39 lines
992 B
C
39 lines
992 B
C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
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*
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* LibTomMath is a library that provides multiple-precision
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* integer arithmetic as well as number theoretic functionality.
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*
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* The library was designed directly after the MPI library by
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* Michael Fromberger but has been written from scratch with
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* additional optimizations in place.
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*
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* The library is free for all purposes without any express
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* guarantee it works.
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*
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* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
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*/
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#include <tommath.h>
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/* determines if mp_reduce_2k can be used */
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int
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mp_reduce_is_2k(mp_int *a)
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{
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int ix, iy;
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if (a->used == 0) {
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return 0;
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} else if (a->used == 1) {
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return 1;
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} else if (a->used > 1) {
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iy = mp_count_bits(a);
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for (ix = DIGIT_BIT; ix < iy; ix++) {
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if ((a->dp[ix/DIGIT_BIT] &
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((mp_digit)1 << (mp_digit)(ix % DIGIT_BIT))) == 0) {
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return 0;
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}
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}
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}
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return 1;
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}
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