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author | William Joye <wjoye@cfa.harvard.edu> | 2016-10-18 17:31:11 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-10-18 17:31:11 (GMT) |
commit | 066971b1e6e77991d9161bb0216a63ba94ea04f9 (patch) | |
tree | 6de02f79b7a4bb08a329581aa67b444fb9001bfd /tcl8.6/libtommath/bn_mp_count_bits.c | |
parent | ba065c2de121da1c1dfddd0aa587d10e7e150f05 (diff) | |
parent | 9966985d896629eede849a84f18e406d1164a16c (diff) | |
download | blt-066971b1e6e77991d9161bb0216a63ba94ea04f9.zip blt-066971b1e6e77991d9161bb0216a63ba94ea04f9.tar.gz blt-066971b1e6e77991d9161bb0216a63ba94ea04f9.tar.bz2 |
Merge commit '9966985d896629eede849a84f18e406d1164a16c' as 'tcl8.6'
Diffstat (limited to 'tcl8.6/libtommath/bn_mp_count_bits.c')
-rw-r--r-- | tcl8.6/libtommath/bn_mp_count_bits.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/tcl8.6/libtommath/bn_mp_count_bits.c b/tcl8.6/libtommath/bn_mp_count_bits.c new file mode 100644 index 0000000..00d364e --- /dev/null +++ b/tcl8.6/libtommath/bn_mp_count_bits.c @@ -0,0 +1,41 @@ +#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://math.libtomcrypt.com + */ + +/* returns the number of bits in an int */ +int +mp_count_bits (const 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 |