annotate libtommath/bn_mp_incr.c @ 1754:064f5be2fc45

Add buf_decrpos()
author Matt Johnston <matt@ucc.asn.au>
date Sat, 24 Oct 2020 18:56:45 +0800
parents 1051e4eea25a
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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1692
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1 #include "tommath_private.h"
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2 #ifdef BN_MP_INCR_C
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3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
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4 /* SPDX-License-Identifier: Unlicense */
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5
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6 /* Increment "a" by one like "a++". Changes input! */
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7 mp_err mp_incr(mp_int *a)
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8 {
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9 if (MP_IS_ZERO(a)) {
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10 mp_set(a,1uL);
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11 return MP_OKAY;
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12 } else if (a->sign == MP_NEG) {
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13 mp_err err;
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14 a->sign = MP_ZPOS;
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15 if ((err = mp_decr(a)) != MP_OKAY) {
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16 return err;
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17 }
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18 /* There is no -0 in LTM */
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19 if (!MP_IS_ZERO(a)) {
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20 a->sign = MP_NEG;
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21 }
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22 return MP_OKAY;
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23 } else if (a->dp[0] < MP_DIGIT_MAX) {
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24 a->dp[0]++;
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25 return MP_OKAY;
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26 } else {
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27 return mp_add_d(a, 1uL,a);
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28 }
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29 }
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30 #endif