Mercurial > dropbear
view libtommath/bn_mp_count_bits.c @ 1692:1051e4eea25a
Update LibTomMath to 1.2.0 (#84)
* update C files
* update other files
* update headers
* update makefiles
* remove mp_set/get_double()
* use ltm 1.2.0 API
* update ltm_desc
* use bundled tommath if system-tommath is too old
* XMALLOC etc. were changed to MP_MALLOC etc.
author | Steffen Jaeckel <s@jaeckel.eu> |
---|---|
date | Tue, 26 May 2020 17:36:47 +0200 |
parents | f52919ffd3b1 |
children |
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#include "tommath_private.h" #ifdef BN_MP_COUNT_BITS_C /* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ /* returns the number of bits in an int */ int mp_count_bits(const mp_int *a) { int r; mp_digit q; /* shortcut */ if (MP_IS_ZERO(a)) { return 0; } /* get number of digits and add that */ r = (a->used - 1) * MP_DIGIT_BIT; /* take the last digit and count the bits in it */ q = a->dp[a->used - 1]; while (q > 0u) { ++r; q >>= 1u; } return r; } #endif