate)pred))) {
1916 0 : default: llvm_unreachable("Unknown relational!");
1917 : case ICmpInst::BAD_ICMP_PREDICATE:
1918 : break; // Couldn't determine anything about these constants.
1919 14074 : case ICmpInst::ICMP_EQ: // We know the constants are equal!
1920 : // If we know the constants are equal, we can decide the result of this
1921 : // computation precisely.
1922 14074 : Result = ICmpInst::isTrueWhenEqual((ICmpInst::Predicate)pred);
1923 14074 : break;
1924 269 : case ICmpInst::ICMP_ULT:
1925 : switch (pred) {
1926 : case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_ULE:
1927 : Result = 1; break;
1928 : case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_UGE:
1929 : Result = 0; break;
1930 : }
1931 : break;
1932 4 : case ICmpInst::ICMP_SLT:
1933 : switch (pred) {
1934 : case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_SLE:
1935 : Result = 1; break;
1936 : case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_SGE:
1937 : Result = 0; break;
1938 : }
1939 : break;
1940 7070 : case ICmpInst::ICMP_UGT:
1941 : switch (pred) {
1942 : case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_UGE:
1943 : Result = 1; break;
1944 : case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_ULE:
1945 : Result = 0; break;
1946 : }
1947 : break;
1948 0 : case ICmpInst::ICMP_SGT:
1949 : switch (pred) {
1950 : case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_NE: case ICmpInst::ICMP_SGE:
1951 : Result = 1; break;
1952 : case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_EQ: case ICmpInst::ICMP_SLE:
1953 : Result = 0; break;
1954 : }
1955 : break;
1956 0 : case ICmpInst::ICMP_ULE:
1957 0 : if (pred == ICmpInst::ICMP_UGT) Result = 0;
1958 0 : if (pred == ICmpInst::ICMP_ULT || pred == ICmpInst::ICMP_ULE) Result = 1;
1959 : break;
1960 0 : case ICmpInst::ICMP_SLE:
1961 0 : if (pred == ICmpInst::ICMP_SGT) Result = 0;
1962 0 : if (pred == ICmpInst::ICMP_SLT || pred == ICmpInst::ICMP_SLE) Result = 1;
1963 : break;
1964 0 : case ICmpInst::ICMP_UGE:
1965 0 : if (pred == ICmpInst::ICMP_ULT) Result = 0;
1966 0 : if (pred == ICmpInst::ICMP_UGT || pred == ICmpInst::ICMP_UGE) Result = 1;
1967 : break;
1968 0 : case ICmpInst::ICMP_SGE:
1969 0 : if (pred == ICmpInst::ICMP_SLT) Result = 0;
1970 0 : if (pred == ICmpInst::ICMP_SGT || pred == ICmpInst::ICMP_SGE) Result = 1;
1971 : break;
1972 219 : case ICmpInst::ICMP_NE:
1973 219 : if (pred == ICmpInst::ICMP_EQ) Result = 0;
1974 219 : if (pred == ICmpInst::ICMP_NE) Result = 1;
1975 : break;
1976 : }
1977 :
1978 : // If we evaluated the result, return it now.
1979 14287 : if (Result != -1)
1980 21599 : return ConstantInt::get(ResultTy, Result);
1981 :
1982 : // If the right hand side is a bitcast, try using its inverse to simplify
1983 : // it by moving it to the left hand side. We can't do this if it would turn
1984 : // a vector compare into a scalar compare or visa versa.
1985 : if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) {
1986 : Constant *CE2Op0 = CE2->getOperand(0);
1987 463 : if (CE2->getOpcode() == Instruction::BitCast &&
1988 136 : CE2->getType()->isVectorTy() == CE2Op0->getType()->isVectorTy()) {
1989 68 : Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType());
1990 68 : return ConstantExpr::getICmp(pred, Inverse, CE2Op0);
1991 : }
1992 : }
1993 :
1994 : // If the left hand side is an extension, try eliminating it.
1995 : if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
1996 0 : if ((CE1->getOpcode() == Instruction::SExt &&
1997 2698 : ICmpInst::isSigned((ICmpInst::Predicate)pred)) ||
1998 732 : (CE1->getOpcode() == Instruction::ZExt &&
1999 732 : !ICmpInst::isSigned((ICmpInst::Predicate)pred))){
2000 : Constant *CE1Op0 = CE1->getOperand(0);
2001 35 : Constant *CE1Inverse = ConstantExpr::getTrunc(CE1, CE1Op0->getType());
2002 35 : if (CE1Inverse == CE1Op0) {
2003 : // Check whether we can safely truncate the right hand side.
2004 35 : Constant *C2Inverse = ConstantExpr::getTrunc(C2, CE1Op0->getType());
2005 70 : if (ConstantExpr::getCast(CE1->getOpcode(), C2Inverse,
2006 : C2->getType()) == C2)
2007 35 : return ConstantExpr::getICmp(pred, CE1Inverse, C2Inverse);
2008 : }
2009 : }
2010 : }
2011 :
2012 5737 : if ((!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) ||
2013 2867 : (C1->isNullValue() && !C2->isNullValue())) {
2014 : // If C2 is a constant expr and C1 isn't, flip them around and fold the
2015 : // other way if possible.
2016 : // Also, if C1 is null and C2 isn't, flip them around.
2017 15 : pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
2018 15 : return ConstantExpr::getICmp(pred, C2, C1);
2019 : }
2020 : }
2021 : return nullptr;
2022 : }
2023 :
2024 : /// Test whether the given sequence of *normalized* indices is "inbounds".
2025 : template<typename IndexTy>
2026 258831 : static bool isInBoundsIndices(ArrayRef<IndexTy> Idxs) {
2027 : // No indices means nothing that could be out of bounds.
2028 258831 : if (Idxs.empty()) return true;
2029 :
2030 : // If the first index is zero, it's in bounds.
2031 258831 : if (cast<Constant>(Idxs[0])->isNullValue()) return true;
2032 :
2033 : // If the first index is one and all the rest are zero, it's in bounds,
2034 : // by the one-past-the-end rule.
2035 235 : if (auto *CI = dyn_cast<ConstantInt>(Idxs[0])) {
2036 234 : if (!CI->isOne())
2037 : return false;
2038 : } else {
2039 : auto *CV = cast<ConstantDataVector>(Idxs[0]);
2040 1 : CI = dyn_cast_or_null<ConstantInt>(CV->getSplatValue());
2041 1 : if (!CI || !CI->isOne())
2042 : return false;
2043 : }
2044 :
2045 151 : for (unsigned i = 1, e = Idxs.size(); i != e; ++i)
2046 136 : if (!cast<Constant>(Idxs[i])->isNullValue())
2047 : return false;
2048 : return true;
2049 : }
2050 :
2051 : /// Test whether a given ConstantInt is in-range for a SequentialType.
2052 18006665 : static bool isIndexInRangeOfArrayType(uint64_t NumElements,
2053 : const ConstantInt *CI) {
2054 : // We cannot bounds check the index if it doesn't fit in an int64_t.
2055 18006665 : if (CI->getValue().getActiveBits() > 64)
2056 : return false;
2057 :
2058 : // A negative index or an index past the end of our sequential type is
2059 : // considered out-of-range.
2060 : int64_t IndexVal = CI->getSExtValue();
2061 18006665 : if (IndexVal < 0 || (NumElements > 0 && (uint64_t)IndexVal >= NumElements))
2062 1351 : return false;
2063 :
2064 : // Otherwise, it is in-range.
2065 : return true;
2066 : }
2067 :
2068 18118848 : Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C,
2069 : bool InBounds,
2070 : Optional<unsigned> InRangeIndex,
2071 : ArrayRef<Value *> Idxs) {
2072 18118848 : if (Idxs.empty()) return C;
2073 :
2074 18118846 : Type *GEPTy = GetElementPtrInst::getGEPReturnType(
2075 : C, makeArrayRef((Value *const *)Idxs.data(), Idxs.size()));
2076 :
2077 18118846 : if (isa<UndefValue>(C))
2078 58 : return UndefValue::get(GEPTy);
2079 :
2080 18118788 : Constant *Idx0 = cast<Constant>(Idxs[0]);
2081 18118788 : if (Idxs.size() == 1 && (Idx0->isNullValue() || isa<UndefValue>(Idx0)))
2082 10 : return GEPTy->isVectorTy() && !C->getType()->isVectorTy()
2083 706 : ? ConstantVector::getSplat(
2084 2 : cast<VectorType>(GEPTy)->getNumElements(), C)
2085 : : C;
2086 :
2087 18118082 : if (C->isNullValue()) {
2088 : bool isNull = true;
2089 4732 : for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
2090 18772 : if (!isa<UndefValue>(Idxs[i]) &&
2091 4693 : !cast<Constant>(Idxs[i])->isNullValue()) {
2092 : isNull = false;
2093 : break;
2094 : }
2095 3008 : if (isNull) {
2096 39 : PointerType *PtrTy = cast<PointerType>(C->getType()->getScalarType());
2097 39 : Type *Ty = GetElementPtrInst::getIndexedType(PointeeTy, Idxs);
2098 :
2099 : assert(Ty && "Invalid indices for GEP!");
2100 39 : Type *OrigGEPTy = PointerType::get(Ty, PtrTy->getAddressSpace());
2101 39 : Type *GEPTy = PointerType::get(Ty, PtrTy->getAddressSpace());
2102 39 : if (VectorType *VT = dyn_cast<VectorType>(C->getType()))
2103 2 : GEPTy = VectorType::get(OrigGEPTy, VT->getNumElements());
2104 :
2105 : // The GEP returns a vector of pointers when one of more of
2106 : // its arguments is a vector.
2107 114 : for (unsigned i = 0, e = Idxs.size(); i != e; ++i) {
2108 156 : if (auto *VT = dyn_cast<VectorType>(Idxs[i]->getType())) {
2109 3 : GEPTy = VectorType::get(OrigGEPTy, VT->getNumElements());
2110 3 : break;
2111 : }
2112 : }
2113 :
2114 39 : return Constant::getNullValue(GEPTy);
2115 : }
2116 : }
2117 :
2118 : if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2119 : // Combine Indices - If the source pointer to this getelementptr instruction
2120 : // is a getelementptr instruction, combine the indices of the two
2121 : // getelementptr instructions into a single instruction.
2122 : //
2123 11965 : if (CE->getOpcode() == Instruction::GetElementPtr) {
2124 : gep_type_iterator LastI = gep_type_end(CE);
2125 23121 : for (gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
2126 23121 : I != E; ++I)
2127 15672 : LastI = I;
2128 :
2129 : // We cannot combine indices if doing so would take us outside of an
2130 : // array or vector. Doing otherwise could trick us if we evaluated such a
2131 : // GEP as part of a load.
2132 : //
2133 : // e.g. Consider if the original GEP was:
2134 : // i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c,
2135 : // i32 0, i32 0, i64 0)
2136 : //
2137 : // If we then tried to offset it by '8' to get to the third element,
2138 : // an i8, we should *not* get:
2139 : // i8* getelementptr ({ [2 x i8], i32, i8, [3 x i8] }* @main.c,
2140 : // i32 0, i32 0, i64 8)
2141 : //
2142 : // This GEP tries to index array element '8 which runs out-of-bounds.
2143 : // Subsequent evaluation would get confused and produce erroneous results.
2144 : //
2145 : // The following prohibits such a GEP from being formed by checking to see
2146 : // if the index is in-range with respect to an array.
2147 : // TODO: This code may be extended to handle vectors as well.
2148 : bool PerformFold = false;
2149 7449 : if (Idx0->isNullValue())
2150 : PerformFold = true;
2151 5317 : else if (LastI.isSequential())
2152 : if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx0))
2153 5201 : PerformFold = (!LastI.isBoundedSequential() ||
2154 5201 : isIndexInRangeOfArrayType(
2155 4038 : LastI.getSequentialNumElements(), CI)) &&
2156 4038 : !CE->getOperand(CE->getNumOperands() - 1)
2157 : ->getType()
2158 4038 : ->isVectorTy();
2159 :
2160 : if (PerformFold) {
2161 : SmallVector<Value*, 16> NewIndices;
2162 6169 : NewIndices.reserve(Idxs.size() + CE->getNumOperands());
2163 12338 : NewIndices.append(CE->op_begin() + 1, CE->op_end() - 1);
2164 :
2165 : // Add the last index of the source with the first index of the new GEP.
2166 : // Make sure to handle the case when they are actually different types.
2167 6169 : Constant *Combined = CE->getOperand(CE->getNumOperands()-1);
2168 : // Otherwise it must be an array.
2169 6169 : if (!Idx0->isNullValue()) {
2170 4037 : Type *IdxTy = Combined->getType();
2171 4037 : if (IdxTy != Idx0->getType()) {
2172 : unsigned CommonExtendedWidth =
2173 307 : std::max(IdxTy->getIntegerBitWidth(),
2174 307 : Idx0->getType()->getIntegerBitWidth());
2175 307 : CommonExtendedWidth = std::max(CommonExtendedWidth, 64U);
2176 :
2177 : Type *CommonTy =
2178 307 : Type::getIntNTy(IdxTy->getContext(), CommonExtendedWidth);
2179 307 : Constant *C1 = ConstantExpr::getSExtOrBitCast(Idx0, CommonTy);
2180 307 : Constant *C2 = ConstantExpr::getSExtOrBitCast(Combined, CommonTy);
2181 307 : Combined = ConstantExpr::get(Instruction::Add, C1, C2);
2182 : } else {
2183 : Combined =
2184 3730 : ConstantExpr::get(Instruction::Add, Idx0, Combined);
2185 : }
2186 : }
2187 :
2188 6169 : NewIndices.push_back(Combined);
2189 6169 : NewIndices.append(Idxs.begin() + 1, Idxs.end());
2190 :
2191 : // The combined GEP normally inherits its index inrange attribute from
2192 : // the inner GEP, but if the inner GEP's last index was adjusted by the
2193 : // outer GEP, any inbounds attribute on that index is invalidated.
2194 : Optional<unsigned> IRIndex = cast<GEPOperator>(CE)->getInRangeIndex();
2195 6169 : if (IRIndex && *IRIndex == CE->getNumOperands() - 2 && !Idx0->isNullValue())
2196 : IRIndex = None;
2197 :
2198 6169 : return ConstantExpr::getGetElementPtr(
2199 : cast<GEPOperator>(CE)->getSourceElementType(), CE->getOperand(0),
2200 6169 : NewIndices, InBounds && cast<GEPOperator>(CE)->isInBounds(),
2201 : IRIndex);
2202 : }
2203 : }
2204 :
2205 : // Attempt to fold casts to the same type away. For example, folding:
2206 : //
2207 : // i32* getelementptr ([2 x i32]* bitcast ([3 x i32]* %X to [2 x i32]*),
2208 : // i64 0, i64 0)
2209 : // into:
2210 : //
2211 : // i32* getelementptr ([3 x i32]* %X, i64 0, i64 0)
2212 : //
2213 : // Don't fold if the cast is changing address spaces.
2214 5796 : if (CE->isCast() && Idxs.size() > 1 && Idx0->isNullValue()) {
2215 : PointerType *SrcPtrTy =
2216 1105 : dyn_cast<PointerType>(CE->getOperand(0)->getType());
2217 1105 : PointerType *DstPtrTy = dyn_cast<PointerType>(CE->getType());
2218 1105 : if (SrcPtrTy && DstPtrTy) {
2219 : ArrayType *SrcArrayTy =
2220 938 : dyn_cast<ArrayType>(SrcPtrTy->getElementType());
2221 : ArrayType *DstArrayTy =
2222 938 : dyn_cast<ArrayType>(DstPtrTy->getElementType());
2223 938 : if (SrcArrayTy && DstArrayTy
2224 115 : && SrcArrayTy->getElementType() == DstArrayTy->getElementType()
2225 1041 : && SrcPtrTy->getAddressSpace() == DstPtrTy->getAddressSpace())
2226 25 : return ConstantExpr::getGetElementPtr(SrcArrayTy,
2227 : (Constant *)CE->getOperand(0),
2228 : Idxs, InBounds, InRangeIndex);
2229 : }
2230 : }
2231 : }
2232 :
2233 : // Check to see if any array indices are not within the corresponding
2234 : // notional array or vector bounds. If so, try to determine if they can be
2235 : // factored out into preceding dimensions.
2236 : SmallVector<Constant *, 8> NewIdxs;
2237 : Type *Ty = PointeeTy;
2238 18111849 : Type *Prev = C->getType();
2239 : bool Unknown =
2240 36223698 : !isa<ConstantInt>(Idxs[0]) && !isa<ConstantDataVector>(Idxs[0]);
2241 36293891 : for (unsigned i = 1, e = Idxs.size(); i != e;
2242 18182042 : Prev = Ty, Ty = cast<CompositeType>(Ty)->getTypeAtIndex(Idxs[i]), ++i) {
2243 54546126 : if (!isa<ConstantInt>(Idxs[i]) && !isa<ConstantDataVector>(Idxs[i])) {
2244 : // We don't know if it's in range or not.
2245 : Unknown = true;
2246 18181975 : continue;
2247 : }
2248 54545952 : if (!isa<ConstantInt>(Idxs[i - 1]) && !isa<ConstantDataVector>(Idxs[i - 1]))
2249 : // Skip if the type of the previous index is not supported.
2250 : continue;
2251 18181972 : if (InRangeIndex && i == *InRangeIndex + 1) {
2252 : // If an index is marked inrange, we cannot apply this canonicalization to
2253 : // the following index, as that will cause the inrange index to point to
2254 : // the wrong element.
2255 : continue;
2256 : }
2257 18124651 : if (isa<StructType>(Ty)) {
2258 : // The verify makes sure that GEPs into a struct are in range.
2259 : continue;
2260 : }
2261 : auto *STy = cast<SequentialType>(Ty);
2262 18001417 : if (isa<VectorType>(STy)) {
2263 : // There can be awkward padding in after a non-power of two vector.
2264 : Unknown = true;
2265 : continue;
2266 : }
2267 : if (ConstantInt *CI = dyn_cast<ConstantInt>(Idxs[i])) {
2268 18001370 : if (isIndexInRangeOfArrayType(STy->getNumElements(), CI))
2269 : // It's in range, skip to the next index.
2270 : continue;
2271 172 : if (CI->getSExtValue() < 0) {
2272 : // It's out of range and negative, don't try to factor it.
2273 : Unknown = true;
2274 : continue;
2275 : }
2276 : } else {
2277 : auto *CV = cast<ConstantDataVector>(Idxs[i]);
2278 : bool InRange = true;
2279 125 : for (unsigned I = 0, E = CV->getNumElements(); I != E; ++I) {
2280 94 : auto *CI = cast<ConstantInt>(CV->getElementAsConstant(I));
2281 94 : InRange &= isIndexInRangeOfArrayType(STy->getNumElements(), CI);
2282 94 : if (CI->getSExtValue() < 0) {
2283 : Unknown = true;
2284 : break;
2285 : }
2286 : }
2287 31 : if (InRange || Unknown)
2288 : // It's in range, skip to the next index.
2289 : // It's out of range and negative, don't try to factor it.
2290 : continue;
2291 : }
2292 99 : if (isa<StructType>(Prev)) {
2293 : // It's out of range, but the prior dimension is a struct
2294 : // so we can't do anything about it.
2295 : Unknown = true;
2296 : continue;
2297 : }
2298 : // It's out of range, but we can factor it into the prior
2299 : // dimension.
2300 67 : NewIdxs.resize(Idxs.size());
2301 : // Determine the number of elements in our sequential type.
2302 : uint64_t NumElements = STy->getArrayNumElements();
2303 :
2304 : // Expand the current index or the previous index to a vector from a scalar
2305 : // if necessary.
2306 67 : Constant *CurrIdx = cast<Constant>(Idxs[i]);
2307 : auto *PrevIdx =
2308 67 : NewIdxs[i - 1] ? NewIdxs[i - 1] : cast<Constant>(Idxs[i - 1]);
2309 67 : bool IsCurrIdxVector = CurrIdx->getType()->isVectorTy();
2310 67 : bool IsPrevIdxVector = PrevIdx->getType()->isVectorTy();
2311 67 : bool UseVector = IsCurrIdxVector || IsPrevIdxVector;
2312 :
2313 67 : if (!IsCurrIdxVector && IsPrevIdxVector)
2314 1 : CurrIdx = ConstantDataVector::getSplat(
2315 : PrevIdx->getType()->getVectorNumElements(), CurrIdx);
2316 :
2317 67 : if (!IsPrevIdxVector && IsCurrIdxVector)
2318 2 : PrevIdx = ConstantDataVector::getSplat(
2319 : CurrIdx->getType()->getVectorNumElements(), PrevIdx);
2320 :
2321 : Constant *Factor =
2322 72 : ConstantInt::get(CurrIdx->getType()->getScalarType(), NumElements);
2323 67 : if (UseVector)
2324 10 : Factor = ConstantDataVector::getSplat(
2325 4 : IsPrevIdxVector ? PrevIdx->getType()->getVectorNumElements()
2326 1 : : CurrIdx->getType()->getVectorNumElements(),
2327 : Factor);
2328 :
2329 67 : NewIdxs[i] = ConstantExpr::getSRem(CurrIdx, Factor);
2330 :
2331 67 : Constant *Div = ConstantExpr::getSDiv(CurrIdx, Factor);
2332 :
2333 : unsigned CommonExtendedWidth =
2334 201 : std::max(PrevIdx->getType()->getScalarSizeInBits(),
2335 67 : Div->getType()->getScalarSizeInBits());
2336 67 : CommonExtendedWidth = std::max(CommonExtendedWidth, 64U);
2337 :
2338 : // Before adding, extend both operands to i64 to avoid
2339 : // overflow trouble.
2340 67 : Type *ExtendedTy = Type::getIntNTy(Div->getContext(), CommonExtendedWidth);
2341 67 : if (UseVector)
2342 10 : ExtendedTy = VectorType::get(
2343 : ExtendedTy, IsPrevIdxVector
2344 4 : ? PrevIdx->getType()->getVectorNumElements()
2345 1 : : CurrIdx->getType()->getVectorNumElements());
2346 :
2347 134 : if (!PrevIdx->getType()->isIntOrIntVectorTy(CommonExtendedWidth))
2348 25 : PrevIdx = ConstantExpr::getSExt(PrevIdx, ExtendedTy);
2349 :
2350 134 : if (!Div->getType()->isIntOrIntVectorTy(CommonExtendedWidth))
2351 17 : Div = ConstantExpr::getSExt(Div, ExtendedTy);
2352 :
2353 67 : NewIdxs[i - 1] = ConstantExpr::getAdd(PrevIdx, Div);
2354 : }
2355 :
2356 : // If we did any factoring, start over with the adjusted indices.
2357 18111849 : if (!NewIdxs.empty()) {
2358 248 : for (unsigned i = 0, e = Idxs.size(); i != e; ++i)
2359 370 : if (!NewIdxs[i]) NewIdxs[i] = cast<Constant>(Idxs[i]);
2360 63 : return ConstantExpr::getGetElementPtr(PointeeTy, C, NewIdxs, InBounds,
2361 : InRangeIndex);
2362 : }
2363 :
2364 : // If all indices are known integers and normalized, we can do a simple
2365 : // check for the "inbounds" property.
2366 18111786 : if (!Unknown && !InBounds)
2367 : if (auto *GV = dyn_cast<GlobalVariable>(C))
2368 258891 : if (!GV->hasExternalWeakLinkage() && isInBoundsIndices(Idxs))
2369 258679 : return ConstantExpr::getGetElementPtr(PointeeTy, C, Idxs,
2370 : /*InBounds=*/true, InRangeIndex);
2371 :
2372 : return nullptr;
2373 : }
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