LLVM  3.7.0
MathExtras.h
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1 //===-- llvm/Support/MathExtras.h - Useful math functions -------*- C++ -*-===//
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 // This file contains some functions that are useful for math stuff.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_SUPPORT_MATHEXTRAS_H
15 #define LLVM_SUPPORT_MATHEXTRAS_H
16 
17 #include "llvm/Support/Compiler.h"
19 #include <cassert>
20 #include <cstring>
21 #include <type_traits>
22 
23 #ifdef _MSC_VER
24 #include <intrin.h>
25 #endif
26 
27 #ifdef __ANDROID_NDK__
28 #include <android/api-level.h>
29 #endif
30 
31 namespace llvm {
32 /// \brief The behavior an operation has on an input of 0.
34  /// \brief The returned value is undefined.
36  /// \brief The returned value is numeric_limits<T>::max()
38  /// \brief The returned value is numeric_limits<T>::digits
40 };
41 
42 namespace detail {
43 template <typename T, std::size_t SizeOfT> struct TrailingZerosCounter {
44  static std::size_t count(T Val, ZeroBehavior) {
45  if (!Val)
46  return std::numeric_limits<T>::digits;
47  if (Val & 0x1)
48  return 0;
49 
50  // Bisection method.
51  std::size_t ZeroBits = 0;
52  T Shift = std::numeric_limits<T>::digits >> 1;
53  T Mask = std::numeric_limits<T>::max() >> Shift;
54  while (Shift) {
55  if ((Val & Mask) == 0) {
56  Val >>= Shift;
57  ZeroBits |= Shift;
58  }
59  Shift >>= 1;
60  Mask >>= Shift;
61  }
62  return ZeroBits;
63  }
64 };
65 
66 #if __GNUC__ >= 4 || _MSC_VER
67 template <typename T> struct TrailingZerosCounter<T, 4> {
68  static std::size_t count(T Val, ZeroBehavior ZB) {
69  if (ZB != ZB_Undefined && Val == 0)
70  return 32;
71 
72 #if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 0)
73  return __builtin_ctz(Val);
74 #elif _MSC_VER
75  unsigned long Index;
76  _BitScanForward(&Index, Val);
77  return Index;
78 #endif
79  }
80 };
81 
82 #if !defined(_MSC_VER) || defined(_M_X64)
83 template <typename T> struct TrailingZerosCounter<T, 8> {
84  static std::size_t count(T Val, ZeroBehavior ZB) {
85  if (ZB != ZB_Undefined && Val == 0)
86  return 64;
87 
88 #if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0)
89  return __builtin_ctzll(Val);
90 #elif _MSC_VER
91  unsigned long Index;
92  _BitScanForward64(&Index, Val);
93  return Index;
94 #endif
95  }
96 };
97 #endif
98 #endif
99 } // namespace detail
100 
101 /// \brief Count number of 0's from the least significant bit to the most
102 /// stopping at the first 1.
103 ///
104 /// Only unsigned integral types are allowed.
105 ///
106 /// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
107 /// valid arguments.
108 template <typename T>
109 std::size_t countTrailingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
110  static_assert(std::numeric_limits<T>::is_integer &&
111  !std::numeric_limits<T>::is_signed,
112  "Only unsigned integral types are allowed.");
114 }
115 
116 namespace detail {
117 template <typename T, std::size_t SizeOfT> struct LeadingZerosCounter {
118  static std::size_t count(T Val, ZeroBehavior) {
119  if (!Val)
120  return std::numeric_limits<T>::digits;
121 
122  // Bisection method.
123  std::size_t ZeroBits = 0;
124  for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) {
125  T Tmp = Val >> Shift;
126  if (Tmp)
127  Val = Tmp;
128  else
129  ZeroBits |= Shift;
130  }
131  return ZeroBits;
132  }
133 };
134 
135 #if __GNUC__ >= 4 || _MSC_VER
136 template <typename T> struct LeadingZerosCounter<T, 4> {
137  static std::size_t count(T Val, ZeroBehavior ZB) {
138  if (ZB != ZB_Undefined && Val == 0)
139  return 32;
140 
141 #if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 0)
142  return __builtin_clz(Val);
143 #elif _MSC_VER
144  unsigned long Index;
145  _BitScanReverse(&Index, Val);
146  return Index ^ 31;
147 #endif
148  }
149 };
150 
151 #if !defined(_MSC_VER) || defined(_M_X64)
152 template <typename T> struct LeadingZerosCounter<T, 8> {
153  static std::size_t count(T Val, ZeroBehavior ZB) {
154  if (ZB != ZB_Undefined && Val == 0)
155  return 64;
156 
157 #if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0)
158  return __builtin_clzll(Val);
159 #elif _MSC_VER
160  unsigned long Index;
161  _BitScanReverse64(&Index, Val);
162  return Index ^ 63;
163 #endif
164  }
165 };
166 #endif
167 #endif
168 } // namespace detail
169 
170 /// \brief Count number of 0's from the most significant bit to the least
171 /// stopping at the first 1.
172 ///
173 /// Only unsigned integral types are allowed.
174 ///
175 /// \param ZB the behavior on an input of 0. Only ZB_Width and ZB_Undefined are
176 /// valid arguments.
177 template <typename T>
178 std::size_t countLeadingZeros(T Val, ZeroBehavior ZB = ZB_Width) {
179  static_assert(std::numeric_limits<T>::is_integer &&
180  !std::numeric_limits<T>::is_signed,
181  "Only unsigned integral types are allowed.");
183 }
184 
185 /// \brief Get the index of the first set bit starting from the least
186 /// significant bit.
187 ///
188 /// Only unsigned integral types are allowed.
189 ///
190 /// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
191 /// valid arguments.
192 template <typename T> T findFirstSet(T Val, ZeroBehavior ZB = ZB_Max) {
193  if (ZB == ZB_Max && Val == 0)
194  return std::numeric_limits<T>::max();
195 
196  return countTrailingZeros(Val, ZB_Undefined);
197 }
198 
199 /// \brief Get the index of the last set bit starting from the least
200 /// significant bit.
201 ///
202 /// Only unsigned integral types are allowed.
203 ///
204 /// \param ZB the behavior on an input of 0. Only ZB_Max and ZB_Undefined are
205 /// valid arguments.
206 template <typename T> T findLastSet(T Val, ZeroBehavior ZB = ZB_Max) {
207  if (ZB == ZB_Max && Val == 0)
208  return std::numeric_limits<T>::max();
209 
210  // Use ^ instead of - because both gcc and llvm can remove the associated ^
211  // in the __builtin_clz intrinsic on x86.
212  return countLeadingZeros(Val, ZB_Undefined) ^
213  (std::numeric_limits<T>::digits - 1);
214 }
215 
216 /// \brief Macro compressed bit reversal table for 256 bits.
217 ///
218 /// http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
219 static const unsigned char BitReverseTable256[256] = {
220 #define R2(n) n, n + 2 * 64, n + 1 * 64, n + 3 * 64
221 #define R4(n) R2(n), R2(n + 2 * 16), R2(n + 1 * 16), R2(n + 3 * 16)
222 #define R6(n) R4(n), R4(n + 2 * 4), R4(n + 1 * 4), R4(n + 3 * 4)
223  R6(0), R6(2), R6(1), R6(3)
224 #undef R2
225 #undef R4
226 #undef R6
227 };
228 
229 /// \brief Reverse the bits in \p Val.
230 template <typename T>
232  unsigned char in[sizeof(Val)];
233  unsigned char out[sizeof(Val)];
234  std::memcpy(in, &Val, sizeof(Val));
235  for (unsigned i = 0; i < sizeof(Val); ++i)
236  out[(sizeof(Val) - i) - 1] = BitReverseTable256[in[i]];
237  std::memcpy(&Val, out, sizeof(Val));
238  return Val;
239 }
240 
241 // NOTE: The following support functions use the _32/_64 extensions instead of
242 // type overloading so that signed and unsigned integers can be used without
243 // ambiguity.
244 
245 /// Hi_32 - This function returns the high 32 bits of a 64 bit value.
246 inline uint32_t Hi_32(uint64_t Value) {
247  return static_cast<uint32_t>(Value >> 32);
248 }
249 
250 /// Lo_32 - This function returns the low 32 bits of a 64 bit value.
251 inline uint32_t Lo_32(uint64_t Value) {
252  return static_cast<uint32_t>(Value);
253 }
254 
255 /// Make_64 - This functions makes a 64-bit integer from a high / low pair of
256 /// 32-bit integers.
257 inline uint64_t Make_64(uint32_t High, uint32_t Low) {
258  return ((uint64_t)High << 32) | (uint64_t)Low;
259 }
260 
261 /// isInt - Checks if an integer fits into the given bit width.
262 template<unsigned N>
263 inline bool isInt(int64_t x) {
264  return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
265 }
266 // Template specializations to get better code for common cases.
267 template<>
268 inline bool isInt<8>(int64_t x) {
269  return static_cast<int8_t>(x) == x;
270 }
271 template<>
272 inline bool isInt<16>(int64_t x) {
273  return static_cast<int16_t>(x) == x;
274 }
275 template<>
276 inline bool isInt<32>(int64_t x) {
277  return static_cast<int32_t>(x) == x;
278 }
279 
280 /// isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted
281 /// left by S.
282 template<unsigned N, unsigned S>
283 inline bool isShiftedInt(int64_t x) {
284  return isInt<N+S>(x) && (x % (1<<S) == 0);
285 }
286 
287 /// isUInt - Checks if an unsigned integer fits into the given bit width.
288 template<unsigned N>
289 inline bool isUInt(uint64_t x) {
290  return N >= 64 || x < (UINT64_C(1)<<(N));
291 }
292 // Template specializations to get better code for common cases.
293 template<>
294 inline bool isUInt<8>(uint64_t x) {
295  return static_cast<uint8_t>(x) == x;
296 }
297 template<>
298 inline bool isUInt<16>(uint64_t x) {
299  return static_cast<uint16_t>(x) == x;
300 }
301 template<>
302 inline bool isUInt<32>(uint64_t x) {
303  return static_cast<uint32_t>(x) == x;
304 }
305 
306 /// isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted
307 /// left by S.
308 template<unsigned N, unsigned S>
309 inline bool isShiftedUInt(uint64_t x) {
310  return isUInt<N+S>(x) && (x % (1<<S) == 0);
311 }
312 
313 /// isUIntN - Checks if an unsigned integer fits into the given (dynamic)
314 /// bit width.
315 inline bool isUIntN(unsigned N, uint64_t x) {
316  return x == (x & (~0ULL >> (64 - N)));
317 }
318 
319 /// isIntN - Checks if an signed integer fits into the given (dynamic)
320 /// bit width.
321 inline bool isIntN(unsigned N, int64_t x) {
322  return N >= 64 || (-(INT64_C(1)<<(N-1)) <= x && x < (INT64_C(1)<<(N-1)));
323 }
324 
325 /// isMask_32 - This function returns true if the argument is a non-empty
326 /// sequence of ones starting at the least significant bit with the remainder
327 /// zero (32 bit version). Ex. isMask_32(0x0000FFFFU) == true.
328 inline bool isMask_32(uint32_t Value) {
329  return Value && ((Value + 1) & Value) == 0;
330 }
331 
332 /// isMask_64 - This function returns true if the argument is a non-empty
333 /// sequence of ones starting at the least significant bit with the remainder
334 /// zero (64 bit version).
335 inline bool isMask_64(uint64_t Value) {
336  return Value && ((Value + 1) & Value) == 0;
337 }
338 
339 /// isShiftedMask_32 - This function returns true if the argument contains a
340 /// non-empty sequence of ones with the remainder zero (32 bit version.)
341 /// Ex. isShiftedMask_32(0x0000FF00U) == true.
342 inline bool isShiftedMask_32(uint32_t Value) {
343  return Value && isMask_32((Value - 1) | Value);
344 }
345 
346 /// isShiftedMask_64 - This function returns true if the argument contains a
347 /// non-empty sequence of ones with the remainder zero (64 bit version.)
348 inline bool isShiftedMask_64(uint64_t Value) {
349  return Value && isMask_64((Value - 1) | Value);
350 }
351 
352 /// isPowerOf2_32 - This function returns true if the argument is a power of
353 /// two > 0. Ex. isPowerOf2_32(0x00100000U) == true (32 bit edition.)
354 inline bool isPowerOf2_32(uint32_t Value) {
355  return Value && !(Value & (Value - 1));
356 }
357 
358 /// isPowerOf2_64 - This function returns true if the argument is a power of two
359 /// > 0 (64 bit edition.)
360 inline bool isPowerOf2_64(uint64_t Value) {
361  return Value && !(Value & (Value - int64_t(1L)));
362 }
363 
364 /// ByteSwap_16 - This function returns a byte-swapped representation of the
365 /// 16-bit argument, Value.
366 inline uint16_t ByteSwap_16(uint16_t Value) {
367  return sys::SwapByteOrder_16(Value);
368 }
369 
370 /// ByteSwap_32 - This function returns a byte-swapped representation of the
371 /// 32-bit argument, Value.
372 inline uint32_t ByteSwap_32(uint32_t Value) {
373  return sys::SwapByteOrder_32(Value);
374 }
375 
376 /// ByteSwap_64 - This function returns a byte-swapped representation of the
377 /// 64-bit argument, Value.
378 inline uint64_t ByteSwap_64(uint64_t Value) {
379  return sys::SwapByteOrder_64(Value);
380 }
381 
382 /// \brief Count the number of ones from the most significant bit to the first
383 /// zero bit.
384 ///
385 /// Ex. CountLeadingOnes(0xFF0FFF00) == 8.
386 /// Only unsigned integral types are allowed.
387 ///
388 /// \param ZB the behavior on an input of all ones. Only ZB_Width and
389 /// ZB_Undefined are valid arguments.
390 template <typename T>
392  static_assert(std::numeric_limits<T>::is_integer &&
393  !std::numeric_limits<T>::is_signed,
394  "Only unsigned integral types are allowed.");
395  return countLeadingZeros(~Value, ZB);
396 }
397 
398 /// \brief Count the number of ones from the least significant bit to the first
399 /// zero bit.
400 ///
401 /// Ex. countTrailingOnes(0x00FF00FF) == 8.
402 /// Only unsigned integral types are allowed.
403 ///
404 /// \param ZB the behavior on an input of all ones. Only ZB_Width and
405 /// ZB_Undefined are valid arguments.
406 template <typename T>
408  static_assert(std::numeric_limits<T>::is_integer &&
409  !std::numeric_limits<T>::is_signed,
410  "Only unsigned integral types are allowed.");
411  return countTrailingZeros(~Value, ZB);
412 }
413 
414 namespace detail {
415 template <typename T, std::size_t SizeOfT> struct PopulationCounter {
416  static unsigned count(T Value) {
417  // Generic version, forward to 32 bits.
418  static_assert(SizeOfT <= 4, "Not implemented!");
419 #if __GNUC__ >= 4
420  return __builtin_popcount(Value);
421 #else
422  uint32_t v = Value;
423  v = v - ((v >> 1) & 0x55555555);
424  v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
425  return ((v + (v >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
426 #endif
427  }
428 };
429 
430 template <typename T> struct PopulationCounter<T, 8> {
431  static unsigned count(T Value) {
432 #if __GNUC__ >= 4
433  return __builtin_popcountll(Value);
434 #else
435  uint64_t v = Value;
436  v = v - ((v >> 1) & 0x5555555555555555ULL);
437  v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL);
438  v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
439  return unsigned((uint64_t)(v * 0x0101010101010101ULL) >> 56);
440 #endif
441  }
442 };
443 } // namespace detail
444 
445 /// \brief Count the number of set bits in a value.
446 /// Ex. countPopulation(0xF000F000) = 8
447 /// Returns 0 if the word is zero.
448 template <typename T>
449 inline unsigned countPopulation(T Value) {
450  static_assert(std::numeric_limits<T>::is_integer &&
451  !std::numeric_limits<T>::is_signed,
452  "Only unsigned integral types are allowed.");
454 }
455 
456 /// Log2 - This function returns the log base 2 of the specified value
457 inline double Log2(double Value) {
458 #if defined(__ANDROID_API__) && __ANDROID_API__ < 18
459  return __builtin_log(Value) / __builtin_log(2.0);
460 #else
461  return log2(Value);
462 #endif
463 }
464 
465 /// Log2_32 - This function returns the floor log base 2 of the specified value,
466 /// -1 if the value is zero. (32 bit edition.)
467 /// Ex. Log2_32(32) == 5, Log2_32(1) == 0, Log2_32(0) == -1, Log2_32(6) == 2
468 inline unsigned Log2_32(uint32_t Value) {
469  return 31 - countLeadingZeros(Value);
470 }
471 
472 /// Log2_64 - This function returns the floor log base 2 of the specified value,
473 /// -1 if the value is zero. (64 bit edition.)
474 inline unsigned Log2_64(uint64_t Value) {
475  return 63 - countLeadingZeros(Value);
476 }
477 
478 /// Log2_32_Ceil - This function returns the ceil log base 2 of the specified
479 /// value, 32 if the value is zero. (32 bit edition).
480 /// Ex. Log2_32_Ceil(32) == 5, Log2_32_Ceil(1) == 0, Log2_32_Ceil(6) == 3
481 inline unsigned Log2_32_Ceil(uint32_t Value) {
482  return 32 - countLeadingZeros(Value - 1);
483 }
484 
485 /// Log2_64_Ceil - This function returns the ceil log base 2 of the specified
486 /// value, 64 if the value is zero. (64 bit edition.)
487 inline unsigned Log2_64_Ceil(uint64_t Value) {
488  return 64 - countLeadingZeros(Value - 1);
489 }
490 
491 /// GreatestCommonDivisor64 - Return the greatest common divisor of the two
492 /// values using Euclid's algorithm.
493 inline uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B) {
494  while (B) {
495  uint64_t T = B;
496  B = A % B;
497  A = T;
498  }
499  return A;
500 }
501 
502 /// BitsToDouble - This function takes a 64-bit integer and returns the bit
503 /// equivalent double.
504 inline double BitsToDouble(uint64_t Bits) {
505  union {
506  uint64_t L;
507  double D;
508  } T;
509  T.L = Bits;
510  return T.D;
511 }
512 
513 /// BitsToFloat - This function takes a 32-bit integer and returns the bit
514 /// equivalent float.
515 inline float BitsToFloat(uint32_t Bits) {
516  union {
517  uint32_t I;
518  float F;
519  } T;
520  T.I = Bits;
521  return T.F;
522 }
523 
524 /// DoubleToBits - This function takes a double and returns the bit
525 /// equivalent 64-bit integer. Note that copying doubles around
526 /// changes the bits of NaNs on some hosts, notably x86, so this
527 /// routine cannot be used if these bits are needed.
528 inline uint64_t DoubleToBits(double Double) {
529  union {
530  uint64_t L;
531  double D;
532  } T;
533  T.D = Double;
534  return T.L;
535 }
536 
537 /// FloatToBits - This function takes a float and returns the bit
538 /// equivalent 32-bit integer. Note that copying floats around
539 /// changes the bits of NaNs on some hosts, notably x86, so this
540 /// routine cannot be used if these bits are needed.
541 inline uint32_t FloatToBits(float Float) {
542  union {
543  uint32_t I;
544  float F;
545  } T;
546  T.F = Float;
547  return T.I;
548 }
549 
550 /// MinAlign - A and B are either alignments or offsets. Return the minimum
551 /// alignment that may be assumed after adding the two together.
552 inline uint64_t MinAlign(uint64_t A, uint64_t B) {
553  // The largest power of 2 that divides both A and B.
554  //
555  // Replace "-Value" by "1+~Value" in the following commented code to avoid
556  // MSVC warning C4146
557  // return (A | B) & -(A | B);
558  return (A | B) & (1 + ~(A | B));
559 }
560 
561 /// \brief Aligns \c Addr to \c Alignment bytes, rounding up.
562 ///
563 /// Alignment should be a power of two. This method rounds up, so
564 /// alignAddr(7, 4) == 8 and alignAddr(8, 4) == 8.
565 inline uintptr_t alignAddr(const void *Addr, size_t Alignment) {
566  assert(Alignment && isPowerOf2_64((uint64_t)Alignment) &&
567  "Alignment is not a power of two!");
568 
569  assert((uintptr_t)Addr + Alignment - 1 >= (uintptr_t)Addr);
570 
571  return (((uintptr_t)Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1));
572 }
573 
574 /// \brief Returns the necessary adjustment for aligning \c Ptr to \c Alignment
575 /// bytes, rounding up.
576 inline size_t alignmentAdjustment(const void *Ptr, size_t Alignment) {
577  return alignAddr(Ptr, Alignment) - (uintptr_t)Ptr;
578 }
579 
580 /// NextPowerOf2 - Returns the next power of two (in 64-bits)
581 /// that is strictly greater than A. Returns zero on overflow.
582 inline uint64_t NextPowerOf2(uint64_t A) {
583  A |= (A >> 1);
584  A |= (A >> 2);
585  A |= (A >> 4);
586  A |= (A >> 8);
587  A |= (A >> 16);
588  A |= (A >> 32);
589  return A + 1;
590 }
591 
592 /// Returns the power of two which is less than or equal to the given value.
593 /// Essentially, it is a floor operation across the domain of powers of two.
594 inline uint64_t PowerOf2Floor(uint64_t A) {
595  if (!A) return 0;
596  return 1ull << (63 - countLeadingZeros(A, ZB_Undefined));
597 }
598 
599 /// Returns the next integer (mod 2**64) that is greater than or equal to
600 /// \p Value and is a multiple of \p Align. \p Align must be non-zero.
601 ///
602 /// Examples:
603 /// \code
604 /// RoundUpToAlignment(5, 8) = 8
605 /// RoundUpToAlignment(17, 8) = 24
606 /// RoundUpToAlignment(~0LL, 8) = 0
607 /// RoundUpToAlignment(321, 255) = 510
608 /// \endcode
609 inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) {
610  return (Value + Align - 1) / Align * Align;
611 }
612 
613 /// Returns the offset to the next integer (mod 2**64) that is greater than
614 /// or equal to \p Value and is a multiple of \p Align. \p Align must be
615 /// non-zero.
616 inline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) {
617  return RoundUpToAlignment(Value, Align) - Value;
618 }
619 
620 /// SignExtend32 - Sign extend B-bit number x to 32-bit int.
621 /// Usage int32_t r = SignExtend32<5>(x);
622 template <unsigned B> inline int32_t SignExtend32(uint32_t x) {
623  return int32_t(x << (32 - B)) >> (32 - B);
624 }
625 
626 /// \brief Sign extend number in the bottom B bits of X to a 32-bit int.
627 /// Requires 0 < B <= 32.
628 inline int32_t SignExtend32(uint32_t X, unsigned B) {
629  return int32_t(X << (32 - B)) >> (32 - B);
630 }
631 
632 /// SignExtend64 - Sign extend B-bit number x to 64-bit int.
633 /// Usage int64_t r = SignExtend64<5>(x);
634 template <unsigned B> inline int64_t SignExtend64(uint64_t x) {
635  return int64_t(x << (64 - B)) >> (64 - B);
636 }
637 
638 /// \brief Sign extend number in the bottom B bits of X to a 64-bit int.
639 /// Requires 0 < B <= 64.
640 inline int64_t SignExtend64(uint64_t X, unsigned B) {
641  return int64_t(X << (64 - B)) >> (64 - B);
642 }
643 
644 extern const float huge_valf;
645 } // End llvm namespace
646 
647 #endif
bool isInt< 32 >(int64_t x)
Definition: MathExtras.h:276
bool isUInt< 8 >(uint64_t x)
Definition: MathExtras.h:294
unsigned Log2_32_Ceil(uint32_t Value)
Log2_32_Ceil - This function returns the ceil log base 2 of the specified value, 32 if the value is z...
Definition: MathExtras.h:481
T findLastSet(T Val, ZeroBehavior ZB=ZB_Max)
Get the index of the last set bit starting from the least significant bit.
Definition: MathExtras.h:206
uint64_t GreatestCommonDivisor64(uint64_t A, uint64_t B)
GreatestCommonDivisor64 - Return the greatest common divisor of the two values using Euclid's algorit...
Definition: MathExtras.h:493
static unsigned count(T Value)
Definition: MathExtras.h:416
float BitsToFloat(uint32_t Bits)
BitsToFloat - This function takes a 32-bit integer and returns the bit equivalent float...
Definition: MathExtras.h:515
ZeroBehavior
The behavior an operation has on an input of 0.
Definition: MathExtras.h:33
bool isUInt(uint64_t x)
isUInt - Checks if an unsigned integer fits into the given bit width.
Definition: MathExtras.h:289
F(f)
std::size_t countLeadingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0's from the most significant bit to the least stopping at the first 1...
Definition: MathExtras.h:178
bool isShiftedMask_32(uint32_t Value)
isShiftedMask_32 - This function returns true if the argument contains a non-empty sequence of ones w...
Definition: MathExtras.h:342
uint32_t SwapByteOrder_32(uint32_t value)
SwapByteOrder_32 - This function returns a byte-swapped representation of the 32-bit argument...
Definition: SwapByteOrder.h:42
The returned value is numeric_limits<T>::digits.
Definition: MathExtras.h:39
std::size_t countTrailingOnes(T Value, ZeroBehavior ZB=ZB_Width)
Count the number of ones from the least significant bit to the first zero bit.
Definition: MathExtras.h:407
The returned value is undefined.
Definition: MathExtras.h:35
bool isInt< 8 >(int64_t x)
Definition: MathExtras.h:268
static unsigned count(T Value)
Definition: MathExtras.h:431
uint32_t ByteSwap_32(uint32_t Value)
ByteSwap_32 - This function returns a byte-swapped representation of the 32-bit argument, Value.
Definition: MathExtras.h:372
bool isShiftedInt(int64_t x)
isShiftedInt<N,S> - Checks if a signed integer is an N bit number shifted left by S...
Definition: MathExtras.h:283
static const unsigned char BitReverseTable256[256]
Macro compressed bit reversal table for 256 bits.
Definition: MathExtras.h:219
uint16_t ByteSwap_16(uint16_t Value)
ByteSwap_16 - This function returns a byte-swapped representation of the 16-bit argument, Value.
Definition: MathExtras.h:366
#define T
bool isMask_64(uint64_t Value)
isMask_64 - This function returns true if the argument is a non-empty sequence of ones starting at th...
Definition: MathExtras.h:335
const float huge_valf
Definition: MathExtras.cpp:29
uint32_t FloatToBits(float Float)
FloatToBits - This function takes a float and returns the bit equivalent 32-bit integer.
Definition: MathExtras.h:541
uint16_t SwapByteOrder_16(uint16_t value)
SwapByteOrder_16 - This function returns a byte-swapped representation of the 16-bit argument...
Definition: SwapByteOrder.h:28
std::size_t countTrailingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0's from the least significant bit to the most stopping at the first 1...
Definition: MathExtras.h:109
size_t alignmentAdjustment(const void *Ptr, size_t Alignment)
Returns the necessary adjustment for aligning Ptr to Alignment bytes, rounding up.
Definition: MathExtras.h:576
uint32_t Lo_32(uint64_t Value)
Lo_32 - This function returns the low 32 bits of a 64 bit value.
Definition: MathExtras.h:251
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang","erlang-compatible garbage collector")
The returned value is numeric_limits<T>::max()
Definition: MathExtras.h:37
bool isIntN(unsigned N, int64_t x)
isIntN - Checks if an signed integer fits into the given (dynamic) bit width.
Definition: MathExtras.h:321
uint64_t NextPowerOf2(uint64_t A)
NextPowerOf2 - Returns the next power of two (in 64-bits) that is strictly greater than A...
Definition: MathExtras.h:582
bool isShiftedUInt(uint64_t x)
isShiftedUInt<N,S> - Checks if a unsigned integer is an N bit number shifted left by S...
Definition: MathExtras.h:309
T findFirstSet(T Val, ZeroBehavior ZB=ZB_Max)
Get the index of the first set bit starting from the least significant bit.
Definition: MathExtras.h:192
uint64_t SwapByteOrder_64(uint64_t value)
SwapByteOrder_64 - This function returns a byte-swapped representation of the 64-bit argument...
Definition: SwapByteOrder.h:58
bool isShiftedMask_64(uint64_t Value)
isShiftedMask_64 - This function returns true if the argument contains a non-empty sequence of ones w...
Definition: MathExtras.h:348
unsigned countPopulation(T Value)
Count the number of set bits in a value.
Definition: MathExtras.h:449
#define R6(n)
int64_t SignExtend64(uint64_t x)
SignExtend64 - Sign extend B-bit number x to 64-bit int.
Definition: MathExtras.h:634
double Log2(double Value)
Log2 - This function returns the log base 2 of the specified value.
Definition: MathExtras.h:457
uint64_t DoubleToBits(double Double)
DoubleToBits - This function takes a double and returns the bit equivalent 64-bit integer...
Definition: MathExtras.h:528
static cl::opt< AlignMode > Align(cl::desc("Load/store alignment support"), cl::Hidden, cl::init(NoStrictAlign), cl::values(clEnumValN(StrictAlign,"aarch64-strict-align","Disallow all unaligned memory accesses"), clEnumValN(NoStrictAlign,"aarch64-no-strict-align","Allow unaligned memory accesses"), clEnumValEnd))
double BitsToDouble(uint64_t Bits)
BitsToDouble - This function takes a 64-bit integer and returns the bit equivalent double...
Definition: MathExtras.h:504
static std::size_t count(T Val, ZeroBehavior)
Definition: MathExtras.h:118
unsigned Log2_64_Ceil(uint64_t Value)
Log2_64_Ceil - This function returns the ceil log base 2 of the specified value, 64 if the value is z...
Definition: MathExtras.h:487
unsigned Log2_32(uint32_t Value)
Log2_32 - This function returns the floor log base 2 of the specified value, -1 if the value is zero...
Definition: MathExtras.h:468
bool isUInt< 32 >(uint64_t x)
Definition: MathExtras.h:302
bool isMask_32(uint32_t Value)
isMask_32 - This function returns true if the argument is a non-empty sequence of ones starting at th...
Definition: MathExtras.h:328
bool isPowerOf2_64(uint64_t Value)
isPowerOf2_64 - This function returns true if the argument is a power of two 0 (64 bit edition...
Definition: MathExtras.h:360
uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align)
Returns the next integer (mod 2**64) that is greater than or equal to Value and is a multiple of Alig...
Definition: MathExtras.h:609
uintptr_t alignAddr(const void *Addr, size_t Alignment)
Aligns Addr to Alignment bytes, rounding up.
Definition: MathExtras.h:565
uint64_t MinAlign(uint64_t A, uint64_t B)
MinAlign - A and B are either alignments or offsets.
Definition: MathExtras.h:552
static std::size_t count(T Val, ZeroBehavior)
Definition: MathExtras.h:44
uint64_t ByteSwap_64(uint64_t Value)
ByteSwap_64 - This function returns a byte-swapped representation of the 64-bit argument, Value.
Definition: MathExtras.h:378
#define I(x, y, z)
Definition: MD5.cpp:54
#define N
int32_t SignExtend32(uint32_t x)
SignExtend32 - Sign extend B-bit number x to 32-bit int.
Definition: MathExtras.h:622
uint32_t Hi_32(uint64_t Value)
Hi_32 - This function returns the high 32 bits of a 64 bit value.
Definition: MathExtras.h:246
uint64_t Make_64(uint32_t High, uint32_t Low)
Make_64 - This functions makes a 64-bit integer from a high / low pair of 32-bit integers.
Definition: MathExtras.h:257
bool isInt< 16 >(int64_t x)
Definition: MathExtras.h:272
uint64_t PowerOf2Floor(uint64_t A)
Returns the power of two which is less than or equal to the given value.
Definition: MathExtras.h:594
LLVM Value Representation.
Definition: Value.h:69
uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align)
Returns the offset to the next integer (mod 2**64) that is greater than or equal to Value and is a mu...
Definition: MathExtras.h:616
bool isUInt< 16 >(uint64_t x)
Definition: MathExtras.h:298
bool isInt(int64_t x)
isInt - Checks if an integer fits into the given bit width.
Definition: MathExtras.h:263
bool isPowerOf2_32(uint32_t Value)
isPowerOf2_32 - This function returns true if the argument is a power of two > 0. ...
Definition: MathExtras.h:354
bool isUIntN(unsigned N, uint64_t x)
isUIntN - Checks if an unsigned integer fits into the given (dynamic) bit width.
Definition: MathExtras.h:315
T reverseBits(T Val)
Reverse the bits in Val.
Definition: MathExtras.h:231
std::size_t countLeadingOnes(T Value, ZeroBehavior ZB=ZB_Width)
Count the number of ones from the most significant bit to the first zero bit.
Definition: MathExtras.h:391
unsigned Log2_64(uint64_t Value)
Log2_64 - This function returns the floor log base 2 of the specified value, -1 if the value is zero...
Definition: MathExtras.h:474