crypto/bn/bn_div.c

194     BIGNUM *tmp, wnum, *snum, *sdiv, *res;
241     sdiv = BN_CTX_get(ctx);
246     if (sdiv == NULL || res == NULL || tmp == NULL || snum == NULL)
251     if (!(BN_lshift(sdiv, divisor, norm_shift)))
253     sdiv->neg = 0;
258     div_n = sdiv->top;
273     /* Get the top 2 words of sdiv */
274     /* div_n=sdiv->top; */
275     d0 = sdiv->d[div_n - 1];
276     d1 = (div_n == 1) ? 0 : sdiv->d[div_n - 2];
292     if (BN_ucmp(&wnum, sdiv) >= 0) {
299         bn_sub_words(wnum.d, wnum.d, sdiv->d, div_n);
315          * the first part of the loop uses the top two words of snum and sdiv
316          * to calculate a BN_ULONG q such that | wnum - sdiv * q | < sdiv
404         l0 = bn_mul_words(tmp->d, sdiv->d, div_n, q);
414              * the calculation of q, sdiv * q might be greater than wnum (but
415              * then (q-1) * sdiv is less or equal than wnum)
418             if (bn_add_words(wnum.d, wnum.d, sdiv->d, div_n))
456     BIGNUM *tmp, wnum, *snum, *sdiv, *res;
476     sdiv = BN_CTX_get(ctx);
481     if (sdiv == NULL || res == NULL)
486     if (!(BN_lshift(sdiv, divisor, norm_shift)))
488     sdiv->neg = 0;
495      * Since we don't know whether snum is larger than sdiv, we pad snum with
498     if (snum->top <= sdiv->top + 1) {
499         if (bn_wexpand(snum, sdiv->top + 2) == NULL)
501         for (i = snum->top; i < sdiv->top + 2; i++)
503         snum->top = sdiv->top + 2;
511     div_n = sdiv->top;
526     /* Get the top 2 words of sdiv */
527     /* div_n=sdiv->top; */
528     d0 = sdiv->d[div_n - 1];
529     d1 = (div_n == 1) ? 0 : sdiv->d[div_n - 2];
557          * the first part of the loop uses the top two words of snum and sdiv
558          * to calculate a BN_ULONG q such that | wnum - sdiv * q | < sdiv
646         l0 = bn_mul_words(tmp->d, sdiv->d, div_n, q);
656              * the calculation of q, sdiv * q might be greater than wnum (but
657              * then (q-1) * sdiv is less or equal than wnum)
660             if (bn_add_words(wnum.d, wnum.d, sdiv->d, div_n))