libstdc++
valarray_array.h
Go to the documentation of this file.
1// The template and inlines for the -*- C++ -*- internal _Array helper class.
2
3// Copyright (C) 1997-2025 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file bits/valarray_array.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{valarray}
28 */
29
30// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
31
32#ifndef _VALARRAY_ARRAY_H
33#define _VALARRAY_ARRAY_H 1
34
35#ifdef _GLIBCXX_SYSHDR
36#pragma GCC system_header
37#endif
38
39#include <bits/c++config.h>
41#include <cstdlib>
42#include <new>
43
44namespace std _GLIBCXX_VISIBILITY(default)
45{
46_GLIBCXX_BEGIN_NAMESPACE_VERSION
47
48 //
49 // Helper functions on raw pointers
50 //
51
52 // We get memory the old fashioned way
53 template<typename _Tp>
54 _Tp*
55 __valarray_get_storage(size_t) __attribute__((__malloc__));
56
57 template<typename _Tp>
58 inline _Tp*
59 __valarray_get_storage(size_t __n)
60 { return static_cast<_Tp*>(operator new(__n * sizeof(_Tp))); }
61
62 // Return memory to the system
63 inline void
64 __valarray_release_memory(void* __p)
65 { operator delete(__p); }
66
67 // Turn raw-memory into an array of _Tp filled with _Tp().
68 // This is used in `valarray<T> v(n);` and in `valarray<T>::shift(n)`.
69 template<typename _Tp>
70 inline void
71 __valarray_default_construct(_Tp* __b, _Tp* __e)
72 {
73 if _GLIBCXX17_CONSTEXPR (__is_trivial(_Tp))
74 __builtin_memset(__b, 0, (__e - __b) * sizeof(_Tp));
75 else
76 while (__b != __e)
77 ::new(static_cast<void*>(__b++)) _Tp();
78 }
79
80 // Turn a raw-memory into an array of _Tp filled with __t
81 // This is the required in valarray<T> v(n, t). Also
82 // used in valarray<>::resize().
83 template<typename _Tp>
84 inline void
85 __valarray_fill_construct(_Tp* __b, _Tp* __e, const _Tp __t)
86 {
87 while (__b != __e)
88 ::new(static_cast<void*>(__b++)) _Tp(__t);
89 }
90
91 // copy-construct raw array [__o, *) from plain array [__b, __e)
92 template<typename _Tp>
93 inline void
94 __valarray_copy_construct(const _Tp* __b, const _Tp* __e,
95 _Tp* __restrict__ __o)
96 {
97 if _GLIBCXX17_CONSTEXPR (__is_trivial(_Tp))
98 {
99 if (__b)
100 __builtin_memcpy(__o, __b, (__e - __b) * sizeof(_Tp));
101 }
102 else
103 while (__b != __e)
104 ::new(static_cast<void*>(__o++)) _Tp(*__b++);
105 }
106
107 // copy-construct raw array [__o, *) from strided array __a[<__n : __s>]
108 template<typename _Tp>
109 inline void
110 __valarray_copy_construct (const _Tp* __restrict__ __a, size_t __n,
111 size_t __s, _Tp* __restrict__ __o)
112 {
113 if _GLIBCXX17_CONSTEXPR (__is_trivial(_Tp))
114 while (__n--)
115 {
116 *__o++ = *__a;
117 __a += __s;
118 }
119 else
120 while (__n--)
121 {
122 new(__o++) _Tp(*__a);
123 __a += __s;
124 }
125 }
126
127 // copy-construct raw array [__o, *) from indexed array __a[__i[<__n>]]
128 template<typename _Tp>
129 inline void
130 __valarray_copy_construct (const _Tp* __restrict__ __a,
131 const size_t* __restrict__ __i,
132 _Tp* __restrict__ __o, size_t __n)
133 {
134 if (__is_trivial(_Tp))
135 while (__n--)
136 *__o++ = __a[*__i++];
137 else
138 while (__n--)
139 new (__o++) _Tp(__a[*__i++]);
140 }
141
142 // Do the necessary cleanup when we're done with arrays.
143 template<typename _Tp>
144 inline void
145 __valarray_destroy_elements(_Tp* __b, _Tp* __e)
146 {
147 if (!__is_trivial(_Tp))
148 while (__b != __e)
149 {
150 __b->~_Tp();
151 ++__b;
152 }
153 }
154
155 // Fill a plain array __a[<__n>] with __t
156 template<typename _Tp>
157 inline void
158 __valarray_fill(_Tp* __restrict__ __a, size_t __n, const _Tp& __t)
159 {
160 while (__n--)
161 *__a++ = __t;
162 }
163
164 // fill strided array __a[<__n-1 : __s>] with __t
165 template<typename _Tp>
166 inline void
167 __valarray_fill(_Tp* __restrict__ __a, size_t __n,
168 size_t __s, const _Tp& __t)
169 {
170 for (size_t __i = 0; __i < __n; ++__i, __a += __s)
171 *__a = __t;
172 }
173
174 // fill indirect array __a[__i[<__n>]] with __i
175 template<typename _Tp>
176 inline void
177 __valarray_fill(_Tp* __restrict__ __a, const size_t* __restrict__ __i,
178 size_t __n, const _Tp& __t)
179 {
180 for (size_t __j = 0; __j < __n; ++__j, ++__i)
181 __a[*__i] = __t;
182 }
183
184 // copy plain array __a[<__n>] in __b[<__n>]
185 // For non-fundamental types, it is wrong to say 'memcpy()'
186 template<typename _Tp, bool>
187 struct _Array_copier
188 {
189 inline static void
190 _S_do_it(const _Tp* __restrict__ __a, size_t __n, _Tp* __restrict__ __b)
191 {
192 while(__n--)
193 *__b++ = *__a++;
194 }
195 };
196
197 template<typename _Tp>
198 struct _Array_copier<_Tp, true>
199 {
200 inline static void
201 _S_do_it(const _Tp* __restrict__ __a, size_t __n, _Tp* __restrict__ __b)
202 {
203 if (__n != 0)
204 __builtin_memcpy(__b, __a, __n * sizeof (_Tp));
205 }
206 };
207
208 // Copy a plain array __a[<__n>] into a play array __b[<>]
209 template<typename _Tp>
210 inline void
211 __valarray_copy(const _Tp* __restrict__ __a, size_t __n,
212 _Tp* __restrict__ __b)
213 {
214 _Array_copier<_Tp, __is_trivial(_Tp)>::_S_do_it(__a, __n, __b);
215 }
216
217 // Copy strided array __a[<__n : __s>] in plain __b[<__n>]
218 template<typename _Tp>
219 inline void
220 __valarray_copy(const _Tp* __restrict__ __a, size_t __n, size_t __s,
221 _Tp* __restrict__ __b)
222 {
223 for (size_t __i = 0; __i < __n; ++__i, ++__b, __a += __s)
224 *__b = *__a;
225 }
226
227 // Copy a plain array __a[<__n>] into a strided array __b[<__n : __s>]
228 template<typename _Tp>
229 inline void
230 __valarray_copy(const _Tp* __restrict__ __a, _Tp* __restrict__ __b,
231 size_t __n, size_t __s)
232 {
233 for (size_t __i = 0; __i < __n; ++__i, ++__a, __b += __s)
234 *__b = *__a;
235 }
236
237 // Copy strided array __src[<__n : __s1>] into another
238 // strided array __dst[< : __s2>]. Their sizes must match.
239 template<typename _Tp>
240 inline void
241 __valarray_copy(const _Tp* __restrict__ __src, size_t __n, size_t __s1,
242 _Tp* __restrict__ __dst, size_t __s2)
243 {
244 for (size_t __i = 0; __i < __n; ++__i)
245 __dst[__i * __s2] = __src[__i * __s1];
246 }
247
248 // Copy an indexed array __a[__i[<__n>]] in plain array __b[<__n>]
249 template<typename _Tp>
250 inline void
251 __valarray_copy(const _Tp* __restrict__ __a,
252 const size_t* __restrict__ __i,
253 _Tp* __restrict__ __b, size_t __n)
254 {
255 for (size_t __j = 0; __j < __n; ++__j, ++__b, ++__i)
256 *__b = __a[*__i];
257 }
258
259 // Copy a plain array __a[<__n>] in an indexed array __b[__i[<__n>]]
260 template<typename _Tp>
261 inline void
262 __valarray_copy(const _Tp* __restrict__ __a, size_t __n,
263 _Tp* __restrict__ __b, const size_t* __restrict__ __i)
264 {
265 for (size_t __j = 0; __j < __n; ++__j, ++__a, ++__i)
266 __b[*__i] = *__a;
267 }
268
269 // Copy the __n first elements of an indexed array __src[<__i>] into
270 // another indexed array __dst[<__j>].
271 template<typename _Tp>
272 inline void
273 __valarray_copy(const _Tp* __restrict__ __src, size_t __n,
274 const size_t* __restrict__ __i,
275 _Tp* __restrict__ __dst, const size_t* __restrict__ __j)
276 {
277 for (size_t __k = 0; __k < __n; ++__k)
278 __dst[*__j++] = __src[*__i++];
279 }
280
281 //
282 // Compute the sum of elements in range [__f, __l) which must not be empty.
283 // This is a naive algorithm. It suffers from cancelling.
284 // In the future try to specialize for _Tp = float, double, long double
285 // using a more accurate algorithm.
286 //
287 template<typename _Tp>
288 inline _Tp
289 __valarray_sum(const _Tp* __f, const _Tp* __l)
290 {
291 _Tp __r = *__f++;
292 while (__f != __l)
293 __r += *__f++;
294 return __r;
295 }
296
297 // Compute the min/max of an array-expression
298 template<typename _Ta>
299 inline typename _Ta::value_type
300 __valarray_min(const _Ta& __a)
301 {
302 size_t __s = __a.size();
303 typedef typename _Ta::value_type _Value_type;
304 _Value_type __r = __s == 0 ? _Value_type() : __a[0];
305 for (size_t __i = 1; __i < __s; ++__i)
306 {
307 _Value_type __t = __a[__i];
308 if (__t < __r)
309 __r = __t;
310 }
311 return __r;
312 }
313
314 template<typename _Ta>
315 inline typename _Ta::value_type
316 __valarray_max(const _Ta& __a)
317 {
318 size_t __s = __a.size();
319 typedef typename _Ta::value_type _Value_type;
320 _Value_type __r = __s == 0 ? _Value_type() : __a[0];
321 for (size_t __i = 1; __i < __s; ++__i)
322 {
323 _Value_type __t = __a[__i];
324 if (__t > __r)
325 __r = __t;
326 }
327 return __r;
328 }
329
330 //
331 // Helper class _Array, first layer of valarray abstraction.
332 // All operations on valarray should be forwarded to this class
333 // whenever possible. -- gdr
334 //
335
336 template<typename _Tp>
337 struct _Array
338 {
339 explicit _Array(_Tp* const __restrict__);
340 explicit _Array(const valarray<_Tp>&);
341 _Array(const _Tp* __restrict__, size_t);
342
343 _Tp* begin() const;
344
345 _Tp* const __restrict__ _M_data;
346 };
347
348
349 // Copy-construct plain array __b[<__n>] from indexed array __a[__i[<__n>]]
350 template<typename _Tp>
351 inline void
352 __valarray_copy_construct(_Array<_Tp> __a, _Array<size_t> __i,
353 _Array<_Tp> __b, size_t __n)
354 { std::__valarray_copy_construct(__a._M_data, __i._M_data,
355 __b._M_data, __n); }
356
357 // Copy-construct plain array __b[<__n>] from strided array __a[<__n : __s>]
358 template<typename _Tp>
359 inline void
360 __valarray_copy_construct(_Array<_Tp> __a, size_t __n, size_t __s,
361 _Array<_Tp> __b)
362 { std::__valarray_copy_construct(__a._M_data, __n, __s, __b._M_data); }
363
364 template<typename _Tp>
365 inline void
366 __valarray_fill (_Array<_Tp> __a, size_t __n, const _Tp& __t)
367 { std::__valarray_fill(__a._M_data, __n, __t); }
368
369 template<typename _Tp>
370 inline void
371 __valarray_fill(_Array<_Tp> __a, size_t __n, size_t __s, const _Tp& __t)
372 { std::__valarray_fill(__a._M_data, __n, __s, __t); }
373
374 template<typename _Tp>
375 inline void
376 __valarray_fill(_Array<_Tp> __a, _Array<size_t> __i,
377 size_t __n, const _Tp& __t)
378 { std::__valarray_fill(__a._M_data, __i._M_data, __n, __t); }
379
380 // Copy a plain array __a[<__n>] into a play array __b[<>]
381 template<typename _Tp>
382 inline void
383 __valarray_copy(_Array<_Tp> __a, size_t __n, _Array<_Tp> __b)
384 { std::__valarray_copy(__a._M_data, __n, __b._M_data); }
385
386 // Copy strided array __a[<__n : __s>] in plain __b[<__n>]
387 template<typename _Tp>
388 inline void
389 __valarray_copy(_Array<_Tp> __a, size_t __n, size_t __s, _Array<_Tp> __b)
390 { std::__valarray_copy(__a._M_data, __n, __s, __b._M_data); }
391
392 // Copy a plain array __a[<__n>] into a strided array __b[<__n : __s>]
393 template<typename _Tp>
394 inline void
395 __valarray_copy(_Array<_Tp> __a, _Array<_Tp> __b, size_t __n, size_t __s)
396 { __valarray_copy(__a._M_data, __b._M_data, __n, __s); }
397
398 // Copy strided array __src[<__n : __s1>] into another
399 // strided array __dst[< : __s2>]. Their sizes must match.
400 template<typename _Tp>
401 inline void
402 __valarray_copy(_Array<_Tp> __a, size_t __n, size_t __s1,
403 _Array<_Tp> __b, size_t __s2)
404 { std::__valarray_copy(__a._M_data, __n, __s1, __b._M_data, __s2); }
405
406 // Copy an indexed array __a[__i[<__n>]] in plain array __b[<__n>]
407 template<typename _Tp>
408 inline void
409 __valarray_copy(_Array<_Tp> __a, _Array<size_t> __i,
410 _Array<_Tp> __b, size_t __n)
411 { std::__valarray_copy(__a._M_data, __i._M_data, __b._M_data, __n); }
412
413 // Copy a plain array __a[<__n>] in an indexed array __b[__i[<__n>]]
414 template<typename _Tp>
415 inline void
416 __valarray_copy(_Array<_Tp> __a, size_t __n, _Array<_Tp> __b,
417 _Array<size_t> __i)
418 { std::__valarray_copy(__a._M_data, __n, __b._M_data, __i._M_data); }
419
420 // Copy the __n first elements of an indexed array __src[<__i>] into
421 // another indexed array __dst[<__j>].
422 template<typename _Tp>
423 inline void
424 __valarray_copy(_Array<_Tp> __src, size_t __n, _Array<size_t> __i,
425 _Array<_Tp> __dst, _Array<size_t> __j)
426 {
427 std::__valarray_copy(__src._M_data, __n, __i._M_data,
428 __dst._M_data, __j._M_data);
429 }
430
431 template<typename _Tp>
432 inline
433 _Array<_Tp>::_Array(_Tp* const __restrict__ __p)
434 : _M_data (__p) {}
435
436 template<typename _Tp>
437 inline
438 _Array<_Tp>::_Array(const valarray<_Tp>& __v)
439 : _M_data (__v._M_data) {}
440
441 template<typename _Tp>
442 inline
443 _Array<_Tp>::_Array(const _Tp* __restrict__ __b, size_t __s)
444 : _M_data(__valarray_get_storage<_Tp>(__s))
445 { std::__valarray_copy_construct(__b, __s, _M_data); }
446
447 template<typename _Tp>
448 inline _Tp*
449 _Array<_Tp>::begin () const
450 { return _M_data; }
451
452#define _DEFINE_ARRAY_FUNCTION(_Op, _Name) \
453 template<typename _Tp> \
454 inline void \
455 _Array_augmented_##_Name(_Array<_Tp> __a, size_t __n, const _Tp& __t) \
456 { \
457 for (_Tp* __p = __a._M_data; __p < __a._M_data + __n; ++__p) \
458 *__p _Op##= __t; \
459 } \
460 \
461 template<typename _Tp> \
462 inline void \
463 _Array_augmented_##_Name(_Array<_Tp> __a, size_t __n, _Array<_Tp> __b) \
464 { \
465 _Tp* __p = __a._M_data; \
466 for (_Tp* __q = __b._M_data; __q < __b._M_data + __n; ++__p, ++__q) \
467 *__p _Op##= *__q; \
468 } \
469 \
470 template<typename _Tp, class _Dom> \
471 void \
472 _Array_augmented_##_Name(_Array<_Tp> __a, \
473 const _Expr<_Dom, _Tp>& __e, size_t __n) \
474 { \
475 _Tp* __p(__a._M_data); \
476 for (size_t __i = 0; __i < __n; ++__i, ++__p) \
477 *__p _Op##= __e[__i]; \
478 } \
479 \
480 template<typename _Tp> \
481 inline void \
482 _Array_augmented_##_Name(_Array<_Tp> __a, size_t __n, size_t __s, \
483 _Array<_Tp> __b) \
484 { \
485 _Tp* __q(__b._M_data); \
486 for (_Tp* __p = __a._M_data; __p < __a._M_data + __s * __n; \
487 __p += __s, ++__q) \
488 *__p _Op##= *__q; \
489 } \
490 \
491 template<typename _Tp> \
492 inline void \
493 _Array_augmented_##_Name(_Array<_Tp> __a, _Array<_Tp> __b, \
494 size_t __n, size_t __s) \
495 { \
496 _Tp* __q(__b._M_data); \
497 for (_Tp* __p = __a._M_data; __p < __a._M_data + __n; \
498 ++__p, __q += __s) \
499 *__p _Op##= *__q; \
500 } \
501 \
502 template<typename _Tp, class _Dom> \
503 void \
504 _Array_augmented_##_Name(_Array<_Tp> __a, size_t __s, \
505 const _Expr<_Dom, _Tp>& __e, size_t __n) \
506 { \
507 _Tp* __p(__a._M_data); \
508 for (size_t __i = 0; __i < __n; ++__i, __p += __s) \
509 *__p _Op##= __e[__i]; \
510 } \
511 \
512 template<typename _Tp> \
513 inline void \
514 _Array_augmented_##_Name(_Array<_Tp> __a, _Array<size_t> __i, \
515 _Array<_Tp> __b, size_t __n) \
516 { \
517 _Tp* __q(__b._M_data); \
518 for (size_t* __j = __i._M_data; __j < __i._M_data + __n; \
519 ++__j, ++__q) \
520 __a._M_data[*__j] _Op##= *__q; \
521 } \
522 \
523 template<typename _Tp> \
524 inline void \
525 _Array_augmented_##_Name(_Array<_Tp> __a, size_t __n, \
526 _Array<_Tp> __b, _Array<size_t> __i) \
527 { \
528 _Tp* __p(__a._M_data); \
529 for (size_t* __j = __i._M_data; __j<__i._M_data + __n; \
530 ++__j, ++__p) \
531 *__p _Op##= __b._M_data[*__j]; \
532 } \
533 \
534 template<typename _Tp, class _Dom> \
535 void \
536 _Array_augmented_##_Name(_Array<_Tp> __a, _Array<size_t> __i, \
537 const _Expr<_Dom, _Tp>& __e, size_t __n) \
538 { \
539 size_t* __j(__i._M_data); \
540 for (size_t __k = 0; __k<__n; ++__k, ++__j) \
541 __a._M_data[*__j] _Op##= __e[__k]; \
542 } \
543 \
544 template<typename _Tp> \
545 void \
546 _Array_augmented_##_Name(_Array<_Tp> __a, _Array<bool> __m, \
547 _Array<_Tp> __b, size_t __n) \
548 { \
549 bool* __ok(__m._M_data); \
550 _Tp* __p(__a._M_data); \
551 for (_Tp* __q = __b._M_data; __q < __b._M_data + __n; \
552 ++__q, ++__ok, ++__p) \
553 { \
554 while (! *__ok) \
555 { \
556 ++__ok; \
557 ++__p; \
558 } \
559 *__p _Op##= *__q; \
560 } \
561 } \
562 \
563 template<typename _Tp> \
564 void \
565 _Array_augmented_##_Name(_Array<_Tp> __a, size_t __n, \
566 _Array<_Tp> __b, _Array<bool> __m) \
567 { \
568 bool* __ok(__m._M_data); \
569 _Tp* __q(__b._M_data); \
570 for (_Tp* __p = __a._M_data; __p < __a._M_data + __n; \
571 ++__p, ++__ok, ++__q) \
572 { \
573 while (! *__ok) \
574 { \
575 ++__ok; \
576 ++__q; \
577 } \
578 *__p _Op##= *__q; \
579 } \
580 } \
581 \
582 template<typename _Tp, class _Dom> \
583 void \
584 _Array_augmented_##_Name(_Array<_Tp> __a, _Array<bool> __m, \
585 const _Expr<_Dom, _Tp>& __e, size_t __n) \
586 { \
587 bool* __ok(__m._M_data); \
588 _Tp* __p(__a._M_data); \
589 for (size_t __i = 0; __i < __n; ++__i, ++__ok, ++__p) \
590 { \
591 while (! *__ok) \
592 { \
593 ++__ok; \
594 ++__p; \
595 } \
596 *__p _Op##= __e[__i]; \
597 } \
598 }
599
600 _DEFINE_ARRAY_FUNCTION(+, __plus)
601 _DEFINE_ARRAY_FUNCTION(-, __minus)
602 _DEFINE_ARRAY_FUNCTION(*, __multiplies)
603 _DEFINE_ARRAY_FUNCTION(/, __divides)
604 _DEFINE_ARRAY_FUNCTION(%, __modulus)
605 _DEFINE_ARRAY_FUNCTION(^, __bitwise_xor)
606 _DEFINE_ARRAY_FUNCTION(|, __bitwise_or)
607 _DEFINE_ARRAY_FUNCTION(&, __bitwise_and)
608 _DEFINE_ARRAY_FUNCTION(<<, __shift_left)
609 _DEFINE_ARRAY_FUNCTION(>>, __shift_right)
610
611#undef _DEFINE_ARRAY_FUNCTION
612
613_GLIBCXX_END_NAMESPACE_VERSION
614} // namespace
615
616# include <bits/valarray_array.tcc>
617
618#endif /* _ARRAY_H */
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition valarray:1229
ISO C++ entities toplevel namespace is std.