29 lines
572 B
C
29 lines
572 B
C
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#include "tommath_private.h"
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#ifdef MP_COUNT_BITS_C
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/* LibTomMath, multiple-precision integer library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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/* returns the number of bits in an int */
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int mp_count_bits(const mp_int *a)
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{
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int r;
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mp_digit q;
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/* shortcut */
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if (mp_iszero(a)) {
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return 0;
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}
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/* get number of digits and add that */
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r = (a->used - 1) * MP_DIGIT_BIT;
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/* take the last digit and count the bits in it */
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q = a->dp[a->used - 1];
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while (q > 0u) {
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++r;
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q >>= 1u;
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}
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return r;
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}
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#endif
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