gnu / binutils-gdb / 777b054cf93ad2525b891ea15bbf8d5cd6a56339 / . / gnulib / import / count-one-bits.h

/* count-one-bits.h -- counts the number of 1-bits in a word. | |

Copyright (C) 2007-2021 Free Software Foundation, Inc. | |

This program is free software: you can redistribute it and/or modify | |

it under the terms of the GNU General Public License as published by | |

the Free Software Foundation; either version 3 of the License, or | |

(at your option) any later version. | |

This program is distributed in the hope that it will be useful, | |

but WITHOUT ANY WARRANTY; without even the implied warranty of | |

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |

GNU General Public License for more details. | |

You should have received a copy of the GNU General Public License | |

along with this program. If not, see <https://www.gnu.org/licenses/>. */ | |

/* Written by Ben Pfaff. */ | |

#ifndef COUNT_ONE_BITS_H | |

#define COUNT_ONE_BITS_H 1 | |

#include <limits.h> | |

#include <stdlib.h> | |

#ifndef _GL_INLINE_HEADER_BEGIN | |

#error "Please include config.h first." | |

#endif | |

_GL_INLINE_HEADER_BEGIN | |

#ifndef COUNT_ONE_BITS_INLINE | |

# define COUNT_ONE_BITS_INLINE _GL_INLINE | |

#endif | |

#ifdef __cplusplus | |

extern "C" { | |

#endif | |

/* Assuming the GCC builtin is GCC_BUILTIN and the MSC builtin is MSC_BUILTIN, | |

expand to code that computes the number of 1-bits of the local | |

variable 'x' of type TYPE (an unsigned integer type) and return it | |

from the current function. */ | |

#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) \ | |

|| (__clang_major__ >= 4) | |

# define COUNT_ONE_BITS(GCC_BUILTIN, MSC_BUILTIN, TYPE) \ | |

return GCC_BUILTIN (x) | |

#else | |

/* Compute and return the number of 1-bits set in the least | |

significant 32 bits of X. */ | |

COUNT_ONE_BITS_INLINE int | |

count_one_bits_32 (unsigned int x) | |

{ | |

x = ((x & 0xaaaaaaaaU) >> 1) + (x & 0x55555555U); | |

x = ((x & 0xccccccccU) >> 2) + (x & 0x33333333U); | |

x = (x >> 16) + (x & 0xffff); | |

x = ((x & 0xf0f0) >> 4) + (x & 0x0f0f); | |

return (x >> 8) + (x & 0x00ff); | |

} | |

/* Expand to code that computes the number of 1-bits of the local | |

variable 'x' of type TYPE (an unsigned integer type) and return it | |

from the current function. */ | |

# define COUNT_ONE_BITS_GENERIC(TYPE) \ | |

do \ | |

{ \ | |

int count = 0; \ | |

int bits; \ | |

for (bits = 0; bits < sizeof (TYPE) * CHAR_BIT; bits += 32) \ | |

{ \ | |

count += count_one_bits_32 (x); \ | |

x = x >> 31 >> 1; \ | |

} \ | |

return count; \ | |

} \ | |

while (0) | |

# if 1500 <= _MSC_VER && (defined _M_IX86 || defined _M_X64) | |

/* While gcc falls back to its own generic code if the machine | |

on which it's running doesn't support popcount, with Microsoft's | |

compiler we need to detect and fallback ourselves. */ | |

# if 0 | |

# include <intrin.h> | |

# else | |

/* Don't pollute the namespace with too many MSVC intrinsics. */ | |

# pragma intrinsic (__cpuid) | |

# pragma intrinsic (__popcnt) | |

# if defined _M_X64 | |

# pragma intrinsic (__popcnt64) | |

# endif | |

# endif | |

# if !defined _M_X64 | |

static inline __popcnt64 (unsigned long long x) | |

{ | |

return __popcnt ((unsigned int) (x >> 32)) + __popcnt ((unsigned int) x); | |

} | |

# endif | |

/* Return nonzero if popcount is supported. */ | |

/* 1 if supported, 0 if not supported, -1 if unknown. */ | |

extern int popcount_support; | |

COUNT_ONE_BITS_INLINE int | |

popcount_supported (void) | |

{ | |

if (popcount_support < 0) | |

{ | |

/* Do as described in | |

<https://docs.microsoft.com/en-us/cpp/intrinsics/popcnt16-popcnt-popcnt64> */ | |

int cpu_info[4]; | |

__cpuid (cpu_info, 1); | |

popcount_support = (cpu_info[2] >> 23) & 1; | |

} | |

return popcount_support; | |

} | |

# define COUNT_ONE_BITS(GCC_BUILTIN, MSC_BUILTIN, TYPE) \ | |

do \ | |

{ \ | |

if (popcount_supported ()) \ | |

return MSC_BUILTIN (x); \ | |

else \ | |

COUNT_ONE_BITS_GENERIC (TYPE); \ | |

} \ | |

while (0) | |

# else | |

# define COUNT_ONE_BITS(GCC_BUILTIN, MSC_BUILTIN, TYPE) \ | |

COUNT_ONE_BITS_GENERIC (TYPE) | |

# endif | |

#endif | |

/* Compute and return the number of 1-bits set in X. */ | |

COUNT_ONE_BITS_INLINE int | |

count_one_bits (unsigned int x) | |

{ | |

COUNT_ONE_BITS (__builtin_popcount, __popcnt, unsigned int); | |

} | |

/* Compute and return the number of 1-bits set in X. */ | |

COUNT_ONE_BITS_INLINE int | |

count_one_bits_l (unsigned long int x) | |

{ | |

COUNT_ONE_BITS (__builtin_popcountl, __popcnt, unsigned long int); | |

} | |

/* Compute and return the number of 1-bits set in X. */ | |

COUNT_ONE_BITS_INLINE int | |

count_one_bits_ll (unsigned long long int x) | |

{ | |

COUNT_ONE_BITS (__builtin_popcountll, __popcnt64, unsigned long long int); | |

} | |

#ifdef __cplusplus | |

} | |

#endif | |

_GL_INLINE_HEADER_END | |

#endif /* COUNT_ONE_BITS_H */ |