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view libtommath/bn_mp_reduce_is_2k_l.c @ 756:bf9dc2d9c2b1 ecc
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author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 27 Mar 2013 00:38:03 +0800 |
parents | 5ff8218bcee9 |
children | 60fc6476e044 |
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#include <tommath.h> #ifdef BN_MP_REDUCE_IS_2K_L_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.com */ /* determines if reduce_2k_l can be used */ int mp_reduce_is_2k_l(mp_int *a) { int ix, iy; if (a->used == 0) { return MP_NO; } else if (a->used == 1) { return MP_YES; } else if (a->used > 1) { /* if more than half of the digits are -1 we're sold */ for (iy = ix = 0; ix < a->used; ix++) { if (a->dp[ix] == MP_MASK) { ++iy; } } return (iy >= (a->used/2)) ? MP_YES : MP_NO; } return MP_NO; } #endif /* $Source: /cvs/libtom/libtommath/bn_mp_reduce_is_2k_l.c,v $ */ /* $Revision: 1.3 $ */ /* $Date: 2006/03/31 14:18:44 $ */