kc3-lang/libtommath/mp_decr.c

• Show log

  Commit

• Hash : 7a68f128
  Author :
  Date : 2019-10-19T16:24:39
  

  Execute move.sh - Rename files from bn_* to match the function names. * git blame <renamed-file> is not affected * git log --follow <renamed-file> can be used to show log across renames

Download

• mp_decr.c

• #include "tommath_private.h"
  #ifdef MP_DECR_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* Decrement "a" by one like "a--". Changes input! */
  mp_err mp_decr(mp_int *a)
  {
     if (MP_IS_ZERO(a)) {
        mp_set(a,1uL);
        a->sign = MP_NEG;
        return MP_OKAY;
     } else if (a->sign == MP_NEG) {
        mp_err err;
        a->sign = MP_ZPOS;
        if ((err = mp_incr(a)) != MP_OKAY) {
           return err;
        }
        /* There is no -0 in LTM */
        if (!MP_IS_ZERO(a)) {
           a->sign = MP_NEG;
        }
        return MP_OKAY;
     } else if (a->dp[0] > 1uL) {
        a->dp[0]--;
        if (a->dp[0] == 0u) {
           mp_zero(a);
        }
        return MP_OKAY;
     } else {
        return mp_sub_d(a, 1uL,a);
     }
  }
  #endif
  

Download