1//===-- ConstantRange.cpp - ConstantRange implementation ------------------===// 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// Represent a range of possible values that may occur when the program is run 11// for an integral value. This keeps track of a lower and upper bound for the 12// constant, which MAY wrap around the end of the numeric range. To do this, it 13// keeps track of a [lower, upper) bound, which specifies an interval just like 14// STL iterators. When used with boolean values, the following are important 15// ranges (other integral ranges use min/max values for special range values): 16// 17// [F, F) = {} = Empty set 18// [T, F) = {T} 19// [F, T) = {F} 20// [T, T) = {F, T} = Full set 21// 22//===----------------------------------------------------------------------===// 23 24#include "llvm/IR/InstrTypes.h" 25#include "llvm/IR/ConstantRange.h" 26#include "llvm/Support/Debug.h" 27#include "llvm/Support/raw_ostream.h" 28using namespace llvm; 29 30/// Initialize a full (the default) or empty set for the specified type. 31/// 32ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) { 33 if (Full) 34 Lower = Upper = APInt::getMaxValue(BitWidth); 35 else 36 Lower = Upper = APInt::getMinValue(BitWidth); 37} 38 39/// Initialize a range to hold the single specified value. 40/// 41ConstantRange::ConstantRange(APIntMoveTy V) 42 : Lower(std::move(V)), Upper(Lower + 1) {} 43 44ConstantRange::ConstantRange(APIntMoveTy L, APIntMoveTy U) 45 : Lower(std::move(L)), Upper(std::move(U)) { 46 assert(Lower.getBitWidth() == Upper.getBitWidth() && 47 "ConstantRange with unequal bit widths"); 48 assert((Lower != Upper || (Lower.isMaxValue() || Lower.isMinValue())) && 49 "Lower == Upper, but they aren't min or max value!"); 50} 51 52ConstantRange ConstantRange::makeAllowedICmpRegion(CmpInst::Predicate Pred, 53 const ConstantRange &CR) { 54 if (CR.isEmptySet()) 55 return CR; 56 57 uint32_t W = CR.getBitWidth(); 58 switch (Pred) { 59 default: 60 llvm_unreachable("Invalid ICmp predicate to makeAllowedICmpRegion()"); 61 case CmpInst::ICMP_EQ: 62 return CR; 63 case CmpInst::ICMP_NE: 64 if (CR.isSingleElement()) 65 return ConstantRange(CR.getUpper(), CR.getLower()); 66 return ConstantRange(W); 67 case CmpInst::ICMP_ULT: { 68 APInt UMax(CR.getUnsignedMax()); 69 if (UMax.isMinValue()) 70 return ConstantRange(W, /* empty */ false); 71 return ConstantRange(APInt::getMinValue(W), UMax); 72 } 73 case CmpInst::ICMP_SLT: { 74 APInt SMax(CR.getSignedMax()); 75 if (SMax.isMinSignedValue()) 76 return ConstantRange(W, /* empty */ false); 77 return ConstantRange(APInt::getSignedMinValue(W), SMax); 78 } 79 case CmpInst::ICMP_ULE: { 80 APInt UMax(CR.getUnsignedMax()); 81 if (UMax.isMaxValue()) 82 return ConstantRange(W); 83 return ConstantRange(APInt::getMinValue(W), UMax + 1); 84 } 85 case CmpInst::ICMP_SLE: { 86 APInt SMax(CR.getSignedMax()); 87 if (SMax.isMaxSignedValue()) 88 return ConstantRange(W); 89 return ConstantRange(APInt::getSignedMinValue(W), SMax + 1); 90 } 91 case CmpInst::ICMP_UGT: { 92 APInt UMin(CR.getUnsignedMin()); 93 if (UMin.isMaxValue()) 94 return ConstantRange(W, /* empty */ false); 95 return ConstantRange(UMin + 1, APInt::getNullValue(W)); 96 } 97 case CmpInst::ICMP_SGT: { 98 APInt SMin(CR.getSignedMin()); 99 if (SMin.isMaxSignedValue()) 100 return ConstantRange(W, /* empty */ false); 101 return ConstantRange(SMin + 1, APInt::getSignedMinValue(W)); 102 } 103 case CmpInst::ICMP_UGE: { 104 APInt UMin(CR.getUnsignedMin()); 105 if (UMin.isMinValue()) 106 return ConstantRange(W); 107 return ConstantRange(UMin, APInt::getNullValue(W)); 108 } 109 case CmpInst::ICMP_SGE: { 110 APInt SMin(CR.getSignedMin()); 111 if (SMin.isMinSignedValue()) 112 return ConstantRange(W); 113 return ConstantRange(SMin, APInt::getSignedMinValue(W)); 114 } 115 } 116} 117 118ConstantRange ConstantRange::makeSatisfyingICmpRegion(CmpInst::Predicate Pred, 119 const ConstantRange &CR) { 120 // Follows from De-Morgan's laws: 121 // 122 // ~(~A union ~B) == A intersect B. 123 // 124 return makeAllowedICmpRegion(CmpInst::getInversePredicate(Pred), CR) 125 .inverse(); 126} 127 128/// isFullSet - Return true if this set contains all of the elements possible 129/// for this data-type 130bool ConstantRange::isFullSet() const { 131 return Lower == Upper && Lower.isMaxValue(); 132} 133 134/// isEmptySet - Return true if this set contains no members. 135/// 136bool ConstantRange::isEmptySet() const { 137 return Lower == Upper && Lower.isMinValue(); 138} 139 140/// isWrappedSet - Return true if this set wraps around the top of the range, 141/// for example: [100, 8) 142/// 143bool ConstantRange::isWrappedSet() const { 144 return Lower.ugt(Upper); 145} 146 147/// isSignWrappedSet - Return true if this set wraps around the INT_MIN of 148/// its bitwidth, for example: i8 [120, 140). 149/// 150bool ConstantRange::isSignWrappedSet() const { 151 return contains(APInt::getSignedMaxValue(getBitWidth())) && 152 contains(APInt::getSignedMinValue(getBitWidth())); 153} 154 155/// getSetSize - Return the number of elements in this set. 156/// 157APInt ConstantRange::getSetSize() const { 158 if (isFullSet()) { 159 APInt Size(getBitWidth()+1, 0); 160 Size.setBit(getBitWidth()); 161 return Size; 162 } 163 164 // This is also correct for wrapped sets. 165 return (Upper - Lower).zext(getBitWidth()+1); 166} 167 168/// getUnsignedMax - Return the largest unsigned value contained in the 169/// ConstantRange. 170/// 171APInt ConstantRange::getUnsignedMax() const { 172 if (isFullSet() || isWrappedSet()) 173 return APInt::getMaxValue(getBitWidth()); 174 return getUpper() - 1; 175} 176 177/// getUnsignedMin - Return the smallest unsigned value contained in the 178/// ConstantRange. 179/// 180APInt ConstantRange::getUnsignedMin() const { 181 if (isFullSet() || (isWrappedSet() && getUpper() != 0)) 182 return APInt::getMinValue(getBitWidth()); 183 return getLower(); 184} 185 186/// getSignedMax - Return the largest signed value contained in the 187/// ConstantRange. 188/// 189APInt ConstantRange::getSignedMax() const { 190 APInt SignedMax(APInt::getSignedMaxValue(getBitWidth())); 191 if (!isWrappedSet()) { 192 if (getLower().sle(getUpper() - 1)) 193 return getUpper() - 1; 194 return SignedMax; 195 } 196 if (getLower().isNegative() == getUpper().isNegative()) 197 return SignedMax; 198 return getUpper() - 1; 199} 200 201/// getSignedMin - Return the smallest signed value contained in the 202/// ConstantRange. 203/// 204APInt ConstantRange::getSignedMin() const { 205 APInt SignedMin(APInt::getSignedMinValue(getBitWidth())); 206 if (!isWrappedSet()) { 207 if (getLower().sle(getUpper() - 1)) 208 return getLower(); 209 return SignedMin; 210 } 211 if ((getUpper() - 1).slt(getLower())) { 212 if (getUpper() != SignedMin) 213 return SignedMin; 214 } 215 return getLower(); 216} 217 218/// contains - Return true if the specified value is in the set. 219/// 220bool ConstantRange::contains(const APInt &V) const { 221 if (Lower == Upper) 222 return isFullSet(); 223 224 if (!isWrappedSet()) 225 return Lower.ule(V) && V.ult(Upper); 226 return Lower.ule(V) || V.ult(Upper); 227} 228 229/// contains - Return true if the argument is a subset of this range. 230/// Two equal sets contain each other. The empty set contained by all other 231/// sets. 232/// 233bool ConstantRange::contains(const ConstantRange &Other) const { 234 if (isFullSet() || Other.isEmptySet()) return true; 235 if (isEmptySet() || Other.isFullSet()) return false; 236 237 if (!isWrappedSet()) { 238 if (Other.isWrappedSet()) 239 return false; 240 241 return Lower.ule(Other.getLower()) && Other.getUpper().ule(Upper); 242 } 243 244 if (!Other.isWrappedSet()) 245 return Other.getUpper().ule(Upper) || 246 Lower.ule(Other.getLower()); 247 248 return Other.getUpper().ule(Upper) && Lower.ule(Other.getLower()); 249} 250 251/// subtract - Subtract the specified constant from the endpoints of this 252/// constant range. 253ConstantRange ConstantRange::subtract(const APInt &Val) const { 254 assert(Val.getBitWidth() == getBitWidth() && "Wrong bit width"); 255 // If the set is empty or full, don't modify the endpoints. 256 if (Lower == Upper) 257 return *this; 258 return ConstantRange(Lower - Val, Upper - Val); 259} 260 261/// \brief Subtract the specified range from this range (aka relative complement 262/// of the sets). 263ConstantRange ConstantRange::difference(const ConstantRange &CR) const { 264 return intersectWith(CR.inverse()); 265} 266 267/// intersectWith - Return the range that results from the intersection of this 268/// range with another range. The resultant range is guaranteed to include all 269/// elements contained in both input ranges, and to have the smallest possible 270/// set size that does so. Because there may be two intersections with the 271/// same set size, A.intersectWith(B) might not be equal to B.intersectWith(A). 272ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const { 273 assert(getBitWidth() == CR.getBitWidth() && 274 "ConstantRange types don't agree!"); 275 276 // Handle common cases. 277 if ( isEmptySet() || CR.isFullSet()) return *this; 278 if (CR.isEmptySet() || isFullSet()) return CR; 279 280 if (!isWrappedSet() && CR.isWrappedSet()) 281 return CR.intersectWith(*this); 282 283 if (!isWrappedSet() && !CR.isWrappedSet()) { 284 if (Lower.ult(CR.Lower)) { 285 if (Upper.ule(CR.Lower)) 286 return ConstantRange(getBitWidth(), false); 287 288 if (Upper.ult(CR.Upper)) 289 return ConstantRange(CR.Lower, Upper); 290 291 return CR; 292 } 293 if (Upper.ult(CR.Upper)) 294 return *this; 295 296 if (Lower.ult(CR.Upper)) 297 return ConstantRange(Lower, CR.Upper); 298 299 return ConstantRange(getBitWidth(), false); 300 } 301 302 if (isWrappedSet() && !CR.isWrappedSet()) { 303 if (CR.Lower.ult(Upper)) { 304 if (CR.Upper.ult(Upper)) 305 return CR; 306 307 if (CR.Upper.ule(Lower)) 308 return ConstantRange(CR.Lower, Upper); 309 310 if (getSetSize().ult(CR.getSetSize())) 311 return *this; 312 return CR; 313 } 314 if (CR.Lower.ult(Lower)) { 315 if (CR.Upper.ule(Lower)) 316 return ConstantRange(getBitWidth(), false); 317 318 return ConstantRange(Lower, CR.Upper); 319 } 320 return CR; 321 } 322 323 if (CR.Upper.ult(Upper)) { 324 if (CR.Lower.ult(Upper)) { 325 if (getSetSize().ult(CR.getSetSize())) 326 return *this; 327 return CR; 328 } 329 330 if (CR.Lower.ult(Lower)) 331 return ConstantRange(Lower, CR.Upper); 332 333 return CR; 334 } 335 if (CR.Upper.ule(Lower)) { 336 if (CR.Lower.ult(Lower)) 337 return *this; 338 339 return ConstantRange(CR.Lower, Upper); 340 } 341 if (getSetSize().ult(CR.getSetSize())) 342 return *this; 343 return CR; 344} 345 346 347/// unionWith - Return the range that results from the union of this range with 348/// another range. The resultant range is guaranteed to include the elements of 349/// both sets, but may contain more. For example, [3, 9) union [12,15) is 350/// [3, 15), which includes 9, 10, and 11, which were not included in either 351/// set before. 352/// 353ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const { 354 assert(getBitWidth() == CR.getBitWidth() && 355 "ConstantRange types don't agree!"); 356 357 if ( isFullSet() || CR.isEmptySet()) return *this; 358 if (CR.isFullSet() || isEmptySet()) return CR; 359 360 if (!isWrappedSet() && CR.isWrappedSet()) return CR.unionWith(*this); 361 362 if (!isWrappedSet() && !CR.isWrappedSet()) { 363 if (CR.Upper.ult(Lower) || Upper.ult(CR.Lower)) { 364 // If the two ranges are disjoint, find the smaller gap and bridge it. 365 APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper; 366 if (d1.ult(d2)) 367 return ConstantRange(Lower, CR.Upper); 368 return ConstantRange(CR.Lower, Upper); 369 } 370 371 APInt L = Lower, U = Upper; 372 if (CR.Lower.ult(L)) 373 L = CR.Lower; 374 if ((CR.Upper - 1).ugt(U - 1)) 375 U = CR.Upper; 376 377 if (L == 0 && U == 0) 378 return ConstantRange(getBitWidth()); 379 380 return ConstantRange(L, U); 381 } 382 383 if (!CR.isWrappedSet()) { 384 // ------U L----- and ------U L----- : this 385 // L--U L--U : CR 386 if (CR.Upper.ule(Upper) || CR.Lower.uge(Lower)) 387 return *this; 388 389 // ------U L----- : this 390 // L---------U : CR 391 if (CR.Lower.ule(Upper) && Lower.ule(CR.Upper)) 392 return ConstantRange(getBitWidth()); 393 394 // ----U L---- : this 395 // L---U : CR 396 // <d1> <d2> 397 if (Upper.ule(CR.Lower) && CR.Upper.ule(Lower)) { 398 APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper; 399 if (d1.ult(d2)) 400 return ConstantRange(Lower, CR.Upper); 401 return ConstantRange(CR.Lower, Upper); 402 } 403 404 // ----U L----- : this 405 // L----U : CR 406 if (Upper.ult(CR.Lower) && Lower.ult(CR.Upper)) 407 return ConstantRange(CR.Lower, Upper); 408 409 // ------U L---- : this 410 // L-----U : CR 411 assert(CR.Lower.ult(Upper) && CR.Upper.ult(Lower) && 412 "ConstantRange::unionWith missed a case with one range wrapped"); 413 return ConstantRange(Lower, CR.Upper); 414 } 415 416 // ------U L---- and ------U L---- : this 417 // -U L----------- and ------------U L : CR 418 if (CR.Lower.ule(Upper) || Lower.ule(CR.Upper)) 419 return ConstantRange(getBitWidth()); 420 421 APInt L = Lower, U = Upper; 422 if (CR.Upper.ugt(U)) 423 U = CR.Upper; 424 if (CR.Lower.ult(L)) 425 L = CR.Lower; 426 427 return ConstantRange(L, U); 428} 429 430/// zeroExtend - Return a new range in the specified integer type, which must 431/// be strictly larger than the current type. The returned range will 432/// correspond to the possible range of values as if the source range had been 433/// zero extended. 434ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const { 435 if (isEmptySet()) return ConstantRange(DstTySize, /*isFullSet=*/false); 436 437 unsigned SrcTySize = getBitWidth(); 438 assert(SrcTySize < DstTySize && "Not a value extension"); 439 if (isFullSet() || isWrappedSet()) { 440 // Change into [0, 1 << src bit width) 441 APInt LowerExt(DstTySize, 0); 442 if (!Upper) // special case: [X, 0) -- not really wrapping around 443 LowerExt = Lower.zext(DstTySize); 444 return ConstantRange(LowerExt, APInt::getOneBitSet(DstTySize, SrcTySize)); 445 } 446 447 return ConstantRange(Lower.zext(DstTySize), Upper.zext(DstTySize)); 448} 449 450/// signExtend - Return a new range in the specified integer type, which must 451/// be strictly larger than the current type. The returned range will 452/// correspond to the possible range of values as if the source range had been 453/// sign extended. 454ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const { 455 if (isEmptySet()) return ConstantRange(DstTySize, /*isFullSet=*/false); 456 457 unsigned SrcTySize = getBitWidth(); 458 assert(SrcTySize < DstTySize && "Not a value extension"); 459 460 // special case: [X, INT_MIN) -- not really wrapping around 461 if (Upper.isMinSignedValue()) 462 return ConstantRange(Lower.sext(DstTySize), Upper.zext(DstTySize)); 463 464 if (isFullSet() || isSignWrappedSet()) { 465 return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1), 466 APInt::getLowBitsSet(DstTySize, SrcTySize-1) + 1); 467 } 468 469 return ConstantRange(Lower.sext(DstTySize), Upper.sext(DstTySize)); 470} 471 472/// truncate - Return a new range in the specified integer type, which must be 473/// strictly smaller than the current type. The returned range will 474/// correspond to the possible range of values as if the source range had been 475/// truncated to the specified type. 476ConstantRange ConstantRange::truncate(uint32_t DstTySize) const { 477 assert(getBitWidth() > DstTySize && "Not a value truncation"); 478 if (isEmptySet()) 479 return ConstantRange(DstTySize, /*isFullSet=*/false); 480 if (isFullSet()) 481 return ConstantRange(DstTySize, /*isFullSet=*/true); 482 483 APInt MaxValue = APInt::getMaxValue(DstTySize).zext(getBitWidth()); 484 APInt MaxBitValue(getBitWidth(), 0); 485 MaxBitValue.setBit(DstTySize); 486 487 APInt LowerDiv(Lower), UpperDiv(Upper); 488 ConstantRange Union(DstTySize, /*isFullSet=*/false); 489 490 // Analyze wrapped sets in their two parts: [0, Upper) \/ [Lower, MaxValue] 491 // We use the non-wrapped set code to analyze the [Lower, MaxValue) part, and 492 // then we do the union with [MaxValue, Upper) 493 if (isWrappedSet()) { 494 // if Upper is greater than Max Value, it covers the whole truncated range. 495 if (Upper.uge(MaxValue)) 496 return ConstantRange(DstTySize, /*isFullSet=*/true); 497 498 Union = ConstantRange(APInt::getMaxValue(DstTySize),Upper.trunc(DstTySize)); 499 UpperDiv = APInt::getMaxValue(getBitWidth()); 500 501 // Union covers the MaxValue case, so return if the remaining range is just 502 // MaxValue. 503 if (LowerDiv == UpperDiv) 504 return Union; 505 } 506 507 // Chop off the most significant bits that are past the destination bitwidth. 508 if (LowerDiv.uge(MaxValue)) { 509 APInt Div(getBitWidth(), 0); 510 APInt::udivrem(LowerDiv, MaxBitValue, Div, LowerDiv); 511 UpperDiv = UpperDiv - MaxBitValue * Div; 512 } 513 514 if (UpperDiv.ule(MaxValue)) 515 return ConstantRange(LowerDiv.trunc(DstTySize), 516 UpperDiv.trunc(DstTySize)).unionWith(Union); 517 518 // The truncated value wrapps around. Check if we can do better than fullset. 519 APInt UpperModulo = UpperDiv - MaxBitValue; 520 if (UpperModulo.ult(LowerDiv)) 521 return ConstantRange(LowerDiv.trunc(DstTySize), 522 UpperModulo.trunc(DstTySize)).unionWith(Union); 523 524 return ConstantRange(DstTySize, /*isFullSet=*/true); 525} 526 527/// zextOrTrunc - make this range have the bit width given by \p DstTySize. The 528/// value is zero extended, truncated, or left alone to make it that width. 529ConstantRange ConstantRange::zextOrTrunc(uint32_t DstTySize) const { 530 unsigned SrcTySize = getBitWidth(); 531 if (SrcTySize > DstTySize) 532 return truncate(DstTySize); 533 if (SrcTySize < DstTySize) 534 return zeroExtend(DstTySize); 535 return *this; 536} 537 538/// sextOrTrunc - make this range have the bit width given by \p DstTySize. The 539/// value is sign extended, truncated, or left alone to make it that width. 540ConstantRange ConstantRange::sextOrTrunc(uint32_t DstTySize) const { 541 unsigned SrcTySize = getBitWidth(); 542 if (SrcTySize > DstTySize) 543 return truncate(DstTySize); 544 if (SrcTySize < DstTySize) 545 return signExtend(DstTySize); 546 return *this; 547} 548 549ConstantRange 550ConstantRange::add(const ConstantRange &Other) const { 551 if (isEmptySet() || Other.isEmptySet()) 552 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 553 if (isFullSet() || Other.isFullSet()) 554 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 555 556 APInt Spread_X = getSetSize(), Spread_Y = Other.getSetSize(); 557 APInt NewLower = getLower() + Other.getLower(); 558 APInt NewUpper = getUpper() + Other.getUpper() - 1; 559 if (NewLower == NewUpper) 560 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 561 562 ConstantRange X = ConstantRange(NewLower, NewUpper); 563 if (X.getSetSize().ult(Spread_X) || X.getSetSize().ult(Spread_Y)) 564 // We've wrapped, therefore, full set. 565 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 566 567 return X; 568} 569 570ConstantRange 571ConstantRange::sub(const ConstantRange &Other) const { 572 if (isEmptySet() || Other.isEmptySet()) 573 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 574 if (isFullSet() || Other.isFullSet()) 575 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 576 577 APInt Spread_X = getSetSize(), Spread_Y = Other.getSetSize(); 578 APInt NewLower = getLower() - Other.getUpper() + 1; 579 APInt NewUpper = getUpper() - Other.getLower(); 580 if (NewLower == NewUpper) 581 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 582 583 ConstantRange X = ConstantRange(NewLower, NewUpper); 584 if (X.getSetSize().ult(Spread_X) || X.getSetSize().ult(Spread_Y)) 585 // We've wrapped, therefore, full set. 586 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 587 588 return X; 589} 590 591ConstantRange 592ConstantRange::multiply(const ConstantRange &Other) const { 593 // TODO: If either operand is a single element and the multiply is known to 594 // be non-wrapping, round the result min and max value to the appropriate 595 // multiple of that element. If wrapping is possible, at least adjust the 596 // range according to the greatest power-of-two factor of the single element. 597 598 if (isEmptySet() || Other.isEmptySet()) 599 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 600 601 // Multiplication is signedness-independent. However different ranges can be 602 // obtained depending on how the input ranges are treated. These different 603 // ranges are all conservatively correct, but one might be better than the 604 // other. We calculate two ranges; one treating the inputs as unsigned 605 // and the other signed, then return the smallest of these ranges. 606 607 // Unsigned range first. 608 APInt this_min = getUnsignedMin().zext(getBitWidth() * 2); 609 APInt this_max = getUnsignedMax().zext(getBitWidth() * 2); 610 APInt Other_min = Other.getUnsignedMin().zext(getBitWidth() * 2); 611 APInt Other_max = Other.getUnsignedMax().zext(getBitWidth() * 2); 612 613 ConstantRange Result_zext = ConstantRange(this_min * Other_min, 614 this_max * Other_max + 1); 615 ConstantRange UR = Result_zext.truncate(getBitWidth()); 616 617 // Now the signed range. Because we could be dealing with negative numbers 618 // here, the lower bound is the smallest of the cartesian product of the 619 // lower and upper ranges; for example: 620 // [-1,4) * [-2,3) = min(-1*-2, -1*2, 3*-2, 3*2) = -6. 621 // Similarly for the upper bound, swapping min for max. 622 623 this_min = getSignedMin().sext(getBitWidth() * 2); 624 this_max = getSignedMax().sext(getBitWidth() * 2); 625 Other_min = Other.getSignedMin().sext(getBitWidth() * 2); 626 Other_max = Other.getSignedMax().sext(getBitWidth() * 2); 627 628 auto L = {this_min * Other_min, this_min * Other_max, 629 this_max * Other_min, this_max * Other_max}; 630 auto Compare = [](const APInt &A, const APInt &B) { return A.slt(B); }; 631 ConstantRange Result_sext(std::min(L, Compare), std::max(L, Compare) + 1); 632 ConstantRange SR = Result_sext.truncate(getBitWidth()); 633 634 return UR.getSetSize().ult(SR.getSetSize()) ? UR : SR; 635} 636 637ConstantRange 638ConstantRange::smax(const ConstantRange &Other) const { 639 // X smax Y is: range(smax(X_smin, Y_smin), 640 // smax(X_smax, Y_smax)) 641 if (isEmptySet() || Other.isEmptySet()) 642 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 643 APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin()); 644 APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1; 645 if (NewU == NewL) 646 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 647 return ConstantRange(NewL, NewU); 648} 649 650ConstantRange 651ConstantRange::umax(const ConstantRange &Other) const { 652 // X umax Y is: range(umax(X_umin, Y_umin), 653 // umax(X_umax, Y_umax)) 654 if (isEmptySet() || Other.isEmptySet()) 655 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 656 APInt NewL = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin()); 657 APInt NewU = APIntOps::umax(getUnsignedMax(), Other.getUnsignedMax()) + 1; 658 if (NewU == NewL) 659 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 660 return ConstantRange(NewL, NewU); 661} 662 663ConstantRange 664ConstantRange::udiv(const ConstantRange &RHS) const { 665 if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax() == 0) 666 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 667 if (RHS.isFullSet()) 668 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 669 670 APInt Lower = getUnsignedMin().udiv(RHS.getUnsignedMax()); 671 672 APInt RHS_umin = RHS.getUnsignedMin(); 673 if (RHS_umin == 0) { 674 // We want the lowest value in RHS excluding zero. Usually that would be 1 675 // except for a range in the form of [X, 1) in which case it would be X. 676 if (RHS.getUpper() == 1) 677 RHS_umin = RHS.getLower(); 678 else 679 RHS_umin = APInt(getBitWidth(), 1); 680 } 681 682 APInt Upper = getUnsignedMax().udiv(RHS_umin) + 1; 683 684 // If the LHS is Full and the RHS is a wrapped interval containing 1 then 685 // this could occur. 686 if (Lower == Upper) 687 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 688 689 return ConstantRange(Lower, Upper); 690} 691 692ConstantRange 693ConstantRange::binaryAnd(const ConstantRange &Other) const { 694 if (isEmptySet() || Other.isEmptySet()) 695 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 696 697 // TODO: replace this with something less conservative 698 699 APInt umin = APIntOps::umin(Other.getUnsignedMax(), getUnsignedMax()); 700 if (umin.isAllOnesValue()) 701 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 702 return ConstantRange(APInt::getNullValue(getBitWidth()), umin + 1); 703} 704 705ConstantRange 706ConstantRange::binaryOr(const ConstantRange &Other) const { 707 if (isEmptySet() || Other.isEmptySet()) 708 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 709 710 // TODO: replace this with something less conservative 711 712 APInt umax = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin()); 713 if (umax.isMinValue()) 714 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 715 return ConstantRange(umax, APInt::getNullValue(getBitWidth())); 716} 717 718ConstantRange 719ConstantRange::shl(const ConstantRange &Other) const { 720 if (isEmptySet() || Other.isEmptySet()) 721 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 722 723 APInt min = getUnsignedMin().shl(Other.getUnsignedMin()); 724 APInt max = getUnsignedMax().shl(Other.getUnsignedMax()); 725 726 // there's no overflow! 727 APInt Zeros(getBitWidth(), getUnsignedMax().countLeadingZeros()); 728 if (Zeros.ugt(Other.getUnsignedMax())) 729 return ConstantRange(min, max + 1); 730 731 // FIXME: implement the other tricky cases 732 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 733} 734 735ConstantRange 736ConstantRange::lshr(const ConstantRange &Other) const { 737 if (isEmptySet() || Other.isEmptySet()) 738 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 739 740 APInt max = getUnsignedMax().lshr(Other.getUnsignedMin()); 741 APInt min = getUnsignedMin().lshr(Other.getUnsignedMax()); 742 if (min == max + 1) 743 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 744 745 return ConstantRange(min, max + 1); 746} 747 748ConstantRange ConstantRange::inverse() const { 749 if (isFullSet()) 750 return ConstantRange(getBitWidth(), /*isFullSet=*/false); 751 if (isEmptySet()) 752 return ConstantRange(getBitWidth(), /*isFullSet=*/true); 753 return ConstantRange(Upper, Lower); 754} 755 756/// print - Print out the bounds to a stream... 757/// 758void ConstantRange::print(raw_ostream &OS) const { 759 if (isFullSet()) 760 OS << "full-set"; 761 else if (isEmptySet()) 762 OS << "empty-set"; 763 else 764 OS << "[" << Lower << "," << Upper << ")"; 765} 766 767/// dump - Allow printing from a debugger easily... 768/// 769void ConstantRange::dump() const { 770 print(dbgs()); 771} 772