Where Online Learning is simpler!

The C and C++ Include Header Files

/usr/include/c++/11/experimental/bits/simd_ppc.h


$ cat -n /usr/include/c++/11/experimental/bits/simd_ppc.h

     1	// Simd PowerPC specific implementations -*- C++ -*-
     2	
     3	// Copyright (C) 2020-2021 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_PPC_H_
    26	#define _GLIBCXX_EXPERIMENTAL_SIMD_PPC_H_
    27	
    28	#if __cplusplus >= 201703L
    29	
    30	#ifndef __ALTIVEC__
    31	#error "simd_ppc.h may only be included when AltiVec/VMX is available"
    32	#endif
    33	#include <altivec.h>
    34	
    35	_GLIBCXX_SIMD_BEGIN_NAMESPACE
    36	
    37	// _SimdImplPpc {{{
    38	template <typename _Abi>
    39	  struct _SimdImplPpc : _SimdImplBuiltin<_Abi>
    40	  {
    41	    using _Base = _SimdImplBuiltin<_Abi>;
    42	
    43	    // Byte and halfword shift instructions on PPC only consider the low 3 or 4
    44	    // bits of the RHS. Consequently, shifting by sizeof(_Tp)*CHAR_BIT (or more)
    45	    // is UB without extra measures. To match scalar behavior, byte and halfword
    46	    // shifts need an extra fixup step.
    47	
    48	    // _S_bit_shift_left {{{
    49	    template <typename _Tp, size_t _Np>
    50	      _GLIBCXX_SIMD_INTRINSIC static constexpr _SimdWrapper<_Tp, _Np>
    51	      _S_bit_shift_left(_SimdWrapper<_Tp, _Np> __x, _SimdWrapper<_Tp, _Np> __y)
    52	      {
    53		__x = _Base::_S_bit_shift_left(__x, __y);
    54		if constexpr (sizeof(_Tp) < sizeof(int))
    55		  __x._M_data
    56		    = (__y._M_data < sizeof(_Tp) * __CHAR_BIT__) & __x._M_data;
    57		return __x;
    58	      }
    59	
    60	    template <typename _Tp, size_t _Np>
    61	      _GLIBCXX_SIMD_INTRINSIC static constexpr _SimdWrapper<_Tp, _Np>
    62	      _S_bit_shift_left(_SimdWrapper<_Tp, _Np> __x, int __y)
    63	      {
    64		__x = _Base::_S_bit_shift_left(__x, __y);
    65		if constexpr (sizeof(_Tp) < sizeof(int))
    66		  {
    67		    if (__y >= int(sizeof(_Tp) * __CHAR_BIT__))
    68		      return {};
    69		  }
    70		return __x;
    71	      }
    72	
    73	    // }}}
    74	    // _S_bit_shift_right {{{
    75	    template <typename _Tp, size_t _Np>
    76	      _GLIBCXX_SIMD_INTRINSIC static constexpr _SimdWrapper<_Tp, _Np>
    77	      _S_bit_shift_right(_SimdWrapper<_Tp, _Np> __x, _SimdWrapper<_Tp, _Np> __y)
    78	      {
    79		if constexpr (sizeof(_Tp) < sizeof(int))
    80		  {
    81		    constexpr int __nbits = sizeof(_Tp) * __CHAR_BIT__;
    82		    if constexpr (is_unsigned_v<_Tp>)
    83		      return (__y._M_data < __nbits)
    84			     & _Base::_S_bit_shift_right(__x, __y)._M_data;
    85		    else
    86		      {
    87			_Base::_S_masked_assign(_SimdWrapper<_Tp, _Np>(__y._M_data
    88								       >= __nbits),
    89						__y, __nbits - 1);
    90			return _Base::_S_bit_shift_right(__x, __y);
    91		      }
    92		  }
    93		else
    94		  return _Base::_S_bit_shift_right(__x, __y);
    95	      }
    96	
    97	    template <typename _Tp, size_t _Np>
    98	      _GLIBCXX_SIMD_INTRINSIC static constexpr _SimdWrapper<_Tp, _Np>
    99	      _S_bit_shift_right(_SimdWrapper<_Tp, _Np> __x, int __y)
   100	      {
   101		if constexpr (sizeof(_Tp) < sizeof(int))
   102		  {
   103		    constexpr int __nbits = sizeof(_Tp) * __CHAR_BIT__;
   104		    if (__y >= __nbits)
   105		      {
   106			if constexpr (is_unsigned_v<_Tp>)
   107			  return {};
   108			else
   109			  return _Base::_S_bit_shift_right(__x, __nbits - 1);
   110		      }
   111		  }
   112		return _Base::_S_bit_shift_right(__x, __y);
   113	      }
   114	
   115	    // }}}
   116	  };
   117	
   118	// }}}
   119	// _MaskImplPpc {{{
   120	template <typename _Abi>
   121	  struct _MaskImplPpc : _MaskImplBuiltin<_Abi>
   122	  {
   123	    using _Base = _MaskImplBuiltin<_Abi>;
   124	
   125	    // _S_popcount {{{
   126	    template <typename _Tp>
   127	      _GLIBCXX_SIMD_INTRINSIC static int
   128	      _S_popcount(simd_mask<_Tp, _Abi> __k)
   129	      {
   130		const auto __kv = __as_vector(__k);
   131		if constexpr (__have_power10vec)
   132		  {
   133		    using _Intrin = __intrinsic_type16_t<make_unsigned_t<__int_for_sizeof_t<_Tp>>>;
   134		    return vec_cntm(reinterpret_cast<_Intrin>(__kv), 1);
   135		  }
   136		else if constexpr (sizeof(_Tp) >= sizeof(int))
   137		  {
   138		    using _Intrin = __intrinsic_type16_t<int>;
   139		    const int __sum = -vec_sums(__intrin_bitcast<_Intrin>(__kv), _Intrin())[3];
   140		    return __sum / (sizeof(_Tp) / sizeof(int));
   141		  }
   142		else
   143		  {
   144		    const auto __summed_to_int = vec_sum4s(__to_intrin(__kv), __intrinsic_type16_t<int>());
   145		    return -vec_sums(__summed_to_int, __intrinsic_type16_t<int>())[3];
   146		  }
   147	      }
   148	
   149	    // }}}
   150	  };
   151	
   152	// }}}
   153	
   154	_GLIBCXX_SIMD_END_NAMESPACE
   155	#endif // __cplusplus >= 201703L
   156	#endif // _GLIBCXX_EXPERIMENTAL_SIMD_PPC_H_
   157	
   158	// vim: foldmethod=marker foldmarker={{{,}}} sw=2 noet ts=8 sts=2 tw=100