1 //===-- ConstantRange.cpp - ConstantRange implementation ------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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):
17 // [F, F) = {} = Empty set
20 // [T, T) = {F, T} = Full set
22 //===----------------------------------------------------------------------===//
24 #include "llvm/InstrTypes.h"
25 #include "llvm/Support/ConstantRange.h"
26 #include "llvm/Support/Debug.h"
27 #include "llvm/Support/raw_ostream.h"
30 /// Initialize a full (the default) or empty set for the specified type.
32 ConstantRange::ConstantRange(uint32_t BitWidth, bool Full) {
34 Lower = Upper = APInt::getMaxValue(BitWidth);
36 Lower = Upper = APInt::getMinValue(BitWidth);
39 /// Initialize a range to hold the single specified value.
41 ConstantRange::ConstantRange(const APInt &V) : Lower(V), Upper(V + 1) {}
43 ConstantRange::ConstantRange(const APInt &L, const APInt &U) :
45 assert(L.getBitWidth() == U.getBitWidth() &&
46 "ConstantRange with unequal bit widths");
47 assert((L != U || (L.isMaxValue() || L.isMinValue())) &&
48 "Lower == Upper, but they aren't min or max value!");
51 ConstantRange ConstantRange::makeICmpRegion(unsigned Pred,
52 const ConstantRange &CR) {
56 uint32_t W = CR.getBitWidth();
58 default: llvm_unreachable("Invalid ICmp predicate to makeICmpRegion()");
59 case CmpInst::ICMP_EQ:
61 case CmpInst::ICMP_NE:
62 if (CR.isSingleElement())
63 return ConstantRange(CR.getUpper(), CR.getLower());
64 return ConstantRange(W);
65 case CmpInst::ICMP_ULT: {
66 APInt UMax(CR.getUnsignedMax());
67 if (UMax.isMinValue())
68 return ConstantRange(W, /* empty */ false);
69 return ConstantRange(APInt::getMinValue(W), UMax);
71 case CmpInst::ICMP_SLT: {
72 APInt SMax(CR.getSignedMax());
73 if (SMax.isMinSignedValue())
74 return ConstantRange(W, /* empty */ false);
75 return ConstantRange(APInt::getSignedMinValue(W), SMax);
77 case CmpInst::ICMP_ULE: {
78 APInt UMax(CR.getUnsignedMax());
79 if (UMax.isMaxValue())
80 return ConstantRange(W);
81 return ConstantRange(APInt::getMinValue(W), UMax + 1);
83 case CmpInst::ICMP_SLE: {
84 APInt SMax(CR.getSignedMax());
85 if (SMax.isMaxSignedValue())
86 return ConstantRange(W);
87 return ConstantRange(APInt::getSignedMinValue(W), SMax + 1);
89 case CmpInst::ICMP_UGT: {
90 APInt UMin(CR.getUnsignedMin());
91 if (UMin.isMaxValue())
92 return ConstantRange(W, /* empty */ false);
93 return ConstantRange(UMin + 1, APInt::getNullValue(W));
95 case CmpInst::ICMP_SGT: {
96 APInt SMin(CR.getSignedMin());
97 if (SMin.isMaxSignedValue())
98 return ConstantRange(W, /* empty */ false);
99 return ConstantRange(SMin + 1, APInt::getSignedMinValue(W));
101 case CmpInst::ICMP_UGE: {
102 APInt UMin(CR.getUnsignedMin());
103 if (UMin.isMinValue())
104 return ConstantRange(W);
105 return ConstantRange(UMin, APInt::getNullValue(W));
107 case CmpInst::ICMP_SGE: {
108 APInt SMin(CR.getSignedMin());
109 if (SMin.isMinSignedValue())
110 return ConstantRange(W);
111 return ConstantRange(SMin, APInt::getSignedMinValue(W));
116 /// isFullSet - Return true if this set contains all of the elements possible
117 /// for this data-type
118 bool ConstantRange::isFullSet() const {
119 return Lower == Upper && Lower.isMaxValue();
122 /// isEmptySet - Return true if this set contains no members.
124 bool ConstantRange::isEmptySet() const {
125 return Lower == Upper && Lower.isMinValue();
128 /// isWrappedSet - Return true if this set wraps around the top of the range,
129 /// for example: [100, 8)
131 bool ConstantRange::isWrappedSet() const {
132 return Lower.ugt(Upper);
135 /// isSignWrappedSet - Return true if this set wraps around the INT_MIN of
136 /// its bitwidth, for example: i8 [120, 140).
138 bool ConstantRange::isSignWrappedSet() const {
139 return contains(APInt::getSignedMaxValue(getBitWidth())) &&
140 contains(APInt::getSignedMinValue(getBitWidth()));
143 /// getSetSize - Return the number of elements in this set.
145 APInt ConstantRange::getSetSize() const {
147 return APInt(getBitWidth()+1, 0);
150 APInt Size(getBitWidth()+1, 0);
151 Size.setBit(getBitWidth());
155 // This is also correct for wrapped sets.
156 return (Upper - Lower).zext(getBitWidth()+1);
159 /// getUnsignedMax - Return the largest unsigned value contained in the
162 APInt ConstantRange::getUnsignedMax() const {
163 if (isFullSet() || isWrappedSet())
164 return APInt::getMaxValue(getBitWidth());
165 return getUpper() - 1;
168 /// getUnsignedMin - Return the smallest unsigned value contained in the
171 APInt ConstantRange::getUnsignedMin() const {
172 if (isFullSet() || (isWrappedSet() && getUpper() != 0))
173 return APInt::getMinValue(getBitWidth());
177 /// getSignedMax - Return the largest signed value contained in the
180 APInt ConstantRange::getSignedMax() const {
181 APInt SignedMax(APInt::getSignedMaxValue(getBitWidth()));
182 if (!isWrappedSet()) {
183 if (getLower().sle(getUpper() - 1))
184 return getUpper() - 1;
187 if (getLower().isNegative() == getUpper().isNegative())
189 return getUpper() - 1;
192 /// getSignedMin - Return the smallest signed value contained in the
195 APInt ConstantRange::getSignedMin() const {
196 APInt SignedMin(APInt::getSignedMinValue(getBitWidth()));
197 if (!isWrappedSet()) {
198 if (getLower().sle(getUpper() - 1))
202 if ((getUpper() - 1).slt(getLower())) {
203 if (getUpper() != SignedMin)
209 /// contains - Return true if the specified value is in the set.
211 bool ConstantRange::contains(const APInt &V) const {
216 return Lower.ule(V) && V.ult(Upper);
217 return Lower.ule(V) || V.ult(Upper);
220 /// contains - Return true if the argument is a subset of this range.
221 /// Two equal sets contain each other. The empty set contained by all other
224 bool ConstantRange::contains(const ConstantRange &Other) const {
225 if (isFullSet() || Other.isEmptySet()) return true;
226 if (isEmptySet() || Other.isFullSet()) return false;
228 if (!isWrappedSet()) {
229 if (Other.isWrappedSet())
232 return Lower.ule(Other.getLower()) && Other.getUpper().ule(Upper);
235 if (!Other.isWrappedSet())
236 return Other.getUpper().ule(Upper) ||
237 Lower.ule(Other.getLower());
239 return Other.getUpper().ule(Upper) && Lower.ule(Other.getLower());
242 /// subtract - Subtract the specified constant from the endpoints of this
244 ConstantRange ConstantRange::subtract(const APInt &Val) const {
245 assert(Val.getBitWidth() == getBitWidth() && "Wrong bit width");
246 // If the set is empty or full, don't modify the endpoints.
249 return ConstantRange(Lower - Val, Upper - Val);
252 /// \brief Subtract the specified range from this range (aka relative complement
254 ConstantRange ConstantRange::difference(const ConstantRange &CR) const {
255 return intersectWith(CR.inverse());
258 /// intersectWith - Return the range that results from the intersection of this
259 /// range with another range. The resultant range is guaranteed to include all
260 /// elements contained in both input ranges, and to have the smallest possible
261 /// set size that does so. Because there may be two intersections with the
262 /// same set size, A.intersectWith(B) might not be equal to B.intersectWith(A).
263 ConstantRange ConstantRange::intersectWith(const ConstantRange &CR) const {
264 assert(getBitWidth() == CR.getBitWidth() &&
265 "ConstantRange types don't agree!");
267 // Handle common cases.
268 if ( isEmptySet() || CR.isFullSet()) return *this;
269 if (CR.isEmptySet() || isFullSet()) return CR;
271 if (!isWrappedSet() && CR.isWrappedSet())
272 return CR.intersectWith(*this);
274 if (!isWrappedSet() && !CR.isWrappedSet()) {
275 if (Lower.ult(CR.Lower)) {
276 if (Upper.ule(CR.Lower))
277 return ConstantRange(getBitWidth(), false);
279 if (Upper.ult(CR.Upper))
280 return ConstantRange(CR.Lower, Upper);
284 if (Upper.ult(CR.Upper))
287 if (Lower.ult(CR.Upper))
288 return ConstantRange(Lower, CR.Upper);
290 return ConstantRange(getBitWidth(), false);
293 if (isWrappedSet() && !CR.isWrappedSet()) {
294 if (CR.Lower.ult(Upper)) {
295 if (CR.Upper.ult(Upper))
298 if (CR.Upper.ule(Lower))
299 return ConstantRange(CR.Lower, Upper);
301 if (getSetSize().ult(CR.getSetSize()))
305 if (CR.Lower.ult(Lower)) {
306 if (CR.Upper.ule(Lower))
307 return ConstantRange(getBitWidth(), false);
309 return ConstantRange(Lower, CR.Upper);
314 if (CR.Upper.ult(Upper)) {
315 if (CR.Lower.ult(Upper)) {
316 if (getSetSize().ult(CR.getSetSize()))
321 if (CR.Lower.ult(Lower))
322 return ConstantRange(Lower, CR.Upper);
326 if (CR.Upper.ule(Lower)) {
327 if (CR.Lower.ult(Lower))
330 return ConstantRange(CR.Lower, Upper);
332 if (getSetSize().ult(CR.getSetSize()))
338 /// unionWith - Return the range that results from the union of this range with
339 /// another range. The resultant range is guaranteed to include the elements of
340 /// both sets, but may contain more. For example, [3, 9) union [12,15) is
341 /// [3, 15), which includes 9, 10, and 11, which were not included in either
344 ConstantRange ConstantRange::unionWith(const ConstantRange &CR) const {
345 assert(getBitWidth() == CR.getBitWidth() &&
346 "ConstantRange types don't agree!");
348 if ( isFullSet() || CR.isEmptySet()) return *this;
349 if (CR.isFullSet() || isEmptySet()) return CR;
351 if (!isWrappedSet() && CR.isWrappedSet()) return CR.unionWith(*this);
353 if (!isWrappedSet() && !CR.isWrappedSet()) {
354 if (CR.Upper.ult(Lower) || Upper.ult(CR.Lower)) {
355 // If the two ranges are disjoint, find the smaller gap and bridge it.
356 APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
358 return ConstantRange(Lower, CR.Upper);
359 return ConstantRange(CR.Lower, Upper);
362 APInt L = Lower, U = Upper;
365 if ((CR.Upper - 1).ugt(U - 1))
368 if (L == 0 && U == 0)
369 return ConstantRange(getBitWidth());
371 return ConstantRange(L, U);
374 if (!CR.isWrappedSet()) {
375 // ------U L----- and ------U L----- : this
377 if (CR.Upper.ule(Upper) || CR.Lower.uge(Lower))
380 // ------U L----- : this
382 if (CR.Lower.ule(Upper) && Lower.ule(CR.Upper))
383 return ConstantRange(getBitWidth());
385 // ----U L---- : this
388 if (Upper.ule(CR.Lower) && CR.Upper.ule(Lower)) {
389 APInt d1 = CR.Lower - Upper, d2 = Lower - CR.Upper;
391 return ConstantRange(Lower, CR.Upper);
392 return ConstantRange(CR.Lower, Upper);
395 // ----U L----- : this
397 if (Upper.ult(CR.Lower) && Lower.ult(CR.Upper))
398 return ConstantRange(CR.Lower, Upper);
400 // ------U L---- : this
402 assert(CR.Lower.ult(Upper) && CR.Upper.ult(Lower) &&
403 "ConstantRange::unionWith missed a case with one range wrapped");
404 return ConstantRange(Lower, CR.Upper);
407 // ------U L---- and ------U L---- : this
408 // -U L----------- and ------------U L : CR
409 if (CR.Lower.ule(Upper) || Lower.ule(CR.Upper))
410 return ConstantRange(getBitWidth());
412 APInt L = Lower, U = Upper;
418 return ConstantRange(L, U);
421 /// zeroExtend - Return a new range in the specified integer type, which must
422 /// be strictly larger than the current type. The returned range will
423 /// correspond to the possible range of values as if the source range had been
425 ConstantRange ConstantRange::zeroExtend(uint32_t DstTySize) const {
426 if (isEmptySet()) return ConstantRange(DstTySize, /*isFullSet=*/false);
428 unsigned SrcTySize = getBitWidth();
429 assert(SrcTySize < DstTySize && "Not a value extension");
430 if (isFullSet() || isWrappedSet())
431 // Change into [0, 1 << src bit width)
432 return ConstantRange(APInt(DstTySize,0), APInt(DstTySize,1).shl(SrcTySize));
434 return ConstantRange(Lower.zext(DstTySize), Upper.zext(DstTySize));
437 /// signExtend - Return a new range in the specified integer type, which must
438 /// be strictly larger than the current type. The returned range will
439 /// correspond to the possible range of values as if the source range had been
441 ConstantRange ConstantRange::signExtend(uint32_t DstTySize) const {
442 if (isEmptySet()) return ConstantRange(DstTySize, /*isFullSet=*/false);
444 unsigned SrcTySize = getBitWidth();
445 assert(SrcTySize < DstTySize && "Not a value extension");
446 if (isFullSet() || isSignWrappedSet()) {
447 return ConstantRange(APInt::getHighBitsSet(DstTySize,DstTySize-SrcTySize+1),
448 APInt::getLowBitsSet(DstTySize, SrcTySize-1) + 1);
451 return ConstantRange(Lower.sext(DstTySize), Upper.sext(DstTySize));
454 /// truncate - Return a new range in the specified integer type, which must be
455 /// strictly smaller than the current type. The returned range will
456 /// correspond to the possible range of values as if the source range had been
457 /// truncated to the specified type.
458 ConstantRange ConstantRange::truncate(uint32_t DstTySize) const {
459 assert(getBitWidth() > DstTySize && "Not a value truncation");
461 return ConstantRange(DstTySize, /*isFullSet=*/false);
463 return ConstantRange(DstTySize, /*isFullSet=*/true);
465 APInt MaxValue = APInt::getMaxValue(DstTySize).zext(getBitWidth());
466 APInt MaxBitValue(getBitWidth(), 0);
467 MaxBitValue.setBit(DstTySize);
469 APInt LowerDiv(Lower), UpperDiv(Upper);
470 ConstantRange Union(DstTySize, /*isFullSet=*/false);
472 // Analyze wrapped sets in their two parts: [0, Upper) \/ [Lower, MaxValue]
473 // We use the non-wrapped set code to analyze the [Lower, MaxValue) part, and
474 // then we do the union with [MaxValue, Upper)
475 if (isWrappedSet()) {
476 // if Upper is greater than Max Value, it covers the whole truncated range.
477 if (Upper.uge(MaxValue))
478 return ConstantRange(DstTySize, /*isFullSet=*/true);
480 Union = ConstantRange(APInt::getMaxValue(DstTySize),Upper.trunc(DstTySize));
481 UpperDiv = APInt::getMaxValue(getBitWidth());
483 // Union covers the MaxValue case, so return if the remaining range is just
485 if (LowerDiv == UpperDiv)
489 // Chop off the most significant bits that are past the destination bitwidth.
490 if (LowerDiv.uge(MaxValue)) {
491 APInt Div(getBitWidth(), 0);
492 APInt::udivrem(LowerDiv, MaxBitValue, Div, LowerDiv);
493 UpperDiv = UpperDiv - MaxBitValue * Div;
496 if (UpperDiv.ule(MaxValue))
497 return ConstantRange(LowerDiv.trunc(DstTySize),
498 UpperDiv.trunc(DstTySize)).unionWith(Union);
500 // The truncated value wrapps around. Check if we can do better than fullset.
501 APInt UpperModulo = UpperDiv - MaxBitValue;
502 if (UpperModulo.ult(LowerDiv))
503 return ConstantRange(LowerDiv.trunc(DstTySize),
504 UpperModulo.trunc(DstTySize)).unionWith(Union);
506 return ConstantRange(DstTySize, /*isFullSet=*/true);
509 /// zextOrTrunc - make this range have the bit width given by \p DstTySize. The
510 /// value is zero extended, truncated, or left alone to make it that width.
511 ConstantRange ConstantRange::zextOrTrunc(uint32_t DstTySize) const {
512 unsigned SrcTySize = getBitWidth();
513 if (SrcTySize > DstTySize)
514 return truncate(DstTySize);
515 if (SrcTySize < DstTySize)
516 return zeroExtend(DstTySize);
520 /// sextOrTrunc - make this range have the bit width given by \p DstTySize. The
521 /// value is sign extended, truncated, or left alone to make it that width.
522 ConstantRange ConstantRange::sextOrTrunc(uint32_t DstTySize) const {
523 unsigned SrcTySize = getBitWidth();
524 if (SrcTySize > DstTySize)
525 return truncate(DstTySize);
526 if (SrcTySize < DstTySize)
527 return signExtend(DstTySize);
532 ConstantRange::add(const ConstantRange &Other) const {
533 if (isEmptySet() || Other.isEmptySet())
534 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
535 if (isFullSet() || Other.isFullSet())
536 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
538 APInt Spread_X = getSetSize(), Spread_Y = Other.getSetSize();
539 APInt NewLower = getLower() + Other.getLower();
540 APInt NewUpper = getUpper() + Other.getUpper() - 1;
541 if (NewLower == NewUpper)
542 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
544 ConstantRange X = ConstantRange(NewLower, NewUpper);
545 if (X.getSetSize().ult(Spread_X) || X.getSetSize().ult(Spread_Y))
546 // We've wrapped, therefore, full set.
547 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
553 ConstantRange::sub(const ConstantRange &Other) const {
554 if (isEmptySet() || Other.isEmptySet())
555 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
556 if (isFullSet() || Other.isFullSet())
557 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
559 APInt Spread_X = getSetSize(), Spread_Y = Other.getSetSize();
560 APInt NewLower = getLower() - Other.getUpper() + 1;
561 APInt NewUpper = getUpper() - Other.getLower();
562 if (NewLower == NewUpper)
563 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
565 ConstantRange X = ConstantRange(NewLower, NewUpper);
566 if (X.getSetSize().ult(Spread_X) || X.getSetSize().ult(Spread_Y))
567 // We've wrapped, therefore, full set.
568 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
574 ConstantRange::multiply(const ConstantRange &Other) const {
575 // TODO: If either operand is a single element and the multiply is known to
576 // be non-wrapping, round the result min and max value to the appropriate
577 // multiple of that element. If wrapping is possible, at least adjust the
578 // range according to the greatest power-of-two factor of the single element.
580 if (isEmptySet() || Other.isEmptySet())
581 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
583 APInt this_min = getUnsignedMin().zext(getBitWidth() * 2);
584 APInt this_max = getUnsignedMax().zext(getBitWidth() * 2);
585 APInt Other_min = Other.getUnsignedMin().zext(getBitWidth() * 2);
586 APInt Other_max = Other.getUnsignedMax().zext(getBitWidth() * 2);
588 ConstantRange Result_zext = ConstantRange(this_min * Other_min,
589 this_max * Other_max + 1);
590 return Result_zext.truncate(getBitWidth());
594 ConstantRange::smax(const ConstantRange &Other) const {
595 // X smax Y is: range(smax(X_smin, Y_smin),
596 // smax(X_smax, Y_smax))
597 if (isEmptySet() || Other.isEmptySet())
598 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
599 APInt NewL = APIntOps::smax(getSignedMin(), Other.getSignedMin());
600 APInt NewU = APIntOps::smax(getSignedMax(), Other.getSignedMax()) + 1;
602 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
603 return ConstantRange(NewL, NewU);
607 ConstantRange::umax(const ConstantRange &Other) const {
608 // X umax Y is: range(umax(X_umin, Y_umin),
609 // umax(X_umax, Y_umax))
610 if (isEmptySet() || Other.isEmptySet())
611 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
612 APInt NewL = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin());
613 APInt NewU = APIntOps::umax(getUnsignedMax(), Other.getUnsignedMax()) + 1;
615 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
616 return ConstantRange(NewL, NewU);
620 ConstantRange::udiv(const ConstantRange &RHS) const {
621 if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax() == 0)
622 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
624 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
626 APInt Lower = getUnsignedMin().udiv(RHS.getUnsignedMax());
628 APInt RHS_umin = RHS.getUnsignedMin();
630 // We want the lowest value in RHS excluding zero. Usually that would be 1
631 // except for a range in the form of [X, 1) in which case it would be X.
632 if (RHS.getUpper() == 1)
633 RHS_umin = RHS.getLower();
635 RHS_umin = APInt(getBitWidth(), 1);
638 APInt Upper = getUnsignedMax().udiv(RHS_umin) + 1;
640 // If the LHS is Full and the RHS is a wrapped interval containing 1 then
643 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
645 return ConstantRange(Lower, Upper);
649 ConstantRange::binaryAnd(const ConstantRange &Other) const {
650 if (isEmptySet() || Other.isEmptySet())
651 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
653 // TODO: replace this with something less conservative
655 APInt umin = APIntOps::umin(Other.getUnsignedMax(), getUnsignedMax());
656 if (umin.isAllOnesValue())
657 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
658 return ConstantRange(APInt::getNullValue(getBitWidth()), umin + 1);
662 ConstantRange::binaryOr(const ConstantRange &Other) const {
663 if (isEmptySet() || Other.isEmptySet())
664 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
666 // TODO: replace this with something less conservative
668 APInt umax = APIntOps::umax(getUnsignedMin(), Other.getUnsignedMin());
669 if (umax.isMinValue())
670 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
671 return ConstantRange(umax, APInt::getNullValue(getBitWidth()));
675 ConstantRange::shl(const ConstantRange &Other) const {
676 if (isEmptySet() || Other.isEmptySet())
677 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
679 APInt min = getUnsignedMin().shl(Other.getUnsignedMin());
680 APInt max = getUnsignedMax().shl(Other.getUnsignedMax());
682 // there's no overflow!
683 APInt Zeros(getBitWidth(), getUnsignedMax().countLeadingZeros());
684 if (Zeros.ugt(Other.getUnsignedMax()))
685 return ConstantRange(min, max + 1);
687 // FIXME: implement the other tricky cases
688 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
692 ConstantRange::lshr(const ConstantRange &Other) const {
693 if (isEmptySet() || Other.isEmptySet())
694 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
696 APInt max = getUnsignedMax().lshr(Other.getUnsignedMin());
697 APInt min = getUnsignedMin().lshr(Other.getUnsignedMax());
699 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
701 return ConstantRange(min, max + 1);
704 ConstantRange ConstantRange::inverse() const {
706 return ConstantRange(getBitWidth(), /*isFullSet=*/false);
708 return ConstantRange(getBitWidth(), /*isFullSet=*/true);
709 return ConstantRange(Upper, Lower);
712 /// print - Print out the bounds to a stream...
714 void ConstantRange::print(raw_ostream &OS) const {
717 else if (isEmptySet())
720 OS << "[" << Lower << "," << Upper << ")";
723 /// dump - Allow printing from a debugger easily...
725 void ConstantRange::dump() const {