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[lld/COFF] Demangle symbol name in discarded section relocation error message (#119726)
[llvm-project.git] / llvm / lib / IR / ConstantRange.cpp
blobd81a292916fdeaa72cd0031c9d0f253b84928567
1 //===- ConstantRange.cpp - ConstantRange implementation -------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Represent a range of possible values that may occur when the program is run
10 // for an integral value. This keeps track of a lower and upper bound for the
11 // constant, which MAY wrap around the end of the numeric range. To do this, it
12 // keeps track of a [lower, upper) bound, which specifies an interval just like
13 // STL iterators. When used with boolean values, the following are important
14 // ranges (other integral ranges use min/max values for special range values):
15 //
16 // [F, F) = {} = Empty set
17 // [T, F) = {T}
18 // [F, T) = {F}
19 // [T, T) = {F, T} = Full set
20 //
21 //===----------------------------------------------------------------------===//
22
23 #include "llvm/IR/ConstantRange.h"
24 #include "llvm/ADT/APInt.h"
25 #include "llvm/Config/llvm-config.h"
26 #include "llvm/IR/Constants.h"
27 #include "llvm/IR/InstrTypes.h"
28 #include "llvm/IR/Instruction.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/Intrinsics.h"
31 #include "llvm/IR/Metadata.h"
32 #include "llvm/IR/Operator.h"
33 #include "llvm/Support/Compiler.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/KnownBits.h"
37 #include "llvm/Support/raw_ostream.h"
38 #include <algorithm>
39 #include <cassert>
40 #include <cstdint>
41 #include <optional>
42
43 using namespace llvm;
44
45 ConstantRange::ConstantRange(uint32_t BitWidth, bool Full)
46 : Lower(Full ? APInt::getMaxValue(BitWidth) : APInt::getMinValue(BitWidth)),
47 Upper(Lower) {}
48
49 ConstantRange::ConstantRange(APInt V)
50 : Lower(std::move(V)), Upper(Lower + 1) {}
51
52 ConstantRange::ConstantRange(APInt L, APInt U)
53 : Lower(std::move(L)), Upper(std::move(U)) {
54 assert(Lower.getBitWidth() == Upper.getBitWidth() &&
55 "ConstantRange with unequal bit widths");
56 assert((Lower != Upper || (Lower.isMaxValue() || Lower.isMinValue())) &&
57 "Lower == Upper, but they aren't min or max value!");
58 }
59
60 ConstantRange ConstantRange::fromKnownBits(const KnownBits &Known,
61 bool IsSigned) {
62 if (Known.hasConflict())
63 return getEmpty(Known.getBitWidth());
64 if (Known.isUnknown())
65 return getFull(Known.getBitWidth());
66
67 // For unsigned ranges, or signed ranges with known sign bit, create a simple
68 // range between the smallest and largest possible value.
69 if (!IsSigned || Known.isNegative() || Known.isNonNegative())
70 return ConstantRange(Known.getMinValue(), Known.getMaxValue() + 1);
71
72 // If we don't know the sign bit, pick the lower bound as a negative number
73 // and the upper bound as a non-negative one.
74 APInt Lower = Known.getMinValue(), Upper = Known.getMaxValue();
75 Lower.setSignBit();
76 Upper.clearSignBit();
77 return ConstantRange(Lower, Upper + 1);
78 }
79
80 KnownBits ConstantRange::toKnownBits() const {
81 // TODO: We could return conflicting known bits here, but consumers are
82 // likely not prepared for that.
83 if (isEmptySet())
84 return KnownBits(getBitWidth());
85
86 // We can only retain the top bits that are the same between min and max.
87 APInt Min = getUnsignedMin();
88 APInt Max = getUnsignedMax();
89 KnownBits Known = KnownBits::makeConstant(Min);
90 if (std::optional<unsigned> DifferentBit =
91 APIntOps::GetMostSignificantDifferentBit(Min, Max)) {
92 Known.Zero.clearLowBits(*DifferentBit + 1);
93 Known.One.clearLowBits(*DifferentBit + 1);
94 }
95 return Known;
96 }
97
98 ConstantRange ConstantRange::makeAllowedICmpRegion(CmpInst::Predicate Pred,
99 const ConstantRange &CR) {
100 if (CR.isEmptySet())
101 return CR;
102
103 uint32_t W = CR.getBitWidth();
104 switch (Pred) {
105 default:
106 llvm_unreachable("Invalid ICmp predicate to makeAllowedICmpRegion()");
107 case CmpInst::ICMP_EQ:
108 return CR;
109 case CmpInst::ICMP_NE:
110 if (CR.isSingleElement())
111 return ConstantRange(CR.getUpper(), CR.getLower());
112 return getFull(W);
113 case CmpInst::ICMP_ULT: {
114 APInt UMax(CR.getUnsignedMax());
115 if (UMax.isMinValue())
116 return getEmpty(W);
117 return ConstantRange(APInt::getMinValue(W), std::move(UMax));
118 }
119 case CmpInst::ICMP_SLT: {
120 APInt SMax(CR.getSignedMax());
121 if (SMax.isMinSignedValue())
122 return getEmpty(W);
123 return ConstantRange(APInt::getSignedMinValue(W), std::move(SMax));
124 }
125 case CmpInst::ICMP_ULE:
126 return getNonEmpty(APInt::getMinValue(W), CR.getUnsignedMax() + 1);
127 case CmpInst::ICMP_SLE:
128 return getNonEmpty(APInt::getSignedMinValue(W), CR.getSignedMax() + 1);
129 case CmpInst::ICMP_UGT: {
130 APInt UMin(CR.getUnsignedMin());
131 if (UMin.isMaxValue())
132 return getEmpty(W);
133 return ConstantRange(std::move(UMin) + 1, APInt::getZero(W));
134 }
135 case CmpInst::ICMP_SGT: {
136 APInt SMin(CR.getSignedMin());
137 if (SMin.isMaxSignedValue())
138 return getEmpty(W);
139 return ConstantRange(std::move(SMin) + 1, APInt::getSignedMinValue(W));
140 }
141 case CmpInst::ICMP_UGE:
142 return getNonEmpty(CR.getUnsignedMin(), APInt::getZero(W));
143 case CmpInst::ICMP_SGE:
144 return getNonEmpty(CR.getSignedMin(), APInt::getSignedMinValue(W));
145 }
146 }
147
148 ConstantRange ConstantRange::makeSatisfyingICmpRegion(CmpInst::Predicate Pred,
149 const ConstantRange &CR) {
150 // Follows from De-Morgan's laws:
151 //
152 // ~(~A union ~B) == A intersect B.
153 //
154 return makeAllowedICmpRegion(CmpInst::getInversePredicate(Pred), CR)
155 .inverse();
156 }
157
158 ConstantRange ConstantRange::makeExactICmpRegion(CmpInst::Predicate Pred,
159 const APInt &C) {
160 // Computes the exact range that is equal to both the constant ranges returned
161 // by makeAllowedICmpRegion and makeSatisfyingICmpRegion. This is always true
162 // when RHS is a singleton such as an APInt and so the assert is valid.
163 // However for non-singleton RHS, for example ult [2,5) makeAllowedICmpRegion
164 // returns [0,4) but makeSatisfyICmpRegion returns [0,2).
165 //
166 assert(makeAllowedICmpRegion(Pred, C) == makeSatisfyingICmpRegion(Pred, C));
167 return makeAllowedICmpRegion(Pred, C);
168 }
169
170 bool ConstantRange::areInsensitiveToSignednessOfICmpPredicate(
171 const ConstantRange &CR1, const ConstantRange &CR2) {
172 if (CR1.isEmptySet() || CR2.isEmptySet())
173 return true;
174
175 return (CR1.isAllNonNegative() && CR2.isAllNonNegative()) ||
176 (CR1.isAllNegative() && CR2.isAllNegative());
177 }
178
179 bool ConstantRange::areInsensitiveToSignednessOfInvertedICmpPredicate(
180 const ConstantRange &CR1, const ConstantRange &CR2) {
181 if (CR1.isEmptySet() || CR2.isEmptySet())
182 return true;
183
184 return (CR1.isAllNonNegative() && CR2.isAllNegative()) ||
185 (CR1.isAllNegative() && CR2.isAllNonNegative());
186 }
187
188 CmpInst::Predicate ConstantRange::getEquivalentPredWithFlippedSignedness(
189 CmpInst::Predicate Pred, const ConstantRange &CR1,
190 const ConstantRange &CR2) {
191 assert(CmpInst::isIntPredicate(Pred) && CmpInst::isRelational(Pred) &&
192 "Only for relational integer predicates!");
193
194 CmpInst::Predicate FlippedSignednessPred =
195 ICmpInst::getFlippedSignednessPredicate(Pred);
196
197 if (areInsensitiveToSignednessOfICmpPredicate(CR1, CR2))
198 return FlippedSignednessPred;
199
200 if (areInsensitiveToSignednessOfInvertedICmpPredicate(CR1, CR2))
201 return CmpInst::getInversePredicate(FlippedSignednessPred);
202
203 return CmpInst::Predicate::BAD_ICMP_PREDICATE;
204 }
205
206 void ConstantRange::getEquivalentICmp(CmpInst::Predicate &Pred,
207 APInt &RHS, APInt &Offset) const {
208 Offset = APInt(getBitWidth(), 0);
209 if (isFullSet() || isEmptySet()) {
210 Pred = isEmptySet() ? CmpInst::ICMP_ULT : CmpInst::ICMP_UGE;
211 RHS = APInt(getBitWidth(), 0);
212 } else if (auto *OnlyElt = getSingleElement()) {
213 Pred = CmpInst::ICMP_EQ;
214 RHS = *OnlyElt;
215 } else if (auto *OnlyMissingElt = getSingleMissingElement()) {
216 Pred = CmpInst::ICMP_NE;
217 RHS = *OnlyMissingElt;
218 } else if (getLower().isMinSignedValue() || getLower().isMinValue()) {
219 Pred =
220 getLower().isMinSignedValue() ? CmpInst::ICMP_SLT : CmpInst::ICMP_ULT;
221 RHS = getUpper();
222 } else if (getUpper().isMinSignedValue() || getUpper().isMinValue()) {
223 Pred =
224 getUpper().isMinSignedValue() ? CmpInst::ICMP_SGE : CmpInst::ICMP_UGE;
225 RHS = getLower();
226 } else {
227 Pred = CmpInst::ICMP_ULT;
228 RHS = getUpper() - getLower();
229 Offset = -getLower();
230 }
231
232 assert(ConstantRange::makeExactICmpRegion(Pred, RHS) == add(Offset) &&
233 "Bad result!");
234 }
235
236 bool ConstantRange::getEquivalentICmp(CmpInst::Predicate &Pred,
237 APInt &RHS) const {
238 APInt Offset;
239 getEquivalentICmp(Pred, RHS, Offset);
240 return Offset.isZero();
241 }
242
243 bool ConstantRange::icmp(CmpInst::Predicate Pred,
244 const ConstantRange &Other) const {
245 if (isEmptySet() || Other.isEmptySet())
246 return true;
247
248 switch (Pred) {
249 case CmpInst::ICMP_EQ:
250 if (const APInt *L = getSingleElement())
251 if (const APInt *R = Other.getSingleElement())
252 return *L == *R;
253 return false;
254 case CmpInst::ICMP_NE:
255 return inverse().contains(Other);
256 case CmpInst::ICMP_ULT:
257 return getUnsignedMax().ult(Other.getUnsignedMin());
258 case CmpInst::ICMP_ULE:
259 return getUnsignedMax().ule(Other.getUnsignedMin());
260 case CmpInst::ICMP_UGT:
261 return getUnsignedMin().ugt(Other.getUnsignedMax());
262 case CmpInst::ICMP_UGE:
263 return getUnsignedMin().uge(Other.getUnsignedMax());
264 case CmpInst::ICMP_SLT:
265 return getSignedMax().slt(Other.getSignedMin());
266 case CmpInst::ICMP_SLE:
267 return getSignedMax().sle(Other.getSignedMin());
268 case CmpInst::ICMP_SGT:
269 return getSignedMin().sgt(Other.getSignedMax());
270 case CmpInst::ICMP_SGE:
271 return getSignedMin().sge(Other.getSignedMax());
272 default:
273 llvm_unreachable("Invalid ICmp predicate");
274 }
275 }
276
277 /// Exact mul nuw region for single element RHS.
278 static ConstantRange makeExactMulNUWRegion(const APInt &V) {
279 unsigned BitWidth = V.getBitWidth();
280 if (V == 0)
281 return ConstantRange::getFull(V.getBitWidth());
282
283 return ConstantRange::getNonEmpty(
284 APIntOps::RoundingUDiv(APInt::getMinValue(BitWidth), V,
285 APInt::Rounding::UP),
286 APIntOps::RoundingUDiv(APInt::getMaxValue(BitWidth), V,
287 APInt::Rounding::DOWN) + 1);
288 }
289
290 /// Exact mul nsw region for single element RHS.
291 static ConstantRange makeExactMulNSWRegion(const APInt &V) {
292 // Handle 0 and -1 separately to avoid division by zero or overflow.
293 unsigned BitWidth = V.getBitWidth();
294 if (V == 0)
295 return ConstantRange::getFull(BitWidth);
296
297 APInt MinValue = APInt::getSignedMinValue(BitWidth);
298 APInt MaxValue = APInt::getSignedMaxValue(BitWidth);
299 // e.g. Returning [-127, 127], represented as [-127, -128).
300 if (V.isAllOnes())
301 return ConstantRange(-MaxValue, MinValue);
302
303 APInt Lower, Upper;
304 if (V.isNegative()) {
305 Lower = APIntOps::RoundingSDiv(MaxValue, V, APInt::Rounding::UP);
306 Upper = APIntOps::RoundingSDiv(MinValue, V, APInt::Rounding::DOWN);
307 } else {
308 Lower = APIntOps::RoundingSDiv(MinValue, V, APInt::Rounding::UP);
309 Upper = APIntOps::RoundingSDiv(MaxValue, V, APInt::Rounding::DOWN);
310 }
311 return ConstantRange::getNonEmpty(Lower, Upper + 1);
312 }
313
314 ConstantRange
315 ConstantRange::makeGuaranteedNoWrapRegion(Instruction::BinaryOps BinOp,
316 const ConstantRange &Other,
317 unsigned NoWrapKind) {
318 using OBO = OverflowingBinaryOperator;
319
320 assert(Instruction::isBinaryOp(BinOp) && "Binary operators only!");
321
322 assert((NoWrapKind == OBO::NoSignedWrap ||
323 NoWrapKind == OBO::NoUnsignedWrap) &&
324 "NoWrapKind invalid!");
325
326 bool Unsigned = NoWrapKind == OBO::NoUnsignedWrap;
327 unsigned BitWidth = Other.getBitWidth();
328
329 switch (BinOp) {
330 default:
331 llvm_unreachable("Unsupported binary op");
332
333 case Instruction::Add: {
334 if (Unsigned)
335 return getNonEmpty(APInt::getZero(BitWidth), -Other.getUnsignedMax());
336
337 APInt SignedMinVal = APInt::getSignedMinValue(BitWidth);
338 APInt SMin = Other.getSignedMin(), SMax = Other.getSignedMax();
339 return getNonEmpty(
340 SMin.isNegative() ? SignedMinVal - SMin : SignedMinVal,
341 SMax.isStrictlyPositive() ? SignedMinVal - SMax : SignedMinVal);
342 }
343
344 case Instruction::Sub: {
345 if (Unsigned)
346 return getNonEmpty(Other.getUnsignedMax(), APInt::getMinValue(BitWidth));
347
348 APInt SignedMinVal = APInt::getSignedMinValue(BitWidth);
349 APInt SMin = Other.getSignedMin(), SMax = Other.getSignedMax();
350 return getNonEmpty(
351 SMax.isStrictlyPositive() ? SignedMinVal + SMax : SignedMinVal,
352 SMin.isNegative() ? SignedMinVal + SMin : SignedMinVal);
353 }
354
355 case Instruction::Mul:
356 if (Unsigned)
357 return makeExactMulNUWRegion(Other.getUnsignedMax());
358
359 // Avoid one makeExactMulNSWRegion() call for the common case of constants.
360 if (const APInt *C = Other.getSingleElement())
361 return makeExactMulNSWRegion(*C);
362
363 return makeExactMulNSWRegion(Other.getSignedMin())
364 .intersectWith(makeExactMulNSWRegion(Other.getSignedMax()));
365
366 case Instruction::Shl: {
367 // For given range of shift amounts, if we ignore all illegal shift amounts
368 // (that always produce poison), what shift amount range is left?
369 ConstantRange ShAmt = Other.intersectWith(
370 ConstantRange(APInt(BitWidth, 0), APInt(BitWidth, (BitWidth - 1) + 1)));
371 if (ShAmt.isEmptySet()) {
372 // If the entire range of shift amounts is already poison-producing,
373 // then we can freely add more poison-producing flags ontop of that.
374 return getFull(BitWidth);
375 }
376 // There are some legal shift amounts, we can compute conservatively-correct
377 // range of no-wrap inputs. Note that by now we have clamped the ShAmtUMax
378 // to be at most bitwidth-1, which results in most conservative range.
379 APInt ShAmtUMax = ShAmt.getUnsignedMax();
380 if (Unsigned)
381 return getNonEmpty(APInt::getZero(BitWidth),
382 APInt::getMaxValue(BitWidth).lshr(ShAmtUMax) + 1);
383 return getNonEmpty(APInt::getSignedMinValue(BitWidth).ashr(ShAmtUMax),
384 APInt::getSignedMaxValue(BitWidth).ashr(ShAmtUMax) + 1);
385 }
386 }
387 }
388
389 ConstantRange ConstantRange::makeExactNoWrapRegion(Instruction::BinaryOps BinOp,
390 const APInt &Other,
391 unsigned NoWrapKind) {
392 // makeGuaranteedNoWrapRegion() is exact for single-element ranges, as
393 // "for all" and "for any" coincide in this case.
394 return makeGuaranteedNoWrapRegion(BinOp, ConstantRange(Other), NoWrapKind);
395 }
396
397 ConstantRange ConstantRange::makeMaskNotEqualRange(const APInt &Mask,
398 const APInt &C) {
399 unsigned BitWidth = Mask.getBitWidth();
400
401 if ((Mask & C) != C)
402 return getFull(BitWidth);
403
404 if (Mask.isZero())
405 return getEmpty(BitWidth);
406
407 // If (Val & Mask) != C, constrained to the non-equality being
408 // satisfiable, then the value must be larger than the lowest set bit of
409 // Mask, offset by constant C.
410 return ConstantRange::getNonEmpty(
411 APInt::getOneBitSet(BitWidth, Mask.countr_zero()) + C, C);
412 }
413
414 bool ConstantRange::isFullSet() const {
415 return Lower == Upper && Lower.isMaxValue();
416 }
417
418 bool ConstantRange::isEmptySet() const {
419 return Lower == Upper && Lower.isMinValue();
420 }
421
422 bool ConstantRange::isWrappedSet() const {
423 return Lower.ugt(Upper) && !Upper.isZero();
424 }
425
426 bool ConstantRange::isUpperWrapped() const {
427 return Lower.ugt(Upper);
428 }
429
430 bool ConstantRange::isSignWrappedSet() const {
431 return Lower.sgt(Upper) && !Upper.isMinSignedValue();
432 }
433
434 bool ConstantRange::isUpperSignWrapped() const {
435 return Lower.sgt(Upper);
436 }
437
438 bool
439 ConstantRange::isSizeStrictlySmallerThan(const ConstantRange &Other) const {
440 assert(getBitWidth() == Other.getBitWidth());
441 if (isFullSet())
442 return false;
443 if (Other.isFullSet())
444 return true;
445 return (Upper - Lower).ult(Other.Upper - Other.Lower);
446 }
447
448 bool
449 ConstantRange::isSizeLargerThan(uint64_t MaxSize) const {
450 // If this a full set, we need special handling to avoid needing an extra bit
451 // to represent the size.
452 if (isFullSet())
453 return MaxSize == 0 || APInt::getMaxValue(getBitWidth()).ugt(MaxSize - 1);
454
455 return (Upper - Lower).ugt(MaxSize);
456 }
457
458 bool ConstantRange::isAllNegative() const {
459 // Empty set is all negative, full set is not.
460 if (isEmptySet())
461 return true;
462 if (isFullSet())
463 return false;
464
465 return !isUpperSignWrapped() && !Upper.isStrictlyPositive();
466 }
467
468 bool ConstantRange::isAllNonNegative() const {
469 // Empty and full set are automatically treated correctly.
470 return !isSignWrappedSet() && Lower.isNonNegative();
471 }
472
473 bool ConstantRange::isAllPositive() const {
474 // Empty set is all positive, full set is not.
475 if (isEmptySet())
476 return true;
477 if (isFullSet())
478 return false;
479
480 return !isSignWrappedSet() && Lower.isStrictlyPositive();
481 }
482
483 APInt ConstantRange::getUnsignedMax() const {
484 if (isFullSet() || isUpperWrapped())
485 return APInt::getMaxValue(getBitWidth());
486 return getUpper() - 1;
487 }
488
489 APInt ConstantRange::getUnsignedMin() const {
490 if (isFullSet() || isWrappedSet())
491 return APInt::getMinValue(getBitWidth());
492 return getLower();
493 }
494
495 APInt ConstantRange::getSignedMax() const {
496 if (isFullSet() || isUpperSignWrapped())
497 return APInt::getSignedMaxValue(getBitWidth());
498 return getUpper() - 1;
499 }
500
501 APInt ConstantRange::getSignedMin() const {
502 if (isFullSet() || isSignWrappedSet())
503 return APInt::getSignedMinValue(getBitWidth());
504 return getLower();
505 }
506
507 bool ConstantRange::contains(const APInt &V) const {
508 if (Lower == Upper)
509 return isFullSet();
510
511 if (!isUpperWrapped())
512 return Lower.ule(V) && V.ult(Upper);
513 return Lower.ule(V) || V.ult(Upper);
514 }
515
516 bool ConstantRange::contains(const ConstantRange &Other) const {
517 if (isFullSet() || Other.isEmptySet()) return true;
518 if (isEmptySet() || Other.isFullSet()) return false;
519
520 if (!isUpperWrapped()) {
521 if (Other.isUpperWrapped())
522 return false;
523
524 return Lower.ule(Other.getLower()) && Other.getUpper().ule(Upper);
525 }
526
527 if (!Other.isUpperWrapped())
528 return Other.getUpper().ule(Upper) ||
529 Lower.ule(Other.getLower());
530
531 return Other.getUpper().ule(Upper) && Lower.ule(Other.getLower());
532 }
533
534 unsigned ConstantRange::getActiveBits() const {
535 if (isEmptySet())
536 return 0;
537
538 return getUnsignedMax().getActiveBits();
539 }
540
541 unsigned ConstantRange::getMinSignedBits() const {
542 if (isEmptySet())
543 return 0;
544
545 return std::max(getSignedMin().getSignificantBits(),
546 getSignedMax().getSignificantBits());
547 }
548
549 ConstantRange ConstantRange::subtract(const APInt &Val) const {
550 assert(Val.getBitWidth() == getBitWidth() && "Wrong bit width");
551 // If the set is empty or full, don't modify the endpoints.
552 if (Lower == Upper)
553 return *this;
554 return ConstantRange(Lower - Val, Upper - Val);
555 }
556
557 ConstantRange ConstantRange::difference(const ConstantRange &CR) const {
558 return intersectWith(CR.inverse());
559 }
560
561 static ConstantRange getPreferredRange(
562 const ConstantRange &CR1, const ConstantRange &CR2,
563 ConstantRange::PreferredRangeType Type) {
564 if (Type == ConstantRange::Unsigned) {
565 if (!CR1.isWrappedSet() && CR2.isWrappedSet())
566 return CR1;
567 if (CR1.isWrappedSet() && !CR2.isWrappedSet())
568 return CR2;
569 } else if (Type == ConstantRange::Signed) {
570 if (!CR1.isSignWrappedSet() && CR2.isSignWrappedSet())
571 return CR1;
572 if (CR1.isSignWrappedSet() && !CR2.isSignWrappedSet())
573 return CR2;
574 }
575
576 if (CR1.isSizeStrictlySmallerThan(CR2))
577 return CR1;
578 return CR2;
579 }
580
581 ConstantRange ConstantRange::intersectWith(const ConstantRange &CR,
582 PreferredRangeType Type) const {
583 assert(getBitWidth() == CR.getBitWidth() &&
584 "ConstantRange types don't agree!");
585
586 // Handle common cases.
587 if ( isEmptySet() || CR.isFullSet()) return *this;
588 if (CR.isEmptySet() || isFullSet()) return CR;
589
590 if (!isUpperWrapped() && CR.isUpperWrapped())
591 return CR.intersectWith(*this, Type);
592
593 if (!isUpperWrapped() && !CR.isUpperWrapped()) {
594 if (Lower.ult(CR.Lower)) {
595 // L---U : this
596 // L---U : CR
597 if (Upper.ule(CR.Lower))
598 return getEmpty();
599
600 // L---U : this
601 // L---U : CR
602 if (Upper.ult(CR.Upper))
603 return ConstantRange(CR.Lower, Upper);
604
605 // L-------U : this
606 // L---U : CR
607 return CR;
608 }
609 // L---U : this
610 // L-------U : CR
611 if (Upper.ult(CR.Upper))
612 return *this;
613
614 // L-----U : this
615 // L-----U : CR
616 if (Lower.ult(CR.Upper))
617 return ConstantRange(Lower, CR.Upper);
618
619 // L---U : this
620 // L---U : CR
621 return getEmpty();
622 }
623
624 if (isUpperWrapped() && !CR.isUpperWrapped()) {
625 if (CR.Lower.ult(Upper)) {
626 // ------U L--- : this
627 // L--U : CR
628 if (CR.Upper.ult(Upper))
629 return CR;
630
631 // ------U L--- : this
632 // L------U : CR
633 if (CR.Upper.ule(Lower))
634 return ConstantRange(CR.Lower, Upper);
635
636 // ------U L--- : this
637 // L----------U : CR
638 return getPreferredRange(*this, CR, Type);
639 }
640 if (CR.Lower.ult(Lower)) {
641 // --U L---- : this
642 // L--U : CR
643 if (CR.Upper.ule(Lower))
644 return getEmpty();
645
646 // --U L---- : this
647 // L------U : CR
648 return ConstantRange(Lower, CR.Upper);
649 }
650
651 // --U L------ : this
652 // L--U : CR
653 return CR;
654 }
655
656 if (CR.Upper.ult(Upper)) {
657 // ------U L-- : this
658 // --U L------ : CR
659 if (CR.Lower.ult(Upper))
660 return getPreferredRange(*this, CR, Type);
661
662 // ----U L-- : this
663 // --U L---- : CR
664 if (CR.Lower.ult(Lower))
665 return ConstantRange(Lower, CR.Upper);
666
667 // ----U L---- : this
668 // --U L-- : CR
669 return CR;
670 }
671 if (CR.Upper.ule(Lower)) {
672 // --U L-- : this
673 // ----U L---- : CR
674 if (CR.Lower.ult(Lower))
675 return *this;
676
677 // --U L---- : this
678 // ----U L-- : CR
679 return ConstantRange(CR.Lower, Upper);
680 }
681
682 // --U L------ : this
683 // ------U L-- : CR
684 return getPreferredRange(*this, CR, Type);
685 }
686
687 ConstantRange ConstantRange::unionWith(const ConstantRange &CR,
688 PreferredRangeType Type) const {
689 assert(getBitWidth() == CR.getBitWidth() &&
690 "ConstantRange types don't agree!");
691
692 if ( isFullSet() || CR.isEmptySet()) return *this;
693 if (CR.isFullSet() || isEmptySet()) return CR;
694
695 if (!isUpperWrapped() && CR.isUpperWrapped())
696 return CR.unionWith(*this, Type);
697
698 if (!isUpperWrapped() && !CR.isUpperWrapped()) {
699 // L---U and L---U : this
700 // L---U L---U : CR
701 // result in one of
702 // L---------U
703 // -----U L-----
704 if (CR.Upper.ult(Lower) || Upper.ult(CR.Lower))
705 return getPreferredRange(
706 ConstantRange(Lower, CR.Upper), ConstantRange(CR.Lower, Upper), Type);
707
708 APInt L = CR.Lower.ult(Lower) ? CR.Lower : Lower;
709 APInt U = (CR.Upper - 1).ugt(Upper - 1) ? CR.Upper : Upper;
710
711 if (L.isZero() && U.isZero())
712 return getFull();
713
714 return ConstantRange(std::move(L), std::move(U));
715 }
716
717 if (!CR.isUpperWrapped()) {
718 // ------U L----- and ------U L----- : this
719 // L--U L--U : CR
720 if (CR.Upper.ule(Upper) || CR.Lower.uge(Lower))
721 return *this;
722
723 // ------U L----- : this
724 // L---------U : CR
725 if (CR.Lower.ule(Upper) && Lower.ule(CR.Upper))
726 return getFull();
727
728 // ----U L---- : this
729 // L---U : CR
730 // results in one of
731 // ----------U L----
732 // ----U L----------
733 if (Upper.ult(CR.Lower) && CR.Upper.ult(Lower))
734 return getPreferredRange(
735 ConstantRange(Lower, CR.Upper), ConstantRange(CR.Lower, Upper), Type);
736
737 // ----U L----- : this
738 // L----U : CR
739 if (Upper.ult(CR.Lower) && Lower.ule(CR.Upper))
740 return ConstantRange(CR.Lower, Upper);
741
742 // ------U L---- : this
743 // L-----U : CR
744 assert(CR.Lower.ule(Upper) && CR.Upper.ult(Lower) &&
745 "ConstantRange::unionWith missed a case with one range wrapped");
746 return ConstantRange(Lower, CR.Upper);
747 }
748
749 // ------U L---- and ------U L---- : this
750 // -U L----------- and ------------U L : CR
751 if (CR.Lower.ule(Upper) || Lower.ule(CR.Upper))
752 return getFull();
753
754 APInt L = CR.Lower.ult(Lower) ? CR.Lower : Lower;
755 APInt U = CR.Upper.ugt(Upper) ? CR.Upper : Upper;
756
757 return ConstantRange(std::move(L), std::move(U));
758 }
759
760 std::optional<ConstantRange>
761 ConstantRange::exactIntersectWith(const ConstantRange &CR) const {
762 // TODO: This can be implemented more efficiently.
763 ConstantRange Result = intersectWith(CR);
764 if (Result == inverse().unionWith(CR.inverse()).inverse())
765 return Result;
766 return std::nullopt;
767 }
768
769 std::optional<ConstantRange>
770 ConstantRange::exactUnionWith(const ConstantRange &CR) const {
771 // TODO: This can be implemented more efficiently.
772 ConstantRange Result = unionWith(CR);
773 if (Result == inverse().intersectWith(CR.inverse()).inverse())
774 return Result;
775 return std::nullopt;
776 }
777
778 ConstantRange ConstantRange::castOp(Instruction::CastOps CastOp,
779 uint32_t ResultBitWidth) const {
780 switch (CastOp) {
781 default:
782 llvm_unreachable("unsupported cast type");
783 case Instruction::Trunc:
784 return truncate(ResultBitWidth);
785 case Instruction::SExt:
786 return signExtend(ResultBitWidth);
787 case Instruction::ZExt:
788 return zeroExtend(ResultBitWidth);
789 case Instruction::BitCast:
790 return *this;
791 case Instruction::FPToUI:
792 case Instruction::FPToSI:
793 if (getBitWidth() == ResultBitWidth)
794 return *this;
795 else
796 return getFull(ResultBitWidth);
797 case Instruction::UIToFP: {
798 // TODO: use input range if available
799 auto BW = getBitWidth();
800 APInt Min = APInt::getMinValue(BW);
801 APInt Max = APInt::getMaxValue(BW);
802 if (ResultBitWidth > BW) {
803 Min = Min.zext(ResultBitWidth);
804 Max = Max.zext(ResultBitWidth);
805 }
806 return getNonEmpty(std::move(Min), std::move(Max) + 1);
807 }
808 case Instruction::SIToFP: {
809 // TODO: use input range if available
810 auto BW = getBitWidth();
811 APInt SMin = APInt::getSignedMinValue(BW);
812 APInt SMax = APInt::getSignedMaxValue(BW);
813 if (ResultBitWidth > BW) {
814 SMin = SMin.sext(ResultBitWidth);
815 SMax = SMax.sext(ResultBitWidth);
816 }
817 return getNonEmpty(std::move(SMin), std::move(SMax) + 1);
818 }
819 case Instruction::FPTrunc:
820 case Instruction::FPExt:
821 case Instruction::IntToPtr:
822 case Instruction::PtrToInt:
823 case Instruction::AddrSpaceCast:
824 // Conservatively return getFull set.
825 return getFull(ResultBitWidth);
826 };
827 }
828
829 ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const {
830 if (isEmptySet()) return getEmpty(DstTySize);
831
832 unsigned SrcTySize = getBitWidth();
833 assert(SrcTySize < DstTySize && "Not a value extension");
834 if (isFullSet() || isUpperWrapped()) {
835 // Change into [0, 1 << src bit width)
836 APInt LowerExt(DstTySize, 0);
837 if (!Upper) // special case: [X, 0) -- not really wrapping around
838 LowerExt = Lower.zext(DstTySize);
839 return ConstantRange(std::move(LowerExt),
840 APInt::getOneBitSet(DstTySize, SrcTySize));
841 }
842
843 return ConstantRange(Lower.zext(DstTySize), Upper.zext(DstTySize));
844 }
845
846 ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const {
847 if (isEmptySet()) return getEmpty(DstTySize);
848
849 unsigned SrcTySize = getBitWidth();
850 assert(SrcTySize < DstTySize && "Not a value extension");
851
852 // special case: [X, INT_MIN) -- not really wrapping around
853 if (Upper.isMinSignedValue())
854 return ConstantRange(Lower.sext(DstTySize), Upper.zext(DstTySize));
855
856 if (isFullSet() || isSignWrappedSet()) {
857 return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1),
858 APInt::getLowBitsSet(DstTySize, SrcTySize-1) + 1);
859 }
860
861 return ConstantRange(Lower.sext(DstTySize), Upper.sext(DstTySize));
862 }
863
864 ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
865 assert(getBitWidth() > DstTySize && "Not a value truncation");
866 if (isEmptySet())
867 return getEmpty(DstTySize);
868 if (isFullSet())
869 return getFull(DstTySize);
870
871 APInt LowerDiv(Lower), UpperDiv(Upper);
872 ConstantRange Union(DstTySize, /*isFullSet=*/false);
873
874 // Analyze wrapped sets in their two parts: [0, Upper) \/ [Lower, MaxValue]
875 // We use the non-wrapped set code to analyze the [Lower, MaxValue) part, and
876 // then we do the union with [MaxValue, Upper)
877 if (isUpperWrapped()) {
878 // If Upper is greater than or equal to MaxValue(DstTy), it covers the whole
879 // truncated range.
880 if (Upper.getActiveBits() > DstTySize || Upper.countr_one() == DstTySize)
881 return getFull(DstTySize);
882
883 Union = ConstantRange(APInt::getMaxValue(DstTySize),Upper.trunc(DstTySize));
884 UpperDiv.setAllBits();
885
886 // Union covers the MaxValue case, so return if the remaining range is just
887 // MaxValue(DstTy).
888 if (LowerDiv == UpperDiv)
889 return Union;
890 }
891
892 // Chop off the most significant bits that are past the destination bitwidth.
893 if (LowerDiv.getActiveBits() > DstTySize) {
894 // Mask to just the signficant bits and subtract from LowerDiv/UpperDiv.
895 APInt Adjust = LowerDiv & APInt::getBitsSetFrom(getBitWidth(), DstTySize);
896 LowerDiv -= Adjust;
897 UpperDiv -= Adjust;
898 }
899
900 unsigned UpperDivWidth = UpperDiv.getActiveBits();
901 if (UpperDivWidth <= DstTySize)
902 return ConstantRange(LowerDiv.trunc(DstTySize),
903 UpperDiv.trunc(DstTySize)).unionWith(Union);
904
905 // The truncated value wraps around. Check if we can do better than fullset.
906 if (UpperDivWidth == DstTySize + 1) {
907 // Clear the MSB so that UpperDiv wraps around.
908 UpperDiv.clearBit(DstTySize);
909 if (UpperDiv.ult(LowerDiv))
910 return ConstantRange(LowerDiv.trunc(DstTySize),
911 UpperDiv.trunc(DstTySize)).unionWith(Union);
912 }
913
914 return getFull(DstTySize);
915 }
916
917 ConstantRange ConstantRange::zextOrTrunc(uint32_t DstTySize) const {
918 unsigned SrcTySize = getBitWidth();
919 if (SrcTySize > DstTySize)
920 return truncate(DstTySize);
921 if (SrcTySize < DstTySize)
922 return zeroExtend(DstTySize);
923 return *this;
924 }
925
926 ConstantRange ConstantRange::sextOrTrunc(uint32_t DstTySize) const {
927 unsigned SrcTySize = getBitWidth();
928 if (SrcTySize > DstTySize)
929 return truncate(DstTySize);
930 if (SrcTySize < DstTySize)
931 return signExtend(DstTySize);
932 return *this;
933 }
934
935 ConstantRange ConstantRange::binaryOp(Instruction::BinaryOps BinOp,
936 const ConstantRange &Other) const {
937 assert(Instruction::isBinaryOp(BinOp) && "Binary operators only!");
938
939 switch (BinOp) {
940 case Instruction::Add:
941 return add(Other);
942 case Instruction::Sub:
943 return sub(Other);
944 case Instruction::Mul:
945 return multiply(Other);
946 case Instruction::UDiv:
947 return udiv(Other);
948 case Instruction::SDiv:
949 return sdiv(Other);
950 case Instruction::URem:
951 return urem(Other);
952 case Instruction::SRem:
953 return srem(Other);
954 case Instruction::Shl:
955 return shl(Other);
956 case Instruction::LShr:
957 return lshr(Other);
958 case Instruction::AShr:
959 return ashr(Other);
960 case Instruction::And:
961 return binaryAnd(Other);
962 case Instruction::Or:
963 return binaryOr(Other);
964 case Instruction::Xor:
965 return binaryXor(Other);
966 // Note: floating point operations applied to abstract ranges are just
967 // ideal integer operations with a lossy representation
968 case Instruction::FAdd:
969 return add(Other);
970 case Instruction::FSub:
971 return sub(Other);
972 case Instruction::FMul:
973 return multiply(Other);
974 default:
975 // Conservatively return getFull set.
976 return getFull();
977 }
978 }
979
980 ConstantRange ConstantRange::overflowingBinaryOp(Instruction::BinaryOps BinOp,
981 const ConstantRange &Other,
982 unsigned NoWrapKind) const {
983 assert(Instruction::isBinaryOp(BinOp) && "Binary operators only!");
984
985 switch (BinOp) {
986 case Instruction::Add:
987 return addWithNoWrap(Other, NoWrapKind);
988 case Instruction::Sub:
989 return subWithNoWrap(Other, NoWrapKind);
990 case Instruction::Mul:
991 return multiplyWithNoWrap(Other, NoWrapKind);
992 case Instruction::Shl:
993 return shlWithNoWrap(Other, NoWrapKind);
994 default:
995 // Don't know about this Overflowing Binary Operation.
996 // Conservatively fallback to plain binop handling.
997 return binaryOp(BinOp, Other);
998 }
999 }
1000
1001 bool ConstantRange::isIntrinsicSupported(Intrinsic::ID IntrinsicID) {
1002 switch (IntrinsicID) {
1003 case Intrinsic::uadd_sat:
1004 case Intrinsic::usub_sat:
1005 case Intrinsic::sadd_sat:
1006 case Intrinsic::ssub_sat:
1007 case Intrinsic::umin:
1008 case Intrinsic::umax:
1009 case Intrinsic::smin:
1010 case Intrinsic::smax:
1011 case Intrinsic::abs:
1012 case Intrinsic::ctlz:
1013 case Intrinsic::cttz:
1014 case Intrinsic::ctpop:
1015 return true;
1016 default:
1017 return false;
1018 }
1019 }
1020
1021 ConstantRange ConstantRange::intrinsic(Intrinsic::ID IntrinsicID,
1022 ArrayRef<ConstantRange> Ops) {
1023 switch (IntrinsicID) {
1024 case Intrinsic::uadd_sat:
1025 return Ops[0].uadd_sat(Ops[1]);
1026 case Intrinsic::usub_sat:
1027 return Ops[0].usub_sat(Ops[1]);
1028 case Intrinsic::sadd_sat:
1029 return Ops[0].sadd_sat(Ops[1]);
1030 case Intrinsic::ssub_sat:
1031 return Ops[0].ssub_sat(Ops[1]);
1032 case Intrinsic::umin:
1033 return Ops[0].umin(Ops[1]);
1034 case Intrinsic::umax:
1035 return Ops[0].umax(Ops[1]);
1036 case Intrinsic::smin:
1037 return Ops[0].smin(Ops[1]);
1038 case Intrinsic::smax:
1039 return Ops[0].smax(Ops[1]);
1040 case Intrinsic::abs: {
1041 const APInt *IntMinIsPoison = Ops[1].getSingleElement();
1042 assert(IntMinIsPoison && "Must be known (immarg)");
1043 assert(IntMinIsPoison->getBitWidth() == 1 && "Must be boolean");
1044 return Ops[0].abs(IntMinIsPoison->getBoolValue());
1045 }
1046 case Intrinsic::ctlz: {
1047 const APInt *ZeroIsPoison = Ops[1].getSingleElement();
1048 assert(ZeroIsPoison && "Must be known (immarg)");
1049 assert(ZeroIsPoison->getBitWidth() == 1 && "Must be boolean");
1050 return Ops[0].ctlz(ZeroIsPoison->getBoolValue());
1051 }
1052 case Intrinsic::cttz: {
1053 const APInt *ZeroIsPoison = Ops[1].getSingleElement();
1054 assert(ZeroIsPoison && "Must be known (immarg)");
1055 assert(ZeroIsPoison->getBitWidth() == 1 && "Must be boolean");
1056 return Ops[0].cttz(ZeroIsPoison->getBoolValue());
1057 }
1058 case Intrinsic::ctpop:
1059 return Ops[0].ctpop();
1060 default:
1061 assert(!isIntrinsicSupported(IntrinsicID) && "Shouldn't be supported");
1062 llvm_unreachable("Unsupported intrinsic");
1063 }
1064 }
1065
1066 ConstantRange
1067 ConstantRange::add(const ConstantRange &Other) const {
1068 if (isEmptySet() || Other.isEmptySet())
1069 return getEmpty();
1070 if (isFullSet() || Other.isFullSet())
1071 return getFull();
1072
1073 APInt NewLower = getLower() + Other.getLower();
1074 APInt NewUpper = getUpper() + Other.getUpper() - 1;
1075 if (NewLower == NewUpper)
1076 return getFull();
1077
1078 ConstantRange X = ConstantRange(std::move(NewLower), std::move(NewUpper));
1079 if (X.isSizeStrictlySmallerThan(*this) ||
1080 X.isSizeStrictlySmallerThan(Other))
1081 // We've wrapped, therefore, full set.
1082 return getFull();
1083 return X;
1084 }
1085
1086 ConstantRange ConstantRange::addWithNoWrap(const ConstantRange &Other,
1087 unsigned NoWrapKind,
1088 PreferredRangeType RangeType) const {
1089 // Calculate the range for "X + Y" which is guaranteed not to wrap(overflow).
1090 // (X is from this, and Y is from Other)
1091 if (isEmptySet() || Other.isEmptySet())
1092 return getEmpty();
1093 if (isFullSet() && Other.isFullSet())
1094 return getFull();
1095
1096 using OBO = OverflowingBinaryOperator;
1097 ConstantRange Result = add(Other);
1098
1099 // If an overflow happens for every value pair in these two constant ranges,
1100 // we must return Empty set. In this case, we get that for free, because we
1101 // get lucky that intersection of add() with uadd_sat()/sadd_sat() results
1102 // in an empty set.
1103
1104 if (NoWrapKind & OBO::NoSignedWrap)
1105 Result = Result.intersectWith(sadd_sat(Other), RangeType);
1106
1107 if (NoWrapKind & OBO::NoUnsignedWrap)
1108 Result = Result.intersectWith(uadd_sat(Other), RangeType);
1109
1110 return Result;
1111 }
1112
1113 ConstantRange
1114 ConstantRange::sub(const ConstantRange &Other) const {
1115 if (isEmptySet() || Other.isEmptySet())
1116 return getEmpty();
1117 if (isFullSet() || Other.isFullSet())
1118 return getFull();
1119
1120 APInt NewLower = getLower() - Other.getUpper() + 1;
1121 APInt NewUpper = getUpper() - Other.getLower();
1122 if (NewLower == NewUpper)
1123 return getFull();
1124
1125 ConstantRange X = ConstantRange(std::move(NewLower), std::move(NewUpper));
1126 if (X.isSizeStrictlySmallerThan(*this) ||
1127 X.isSizeStrictlySmallerThan(Other))
1128 // We've wrapped, therefore, full set.
1129 return getFull();
1130 return X;
1131 }
1132
1133 ConstantRange ConstantRange::subWithNoWrap(const ConstantRange &Other,
1134 unsigned NoWrapKind,
1135 PreferredRangeType RangeType) const {
1136 // Calculate the range for "X - Y" which is guaranteed not to wrap(overflow).
1137 // (X is from this, and Y is from Other)
1138 if (isEmptySet() || Other.isEmptySet())
1139 return getEmpty();
1140 if (isFullSet() && Other.isFullSet())
1141 return getFull();
1142
1143 using OBO = OverflowingBinaryOperator;
1144 ConstantRange Result = sub(Other);
1145
1146 // If an overflow happens for every value pair in these two constant ranges,
1147 // we must return Empty set. In signed case, we get that for free, because we
1148 // get lucky that intersection of sub() with ssub_sat() results in an
1149 // empty set. But for unsigned we must perform the overflow check manually.
1150
1151 if (NoWrapKind & OBO::NoSignedWrap)
1152 Result = Result.intersectWith(ssub_sat(Other), RangeType);
1153
1154 if (NoWrapKind & OBO::NoUnsignedWrap) {
1155 if (getUnsignedMax().ult(Other.getUnsignedMin()))
1156 return getEmpty(); // Always overflows.
1157 Result = Result.intersectWith(usub_sat(Other), RangeType);
1158 }
1159
1160 return Result;
1161 }
1162
1163 ConstantRange
1164 ConstantRange::multiply(const ConstantRange &Other) const {
1165 // TODO: If either operand is a single element and the multiply is known to
1166 // be non-wrapping, round the result min and max value to the appropriate
1167 // multiple of that element. If wrapping is possible, at least adjust the
1168 // range according to the greatest power-of-two factor of the single element.
1169
1170 if (isEmptySet() || Other.isEmptySet())
1171 return getEmpty();
1172
1173 if (const APInt *C = getSingleElement()) {
1174 if (C->isOne())
1175 return Other;
1176 if (C->isAllOnes())
1177 return ConstantRange(APInt::getZero(getBitWidth())).sub(Other);
1178 }
1179
1180 if (const APInt *C = Other.getSingleElement()) {
1181 if (C->isOne())
1182 return *this;
1183 if (C->isAllOnes())
1184 return ConstantRange(APInt::getZero(getBitWidth())).sub(*this);
1185 }
1186
1187 // Multiplication is signedness-independent. However different ranges can be
1188 // obtained depending on how the input ranges are treated. These different
1189 // ranges are all conservatively correct, but one might be better than the
1190 // other. We calculate two ranges; one treating the inputs as unsigned
1191 // and the other signed, then return the smallest of these ranges.
1192
1193 // Unsigned range first.
1194 APInt this_min = getUnsignedMin().zext(getBitWidth() * 2);
1195 APInt this_max = getUnsignedMax().zext(getBitWidth() * 2);
1196 APInt Other_min = Other.getUnsignedMin().zext(getBitWidth() * 2);
1197 APInt Other_max = Other.getUnsignedMax().zext(getBitWidth() * 2);
1198
1199 ConstantRange Result_zext = ConstantRange(this_min * Other_min,
1200 this_max * Other_max + 1);
1201 ConstantRange UR = Result_zext.truncate(getBitWidth());
1202
1203 // If the unsigned range doesn't wrap, and isn't negative then it's a range
1204 // from one positive number to another which is as good as we can generate.
1205 // In this case, skip the extra work of generating signed ranges which aren't
1206 // going to be better than this range.
1207 if (!UR.isUpperWrapped() &&
1208 (UR.getUpper().isNonNegative() || UR.getUpper().isMinSignedValue()))
1209 return UR;
1210
1211 // Now the signed range. Because we could be dealing with negative numbers
1212 // here, the lower bound is the smallest of the cartesian product of the
1213 // lower and upper ranges; for example:
1214 // [-1,4) * [-2,3) = min(-1*-2, -1*2, 3*-2, 3*2) = -6.
1215 // Similarly for the upper bound, swapping min for max.
1216
1217 this_min = getSignedMin().sext(getBitWidth() * 2);
1218 this_max = getSignedMax().sext(getBitWidth() * 2);
1219 Other_min = Other.getSignedMin().sext(getBitWidth() * 2);
1220 Other_max = Other.getSignedMax().sext(getBitWidth() * 2);
1221
1222 auto L = {this_min * Other_min, this_min * Other_max,
1223 this_max * Other_min, this_max * Other_max};
1224 auto Compare = [](const APInt &A, const APInt &B) { return A.slt(B); };
1225 ConstantRange Result_sext(std::min(L, Compare), std::max(L, Compare) + 1);
1226 ConstantRange SR = Result_sext.truncate(getBitWidth());
1227
1228 return UR.isSizeStrictlySmallerThan(SR) ? UR : SR;
1229 }
1230
1231 ConstantRange
1232 ConstantRange::multiplyWithNoWrap(const ConstantRange &Other,
1233 unsigned NoWrapKind,
1234 PreferredRangeType RangeType) const {
1235 if (isEmptySet() || Other.isEmptySet())
1236 return getEmpty();
1237 if (isFullSet() && Other.isFullSet())
1238 return getFull();
1239
1240 ConstantRange Result = multiply(Other);
1241
1242 if (NoWrapKind & OverflowingBinaryOperator::NoSignedWrap)
1243 Result = Result.intersectWith(smul_sat(Other), RangeType);
1244
1245 if (NoWrapKind & OverflowingBinaryOperator::NoUnsignedWrap)
1246 Result = Result.intersectWith(umul_sat(Other), RangeType);
1247
1248 // mul nsw nuw X, Y s>= 0 if X s> 1 or Y s> 1
1249 if ((NoWrapKind == (OverflowingBinaryOperator::NoSignedWrap |
1250 OverflowingBinaryOperator::NoUnsignedWrap)) &&
1251 !Result.isAllNonNegative()) {
1252 if (getSignedMin().sgt(1) || Other.getSignedMin().sgt(1))
1253 Result = Result.intersectWith(
1254 getNonEmpty(APInt::getZero(getBitWidth()),
1255 APInt::getSignedMinValue(getBitWidth())),
1256 RangeType);
1257 }
1258
1259 return Result;
1260 }
1261
1262 ConstantRange ConstantRange::smul_fast(const ConstantRange &Other) const {
1263 if (isEmptySet() || Other.isEmptySet())
1264 return getEmpty();
1265
1266 APInt Min = getSignedMin();
1267 APInt Max = getSignedMax();
1268 APInt OtherMin = Other.getSignedMin();
1269 APInt OtherMax = Other.getSignedMax();
1270
1271 bool O1, O2, O3, O4;
1272 auto Muls = {Min.smul_ov(OtherMin, O1), Min.smul_ov(OtherMax, O2),
1273 Max.smul_ov(OtherMin, O3), Max.smul_ov(OtherMax, O4)};
1274 if (O1 || O2 || O3 || O4)
1275 return getFull();
1276
1277 auto Compare = [](const APInt &A, const APInt &B) { return A.slt(B); };
1278 return getNonEmpty(std::min(Muls, Compare), std::max(Muls, Compare) + 1);
1279 }
1280
1281 ConstantRange
1282 ConstantRange::smax(const ConstantRange &Other) const {
1283 // X smax Y is: range(smax(X_smin, Y_smin),
1284 // smax(X_smax, Y_smax))
1285 if (isEmptySet() || Other.isEmptySet())
1286 return getEmpty();
1287 APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin());
1288 APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1;
1289 ConstantRange Res = getNonEmpty(std::move(NewL), std::move(NewU));
1290 if (isSignWrappedSet() || Other.isSignWrappedSet())
1291 return Res.intersectWith(unionWith(Other, Signed), Signed);
1292 return Res;
1293 }
1294
1295 ConstantRange
1296 ConstantRange::umax(const ConstantRange &Other) const {
1297 // X umax Y is: range(umax(X_umin, Y_umin),
1298 // umax(X_umax, Y_umax))
1299 if (isEmptySet() || Other.isEmptySet())
1300 return getEmpty();
1301 APInt NewL = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin());
1302 APInt NewU = APIntOps::umax(getUnsignedMax(), Other.getUnsignedMax()) + 1;
1303 ConstantRange Res = getNonEmpty(std::move(NewL), std::move(NewU));
1304 if (isWrappedSet() || Other.isWrappedSet())
1305 return Res.intersectWith(unionWith(Other, Unsigned), Unsigned);
1306 return Res;
1307 }
1308
1309 ConstantRange
1310 ConstantRange::smin(const ConstantRange &Other) const {
1311 // X smin Y is: range(smin(X_smin, Y_smin),
1312 // smin(X_smax, Y_smax))
1313 if (isEmptySet() || Other.isEmptySet())
1314 return getEmpty();
1315 APInt NewL = APIntOps::smin(getSignedMin(), Other.getSignedMin());
1316 APInt NewU = APIntOps::smin(getSignedMax(), Other.getSignedMax()) + 1;
1317 ConstantRange Res = getNonEmpty(std::move(NewL), std::move(NewU));
1318 if (isSignWrappedSet() || Other.isSignWrappedSet())
1319 return Res.intersectWith(unionWith(Other, Signed), Signed);
1320 return Res;
1321 }
1322
1323 ConstantRange
1324 ConstantRange::umin(const ConstantRange &Other) const {
1325 // X umin Y is: range(umin(X_umin, Y_umin),
1326 // umin(X_umax, Y_umax))
1327 if (isEmptySet() || Other.isEmptySet())
1328 return getEmpty();
1329 APInt NewL = APIntOps::umin(getUnsignedMin(), Other.getUnsignedMin());
1330 APInt NewU = APIntOps::umin(getUnsignedMax(), Other.getUnsignedMax()) + 1;
1331 ConstantRange Res = getNonEmpty(std::move(NewL), std::move(NewU));
1332 if (isWrappedSet() || Other.isWrappedSet())
1333 return Res.intersectWith(unionWith(Other, Unsigned), Unsigned);
1334 return Res;
1335 }
1336
1337 ConstantRange
1338 ConstantRange::udiv(const ConstantRange &RHS) const {
1339 if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax().isZero())
1340 return getEmpty();
1341
1342 APInt Lower = getUnsignedMin().udiv(RHS.getUnsignedMax());
1343
1344 APInt RHS_umin = RHS.getUnsignedMin();
1345 if (RHS_umin.isZero()) {
1346 // We want the lowest value in RHS excluding zero. Usually that would be 1
1347 // except for a range in the form of [X, 1) in which case it would be X.
1348 if (RHS.getUpper() == 1)
1349 RHS_umin = RHS.getLower();
1350 else
1351 RHS_umin = 1;
1352 }
1353
1354 APInt Upper = getUnsignedMax().udiv(RHS_umin) + 1;
1355 return getNonEmpty(std::move(Lower), std::move(Upper));
1356 }
1357
1358 ConstantRange ConstantRange::sdiv(const ConstantRange &RHS) const {
1359 // We split up the LHS and RHS into positive and negative components
1360 // and then also compute the positive and negative components of the result
1361 // separately by combining division results with the appropriate signs.
1362 APInt Zero = APInt::getZero(getBitWidth());
1363 APInt SignedMin = APInt::getSignedMinValue(getBitWidth());
1364 // There are no positive 1-bit values. The 1 would get interpreted as -1.
1365 ConstantRange PosFilter =
1366 getBitWidth() == 1 ? getEmpty()
1367 : ConstantRange(APInt(getBitWidth(), 1), SignedMin);
1368 ConstantRange NegFilter(SignedMin, Zero);
1369 ConstantRange PosL = intersectWith(PosFilter);
1370 ConstantRange NegL = intersectWith(NegFilter);
1371 ConstantRange PosR = RHS.intersectWith(PosFilter);
1372 ConstantRange NegR = RHS.intersectWith(NegFilter);
1373
1374 ConstantRange PosRes = getEmpty();
1375 if (!PosL.isEmptySet() && !PosR.isEmptySet())
1376 // pos / pos = pos.
1377 PosRes = ConstantRange(PosL.Lower.sdiv(PosR.Upper - 1),
1378 (PosL.Upper - 1).sdiv(PosR.Lower) + 1);
1379
1380 if (!NegL.isEmptySet() && !NegR.isEmptySet()) {
1381 // neg / neg = pos.
1382 //
1383 // We need to deal with one tricky case here: SignedMin / -1 is UB on the
1384 // IR level, so we'll want to exclude this case when calculating bounds.
1385 // (For APInts the operation is well-defined and yields SignedMin.) We
1386 // handle this by dropping either SignedMin from the LHS or -1 from the RHS.
1387 APInt Lo = (NegL.Upper - 1).sdiv(NegR.Lower);
1388 if (NegL.Lower.isMinSignedValue() && NegR.Upper.isZero()) {
1389 // Remove -1 from the LHS. Skip if it's the only element, as this would
1390 // leave us with an empty set.
1391 if (!NegR.Lower.isAllOnes()) {
1392 APInt AdjNegRUpper;
1393 if (RHS.Lower.isAllOnes())
1394 // Negative part of [-1, X] without -1 is [SignedMin, X].
1395 AdjNegRUpper = RHS.Upper;
1396 else
1397 // [X, -1] without -1 is [X, -2].
1398 AdjNegRUpper = NegR.Upper - 1;
1399
1400 PosRes = PosRes.unionWith(
1401 ConstantRange(Lo, NegL.Lower.sdiv(AdjNegRUpper - 1) + 1));
1402 }
1403
1404 // Remove SignedMin from the RHS. Skip if it's the only element, as this
1405 // would leave us with an empty set.
1406 if (NegL.Upper != SignedMin + 1) {
1407 APInt AdjNegLLower;
1408 if (Upper == SignedMin + 1)
1409 // Negative part of [X, SignedMin] without SignedMin is [X, -1].
1410 AdjNegLLower = Lower;
1411 else
1412 // [SignedMin, X] without SignedMin is [SignedMin + 1, X].
1413 AdjNegLLower = NegL.Lower + 1;
1414
1415 PosRes = PosRes.unionWith(
1416 ConstantRange(std::move(Lo),
1417 AdjNegLLower.sdiv(NegR.Upper - 1) + 1));
1418 }
1419 } else {
1420 PosRes = PosRes.unionWith(
1421 ConstantRange(std::move(Lo), NegL.Lower.sdiv(NegR.Upper - 1) + 1));
1422 }
1423 }
1424
1425 ConstantRange NegRes = getEmpty();
1426 if (!PosL.isEmptySet() && !NegR.isEmptySet())
1427 // pos / neg = neg.
1428 NegRes = ConstantRange((PosL.Upper - 1).sdiv(NegR.Upper - 1),
1429 PosL.Lower.sdiv(NegR.Lower) + 1);
1430
1431 if (!NegL.isEmptySet() && !PosR.isEmptySet())
1432 // neg / pos = neg.
1433 NegRes = NegRes.unionWith(
1434 ConstantRange(NegL.Lower.sdiv(PosR.Lower),
1435 (NegL.Upper - 1).sdiv(PosR.Upper - 1) + 1));
1436
1437 // Prefer a non-wrapping signed range here.
1438 ConstantRange Res = NegRes.unionWith(PosRes, PreferredRangeType::Signed);
1439
1440 // Preserve the zero that we dropped when splitting the LHS by sign.
1441 if (contains(Zero) && (!PosR.isEmptySet() || !NegR.isEmptySet()))
1442 Res = Res.unionWith(ConstantRange(Zero));
1443 return Res;
1444 }
1445
1446 ConstantRange ConstantRange::urem(const ConstantRange &RHS) const {
1447 if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax().isZero())
1448 return getEmpty();
1449
1450 if (const APInt *RHSInt = RHS.getSingleElement()) {
1451 // UREM by null is UB.
1452 if (RHSInt->isZero())
1453 return getEmpty();
1454 // Use APInt's implementation of UREM for single element ranges.
1455 if (const APInt *LHSInt = getSingleElement())
1456 return {LHSInt->urem(*RHSInt)};
1457 }
1458
1459 // L % R for L < R is L.
1460 if (getUnsignedMax().ult(RHS.getUnsignedMin()))
1461 return *this;
1462
1463 // L % R is <= L and < R.
1464 APInt Upper = APIntOps::umin(getUnsignedMax(), RHS.getUnsignedMax() - 1) + 1;
1465 return getNonEmpty(APInt::getZero(getBitWidth()), std::move(Upper));
1466 }
1467
1468 ConstantRange ConstantRange::srem(const ConstantRange &RHS) const {
1469 if (isEmptySet() || RHS.isEmptySet())
1470 return getEmpty();
1471
1472 if (const APInt *RHSInt = RHS.getSingleElement()) {
1473 // SREM by null is UB.
1474 if (RHSInt->isZero())
1475 return getEmpty();
1476 // Use APInt's implementation of SREM for single element ranges.
1477 if (const APInt *LHSInt = getSingleElement())
1478 return {LHSInt->srem(*RHSInt)};
1479 }
1480
1481 ConstantRange AbsRHS = RHS.abs();
1482 APInt MinAbsRHS = AbsRHS.getUnsignedMin();
1483 APInt MaxAbsRHS = AbsRHS.getUnsignedMax();
1484
1485 // Modulus by zero is UB.
1486 if (MaxAbsRHS.isZero())
1487 return getEmpty();
1488
1489 if (MinAbsRHS.isZero())
1490 ++MinAbsRHS;
1491
1492 APInt MinLHS = getSignedMin(), MaxLHS = getSignedMax();
1493
1494 if (MinLHS.isNonNegative()) {
1495 // L % R for L < R is L.
1496 if (MaxLHS.ult(MinAbsRHS))
1497 return *this;
1498
1499 // L % R is <= L and < R.
1500 APInt Upper = APIntOps::umin(MaxLHS, MaxAbsRHS - 1) + 1;
1501 return ConstantRange(APInt::getZero(getBitWidth()), std::move(Upper));
1502 }
1503
1504 // Same basic logic as above, but the result is negative.
1505 if (MaxLHS.isNegative()) {
1506 if (MinLHS.ugt(-MinAbsRHS))
1507 return *this;
1508
1509 APInt Lower = APIntOps::umax(MinLHS, -MaxAbsRHS + 1);
1510 return ConstantRange(std::move(Lower), APInt(getBitWidth(), 1));
1511 }
1512
1513 // LHS range crosses zero.
1514 APInt Lower = APIntOps::umax(MinLHS, -MaxAbsRHS + 1);
1515 APInt Upper = APIntOps::umin(MaxLHS, MaxAbsRHS - 1) + 1;
1516 return ConstantRange(std::move(Lower), std::move(Upper));
1517 }
1518
1519 ConstantRange ConstantRange::binaryNot() const {
1520 return ConstantRange(APInt::getAllOnes(getBitWidth())).sub(*this);
1521 }
1522
1523 ConstantRange ConstantRange::binaryAnd(const ConstantRange &Other) const {
1524 if (isEmptySet() || Other.isEmptySet())
1525 return getEmpty();
1526
1527 ConstantRange KnownBitsRange =
1528 fromKnownBits(toKnownBits() & Other.toKnownBits(), false);
1529 ConstantRange UMinUMaxRange =
1530 getNonEmpty(APInt::getZero(getBitWidth()),
1531 APIntOps::umin(Other.getUnsignedMax(), getUnsignedMax()) + 1);
1532 return KnownBitsRange.intersectWith(UMinUMaxRange);
1533 }
1534
1535 ConstantRange ConstantRange::binaryOr(const ConstantRange &Other) const {
1536 if (isEmptySet() || Other.isEmptySet())
1537 return getEmpty();
1538
1539 ConstantRange KnownBitsRange =
1540 fromKnownBits(toKnownBits() | Other.toKnownBits(), false);
1541 // Upper wrapped range.
1542 ConstantRange UMaxUMinRange =
1543 getNonEmpty(APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin()),
1544 APInt::getZero(getBitWidth()));
1545 return KnownBitsRange.intersectWith(UMaxUMinRange);
1546 }
1547
1548 ConstantRange ConstantRange::binaryXor(const ConstantRange &Other) const {
1549 if (isEmptySet() || Other.isEmptySet())
1550 return getEmpty();
1551
1552 // Use APInt's implementation of XOR for single element ranges.
1553 if (isSingleElement() && Other.isSingleElement())
1554 return {*getSingleElement() ^ *Other.getSingleElement()};
1555
1556 // Special-case binary complement, since we can give a precise answer.
1557 if (Other.isSingleElement() && Other.getSingleElement()->isAllOnes())
1558 return binaryNot();
1559 if (isSingleElement() && getSingleElement()->isAllOnes())
1560 return Other.binaryNot();
1561
1562 KnownBits LHSKnown = toKnownBits();
1563 KnownBits RHSKnown = Other.toKnownBits();
1564 KnownBits Known = LHSKnown ^ RHSKnown;
1565 ConstantRange CR = fromKnownBits(Known, /*IsSigned*/ false);
1566 // Typically the following code doesn't improve the result if BW = 1.
1567 if (getBitWidth() == 1)
1568 return CR;
1569
1570 // If LHS is known to be the subset of RHS, treat LHS ^ RHS as RHS -nuw/nsw
1571 // LHS. If RHS is known to be the subset of LHS, treat LHS ^ RHS as LHS
1572 // -nuw/nsw RHS.
1573 if ((~LHSKnown.Zero).isSubsetOf(RHSKnown.One))
1574 CR = CR.intersectWith(Other.sub(*this), PreferredRangeType::Unsigned);
1575 else if ((~RHSKnown.Zero).isSubsetOf(LHSKnown.One))
1576 CR = CR.intersectWith(this->sub(Other), PreferredRangeType::Unsigned);
1577 return CR;
1578 }
1579
1580 ConstantRange
1581 ConstantRange::shl(const ConstantRange &Other) const {
1582 if (isEmptySet() || Other.isEmptySet())
1583 return getEmpty();
1584
1585 APInt Min = getUnsignedMin();
1586 APInt Max = getUnsignedMax();
1587 if (const APInt *RHS = Other.getSingleElement()) {
1588 unsigned BW = getBitWidth();
1589 if (RHS->uge(BW))
1590 return getEmpty();
1591
1592 unsigned EqualLeadingBits = (Min ^ Max).countl_zero();
1593 if (RHS->ule(EqualLeadingBits))
1594 return getNonEmpty(Min << *RHS, (Max << *RHS) + 1);
1595
1596 return getNonEmpty(APInt::getZero(BW),
1597 APInt::getBitsSetFrom(BW, RHS->getZExtValue()) + 1);
1598 }
1599
1600 APInt OtherMax = Other.getUnsignedMax();
1601 if (isAllNegative() && OtherMax.ule(Min.countl_one())) {
1602 // For negative numbers, if the shift does not overflow in a signed sense,
1603 // a larger shift will make the number smaller.
1604 Max <<= Other.getUnsignedMin();
1605 Min <<= OtherMax;
1606 return ConstantRange::getNonEmpty(std::move(Min), std::move(Max) + 1);
1607 }
1608
1609 // There's overflow!
1610 if (OtherMax.ugt(Max.countl_zero()))
1611 return getFull();
1612
1613 // FIXME: implement the other tricky cases
1614
1615 Min <<= Other.getUnsignedMin();
1616 Max <<= OtherMax;
1617
1618 return ConstantRange::getNonEmpty(std::move(Min), std::move(Max) + 1);
1619 }
1620
1621 static ConstantRange computeShlNUW(const ConstantRange &LHS,
1622 const ConstantRange &RHS) {
1623 unsigned BitWidth = LHS.getBitWidth();
1624 bool Overflow;
1625 APInt LHSMin = LHS.getUnsignedMin();
1626 unsigned RHSMin = RHS.getUnsignedMin().getLimitedValue(BitWidth);
1627 APInt MinShl = LHSMin.ushl_ov(RHSMin, Overflow);
1628 if (Overflow)
1629 return ConstantRange::getEmpty(BitWidth);
1630 APInt LHSMax = LHS.getUnsignedMax();
1631 unsigned RHSMax = RHS.getUnsignedMax().getLimitedValue(BitWidth);
1632 APInt MaxShl = MinShl;
1633 unsigned MaxShAmt = LHSMax.countLeadingZeros();
1634 if (RHSMin <= MaxShAmt)
1635 MaxShl = LHSMax << std::min(RHSMax, MaxShAmt);
1636 RHSMin = std::max(RHSMin, MaxShAmt + 1);
1637 RHSMax = std::min(RHSMax, LHSMin.countLeadingZeros());
1638 if (RHSMin <= RHSMax)
1639 MaxShl = APIntOps::umax(MaxShl,
1640 APInt::getHighBitsSet(BitWidth, BitWidth - RHSMin));
1641 return ConstantRange::getNonEmpty(MinShl, MaxShl + 1);
1642 }
1643
1644 static ConstantRange computeShlNSWWithNNegLHS(const APInt &LHSMin,
1645 const APInt &LHSMax,
1646 unsigned RHSMin,
1647 unsigned RHSMax) {
1648 unsigned BitWidth = LHSMin.getBitWidth();
1649 bool Overflow;
1650 APInt MinShl = LHSMin.sshl_ov(RHSMin, Overflow);
1651 if (Overflow)
1652 return ConstantRange::getEmpty(BitWidth);
1653 APInt MaxShl = MinShl;
1654 unsigned MaxShAmt = LHSMax.countLeadingZeros() - 1;
1655 if (RHSMin <= MaxShAmt)
1656 MaxShl = LHSMax << std::min(RHSMax, MaxShAmt);
1657 RHSMin = std::max(RHSMin, MaxShAmt + 1);
1658 RHSMax = std::min(RHSMax, LHSMin.countLeadingZeros() - 1);
1659 if (RHSMin <= RHSMax)
1660 MaxShl = APIntOps::umax(MaxShl,
1661 APInt::getBitsSet(BitWidth, RHSMin, BitWidth - 1));
1662 return ConstantRange::getNonEmpty(MinShl, MaxShl + 1);
1663 }
1664
1665 static ConstantRange computeShlNSWWithNegLHS(const APInt &LHSMin,
1666 const APInt &LHSMax,
1667 unsigned RHSMin, unsigned RHSMax) {
1668 unsigned BitWidth = LHSMin.getBitWidth();
1669 bool Overflow;
1670 APInt MaxShl = LHSMax.sshl_ov(RHSMin, Overflow);
1671 if (Overflow)
1672 return ConstantRange::getEmpty(BitWidth);
1673 APInt MinShl = MaxShl;
1674 unsigned MaxShAmt = LHSMin.countLeadingOnes() - 1;
1675 if (RHSMin <= MaxShAmt)
1676 MinShl = LHSMin.shl(std::min(RHSMax, MaxShAmt));
1677 RHSMin = std::max(RHSMin, MaxShAmt + 1);
1678 RHSMax = std::min(RHSMax, LHSMax.countLeadingOnes() - 1);
1679 if (RHSMin <= RHSMax)
1680 MinShl = APInt::getSignMask(BitWidth);
1681 return ConstantRange::getNonEmpty(MinShl, MaxShl + 1);
1682 }
1683
1684 static ConstantRange computeShlNSW(const ConstantRange &LHS,
1685 const ConstantRange &RHS) {
1686 unsigned BitWidth = LHS.getBitWidth();
1687 unsigned RHSMin = RHS.getUnsignedMin().getLimitedValue(BitWidth);
1688 unsigned RHSMax = RHS.getUnsignedMax().getLimitedValue(BitWidth);
1689 APInt LHSMin = LHS.getSignedMin();
1690 APInt LHSMax = LHS.getSignedMax();
1691 if (LHSMin.isNonNegative())
1692 return computeShlNSWWithNNegLHS(LHSMin, LHSMax, RHSMin, RHSMax);
1693 else if (LHSMax.isNegative())
1694 return computeShlNSWWithNegLHS(LHSMin, LHSMax, RHSMin, RHSMax);
1695 return computeShlNSWWithNNegLHS(APInt::getZero(BitWidth), LHSMax, RHSMin,
1696 RHSMax)
1697 .unionWith(computeShlNSWWithNegLHS(LHSMin, APInt::getAllOnes(BitWidth),
1698 RHSMin, RHSMax),
1699 ConstantRange::Signed);
1700 }
1701
1702 ConstantRange ConstantRange::shlWithNoWrap(const ConstantRange &Other,
1703 unsigned NoWrapKind,
1704 PreferredRangeType RangeType) const {
1705 if (isEmptySet() || Other.isEmptySet())
1706 return getEmpty();
1707
1708 switch (NoWrapKind) {
1709 case 0:
1710 return shl(Other);
1711 case OverflowingBinaryOperator::NoSignedWrap:
1712 return computeShlNSW(*this, Other);
1713 case OverflowingBinaryOperator::NoUnsignedWrap:
1714 return computeShlNUW(*this, Other);
1715 case OverflowingBinaryOperator::NoSignedWrap |
1716 OverflowingBinaryOperator::NoUnsignedWrap:
1717 return computeShlNSW(*this, Other)
1718 .intersectWith(computeShlNUW(*this, Other), RangeType);
1719 default:
1720 llvm_unreachable("Invalid NoWrapKind");
1721 }
1722 }
1723
1724 ConstantRange
1725 ConstantRange::lshr(const ConstantRange &Other) const {
1726 if (isEmptySet() || Other.isEmptySet())
1727 return getEmpty();
1728
1729 APInt max = getUnsignedMax().lshr(Other.getUnsignedMin()) + 1;
1730 APInt min = getUnsignedMin().lshr(Other.getUnsignedMax());
1731 return getNonEmpty(std::move(min), std::move(max));
1732 }
1733
1734 ConstantRange
1735 ConstantRange::ashr(const ConstantRange &Other) const {
1736 if (isEmptySet() || Other.isEmptySet())
1737 return getEmpty();
1738
1739 // May straddle zero, so handle both positive and negative cases.
1740 // 'PosMax' is the upper bound of the result of the ashr
1741 // operation, when Upper of the LHS of ashr is a non-negative.
1742 // number. Since ashr of a non-negative number will result in a
1743 // smaller number, the Upper value of LHS is shifted right with
1744 // the minimum value of 'Other' instead of the maximum value.
1745 APInt PosMax = getSignedMax().ashr(Other.getUnsignedMin()) + 1;
1746
1747 // 'PosMin' is the lower bound of the result of the ashr
1748 // operation, when Lower of the LHS is a non-negative number.
1749 // Since ashr of a non-negative number will result in a smaller
1750 // number, the Lower value of LHS is shifted right with the
1751 // maximum value of 'Other'.
1752 APInt PosMin = getSignedMin().ashr(Other.getUnsignedMax());
1753
1754 // 'NegMax' is the upper bound of the result of the ashr
1755 // operation, when Upper of the LHS of ashr is a negative number.
1756 // Since 'ashr' of a negative number will result in a bigger
1757 // number, the Upper value of LHS is shifted right with the
1758 // maximum value of 'Other'.
1759 APInt NegMax = getSignedMax().ashr(Other.getUnsignedMax()) + 1;
1760
1761 // 'NegMin' is the lower bound of the result of the ashr
1762 // operation, when Lower of the LHS of ashr is a negative number.
1763 // Since 'ashr' of a negative number will result in a bigger
1764 // number, the Lower value of LHS is shifted right with the
1765 // minimum value of 'Other'.
1766 APInt NegMin = getSignedMin().ashr(Other.getUnsignedMin());
1767
1768 APInt max, min;
1769 if (getSignedMin().isNonNegative()) {
1770 // Upper and Lower of LHS are non-negative.
1771 min = PosMin;
1772 max = PosMax;
1773 } else if (getSignedMax().isNegative()) {
1774 // Upper and Lower of LHS are negative.
1775 min = NegMin;
1776 max = NegMax;
1777 } else {
1778 // Upper is non-negative and Lower is negative.
1779 min = NegMin;
1780 max = PosMax;
1781 }
1782 return getNonEmpty(std::move(min), std::move(max));
1783 }
1784
1785 ConstantRange ConstantRange::uadd_sat(const ConstantRange &Other) const {
1786 if (isEmptySet() || Other.isEmptySet())
1787 return getEmpty();
1788
1789 APInt NewL = getUnsignedMin().uadd_sat(Other.getUnsignedMin());
1790 APInt NewU = getUnsignedMax().uadd_sat(Other.getUnsignedMax()) + 1;
1791 return getNonEmpty(std::move(NewL), std::move(NewU));
1792 }
1793
1794 ConstantRange ConstantRange::sadd_sat(const ConstantRange &Other) const {
1795 if (isEmptySet() || Other.isEmptySet())
1796 return getEmpty();
1797
1798 APInt NewL = getSignedMin().sadd_sat(Other.getSignedMin());
1799 APInt NewU = getSignedMax().sadd_sat(Other.getSignedMax()) + 1;
1800 return getNonEmpty(std::move(NewL), std::move(NewU));
1801 }
1802
1803 ConstantRange ConstantRange::usub_sat(const ConstantRange &Other) const {
1804 if (isEmptySet() || Other.isEmptySet())
1805 return getEmpty();
1806
1807 APInt NewL = getUnsignedMin().usub_sat(Other.getUnsignedMax());
1808 APInt NewU = getUnsignedMax().usub_sat(Other.getUnsignedMin()) + 1;
1809 return getNonEmpty(std::move(NewL), std::move(NewU));
1810 }
1811
1812 ConstantRange ConstantRange::ssub_sat(const ConstantRange &Other) const {
1813 if (isEmptySet() || Other.isEmptySet())
1814 return getEmpty();
1815
1816 APInt NewL = getSignedMin().ssub_sat(Other.getSignedMax());
1817 APInt NewU = getSignedMax().ssub_sat(Other.getSignedMin()) + 1;
1818 return getNonEmpty(std::move(NewL), std::move(NewU));
1819 }
1820
1821 ConstantRange ConstantRange::umul_sat(const ConstantRange &Other) const {
1822 if (isEmptySet() || Other.isEmptySet())
1823 return getEmpty();
1824
1825 APInt NewL = getUnsignedMin().umul_sat(Other.getUnsignedMin());
1826 APInt NewU = getUnsignedMax().umul_sat(Other.getUnsignedMax()) + 1;
1827 return getNonEmpty(std::move(NewL), std::move(NewU));
1828 }
1829
1830 ConstantRange ConstantRange::smul_sat(const ConstantRange &Other) const {
1831 if (isEmptySet() || Other.isEmptySet())
1832 return getEmpty();
1833
1834 // Because we could be dealing with negative numbers here, the lower bound is
1835 // the smallest of the cartesian product of the lower and upper ranges;
1836 // for example:
1837 // [-1,4) * [-2,3) = min(-1*-2, -1*2, 3*-2, 3*2) = -6.
1838 // Similarly for the upper bound, swapping min for max.
1839
1840 APInt Min = getSignedMin();
1841 APInt Max = getSignedMax();
1842 APInt OtherMin = Other.getSignedMin();
1843 APInt OtherMax = Other.getSignedMax();
1844
1845 auto L = {Min.smul_sat(OtherMin), Min.smul_sat(OtherMax),
1846 Max.smul_sat(OtherMin), Max.smul_sat(OtherMax)};
1847 auto Compare = [](const APInt &A, const APInt &B) { return A.slt(B); };
1848 return getNonEmpty(std::min(L, Compare), std::max(L, Compare) + 1);
1849 }
1850
1851 ConstantRange ConstantRange::ushl_sat(const ConstantRange &Other) const {
1852 if (isEmptySet() || Other.isEmptySet())
1853 return getEmpty();
1854
1855 APInt NewL = getUnsignedMin().ushl_sat(Other.getUnsignedMin());
1856 APInt NewU = getUnsignedMax().ushl_sat(Other.getUnsignedMax()) + 1;
1857 return getNonEmpty(std::move(NewL), std::move(NewU));
1858 }
1859
1860 ConstantRange ConstantRange::sshl_sat(const ConstantRange &Other) const {
1861 if (isEmptySet() || Other.isEmptySet())
1862 return getEmpty();
1863
1864 APInt Min = getSignedMin(), Max = getSignedMax();
1865 APInt ShAmtMin = Other.getUnsignedMin(), ShAmtMax = Other.getUnsignedMax();
1866 APInt NewL = Min.sshl_sat(Min.isNonNegative() ? ShAmtMin : ShAmtMax);
1867 APInt NewU = Max.sshl_sat(Max.isNegative() ? ShAmtMin : ShAmtMax) + 1;
1868 return getNonEmpty(std::move(NewL), std::move(NewU));
1869 }
1870
1871 ConstantRange ConstantRange::inverse() const {
1872 if (isFullSet())
1873 return getEmpty();
1874 if (isEmptySet())
1875 return getFull();
1876 return ConstantRange(Upper, Lower);
1877 }
1878
1879 ConstantRange ConstantRange::abs(bool IntMinIsPoison) const {
1880 if (isEmptySet())
1881 return getEmpty();
1882
1883 if (isSignWrappedSet()) {
1884 APInt Lo;
1885 // Check whether the range crosses zero.
1886 if (Upper.isStrictlyPositive() || !Lower.isStrictlyPositive())
1887 Lo = APInt::getZero(getBitWidth());
1888 else
1889 Lo = APIntOps::umin(Lower, -Upper + 1);
1890
1891 // If SignedMin is not poison, then it is included in the result range.
1892 if (IntMinIsPoison)
1893 return ConstantRange(Lo, APInt::getSignedMinValue(getBitWidth()));
1894 else
1895 return ConstantRange(Lo, APInt::getSignedMinValue(getBitWidth()) + 1);
1896 }
1897
1898 APInt SMin = getSignedMin(), SMax = getSignedMax();
1899
1900 // Skip SignedMin if it is poison.
1901 if (IntMinIsPoison && SMin.isMinSignedValue()) {
1902 // The range may become empty if it *only* contains SignedMin.
1903 if (SMax.isMinSignedValue())
1904 return getEmpty();
1905 ++SMin;
1906 }
1907
1908 // All non-negative.
1909 if (SMin.isNonNegative())
1910 return ConstantRange(SMin, SMax + 1);
1911
1912 // All negative.
1913 if (SMax.isNegative())
1914 return ConstantRange(-SMax, -SMin + 1);
1915
1916 // Range crosses zero.
1917 return ConstantRange::getNonEmpty(APInt::getZero(getBitWidth()),
1918 APIntOps::umax(-SMin, SMax) + 1);
1919 }
1920
1921 ConstantRange ConstantRange::ctlz(bool ZeroIsPoison) const {
1922 if (isEmptySet())
1923 return getEmpty();
1924
1925 APInt Zero = APInt::getZero(getBitWidth());
1926 if (ZeroIsPoison && contains(Zero)) {
1927 // ZeroIsPoison is set, and zero is contained. We discern three cases, in
1928 // which a zero can appear:
1929 // 1) Lower is zero, handling cases of kind [0, 1), [0, 2), etc.
1930 // 2) Upper is zero, wrapped set, handling cases of kind [3, 0], etc.
1931 // 3) Zero contained in a wrapped set, e.g., [3, 2), [3, 1), etc.
1932
1933 if (getLower().isZero()) {
1934 if ((getUpper() - 1).isZero()) {
1935 // We have in input interval of kind [0, 1). In this case we cannot
1936 // really help but return empty-set.
1937 return getEmpty();
1938 }
1939
1940 // Compute the resulting range by excluding zero from Lower.
1941 return ConstantRange(
1942 APInt(getBitWidth(), (getUpper() - 1).countl_zero()),
1943 APInt(getBitWidth(), (getLower() + 1).countl_zero() + 1));
1944 } else if ((getUpper() - 1).isZero()) {
1945 // Compute the resulting range by excluding zero from Upper.
1946 return ConstantRange(Zero,
1947 APInt(getBitWidth(), getLower().countl_zero() + 1));
1948 } else {
1949 return ConstantRange(Zero, APInt(getBitWidth(), getBitWidth()));
1950 }
1951 }
1952
1953 // Zero is either safe or not in the range. The output range is composed by
1954 // the result of countLeadingZero of the two extremes.
1955 return getNonEmpty(APInt(getBitWidth(), getUnsignedMax().countl_zero()),
1956 APInt(getBitWidth(), getUnsignedMin().countl_zero()) + 1);
1957 }
1958
1959 static ConstantRange getUnsignedCountTrailingZerosRange(const APInt &Lower,
1960 const APInt &Upper) {
1961 assert(!ConstantRange(Lower, Upper).isWrappedSet() &&
1962 "Unexpected wrapped set.");
1963 assert(Lower != Upper && "Unexpected empty set.");
1964 unsigned BitWidth = Lower.getBitWidth();
1965 if (Lower + 1 == Upper)
1966 return ConstantRange(APInt(BitWidth, Lower.countr_zero()));
1967 if (Lower.isZero())
1968 return ConstantRange(APInt::getZero(BitWidth),
1969 APInt(BitWidth, BitWidth + 1));
1970
1971 // Calculate longest common prefix.
1972 unsigned LCPLength = (Lower ^ (Upper - 1)).countl_zero();
1973 // If Lower is {LCP, 000...}, the maximum is Lower.countr_zero().
1974 // Otherwise, the maximum is BitWidth - LCPLength - 1 ({LCP, 100...}).
1975 return ConstantRange(
1976 APInt::getZero(BitWidth),
1977 APInt(BitWidth,
1978 std::max(BitWidth - LCPLength - 1, Lower.countr_zero()) + 1));
1979 }
1980
1981 ConstantRange ConstantRange::cttz(bool ZeroIsPoison) const {
1982 if (isEmptySet())
1983 return getEmpty();
1984
1985 unsigned BitWidth = getBitWidth();
1986 APInt Zero = APInt::getZero(BitWidth);
1987 if (ZeroIsPoison && contains(Zero)) {
1988 // ZeroIsPoison is set, and zero is contained. We discern three cases, in
1989 // which a zero can appear:
1990 // 1) Lower is zero, handling cases of kind [0, 1), [0, 2), etc.
1991 // 2) Upper is zero, wrapped set, handling cases of kind [3, 0], etc.
1992 // 3) Zero contained in a wrapped set, e.g., [3, 2), [3, 1), etc.
1993
1994 if (Lower.isZero()) {
1995 if (Upper == 1) {
1996 // We have in input interval of kind [0, 1). In this case we cannot
1997 // really help but return empty-set.
1998 return getEmpty();
1999 }
2000
2001 // Compute the resulting range by excluding zero from Lower.
2002 return getUnsignedCountTrailingZerosRange(APInt(BitWidth, 1), Upper);
2003 } else if (Upper == 1) {
2004 // Compute the resulting range by excluding zero from Upper.
2005 return getUnsignedCountTrailingZerosRange(Lower, Zero);
2006 } else {
2007 ConstantRange CR1 = getUnsignedCountTrailingZerosRange(Lower, Zero);
2008 ConstantRange CR2 =
2009 getUnsignedCountTrailingZerosRange(APInt(BitWidth, 1), Upper);
2010 return CR1.unionWith(CR2);
2011 }
2012 }
2013
2014 if (isFullSet())
2015 return getNonEmpty(Zero, APInt(BitWidth, BitWidth) + 1);
2016 if (!isWrappedSet())
2017 return getUnsignedCountTrailingZerosRange(Lower, Upper);
2018 // The range is wrapped. We decompose it into two ranges, [0, Upper) and
2019 // [Lower, 0).
2020 // Handle [Lower, 0)
2021 ConstantRange CR1 = getUnsignedCountTrailingZerosRange(Lower, Zero);
2022 // Handle [0, Upper)
2023 ConstantRange CR2 = getUnsignedCountTrailingZerosRange(Zero, Upper);
2024 return CR1.unionWith(CR2);
2025 }
2026
2027 static ConstantRange getUnsignedPopCountRange(const APInt &Lower,
2028 const APInt &Upper) {
2029 assert(!ConstantRange(Lower, Upper).isWrappedSet() &&
2030 "Unexpected wrapped set.");
2031 assert(Lower != Upper && "Unexpected empty set.");
2032 unsigned BitWidth = Lower.getBitWidth();
2033 if (Lower + 1 == Upper)
2034 return ConstantRange(APInt(BitWidth, Lower.popcount()));
2035
2036 APInt Max = Upper - 1;
2037 // Calculate longest common prefix.
2038 unsigned LCPLength = (Lower ^ Max).countl_zero();
2039 unsigned LCPPopCount = Lower.getHiBits(LCPLength).popcount();
2040 // If Lower is {LCP, 000...}, the minimum is the popcount of LCP.
2041 // Otherwise, the minimum is the popcount of LCP + 1.
2042 unsigned MinBits =
2043 LCPPopCount + (Lower.countr_zero() < BitWidth - LCPLength ? 1 : 0);
2044 // If Max is {LCP, 111...}, the maximum is the popcount of LCP + (BitWidth -
2045 // length of LCP).
2046 // Otherwise, the minimum is the popcount of LCP + (BitWidth -
2047 // length of LCP - 1).
2048 unsigned MaxBits = LCPPopCount + (BitWidth - LCPLength) -
2049 (Max.countr_one() < BitWidth - LCPLength ? 1 : 0);
2050 return ConstantRange(APInt(BitWidth, MinBits), APInt(BitWidth, MaxBits + 1));
2051 }
2052
2053 ConstantRange ConstantRange::ctpop() const {
2054 if (isEmptySet())
2055 return getEmpty();
2056
2057 unsigned BitWidth = getBitWidth();
2058 APInt Zero = APInt::getZero(BitWidth);
2059 if (isFullSet())
2060 return getNonEmpty(Zero, APInt(BitWidth, BitWidth) + 1);
2061 if (!isWrappedSet())
2062 return getUnsignedPopCountRange(Lower, Upper);
2063 // The range is wrapped. We decompose it into two ranges, [0, Upper) and
2064 // [Lower, 0).
2065 // Handle [Lower, 0) == [Lower, Max]
2066 ConstantRange CR1 = ConstantRange(APInt(BitWidth, Lower.countl_one()),
2067 APInt(BitWidth, BitWidth + 1));
2068 // Handle [0, Upper)
2069 ConstantRange CR2 = getUnsignedPopCountRange(Zero, Upper);
2070 return CR1.unionWith(CR2);
2071 }
2072
2073 ConstantRange::OverflowResult ConstantRange::unsignedAddMayOverflow(
2074 const ConstantRange &Other) const {
2075 if (isEmptySet() || Other.isEmptySet())
2076 return OverflowResult::MayOverflow;
2077
2078 APInt Min = getUnsignedMin(), Max = getUnsignedMax();
2079 APInt OtherMin = Other.getUnsignedMin(), OtherMax = Other.getUnsignedMax();
2080
2081 // a u+ b overflows high iff a u> ~b.
2082 if (Min.ugt(~OtherMin))
2083 return OverflowResult::AlwaysOverflowsHigh;
2084 if (Max.ugt(~OtherMax))
2085 return OverflowResult::MayOverflow;
2086 return OverflowResult::NeverOverflows;
2087 }
2088
2089 ConstantRange::OverflowResult ConstantRange::signedAddMayOverflow(
2090 const ConstantRange &Other) const {
2091 if (isEmptySet() || Other.isEmptySet())
2092 return OverflowResult::MayOverflow;
2093
2094 APInt Min = getSignedMin(), Max = getSignedMax();
2095 APInt OtherMin = Other.getSignedMin(), OtherMax = Other.getSignedMax();
2096
2097 APInt SignedMin = APInt::getSignedMinValue(getBitWidth());
2098 APInt SignedMax = APInt::getSignedMaxValue(getBitWidth());
2099
2100 // a s+ b overflows high iff a s>=0 && b s>= 0 && a s> smax - b.
2101 // a s+ b overflows low iff a s< 0 && b s< 0 && a s< smin - b.
2102 if (Min.isNonNegative() && OtherMin.isNonNegative() &&
2103 Min.sgt(SignedMax - OtherMin))
2104 return OverflowResult::AlwaysOverflowsHigh;
2105 if (Max.isNegative() && OtherMax.isNegative() &&
2106 Max.slt(SignedMin - OtherMax))
2107 return OverflowResult::AlwaysOverflowsLow;
2108
2109 if (Max.isNonNegative() && OtherMax.isNonNegative() &&
2110 Max.sgt(SignedMax - OtherMax))
2111 return OverflowResult::MayOverflow;
2112 if (Min.isNegative() && OtherMin.isNegative() &&
2113 Min.slt(SignedMin - OtherMin))
2114 return OverflowResult::MayOverflow;
2115
2116 return OverflowResult::NeverOverflows;
2117 }
2118
2119 ConstantRange::OverflowResult ConstantRange::unsignedSubMayOverflow(
2120 const ConstantRange &Other) const {
2121 if (isEmptySet() || Other.isEmptySet())
2122 return OverflowResult::MayOverflow;
2123
2124 APInt Min = getUnsignedMin(), Max = getUnsignedMax();
2125 APInt OtherMin = Other.getUnsignedMin(), OtherMax = Other.getUnsignedMax();
2126
2127 // a u- b overflows low iff a u< b.
2128 if (Max.ult(OtherMin))
2129 return OverflowResult::AlwaysOverflowsLow;
2130 if (Min.ult(OtherMax))
2131 return OverflowResult::MayOverflow;
2132 return OverflowResult::NeverOverflows;
2133 }
2134
2135 ConstantRange::OverflowResult ConstantRange::signedSubMayOverflow(
2136 const ConstantRange &Other) const {
2137 if (isEmptySet() || Other.isEmptySet())
2138 return OverflowResult::MayOverflow;
2139
2140 APInt Min = getSignedMin(), Max = getSignedMax();
2141 APInt OtherMin = Other.getSignedMin(), OtherMax = Other.getSignedMax();
2142
2143 APInt SignedMin = APInt::getSignedMinValue(getBitWidth());
2144 APInt SignedMax = APInt::getSignedMaxValue(getBitWidth());
2145
2146 // a s- b overflows high iff a s>=0 && b s< 0 && a s> smax + b.
2147 // a s- b overflows low iff a s< 0 && b s>= 0 && a s< smin + b.
2148 if (Min.isNonNegative() && OtherMax.isNegative() &&
2149 Min.sgt(SignedMax + OtherMax))
2150 return OverflowResult::AlwaysOverflowsHigh;
2151 if (Max.isNegative() && OtherMin.isNonNegative() &&
2152 Max.slt(SignedMin + OtherMin))
2153 return OverflowResult::AlwaysOverflowsLow;
2154
2155 if (Max.isNonNegative() && OtherMin.isNegative() &&
2156 Max.sgt(SignedMax + OtherMin))
2157 return OverflowResult::MayOverflow;
2158 if (Min.isNegative() && OtherMax.isNonNegative() &&
2159 Min.slt(SignedMin + OtherMax))
2160 return OverflowResult::MayOverflow;
2161
2162 return OverflowResult::NeverOverflows;
2163 }
2164
2165 ConstantRange::OverflowResult ConstantRange::unsignedMulMayOverflow(
2166 const ConstantRange &Other) const {
2167 if (isEmptySet() || Other.isEmptySet())
2168 return OverflowResult::MayOverflow;
2169
2170 APInt Min = getUnsignedMin(), Max = getUnsignedMax();
2171 APInt OtherMin = Other.getUnsignedMin(), OtherMax = Other.getUnsignedMax();
2172 bool Overflow;
2173
2174 (void) Min.umul_ov(OtherMin, Overflow);
2175 if (Overflow)
2176 return OverflowResult::AlwaysOverflowsHigh;
2177
2178 (void) Max.umul_ov(OtherMax, Overflow);
2179 if (Overflow)
2180 return OverflowResult::MayOverflow;
2181
2182 return OverflowResult::NeverOverflows;
2183 }
2184
2185 void ConstantRange::print(raw_ostream &OS) const {
2186 if (isFullSet())
2187 OS << "full-set";
2188 else if (isEmptySet())
2189 OS << "empty-set";
2190 else
2191 OS << "[" << Lower << "," << Upper << ")";
2192 }
2193
2194 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2195 LLVM_DUMP_METHOD void ConstantRange::dump() const {
2196 print(dbgs());
2197 }
2198 #endif
2199
2200 ConstantRange llvm::getConstantRangeFromMetadata(const MDNode &Ranges) {
2201 const unsigned NumRanges = Ranges.getNumOperands() / 2;
2202 assert(NumRanges >= 1 && "Must have at least one range!");
2203 assert(Ranges.getNumOperands() % 2 == 0 && "Must be a sequence of pairs");
2204
2205 auto *FirstLow = mdconst::extract<ConstantInt>(Ranges.getOperand(0));
2206 auto *FirstHigh = mdconst::extract<ConstantInt>(Ranges.getOperand(1));
2207
2208 ConstantRange CR(FirstLow->getValue(), FirstHigh->getValue());
2209
2210 for (unsigned i = 1; i < NumRanges; ++i) {
2211 auto *Low = mdconst::extract<ConstantInt>(Ranges.getOperand(2 * i + 0));
2212 auto *High = mdconst::extract<ConstantInt>(Ranges.getOperand(2 * i + 1));
2213
2214 // Note: unionWith will potentially create a range that contains values not
2215 // contained in any of the original N ranges.
2216 CR = CR.unionWith(ConstantRange(Low->getValue(), High->getValue()));
2217 }
2218
2219 return CR;
2220 }
LLVM monorepo