diff options
| author | Stanislav Sedov <stas@FreeBSD.org> | 2011-10-05 07:23:29 +0000 |
|---|---|---|
| committer | Stanislav Sedov <stas@FreeBSD.org> | 2011-10-05 07:23:29 +0000 |
| commit | 7c450da7b446c557e05f34a100b597800967d987 (patch) | |
| tree | 57a48e7e9b592f2d5b713e80a4455820625c2b7b /lib/hcrypto/libtommath/bn_mp_count_bits.c | |
| parent | b4e3a10e9339a8400197298021d6ca9b8e3aa039 (diff) | |
Diffstat (limited to 'lib/hcrypto/libtommath/bn_mp_count_bits.c')
| -rw-r--r-- | lib/hcrypto/libtommath/bn_mp_count_bits.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/lib/hcrypto/libtommath/bn_mp_count_bits.c b/lib/hcrypto/libtommath/bn_mp_count_bits.c new file mode 100644 index 000000000000..5dfd5f375cb6 --- /dev/null +++ b/lib/hcrypto/libtommath/bn_mp_count_bits.c @@ -0,0 +1,45 @@ +#include <tommath.h> +#ifdef BN_MP_COUNT_BITS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ + +/* returns the number of bits in an int */ +int +mp_count_bits (mp_int * a) +{ + int r; + mp_digit q; + + /* shortcut */ + if (a->used == 0) { + return 0; + } + + /* get number of digits and add that */ + r = (a->used - 1) * DIGIT_BIT; + + /* take the last digit and count the bits in it */ + q = a->dp[a->used - 1]; + while (q > ((mp_digit) 0)) { + ++r; + q >>= ((mp_digit) 1); + } + return r; +} +#endif + +/* $Source: /cvs/libtom/libtommath/bn_mp_count_bits.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/12/28 01:25:13 $ */ |
