30 lines
719 B
C
30 lines
719 B
C
#include "amplify_tommath_private.h"
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#ifdef AMPLIFY_BN_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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/* Modifications Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. */
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/* returns the number of bits in an int */
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int amplify_mp_count_bits(const amplify_mp_int *a)
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{
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int r;
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amplify_mp_digit q;
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/* shortcut */
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if (AMPLIFY_MP_IS_ZERO(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) * AMPLIFY_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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