/* -*-c-*-
*
- * $Id: mp-arith.c,v 1.4 1999/12/13 15:35:16 mdw Exp $
+ * $Id: mp-arith.c,v 1.5 1999/12/22 15:54:41 mdw Exp $
*
* Basic arithmetic on multiprecision integers
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mp-arith.c,v $
+ * Revision 1.5 1999/12/22 15:54:41 mdw
+ * Adjust Karatsuba parameters. Calculate destination size better.
+ *
* Revision 1.4 1999/12/13 15:35:16 mdw
* Slightly different rules on memory allocation.
*
mp *mp_mul(mp *d, mp *a, mp *b)
{
- size_t m = MAX(MP_LEN(a), MP_LEN(b)) * 2 + KARATSUBA_SLOP;
-
a = MP_COPY(a);
b = MP_COPY(b);
MP_MODIFY(d, MP_LEN(a) + MP_LEN(b));
mpx_umul(d->v, d->vl, a->v, a->vl, b->v, b->vl);
} else {
+ size_t m = 2 * MAX(MP_LEN(a), MP_LEN(b)) + 2;
mpw *s;
- m += 32;
+ MP_MODIFY(d, m);
+ m += KARATSUBA_SLOP;
s = MP_ALLOC(m);
- MP_MODIFY(d, 2 * m + 2);
mpx_kmul(d->v, d->vl, a->v, a->vl, b->v, b->vl, s, s + m);
MP_FREE(s);
}
MP_MODIFY(d, 2 * m + 2);
if (m > KARATSUBA_CUTOFF) {
mpw *s;
- m = 2 * (m + 1) + 32;
+ m = 2 * (m + 1) + KARATSUBA_SLOP;
s = MP_ALLOC(m);
mpx_ksqr(d->v, d->vl, a->v, a->vl, s, s + m);
MP_FREE(s);