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