Mercurial > dropbear
view bn_mp_count_bits.c @ 385:fa7a368e12b1 libtommath-dropbear
Refer to local headers locally with #include "" not #include <>.
Required now that we've got rid of the libtomcrypt variants that were
'accidentally' being included in the -I path
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 11 Jan 2007 03:09:09 +0000 |
parents | 91fbc376f010 |
children | 97db060d0ef5 |
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#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, [email protected], http://math.libtomcrypt.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