libstdc++
simd_neon.h
1// Simd NEON specific implementations -*- C++ -*-
2
3// Copyright (C) 2020-2022 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#ifndef _GLIBCXX_EXPERIMENTAL_SIMD_NEON_H_
26#define _GLIBCXX_EXPERIMENTAL_SIMD_NEON_H_
27
28#if __cplusplus >= 201703L
29
30#if !_GLIBCXX_SIMD_HAVE_NEON
31#error "simd_neon.h may only be included when NEON on ARM is available"
32#endif
33
34_GLIBCXX_SIMD_BEGIN_NAMESPACE
35
36// _CommonImplNeon {{{
37struct _CommonImplNeon : _CommonImplBuiltin
38{
39 // _S_store {{{
40 using _CommonImplBuiltin::_S_store;
41
42 // }}}
43};
44
45// }}}
46// _SimdImplNeon {{{
47template <typename _Abi, typename>
48 struct _SimdImplNeon : _SimdImplBuiltin<_Abi>
49 {
50 using _Base = _SimdImplBuiltin<_Abi>;
51
52 template <typename _Tp>
53 using _MaskMember = typename _Base::template _MaskMember<_Tp>;
54
55 template <typename _Tp>
56 static constexpr size_t _S_max_store_size = 16;
57
58 // _S_masked_load {{{
59 template <typename _Tp, size_t _Np, typename _Up>
60 static inline _SimdWrapper<_Tp, _Np>
61 _S_masked_load(_SimdWrapper<_Tp, _Np> __merge, _MaskMember<_Tp> __k,
62 const _Up* __mem) noexcept
63 {
64 __execute_n_times<_Np>([&](auto __i) {
65 if (__k[__i] != 0)
66 __merge._M_set(__i, static_cast<_Tp>(__mem[__i]));
67 });
68 return __merge;
69 }
70
71 // }}}
72 // _S_masked_store_nocvt {{{
73 template <typename _Tp, size_t _Np>
74 _GLIBCXX_SIMD_INTRINSIC static void
75 _S_masked_store_nocvt(_SimdWrapper<_Tp, _Np> __v, _Tp* __mem,
76 _MaskMember<_Tp> __k)
77 {
78 __execute_n_times<_Np>([&](auto __i) {
79 if (__k[__i] != 0)
80 __mem[__i] = __v[__i];
81 });
82 }
83
84 // }}}
85 // _S_reduce {{{
86 template <typename _Tp, typename _BinaryOperation>
87 _GLIBCXX_SIMD_INTRINSIC static _Tp
88 _S_reduce(simd<_Tp, _Abi> __x, _BinaryOperation&& __binary_op)
89 {
90 constexpr size_t _Np = __x.size();
91 if constexpr (sizeof(__x) == 16 && _Np >= 4
92 && !_Abi::template _S_is_partial<_Tp>)
93 {
94 const auto __halves = split<simd<_Tp, simd_abi::_Neon<8>>>(__x);
95 const auto __y = __binary_op(__halves[0], __halves[1]);
96 return _SimdImplNeon<simd_abi::_Neon<8>>::_S_reduce(
97 __y, static_cast<_BinaryOperation&&>(__binary_op));
98 }
99 else if constexpr (_Np == 8)
100 {
101 __x = __binary_op(__x, _Base::template _M_make_simd<_Tp, _Np>(
102 __vector_permute<1, 0, 3, 2, 5, 4, 7, 6>(
103 __x._M_data)));
104 __x = __binary_op(__x, _Base::template _M_make_simd<_Tp, _Np>(
105 __vector_permute<3, 2, 1, 0, 7, 6, 5, 4>(
106 __x._M_data)));
107 __x = __binary_op(__x, _Base::template _M_make_simd<_Tp, _Np>(
108 __vector_permute<7, 6, 5, 4, 3, 2, 1, 0>(
109 __x._M_data)));
110 return __x[0];
111 }
112 else if constexpr (_Np == 4)
113 {
114 __x
115 = __binary_op(__x, _Base::template _M_make_simd<_Tp, _Np>(
116 __vector_permute<1, 0, 3, 2>(__x._M_data)));
117 __x
118 = __binary_op(__x, _Base::template _M_make_simd<_Tp, _Np>(
119 __vector_permute<3, 2, 1, 0>(__x._M_data)));
120 return __x[0];
121 }
122 else if constexpr (_Np == 2)
123 {
124 __x = __binary_op(__x, _Base::template _M_make_simd<_Tp, _Np>(
125 __vector_permute<1, 0>(__x._M_data)));
126 return __x[0];
127 }
128 else
129 return _Base::_S_reduce(__x,
130 static_cast<_BinaryOperation&&>(__binary_op));
131 }
132
133 // }}}
134 // math {{{
135 // _S_sqrt {{{
136 template <typename _Tp, typename _TVT = _VectorTraits<_Tp>>
137 _GLIBCXX_SIMD_INTRINSIC static _Tp _S_sqrt(_Tp __x)
138 {
139 if constexpr (__have_neon_a64)
140 {
141 const auto __intrin = __to_intrin(__x);
142 if constexpr (_TVT::template _S_is<float, 2>)
143 return vsqrt_f32(__intrin);
144 else if constexpr (_TVT::template _S_is<float, 4>)
145 return vsqrtq_f32(__intrin);
146 else if constexpr (_TVT::template _S_is<double, 1>)
147 return vsqrt_f64(__intrin);
148 else if constexpr (_TVT::template _S_is<double, 2>)
149 return vsqrtq_f64(__intrin);
150 else
151 __assert_unreachable<_Tp>();
152 }
153 else
154 return _Base::_S_sqrt(__x);
155 }
156
157 // }}}
158 // _S_trunc {{{
159 template <typename _TW, typename _TVT = _VectorTraits<_TW>>
160 _GLIBCXX_SIMD_INTRINSIC static _TW _S_trunc(_TW __x)
161 {
162 using _Tp = typename _TVT::value_type;
163 if constexpr (__have_neon_a32)
164 {
165 const auto __intrin = __to_intrin(__x);
166 if constexpr (_TVT::template _S_is<float, 2>)
167 return vrnd_f32(__intrin);
168 else if constexpr (_TVT::template _S_is<float, 4>)
169 return vrndq_f32(__intrin);
170 else if constexpr (_TVT::template _S_is<double, 1>)
171 return vrnd_f64(__intrin);
172 else if constexpr (_TVT::template _S_is<double, 2>)
173 return vrndq_f64(__intrin);
174 else
175 __assert_unreachable<_Tp>();
176 }
177 else if constexpr (is_same_v<_Tp, float>)
178 {
179 auto __intrin = __to_intrin(__x);
180 if constexpr (sizeof(__x) == 16)
181 __intrin = vcvtq_f32_s32(vcvtq_s32_f32(__intrin));
182 else
183 __intrin = vcvt_f32_s32(vcvt_s32_f32(__intrin));
184 return _Base::_S_abs(__x)._M_data < 0x1p23f
185 ? __vector_bitcast<float>(__intrin)
186 : __x._M_data;
187 }
188 else
189 return _Base::_S_trunc(__x);
190 }
191
192 // }}}
193 // _S_round {{{
194 template <typename _Tp, size_t _Np>
195 _GLIBCXX_SIMD_INTRINSIC static _SimdWrapper<_Tp, _Np>
196 _S_round(_SimdWrapper<_Tp, _Np> __x)
197 {
198 if constexpr (__have_neon_a32)
199 {
200 const auto __intrin = __to_intrin(__x);
201 if constexpr (sizeof(_Tp) == 4 && sizeof(__x) == 8)
202 return vrnda_f32(__intrin);
203 else if constexpr (sizeof(_Tp) == 4 && sizeof(__x) == 16)
204 return vrndaq_f32(__intrin);
205 else if constexpr (sizeof(_Tp) == 8 && sizeof(__x) == 8)
206 return vrnda_f64(__intrin);
207 else if constexpr (sizeof(_Tp) == 8 && sizeof(__x) == 16)
208 return vrndaq_f64(__intrin);
209 else
210 __assert_unreachable<_Tp>();
211 }
212 else
213 return _Base::_S_round(__x);
214 }
215
216 // }}}
217 // _S_floor {{{
218 template <typename _Tp, typename _TVT = _VectorTraits<_Tp>>
219 _GLIBCXX_SIMD_INTRINSIC static _Tp _S_floor(_Tp __x)
220 {
221 if constexpr (__have_neon_a32)
222 {
223 const auto __intrin = __to_intrin(__x);
224 if constexpr (_TVT::template _S_is<float, 2>)
225 return vrndm_f32(__intrin);
226 else if constexpr (_TVT::template _S_is<float, 4>)
227 return vrndmq_f32(__intrin);
228 else if constexpr (_TVT::template _S_is<double, 1>)
229 return vrndm_f64(__intrin);
230 else if constexpr (_TVT::template _S_is<double, 2>)
231 return vrndmq_f64(__intrin);
232 else
233 __assert_unreachable<_Tp>();
234 }
235 else
236 return _Base::_S_floor(__x);
237 }
238
239 // }}}
240 // _S_ceil {{{
241 template <typename _Tp, typename _TVT = _VectorTraits<_Tp>>
242 _GLIBCXX_SIMD_INTRINSIC static _Tp _S_ceil(_Tp __x)
243 {
244 if constexpr (__have_neon_a32)
245 {
246 const auto __intrin = __to_intrin(__x);
247 if constexpr (_TVT::template _S_is<float, 2>)
248 return vrndp_f32(__intrin);
249 else if constexpr (_TVT::template _S_is<float, 4>)
250 return vrndpq_f32(__intrin);
251 else if constexpr (_TVT::template _S_is<double, 1>)
252 return vrndp_f64(__intrin);
253 else if constexpr (_TVT::template _S_is<double, 2>)
254 return vrndpq_f64(__intrin);
255 else
256 __assert_unreachable<_Tp>();
257 }
258 else
259 return _Base::_S_ceil(__x);
260 }
261
262 //}}} }}}
263 }; // }}}
264// _MaskImplNeonMixin {{{
265struct _MaskImplNeonMixin
266{
267 using _Base = _MaskImplBuiltinMixin;
268
269 template <typename _Tp, size_t _Np>
270 _GLIBCXX_SIMD_INTRINSIC static constexpr _SanitizedBitMask<_Np>
271 _S_to_bits(_SimdWrapper<_Tp, _Np> __x)
272 {
273 if (__builtin_is_constant_evaluated())
274 return _Base::_S_to_bits(__x);
275
276 using _I = __int_for_sizeof_t<_Tp>;
277 if constexpr (sizeof(__x) == 16)
278 {
279 auto __asint = __vector_bitcast<_I>(__x);
280#ifdef __aarch64__
281 [[maybe_unused]] constexpr auto __zero = decltype(__asint)();
282#else
283 [[maybe_unused]] constexpr auto __zero = decltype(__lo64(__asint))();
284#endif
285 if constexpr (sizeof(_Tp) == 1)
286 {
287 constexpr auto __bitsel
288 = __generate_from_n_evaluations<16, __vector_type_t<_I, 16>>(
289 [&](auto __i) {
290 return static_cast<_I>(
291 __i < _Np ? (__i < 8 ? 1 << __i : 1 << (__i - 8)) : 0);
292 });
293 __asint &= __bitsel;
294#ifdef __aarch64__
295 return __vector_bitcast<_UShort>(
296 vpaddq_s8(vpaddq_s8(vpaddq_s8(__asint, __zero), __zero),
297 __zero))[0];
298#else
299 return __vector_bitcast<_UShort>(
300 vpadd_s8(vpadd_s8(vpadd_s8(__lo64(__asint), __hi64(__asint)),
301 __zero),
302 __zero))[0];
303#endif
304 }
305 else if constexpr (sizeof(_Tp) == 2)
306 {
307 constexpr auto __bitsel
308 = __generate_from_n_evaluations<8, __vector_type_t<_I, 8>>(
309 [&](auto __i) {
310 return static_cast<_I>(__i < _Np ? 1 << __i : 0);
311 });
312 __asint &= __bitsel;
313#ifdef __aarch64__
314 return vaddvq_s16(__asint);
315#else
316 return vpadd_s16(
317 vpadd_s16(vpadd_s16(__lo64(__asint), __hi64(__asint)), __zero),
318 __zero)[0];
319#endif
320 }
321 else if constexpr (sizeof(_Tp) == 4)
322 {
323 constexpr auto __bitsel
324 = __generate_from_n_evaluations<4, __vector_type_t<_I, 4>>(
325 [&](auto __i) {
326 return static_cast<_I>(__i < _Np ? 1 << __i : 0);
327 });
328 __asint &= __bitsel;
329#ifdef __aarch64__
330 return vaddvq_s32(__asint);
331#else
332 return vpadd_s32(vpadd_s32(__lo64(__asint), __hi64(__asint)),
333 __zero)[0];
334#endif
335 }
336 else if constexpr (sizeof(_Tp) == 8)
337 return (__asint[0] & 1) | (__asint[1] & 2);
338 else
339 __assert_unreachable<_Tp>();
340 }
341 else if constexpr (sizeof(__x) == 8)
342 {
343 auto __asint = __vector_bitcast<_I>(__x);
344 [[maybe_unused]] constexpr auto __zero = decltype(__asint)();
345 if constexpr (sizeof(_Tp) == 1)
346 {
347 constexpr auto __bitsel
348 = __generate_from_n_evaluations<8, __vector_type_t<_I, 8>>(
349 [&](auto __i) {
350 return static_cast<_I>(__i < _Np ? 1 << __i : 0);
351 });
352 __asint &= __bitsel;
353#ifdef __aarch64__
354 return vaddv_s8(__asint);
355#else
356 return vpadd_s8(vpadd_s8(vpadd_s8(__asint, __zero), __zero),
357 __zero)[0];
358#endif
359 }
360 else if constexpr (sizeof(_Tp) == 2)
361 {
362 constexpr auto __bitsel
363 = __generate_from_n_evaluations<4, __vector_type_t<_I, 4>>(
364 [&](auto __i) {
365 return static_cast<_I>(__i < _Np ? 1 << __i : 0);
366 });
367 __asint &= __bitsel;
368#ifdef __aarch64__
369 return vaddv_s16(__asint);
370#else
371 return vpadd_s16(vpadd_s16(__asint, __zero), __zero)[0];
372#endif
373 }
374 else if constexpr (sizeof(_Tp) == 4)
375 {
376 __asint &= __make_vector<_I>(0x1, 0x2);
377#ifdef __aarch64__
378 return vaddv_s32(__asint);
379#else
380 return vpadd_s32(__asint, __zero)[0];
381#endif
382 }
383 else
384 __assert_unreachable<_Tp>();
385 }
386 else
387 return _Base::_S_to_bits(__x);
388 }
389};
390
391// }}}
392// _MaskImplNeon {{{
393template <typename _Abi, typename>
394 struct _MaskImplNeon : _MaskImplNeonMixin, _MaskImplBuiltin<_Abi>
395 {
396 using _MaskImplBuiltinMixin::_S_to_maskvector;
397 using _MaskImplNeonMixin::_S_to_bits;
398 using _Base = _MaskImplBuiltin<_Abi>;
399 using _Base::_S_convert;
400
401 // _S_all_of {{{
402 template <typename _Tp>
403 _GLIBCXX_SIMD_INTRINSIC static bool _S_all_of(simd_mask<_Tp, _Abi> __k)
404 {
405 const auto __kk
406 = __vector_bitcast<char>(__k._M_data)
407 | ~__vector_bitcast<char>(_Abi::template _S_implicit_mask<_Tp>());
408 if constexpr (sizeof(__k) == 16)
409 {
410 const auto __x = __vector_bitcast<long long>(__kk);
411 return __x[0] + __x[1] == -2;
412 }
413 else if constexpr (sizeof(__k) <= 8)
414 return __bit_cast<__int_for_sizeof_t<decltype(__kk)>>(__kk) == -1;
415 else
416 __assert_unreachable<_Tp>();
417 }
418
419 // }}}
420 // _S_any_of {{{
421 template <typename _Tp>
422 _GLIBCXX_SIMD_INTRINSIC static bool _S_any_of(simd_mask<_Tp, _Abi> __k)
423 {
424 const auto __kk
425 = __vector_bitcast<char>(__k._M_data)
426 | ~__vector_bitcast<char>(_Abi::template _S_implicit_mask<_Tp>());
427 if constexpr (sizeof(__k) == 16)
428 {
429 const auto __x = __vector_bitcast<long long>(__kk);
430 return (__x[0] | __x[1]) != 0;
431 }
432 else if constexpr (sizeof(__k) <= 8)
433 return __bit_cast<__int_for_sizeof_t<decltype(__kk)>>(__kk) != 0;
434 else
435 __assert_unreachable<_Tp>();
436 }
437
438 // }}}
439 // _S_none_of {{{
440 template <typename _Tp>
441 _GLIBCXX_SIMD_INTRINSIC static bool _S_none_of(simd_mask<_Tp, _Abi> __k)
442 {
443 const auto __kk = _Abi::_S_masked(__k._M_data);
444 if constexpr (sizeof(__k) == 16)
445 {
446 const auto __x = __vector_bitcast<long long>(__kk);
447 return (__x[0] | __x[1]) == 0;
448 }
449 else if constexpr (sizeof(__k) <= 8)
450 return __bit_cast<__int_for_sizeof_t<decltype(__kk)>>(__kk) == 0;
451 else
452 __assert_unreachable<_Tp>();
453 }
454
455 // }}}
456 // _S_some_of {{{
457 template <typename _Tp>
458 _GLIBCXX_SIMD_INTRINSIC static bool _S_some_of(simd_mask<_Tp, _Abi> __k)
459 {
460 if constexpr (sizeof(__k) <= 8)
461 {
462 const auto __kk = __vector_bitcast<char>(__k._M_data)
463 | ~__vector_bitcast<char>(
464 _Abi::template _S_implicit_mask<_Tp>());
465 using _Up = make_unsigned_t<__int_for_sizeof_t<decltype(__kk)>>;
466 return __bit_cast<_Up>(__kk) + 1 > 1;
467 }
468 else
469 return _Base::_S_some_of(__k);
470 }
471
472 // }}}
473 // _S_popcount {{{
474 template <typename _Tp>
475 _GLIBCXX_SIMD_INTRINSIC static int _S_popcount(simd_mask<_Tp, _Abi> __k)
476 {
477 if constexpr (sizeof(_Tp) == 1)
478 {
479 const auto __s8 = __vector_bitcast<_SChar>(__k._M_data);
480 int8x8_t __tmp = __lo64(__s8) + __hi64z(__s8);
481 return -vpadd_s8(vpadd_s8(vpadd_s8(__tmp, int8x8_t()), int8x8_t()),
482 int8x8_t())[0];
483 }
484 else if constexpr (sizeof(_Tp) == 2)
485 {
486 const auto __s16 = __vector_bitcast<short>(__k._M_data);
487 int16x4_t __tmp = __lo64(__s16) + __hi64z(__s16);
488 return -vpadd_s16(vpadd_s16(__tmp, int16x4_t()), int16x4_t())[0];
489 }
490 else if constexpr (sizeof(_Tp) == 4)
491 {
492 const auto __s32 = __vector_bitcast<int>(__k._M_data);
493 int32x2_t __tmp = __lo64(__s32) + __hi64z(__s32);
494 return -vpadd_s32(__tmp, int32x2_t())[0];
495 }
496 else if constexpr (sizeof(_Tp) == 8)
497 {
498 static_assert(sizeof(__k) == 16);
499 const auto __s64 = __vector_bitcast<long>(__k._M_data);
500 return -(__s64[0] + __s64[1]);
501 }
502 }
503
504 // }}}
505 // _S_find_first_set {{{
506 template <typename _Tp>
507 _GLIBCXX_SIMD_INTRINSIC static int
508 _S_find_first_set(simd_mask<_Tp, _Abi> __k)
509 {
510 // TODO: the _Base implementation is not optimal for NEON
511 return _Base::_S_find_first_set(__k);
512 }
513
514 // }}}
515 // _S_find_last_set {{{
516 template <typename _Tp>
517 _GLIBCXX_SIMD_INTRINSIC static int
518 _S_find_last_set(simd_mask<_Tp, _Abi> __k)
519 {
520 // TODO: the _Base implementation is not optimal for NEON
521 return _Base::_S_find_last_set(__k);
522 }
523
524 // }}}
525 }; // }}}
526
527_GLIBCXX_SIMD_END_NAMESPACE
528#endif // __cplusplus >= 201703L
529#endif // _GLIBCXX_EXPERIMENTAL_SIMD_NEON_H_
530// vim: foldmethod=marker sw=2 noet ts=8 sts=2 tw=80
std::make_unsigned_t
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition: type_traits:1937