summaryrefslogtreecommitdiff
path: root/include/llvm/Support/IntegersSubset.h
blob: d6a3b2f541b2a424177848dfa281a8cb9ad3e224 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
//===-- llvm/IntegersSubset.h - The subset of integers ----------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// @file
/// This file contains class that implements constant set of ranges:
/// [<Low0,High0>,...,<LowN,HighN>]. Initially, this class was created for
/// SwitchInst and was used for case value representation that may contain
/// multiple ranges for a single successor.
//
//===----------------------------------------------------------------------===//

#ifndef CONSTANTRANGESSET_H_
#define CONSTANTRANGESSET_H_

#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/LLVMContext.h"
#include <list>

namespace llvm {

  // The IntItem is a wrapper for APInt.
  // 1. It determines sign of integer, it allows to use
  //    comparison operators >,<,>=,<=, and as result we got shorter and cleaner
  //    constructions.
  // 2. It helps to implement PR1255 (case ranges) as a series of small patches.
  // 3. Currently we can interpret IntItem both as ConstantInt and as APInt.
  //    It allows to provide SwitchInst methods that works with ConstantInt for
  //    non-updated passes. And it allows to use APInt interface for new methods.
  // 4. IntItem can be easily replaced with APInt.

  // The set of macros that allows to propagate APInt operators to the IntItem.

#define INT_ITEM_DEFINE_COMPARISON(op,func) \
  bool operator op (const APInt& RHS) const { \
    return getAPIntValue().func(RHS); \
  }

#define INT_ITEM_DEFINE_UNARY_OP(op) \
  IntItem operator op () const { \
    APInt res = op(getAPIntValue()); \
    Constant *NewVal = ConstantInt::get(ConstantIntVal->getContext(), res); \
    return IntItem(cast<ConstantInt>(NewVal)); \
  }

#define INT_ITEM_DEFINE_BINARY_OP(op) \
  IntItem operator op (const APInt& RHS) const { \
    APInt res = getAPIntValue() op RHS; \
    Constant *NewVal = ConstantInt::get(ConstantIntVal->getContext(), res); \
    return IntItem(cast<ConstantInt>(NewVal)); \
  }

#define INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(op) \
  IntItem& operator op (const APInt& RHS) {\
    APInt res = getAPIntValue();\
    res op RHS; \
    Constant *NewVal = ConstantInt::get(ConstantIntVal->getContext(), res); \
    ConstantIntVal = cast<ConstantInt>(NewVal); \
    return *this; \
  }

#define INT_ITEM_DEFINE_PREINCDEC(op) \
    IntItem& operator op () { \
      APInt res = getAPIntValue(); \
      op(res); \
      Constant *NewVal = ConstantInt::get(ConstantIntVal->getContext(), res); \
      ConstantIntVal = cast<ConstantInt>(NewVal); \
      return *this; \
    }

#define INT_ITEM_DEFINE_POSTINCDEC(op) \
    IntItem& operator op (int) { \
      APInt res = getAPIntValue();\
      op(res); \
      Constant *NewVal = ConstantInt::get(ConstantIntVal->getContext(), res); \
      OldConstantIntVal = ConstantIntVal; \
      ConstantIntVal = cast<ConstantInt>(NewVal); \
      return IntItem(OldConstantIntVal); \
    }

#define INT_ITEM_DEFINE_OP_STANDARD_INT(RetTy, op, IntTy) \
  RetTy operator op (IntTy RHS) const { \
    return (*this) op APInt(getAPIntValue().getBitWidth(), RHS); \
  }

class IntItem {
  ConstantInt *ConstantIntVal;
  const APInt* APIntVal;
  IntItem(const ConstantInt *V) :
    ConstantIntVal(const_cast<ConstantInt*>(V)),
    APIntVal(&ConstantIntVal->getValue()){}
  const APInt& getAPIntValue() const {
    return *APIntVal;
  }
public:

  IntItem() {}

  operator const APInt&() const {
    return getAPIntValue();
  }

  // Propagate APInt operators.
  // Note, that
  // /,/=,>>,>>= are not implemented in APInt.
  // <<= is implemented for unsigned RHS, but not implemented for APInt RHS.

  INT_ITEM_DEFINE_COMPARISON(<, ult)
  INT_ITEM_DEFINE_COMPARISON(>, ugt)
  INT_ITEM_DEFINE_COMPARISON(<=, ule)
  INT_ITEM_DEFINE_COMPARISON(>=, uge)

  INT_ITEM_DEFINE_COMPARISON(==, eq)
  INT_ITEM_DEFINE_OP_STANDARD_INT(bool,==,uint64_t)

  INT_ITEM_DEFINE_COMPARISON(!=, ne)
  INT_ITEM_DEFINE_OP_STANDARD_INT(bool,!=,uint64_t)

  INT_ITEM_DEFINE_BINARY_OP(*)
  INT_ITEM_DEFINE_BINARY_OP(+)
  INT_ITEM_DEFINE_OP_STANDARD_INT(IntItem,+,uint64_t)
  INT_ITEM_DEFINE_BINARY_OP(-)
  INT_ITEM_DEFINE_OP_STANDARD_INT(IntItem,-,uint64_t)
  INT_ITEM_DEFINE_BINARY_OP(<<)
  INT_ITEM_DEFINE_OP_STANDARD_INT(IntItem,<<,unsigned)
  INT_ITEM_DEFINE_BINARY_OP(&)
  INT_ITEM_DEFINE_BINARY_OP(^)
  INT_ITEM_DEFINE_BINARY_OP(|)

  INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(*=)
  INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(+=)
  INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(-=)
  INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(&=)
  INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(^=)
  INT_ITEM_DEFINE_ASSIGNMENT_BY_OP(|=)

  // Special case for <<=
  IntItem& operator <<= (unsigned RHS) {
    APInt res = getAPIntValue();
    res <<= RHS;
    Constant *NewVal = ConstantInt::get(ConstantIntVal->getContext(), res);
    ConstantIntVal = cast<ConstantInt>(NewVal);
    return *this;
  }

  INT_ITEM_DEFINE_UNARY_OP(-)
  INT_ITEM_DEFINE_UNARY_OP(~)

  INT_ITEM_DEFINE_PREINCDEC(++)
  INT_ITEM_DEFINE_PREINCDEC(--)

  // The set of workarounds, since currently we use ConstantInt implemented
  // integer.

  static IntItem fromConstantInt(const ConstantInt *V) {
    return IntItem(V);
  }
  static IntItem fromType(Type* Ty, const APInt& V) {
    ConstantInt *C = cast<ConstantInt>(ConstantInt::get(Ty, V));
    return fromConstantInt(C);
  }
  static IntItem withImplLikeThis(const IntItem& LikeThis, const APInt& V) {
    ConstantInt *C = cast<ConstantInt>(ConstantInt::get(
        LikeThis.ConstantIntVal->getContext(), V));
    return fromConstantInt(C);
  }
  ConstantInt *toConstantInt() const {
    return ConstantIntVal;
  }
};

template<class IntType>
class IntRange {
protected:
    IntType Low;
    IntType High;
    bool IsEmpty : 1;
    bool IsSingleNumber : 1;

public:
    typedef IntRange<IntType> self;
    typedef std::pair<self, self> SubRes;

    IntRange() : IsEmpty(true) {}
    IntRange(const self &RHS) :
      Low(RHS.Low), High(RHS.High),
      IsEmpty(RHS.IsEmpty), IsSingleNumber(RHS.IsSingleNumber) {}
    IntRange(const IntType &C) :
      Low(C), High(C), IsEmpty(false), IsSingleNumber(true) {}

    IntRange(const IntType &L, const IntType &H) : Low(L), High(H),
      IsEmpty(false), IsSingleNumber(Low == High) {}

    bool isEmpty() const { return IsEmpty; }
    bool isSingleNumber() const { return IsSingleNumber; }

    const IntType& getLow() const {
      assert(!IsEmpty && "Range is empty.");
      return Low;
    }
    const IntType& getHigh() const {
      assert(!IsEmpty && "Range is empty.");
      return High;
    }

    bool operator<(const self &RHS) const {
      assert(!IsEmpty && "Left range is empty.");
      assert(!RHS.IsEmpty && "Right range is empty.");
      if (Low == RHS.Low) {
        if (High > RHS.High)
          return true;
        return false;
      }
      if (Low < RHS.Low)
        return true;
      return false;
    }

    bool operator==(const self &RHS) const {
      assert(!IsEmpty && "Left range is empty.");
      assert(!RHS.IsEmpty && "Right range is empty.");
      return Low == RHS.Low && High == RHS.High;
    }

    bool operator!=(const self &RHS) const {
      return !operator ==(RHS);
    }

    static bool LessBySize(const self &LHS, const self &RHS) {
      return (LHS.High - LHS.Low) < (RHS.High - RHS.Low);
    }

    bool isInRange(const IntType &IntVal) const {
      assert(!IsEmpty && "Range is empty.");
      return IntVal >= Low && IntVal <= High;
    }

    SubRes sub(const self &RHS) const {
      SubRes Res;

      // RHS is either more global and includes this range or
      // if it doesn't intersected with this range.
      if (!isInRange(RHS.Low) && !isInRange(RHS.High)) {

        // If RHS more global (it is enough to check
        // only one border in this case.
        if (RHS.isInRange(Low))
          return std::make_pair(self(Low, High), self());

        return Res;
      }

      if (Low < RHS.Low) {
        Res.first.Low = Low;
        IntType NewHigh = RHS.Low;
        --NewHigh;
        Res.first.High = NewHigh;
      }
      if (High > RHS.High) {
        IntType NewLow = RHS.High;
        ++NewLow;
        Res.second.Low = NewLow;
        Res.second.High = High;
      }
      return Res;
    }
  };

//===----------------------------------------------------------------------===//
/// IntegersSubsetGeneric - class that implements the subset of integers. It
/// consists from ranges and single numbers.
template <class IntTy>
class IntegersSubsetGeneric {
public:
  // Use Chris Lattner idea, that was initially described here:
  // http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120213/136954.html
  // In short, for more compact memory consumption we can store flat
  // numbers collection, and define range as pair of indices.
  // In that case we can safe some memory on 32 bit machines.
  typedef std::vector<IntTy> FlatCollectionTy;
  typedef std::pair<IntTy*, IntTy*> RangeLinkTy;
  typedef std::vector<RangeLinkTy> RangeLinksTy;
  typedef typename RangeLinksTy::const_iterator RangeLinksConstIt;

  typedef IntegersSubsetGeneric<IntTy> self;

protected:

  FlatCollectionTy FlatCollection;
  RangeLinksTy RangeLinks;

  bool IsSingleNumber;
  bool IsSingleNumbersOnly;

public:

  template<class RangesCollectionTy>
  explicit IntegersSubsetGeneric(const RangesCollectionTy& Links) {
    assert(Links.size() && "Empty ranges are not allowed.");

    // In case of big set of single numbers consumes additional RAM space,
    // but allows to avoid additional reallocation.
    FlatCollection.reserve(Links.size() * 2);
    RangeLinks.reserve(Links.size());
    IsSingleNumbersOnly = true;
    for (typename RangesCollectionTy::const_iterator i = Links.begin(),
         e = Links.end(); i != e; ++i) {
      RangeLinkTy RangeLink;
      FlatCollection.push_back(i->getLow());
      RangeLink.first = &FlatCollection.back();
      if (i->getLow() != i->getHigh()) {
        FlatCollection.push_back(i->getHigh());
        IsSingleNumbersOnly = false;
      }
      RangeLink.second = &FlatCollection.back();
      RangeLinks.push_back(RangeLink);
    }
    IsSingleNumber = IsSingleNumbersOnly && RangeLinks.size() == 1;
  }

  IntegersSubsetGeneric(const self& RHS) {
    *this = RHS;
  }

  self& operator=(const self& RHS) {
    FlatCollection.clear();
    RangeLinks.clear();
    FlatCollection.reserve(RHS.RangeLinks.size() * 2);
    RangeLinks.reserve(RHS.RangeLinks.size());
    for (RangeLinksConstIt i = RHS.RangeLinks.begin(), e = RHS.RangeLinks.end();
         i != e; ++i) {
      RangeLinkTy RangeLink;
      FlatCollection.push_back(*(i->first));
      RangeLink.first = &FlatCollection.back();
      if (i->first != i->second)
        FlatCollection.push_back(*(i->second));
      RangeLink.second = &FlatCollection.back();
      RangeLinks.push_back(RangeLink);
    }
    IsSingleNumber = RHS.IsSingleNumber;
    IsSingleNumbersOnly = RHS.IsSingleNumbersOnly;
    return *this;
  }

  typedef IntRange<IntTy> Range;

  /// Checks is the given constant satisfies this case. Returns
  /// true if it equals to one of contained values or belongs to the one of
  /// contained ranges.
  bool isSatisfies(const IntTy &CheckingVal) const {
    if (IsSingleNumber)
      return FlatCollection.front() == CheckingVal;
    if (IsSingleNumbersOnly)
      return std::find(FlatCollection.begin(),
                       FlatCollection.end(),
                       CheckingVal) != FlatCollection.end();

    for (unsigned i = 0, e = getNumItems(); i < e; ++i) {
      if (RangeLinks[i].first == RangeLinks[i].second) {
        if (*RangeLinks[i].first == CheckingVal)
          return true;
      } else if (*RangeLinks[i].first <= CheckingVal &&
                 *RangeLinks[i].second >= CheckingVal)
        return true;
    }
    return false;
  }

  /// Returns set's item with given index.
  Range getItem(unsigned idx) const {
    const RangeLinkTy &Link = RangeLinks[idx];
    if (Link.first != Link.second)
      return Range(*Link.first, *Link.second);
    else
      return Range(*Link.first);
  }

  /// Return number of items (ranges) stored in set.
  unsigned getNumItems() const {
    return RangeLinks.size();
  }

  /// Returns true if whole subset contains single element.
  bool isSingleNumber() const {
    return IsSingleNumber;
  }

  /// Returns true if whole subset contains only single numbers, no ranges.
  bool isSingleNumbersOnly() const {
    return IsSingleNumbersOnly;
  }

  /// Does the same like getItem(idx).isSingleNumber(), but
  /// works faster, since we avoid creation of temporary range object.
  bool isSingleNumber(unsigned idx) const {
    return RangeLinks[idx].first == RangeLinks[idx].second;
  }

  /// Returns set the size, that equals number of all values + sizes of all
  /// ranges.
  /// Ranges set is considered as flat numbers collection.
  /// E.g.: for range [<0>, <1>, <4,8>] the size will 7;
  ///       for range [<0>, <1>, <5>] the size will 3
  unsigned getSize() const {
    APInt sz(((const APInt&)getItem(0).getLow()).getBitWidth(), 0);
    for (unsigned i = 0, e = getNumItems(); i != e; ++i) {
      const APInt Low = getItem(i).getLow();
      const APInt High = getItem(i).getHigh();
      APInt S = High - Low + 1;
      sz += S;
    }
    return sz.getZExtValue();
  }

  /// Allows to access single value even if it belongs to some range.
  /// Ranges set is considered as flat numbers collection.
  /// [<1>, <4,8>] is considered as [1,4,5,6,7,8]
  /// For range [<1>, <4,8>] getSingleValue(3) returns 6.
  APInt getSingleValue(unsigned idx) const {
    APInt sz(((const APInt&)getItem(0).getLow()).getBitWidth(), 0);
    for (unsigned i = 0, e = getNumItems(); i != e; ++i) {
      const APInt Low = getItem(i).getLow();
      const APInt High = getItem(i).getHigh();
      APInt S = High - Low + 1;
      APInt oldSz = sz;
      sz += S;
      if (sz.ugt(idx)) {
        APInt Res = Low;
        APInt Offset(oldSz.getBitWidth(), idx);
        Offset -= oldSz;
        Res += Offset;
        return Res;
      }
    }
    assert(0 && "Index exceeds high border.");
    return sz;
  }

  /// Does the same as getSingleValue, but works only if subset contains
  /// single numbers only.
  const IntTy& getSingleNumber(unsigned idx) const {
    assert(IsSingleNumbersOnly && "This method works properly if subset "
                                  "contains single numbers only.");
    return FlatCollection[idx];
  }
};

//===----------------------------------------------------------------------===//
/// IntegersSubset - currently is extension of IntegersSubsetGeneric
/// that also supports conversion to/from Constant* object.
class IntegersSubset : public IntegersSubsetGeneric<IntItem> {

  typedef IntegersSubsetGeneric<IntItem> ParentTy;

  Constant *Holder;

  static unsigned getNumItemsFromConstant(Constant *C) {
    return cast<ArrayType>(C->getType())->getNumElements();
  }

  static Range getItemFromConstant(Constant *C, unsigned idx) {
    const Constant *CV = C->getAggregateElement(idx);

    unsigned NumEls = cast<VectorType>(CV->getType())->getNumElements();
    switch (NumEls) {
    case 1:
      return Range(IntItem::fromConstantInt(
                     cast<ConstantInt>(CV->getAggregateElement(0U))),
                   IntItem::fromConstantInt(cast<ConstantInt>(
                     cast<ConstantInt>(CV->getAggregateElement(0U)))));
    case 2:
      return Range(IntItem::fromConstantInt(
                     cast<ConstantInt>(CV->getAggregateElement(0U))),
                   IntItem::fromConstantInt(
                   cast<ConstantInt>(CV->getAggregateElement(1))));
    default:
      assert(0 && "Only pairs and single numbers are allowed here.");
      return Range();
    }
  }

  std::vector<Range> rangesFromConstant(Constant *C) {
    unsigned NumItems = getNumItemsFromConstant(C);
    std::vector<Range> r;
    r.reserve(NumItems);
    for (unsigned i = 0, e = NumItems; i != e; ++i)
      r.push_back(getItemFromConstant(C, i));
    return r;
  }

public:

  explicit IntegersSubset(Constant *C) : ParentTy(rangesFromConstant(C)),
                          Holder(C) {}

  IntegersSubset(const IntegersSubset& RHS) :
    ParentTy(*(const ParentTy *)&RHS), // FIXME: tweak for msvc.
    Holder(RHS.Holder) {}

  template<class RangesCollectionTy>
  explicit IntegersSubset(const RangesCollectionTy& Src) : ParentTy(Src) {
    std::vector<Constant*> Elts;
    Elts.reserve(Src.size());
    for (typename RangesCollectionTy::const_iterator i = Src.begin(),
         e = Src.end(); i != e; ++i) {
      const Range &R = *i;
      std::vector<Constant*> r;
      if (R.isSingleNumber()) {
        r.reserve(2);
        // FIXME: Since currently we have ConstantInt based numbers
        // use hack-conversion of IntItem to ConstantInt
        r.push_back(R.getLow().toConstantInt());
        r.push_back(R.getHigh().toConstantInt());
      } else {
        r.reserve(1);
        r.push_back(R.getLow().toConstantInt());
      }
      Constant *CV = ConstantVector::get(r);
      Elts.push_back(CV);
    }
    ArrayType *ArrTy =
        ArrayType::get(Elts.front()->getType(), (uint64_t)Elts.size());
    Holder = ConstantArray::get(ArrTy, Elts);
  }

  operator Constant*() { return Holder; }
  operator const Constant*() const { return Holder; }
  Constant *operator->() { return Holder; }
  const Constant *operator->() const { return Holder; }
};

}

#endif /* CONSTANTRANGESSET_H_ */