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src/int_ceil_log2.c
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Vincent Lefevre
Updated the "Contributed" lines.
02 фев 2025, 02:39
02 фев 2025, 02:39
a774f60
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/* __gmpfr_int_ceil_log2 -- Integer ceil of log2(x) Copyright 2004-2025 Free Software Foundation, Inc. Contributed by the Pascaline and Caramba projects, INRIA. This file is part of the GNU MPFR Library. The GNU MPFR Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. The GNU MPFR Library 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see <https://www.gnu.org/licenses/>. */ #define MPFR_NEED_LONGLONG_H /* for count_leading_zeros */ #include "mpfr-impl.h" int __gmpfr_int_ceil_log2 (unsigned long n) { if (MPFR_UNLIKELY (n == 1)) return 0; else #ifdef MPFR_LONG_WITHIN_LIMB { int b; mp_limb_t limb; MPFR_ASSERTN (n > 1); limb = n - 1; MPFR_ASSERTN (limb == n - 1); count_leading_zeros (b, limb); b = GMP_NUMB_BITS - b; MPFR_ASSERTD (b >= 0); return b; } #else return mpfr_nbits_ulong (n - 1); #endif }