annotate libtommath/bn_mp_sqr.c @ 376:4f2dbd1c3685 channel-fix

Add some code for testing whether a writefd is closed (by read()ing from it)
author Matt Johnston <matt@ucc.asn.au>
date Tue, 05 Dec 2006 15:23:06 +0000
parents eed26cff980b
children 5ff8218bcee9
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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284
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1 #include <tommath.h>
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2 #ifdef BN_MP_SQR_C
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
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4 *
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5 * LibTomMath is a library that provides multiple-precision
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6 * integer arithmetic as well as number theoretic functionality.
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7 *
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8 * The library was designed directly after the MPI library by
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9 * Michael Fromberger but has been written from scratch with
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10 * additional optimizations in place.
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11 *
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12 * The library is free for all purposes without any express
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13 * guarantee it works.
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14 *
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15 * Tom St Denis, [email protected], http://math.libtomcrypt.org
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16 */
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17
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18 /* computes b = a*a */
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19 int
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20 mp_sqr (mp_int * a, mp_int * b)
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21 {
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22 int res;
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23
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24 #ifdef BN_MP_TOOM_SQR_C
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25 /* use Toom-Cook? */
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26 if (a->used >= TOOM_SQR_CUTOFF) {
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27 res = mp_toom_sqr(a, b);
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28 /* Karatsuba? */
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29 } else
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30 #endif
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31 #ifdef BN_MP_KARATSUBA_SQR_C
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32 if (a->used >= KARATSUBA_SQR_CUTOFF) {
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33 res = mp_karatsuba_sqr (a, b);
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34 } else
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35 #endif
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36 {
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37 #ifdef BN_FAST_S_MP_SQR_C
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38 /* can we use the fast comba multiplier? */
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39 if ((a->used * 2 + 1) < MP_WARRAY &&
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40 a->used <
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41 (1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) {
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42 res = fast_s_mp_sqr (a, b);
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43 } else
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44 #endif
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45 #ifdef BN_S_MP_SQR_C
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46 res = s_mp_sqr (a, b);
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47 #else
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48 res = MP_VAL;
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49 #endif
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50 }
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51 b->sign = MP_ZPOS;
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52 return res;
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53 }
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54 #endif