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annotate tomsfastmath/src/bit/fp_count_bits.c @ 645:8622ee48fab5 dropbear-tfm

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- Work around broken asm constraint behaviour on 32bit x86 OS X
author Matt Johnston <matt@ucc.asn.au>
date Wed, 30 Nov 2011 22:27:26 +0800
parents a362b62d38b2
children
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a362b62d38b2 Add tomsfastmath from git rev bfa4582842bc3bab42e4be4aed5703437049502a
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1 /* TomsFastMath, a fast ISO C bignum library.
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2 *
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3 * This project is meant to fill in where LibTomMath
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4 * falls short. That is speed ;-)
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5 *
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6 * This project is public domain and free for all purposes.
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7 *
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8 * Tom St Denis, [email protected]
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9 */
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10 #include <tfm.h>
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12 int fp_count_bits (fp_int * a)
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13 {
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14 int r;
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15 fp_digit q;
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17 /* shortcut */
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18 if (a->used == 0) {
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19 return 0;
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20 }
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22 /* get number of digits and add that */
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23 r = (a->used - 1) * DIGIT_BIT;
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25 /* take the last digit and count the bits in it */
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26 q = a->dp[a->used - 1];
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27 while (q > ((fp_digit) 0)) {
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28 ++r;
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29 q >>= ((fp_digit) 1);
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30 }
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31 return r;
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32 }
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34 /* $Source$ */
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35 /* $Revision$ */
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36 /* $Date$ */