llvm.org GIT mirror llvm / 1b27914 include / llvm / Support / MathExtras.h
1b27914

Tree @1b27914 (Download .tar.gz)

MathExtras.h @1b27914raw · history · blame

  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
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
//===-- llvm/Support/MathExtras.h - Useful math functions -------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains some functions that are useful for math stuff.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_MATHEXTRAS_H
#define LLVM_SUPPORT_MATHEXTRAS_H

#include "llvm/Support/Compiler.h"
#include "llvm/Support/SwapByteOrder.h"
#include <cassert>
#include <cstring>
#include <type_traits>

#ifdef _MSC_VER
#include <intrin.h>
#endif

namespace llvm {
/// \brief The behavior an operation has on an input of 0.
enum ZeroBehavior {
  /// \brief The returned value is undefined.
  ZB_Undefined,
  /// \brief The returned value is numeric_limits<T>::max()
  ZB_Max,
  /// \brief The returned value is numeric_limits<T>::digits
  ZB_Width
};

/// \brief Count number of 0's from the least significant bit to the most
///   stopping at the first 1.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
///   valid arguments.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        !std::numeric_limits<T>::is_signed, std::size_t>::type
countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
  (void)ZB;

  if (!Val)
    return std::numeric_limits<T>::digits;
  if (Val & 0x1)
    return 0;

  // Bisection method.
  std::size_t ZeroBits = 0;
  T Shift = std::numeric_limits<T>::digits >> 1;
  T Mask = std::numeric_limits<T>::max() >> Shift;
  while (Shift) {
    if ((Val & Mask) == 0) {
      Val >>= Shift;
      ZeroBits |= Shift;
    }
    Shift >>= 1;
    Mask >>= Shift;
  }
  return ZeroBits;
}

// Disable signed.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        std::numeric_limits<T>::is_signed, std::size_t>::type
countTrailingZeros(T, ZeroBehavior = ZB_Width) LLVM_DELETED_FUNCTION;

#if __GNUC__ >= 4 || _MSC_VER
template <>
inline std::size_t countTrailingZeros<uint32_t>(uint32_t Val, ZeroBehavior ZB) {
  if (ZB != ZB_Undefined && Val == 0)
    return 32;

#if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 0)
  return __builtin_ctz(Val);
#elif _MSC_VER
  unsigned long Index;
  _BitScanForward(&Index, Val);
  return Index;
#endif
}

#if !defined(_MSC_VER) || defined(_M_X64)
template <>
inline std::size_t countTrailingZeros<uint64_t>(uint64_t Val, ZeroBehavior ZB) {
  if (ZB != ZB_Undefined && Val == 0)
    return 64;

#if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0)
  return __builtin_ctzll(Val);
#elif _MSC_VER
  unsigned long Index;
  _BitScanForward64(&Index, Val);
  return Index;
#endif
}
#endif
#endif

/// \brief Count number of 0's from the most significant bit to the least
///   stopping at the first 1.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
///   valid arguments.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        !std::numeric_limits<T>::is_signed, std::size_t>::type
countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
  (void)ZB;

  if (!Val)
    return std::numeric_limits<T>::digits;

  // Bisection method.
  std::size_t ZeroBits = 0;
  for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) {
    T Tmp = Val >> Shift;
    if (Tmp)
      Val = Tmp;
    else
      ZeroBits |= Shift;
  }
  return ZeroBits;
}

// Disable signed.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        std::numeric_limits<T>::is_signed, std::size_t>::type
countLeadingZeros(T, ZeroBehavior = ZB_Width) LLVM_DELETED_FUNCTION;

#if __GNUC__ >= 4 || _MSC_VER
template <>
inline std::size_t countLeadingZeros<uint32_t>(uint32_t Val, ZeroBehavior ZB) {
  if (ZB != ZB_Undefined && Val == 0)
    return 32;

#if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 0)
  return __builtin_clz(Val);
#elif _MSC_VER
  unsigned long Index;
  _BitScanReverse(&Index, Val);
  return Index ^ 31;
#endif
}

#if !defined(_MSC_VER) || defined(_M_X64)
template <>
inline std::size_t countLeadingZeros<uint64_t>(uint64_t Val, ZeroBehavior ZB) {
  if (ZB != ZB_Undefined && Val == 0)
    return 64;

#if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0)
  return __builtin_clzll(Val);
#elif _MSC_VER
  unsigned long Index;
  _BitScanReverse64(&Index, Val);
  return Index ^ 63;
#endif
}
#endif
#endif

/// \brief Get the index of the first set bit starting from the least
///   significant bit.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
///   valid arguments.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                       !std::numeric_limits<T>::is_signed, T>::type
findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {
  if (ZB == ZB_Max && Val == 0)
    return std::numeric_limits<T>::max();

  return countTrailingZeros(Val, ZB_Undefined);
}

// Disable signed.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        std::numeric_limits<T>::is_signed, T>::type
findFirstSet(T, ZeroBehavior = ZB_Max) LLVM_DELETED_FUNCTION;

/// \brief Get the index of the last set bit starting from the least
///   significant bit.
///
/// Only unsigned integral types are allowed.
///
/// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
///   valid arguments.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        !std::numeric_limits<T>::is_signed, T>::type
findLastSet(T Val, ZeroBehavior ZB = ZB_Max) {
  if (ZB == ZB_Max && Val == 0)
    return std::numeric_limits<T>::max();

  // Use ^ instead of - because both gcc and llvm can remove the associated ^
  // in the __builtin_clz intrinsic on x86.
  return countLeadingZeros(Val, ZB_Undefined) ^
         (std::numeric_limits<T>::digits - 1);
}

// Disable signed.
template <typename T>
typename std::enable_if<std::numeric_limits<T>::is_integer &&
                        std::numeric_limits<T>::is_signed, T>::type
findLastSet(T, ZeroBehavior = ZB_Max) LLVM_DELETED_FUNCTION;

/// \brief Macro compressed bit reversal table for 256 bits.
///
/// http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
static const unsigned char BitReverseTable256[256] = {
#define R2(n) n, n + 2 * 64, n + 1 * 64, n + 3 * 64
#define R4(n) R2(n), R2(n + 2 * 16), R2(n + 1 * 16), R2(n + 3 * 16)
#define R6(n) R4(n), R4(n + 2 * 4), R4(n + 1 * 4), R4(n + 3 * 4)
  R6(0), R6(2), R6(1), R6(3)
#undef R2
#undef R4
#undef R6
};

/// \brief Reverse the bits in \p Val.
template <typename T>
T reverseBits(T Val) {
  unsigned char in[sizeof(Val)];
  unsigned char out[sizeof(Val)];
  std::memcpy(in, &Val, sizeof(Val));
  for (unsigned i = 0; i < sizeof(Val); ++i)
    out[(sizeof(Val) - i) - 1] = BitReverseTable256[in[i]];
  std::memcpy(&Val, out, sizeof(Val));
  return Val;
}

// NOTE: The following support functions use the _32/_64 extensions instead of
// type overloading so that signed and unsigned integers can be used without
// ambiguity.

/// Hi_32 - This function returns the high 32 bits of a 64 bit value.
inline uint32_t Hi_32(uint64_t Value) {
  return static_cast<uint32_t>(Value >> 32);
}

/// Lo_32 - This function returns the low 32 bits of a 64 bit value.
inline uint32_t Lo_32(uint64_t Value) {
  return static_cast<uint32_t>(Value);
}

/// Make_64 - This functions makes a 64-bit integer from a high / low pair of
///           32-bit integers.
inline uint64_t Make_64(uint32_t High, uint32_t Low) {
  return ((uint64_t)High << 32) | (uint64_t)Low;
}

/// isInt - Checks if an integer fits into the given bit width.
template<unsigned N>
inline bool isInt(int64_t x) {
  return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
}
// Template specializations to get better code for common cases.
template<>
inline bool isInt<8>(int64_t x) {
  return static_cast<int8_t>(x) == x;
}
template<>
inline bool isInt<16>(int64_t x) {
  return static_cast<int16_t>(x) == x;
}
template<>
inline bool isInt<32>(int64_t x) {
  return static_cast<int32_t>(x) == x;
}

/// isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted
///                     left by S.
template<unsigned N, unsigned S>
inline bool isShiftedInt(int64_t x) {
  return isInt<N+S>(x) && (x % (1<<S) == 0);
}

/// isUInt - Checks if an unsigned integer fits into the given bit width.
template<unsigned N>
inline bool isUInt(uint64_t x) {
  return N >= 64 || x < (UINT64_C(1)<<(N));
}
// Template specializations to get better code for common cases.
template<>
inline bool isUInt<8>(uint64_t x) {
  return static_cast<uint8_t>(x) == x;
}
template<>
inline bool isUInt<16>(uint64_t x) {
  return static_cast<uint16_t>(x) == x;
}
template<>
inline bool isUInt<32>(uint64_t x) {
  return static_cast<uint32_t>(x) == x;
}

/// isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted
///                     left by S.
template<unsigned N, unsigned S>
inline bool isShiftedUInt(uint64_t x) {
  return isUInt<N+S>(x) && (x % (1<<S) == 0);
}

/// isUIntN - Checks if an unsigned integer fits into the given (dynamic)
/// bit width.
inline bool isUIntN(unsigned N, uint64_t x) {
  return x == (x & (~0ULL >> (64 - N)));
}

/// isIntN - Checks if an signed integer fits into the given (dynamic)
/// bit width.
inline bool isIntN(unsigned N, int64_t x) {
  return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
}

/// isMask_32 - This function returns true if the argument is a sequence of ones
/// starting at the least significant bit with the remainder zero (32 bit
/// version).   Ex. isMask_32(0x0000FFFFU) == true.
inline bool isMask_32(uint32_t Value) {
  return Value && ((Value + 1) & Value) == 0;
}

/// isMask_64 - This function returns true if the argument is a sequence of ones
/// starting at the least significant bit with the remainder zero (64 bit
/// version).
inline bool isMask_64(uint64_t Value) {
  return Value && ((Value + 1) & Value) == 0;
}

/// isShiftedMask_32 - This function returns true if the argument contains a
/// sequence of ones with the remainder zero (32 bit version.)
/// Ex. isShiftedMask_32(0x0000FF00U) == true.
inline bool isShiftedMask_32(uint32_t Value) {
  return isMask_32((Value - 1) | Value);
}

/// isShiftedMask_64 - This function returns true if the argument contains a
/// sequence of ones with the remainder zero (64 bit version.)
inline bool isShiftedMask_64(uint64_t Value) {
  return isMask_64((Value - 1) | Value);
}

/// isPowerOf2_32 - This function returns true if the argument is a power of
/// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.)
inline bool isPowerOf2_32(uint32_t Value) {
  return Value && !(Value & (Value - 1));
}

/// isPowerOf2_64 - This function returns true if the argument is a power of two
/// > 0 (64 bit edition.)
inline bool isPowerOf2_64(uint64_t Value) {
  return Value && !(Value & (Value - int64_t(1L)));
}

/// ByteSwap_16 - This function returns a byte-swapped representation of the
/// 16-bit argument, Value.
inline uint16_t ByteSwap_16(uint16_t Value) {
  return sys::SwapByteOrder_16(Value);
}

/// ByteSwap_32 - This function returns a byte-swapped representation of the
/// 32-bit argument, Value.
inline uint32_t ByteSwap_32(uint32_t Value) {
  return sys::SwapByteOrder_32(Value);
}

/// ByteSwap_64 - This function returns a byte-swapped representation of the
/// 64-bit argument, Value.
inline uint64_t ByteSwap_64(uint64_t Value) {
  return sys::SwapByteOrder_64(Value);
}

/// CountLeadingOnes_32 - this function performs the operation of
/// counting the number of ones from the most significant bit to the first zero
/// bit.  Ex. CountLeadingOnes_32(0xFF0FFF00) == 8.
/// Returns 32 if the word is all ones.
inline unsigned CountLeadingOnes_32(uint32_t Value) {
  return countLeadingZeros(~Value);
}

/// CountLeadingOnes_64 - This function performs the operation
/// of counting the number of ones from the most significant bit to the first
/// zero bit (64 bit edition.)
/// Returns 64 if the word is all ones.
inline unsigned CountLeadingOnes_64(uint64_t Value) {
  return countLeadingZeros(~Value);
}

/// CountTrailingOnes_32 - this function performs the operation of
/// counting the number of ones from the least significant bit to the first zero
/// bit.  Ex. CountTrailingOnes_32(0x00FF00FF) == 8.
/// Returns 32 if the word is all ones.
inline unsigned CountTrailingOnes_32(uint32_t Value) {
  return countTrailingZeros(~Value);
}

/// CountTrailingOnes_64 - This function performs the operation
/// of counting the number of ones from the least significant bit to the first
/// zero bit (64 bit edition.)
/// Returns 64 if the word is all ones.
inline unsigned CountTrailingOnes_64(uint64_t Value) {
  return countTrailingZeros(~Value);
}

/// CountPopulation_32 - this function counts the number of set bits in a value.
/// Ex. CountPopulation(0xF000F000) = 8
/// Returns 0 if the word is zero.
inline unsigned CountPopulation_32(uint32_t Value) {
#if __GNUC__ >= 4
  return __builtin_popcount(Value);
#else
  uint32_t v = Value - ((Value >> 1) & 0x55555555);
  v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
  return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
#endif
}

/// CountPopulation_64 - this function counts the number of set bits in a value,
/// (64 bit edition.)
inline unsigned CountPopulation_64(uint64_t Value) {
#if __GNUC__ >= 4
  return __builtin_popcountll(Value);
#else
  uint64_t v = Value - ((Value >> 1) & 0x5555555555555555ULL);
  v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL);
  v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
  return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56);
#endif
}

/// Log2_32 - This function returns the floor log base 2 of the specified value,
/// -1 if the value is zero. (32 bit edition.)
/// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1, Log2_32(6) == 2
inline unsigned Log2_32(uint32_t Value) {
  return 31 - countLeadingZeros(Value);
}

/// Log2_64 - This function returns the floor log base 2 of the specified value,
/// -1 if the value is zero. (64 bit edition.)
inline unsigned Log2_64(uint64_t Value) {
  return 63 - countLeadingZeros(Value);
}

/// Log2_32_Ceil - This function returns the ceil log base 2 of the specified
/// value, 32 if the value is zero. (32 bit edition).
/// Ex. Log2_32_Ceil(32) == 5, Log2_32_Ceil(1) == 0, Log2_32_Ceil(6) == 3
inline unsigned Log2_32_Ceil(uint32_t Value) {
  return 32 - countLeadingZeros(Value - 1);
}

/// Log2_64_Ceil - This function returns the ceil log base 2 of the specified
/// value, 64 if the value is zero. (64 bit edition.)
inline unsigned Log2_64_Ceil(uint64_t Value) {
  return 64 - countLeadingZeros(Value - 1);
}

/// GreatestCommonDivisor64 - Return the greatest common divisor of the two
/// values using Euclid's algorithm.
inline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) {
  while (B) {
    uint64_t T = B;
    B = A % B;
    A = T;
  }
  return A;
}

/// BitsToDouble - This function takes a 64-bit integer and returns the bit
/// equivalent double.
inline double BitsToDouble(uint64_t Bits) {
  union {
    uint64_t L;
    double D;
  } T;
  T.L = Bits;
  return T.D;
}

/// BitsToFloat - This function takes a 32-bit integer and returns the bit
/// equivalent float.
inline float BitsToFloat(uint32_t Bits) {
  union {
    uint32_t I;
    float F;
  } T;
  T.I = Bits;
  return T.F;
}

/// DoubleToBits - This function takes a double and returns the bit
/// equivalent 64-bit integer.  Note that copying doubles around
/// changes the bits of NaNs on some hosts, notably x86, so this
/// routine cannot be used if these bits are needed.
inline uint64_t DoubleToBits(double Double) {
  union {
    uint64_t L;
    double D;
  } T;
  T.D = Double;
  return T.L;
}

/// FloatToBits - This function takes a float and returns the bit
/// equivalent 32-bit integer.  Note that copying floats around
/// changes the bits of NaNs on some hosts, notably x86, so this
/// routine cannot be used if these bits are needed.
inline uint32_t FloatToBits(float Float) {
  union {
    uint32_t I;
    float F;
  } T;
  T.F = Float;
  return T.I;
}

/// Platform-independent wrappers for the C99 isnan() function.
int IsNAN(float f);
int IsNAN(double d);

/// Platform-independent wrappers for the C99 isinf() function.
int IsInf(float f);
int IsInf(double d);

/// MinAlign - A and B are either alignments or offsets.  Return the minimum
/// alignment that may be assumed after adding the two together.
inline uint64_t MinAlign(uint64_t A, uint64_t B) {
  // The largest power of 2 that divides both A and B.
  //
  // Replace "-Value" by "1+~Value" in the following commented code to avoid 
  // MSVC warning C4146
  //    return (A | B) & -(A | B);
  return (A | B) & (1 + ~(A | B));
}

/// \brief Aligns \c Addr to \c Alignment bytes, rounding up.
///
/// Alignment should be a power of two.  This method rounds up, so
/// alignAddr(7, 4) == 8 and alignAddr(8, 4) == 8.
inline uintptr_t alignAddr(void *Addr, size_t Alignment) {
  assert(Alignment && isPowerOf2_64((uint64_t)Alignment) &&
         "Alignment is not a power of two!");

  assert((uintptr_t)Addr + Alignment - 1 >= (uintptr_t)Addr);

  return (((uintptr_t)Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1));
}

/// \brief Returns the necessary adjustment for aligning \c Ptr to \c Alignment
/// bytes, rounding up.
inline size_t alignmentAdjustment(void *Ptr, size_t Alignment) {
  return alignAddr(Ptr, Alignment) - (uintptr_t)Ptr;
}

/// NextPowerOf2 - Returns the next power of two (in 64-bits)
/// that is strictly greater than A.  Returns zero on overflow.
inline uint64_t NextPowerOf2(uint64_t A) {
  A |= (A >> 1);
  A |= (A >> 2);
  A |= (A >> 4);
  A |= (A >> 8);
  A |= (A >> 16);
  A |= (A >> 32);
  return A + 1;
}

/// Returns the power of two which is less than or equal to the given value.
/// Essentially, it is a floor operation across the domain of powers of two.
inline uint64_t PowerOf2Floor(uint64_t A) {
  if (!A) return 0;
  return 1ull << (63 - countLeadingZeros(A, ZB_Undefined));
}

/// Returns the next integer (mod 2**64) that is greater than or equal to
/// \p Value and is a multiple of \p Align. \p Align must be non-zero.
///
/// Examples:
/// \code
///   RoundUpToAlignment(5, 8) = 8
///   RoundUpToAlignment(17, 8) = 24
///   RoundUpToAlignment(~0LL, 8) = 0
///   RoundUpToAlignment(321, 255) = 510
/// \endcode
inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) {
  return (Value + Align - 1) / Align * Align;
}

/// Returns the offset to the next integer (mod 2**64) that is greater than
/// or equal to \p Value and is a multiple of \p Align. \p Align must be
/// non-zero.
inline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) {
  return RoundUpToAlignment(Value, Align) - Value;
}

/// abs64 - absolute value of a 64-bit int.  Not all environments support
/// "abs" on whatever their name for the 64-bit int type is.  The absolute
/// value of the largest negative number is undefined, as with "abs".
inline int64_t abs64(int64_t x) {
  return (x < 0) ? -x : x;
}

/// SignExtend32 - Sign extend B-bit number x to 32-bit int.
/// Usage int32_t r = SignExtend32<5>(x);
template <unsigned B> inline int32_t SignExtend32(uint32_t x) {
  return int32_t(x << (32 - B)) >> (32 - B);
}

/// \brief Sign extend number in the bottom B bits of X to a 32-bit int.
/// Requires 0 < B <= 32.
inline int32_t SignExtend32(uint32_t X, unsigned B) {
  return int32_t(X << (32 - B)) >> (32 - B);
}

/// SignExtend64 - Sign extend B-bit number x to 64-bit int.
/// Usage int64_t r = SignExtend64<5>(x);
template <unsigned B> inline int64_t SignExtend64(uint64_t x) {
  return int64_t(x << (64 - B)) >> (64 - B);
}

/// \brief Sign extend number in the bottom B bits of X to a 64-bit int.
/// Requires 0 < B <= 64.
inline int64_t SignExtend64(uint64_t X, unsigned B) {
  return int64_t(X << (64 - B)) >> (64 - B);
}

extern const float huge_valf;
} // End llvm namespace

#endif