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author | gahr <gahr@gahr.ch> | 2016-03-13 17:23:31 (GMT) |
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committer | gahr <gahr@gahr.ch> | 2016-03-13 17:23:31 (GMT) |
commit | 8377ed833a9566731442ef744b419425638d5040 (patch) | |
tree | d6711e0d2ce406178c1d54c9db8a541b792b6b0b /libtommath/bn_mp_get_long.c | |
parent | 48a3d3e4dca22efb2981fd8eb9b505b19438a704 (diff) | |
download | tcl-8377ed833a9566731442ef744b419425638d5040.zip tcl-8377ed833a9566731442ef744b419425638d5040.tar.gz tcl-8377ed833a9566731442ef744b419425638d5040.tar.bz2 |
[e6f27aa56f] Add files I missed in my previous commit
Diffstat (limited to 'libtommath/bn_mp_get_long.c')
-rw-r--r-- | libtommath/bn_mp_get_long.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/libtommath/bn_mp_get_long.c b/libtommath/bn_mp_get_long.c new file mode 100644 index 0000000..7c3d0fe --- /dev/null +++ b/libtommath/bn_mp_get_long.c @@ -0,0 +1,41 @@ +#include <tommath_private.h> +#ifdef BN_MP_GET_LONG_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, tstdenis82@gmail.com, http://libtom.org + */ + +/* get the lower unsigned long of an mp_int, platform dependent */ +unsigned long mp_get_long(mp_int * a) +{ + int i; + unsigned long res; + + if (a->used == 0) { + return 0; + } + + /* get number of digits of the lsb we have to read */ + i = MIN(a->used,(int)(((sizeof(unsigned long) * CHAR_BIT) + DIGIT_BIT - 1) / DIGIT_BIT)) - 1; + + /* get most significant digit of result */ + res = DIGIT(a,i); + +#if (ULONG_MAX != 0xffffffffuL) || (DIGIT_BIT < 32) + while (--i >= 0) { + res = (res << DIGIT_BIT) | DIGIT(a,i); + } +#endif + return res; +} +#endif |