/* -*-c-*-
*
- * $Id: mp-sqrt.c,v 1.2 2000/10/08 12:02:21 mdw Exp $
+ * $Id$
*
* Compute integer square roots
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: mp-sqrt.c,v $
- * Revision 1.2 2000/10/08 12:02:21 mdw
- * Use @MP_EQ@ instead of @MP_CMP@.
- *
- * Revision 1.1 2000/06/22 19:01:44 mdw
- * Compute (approximations to) integer square roots.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include "mp.h"
/* --- Sanity preservation --- */
- assert(((void)"imaginary root in mp_sqrt", !(a->f & MP_NEG)));
+ assert(!MP_NEGP(a));
/* --- Deal with trivial cases --- */
MP_SHRINK(a);
- if (a->v == a->vl) {
- if (d)
- mp_drop(d);
+ if (MP_ZEROP(a)) {
+ mp_drop(d);
return (MP_ZERO);
}
z >>= 1;
mp_copy(a);
d = mp_lsr(d, a, z);
- mp_drop(a);
/* --- Main approximation --- *
*
for (;;) {
q = mp_sqr(q, d);
q = mp_sub(q, q, a);
- if (q->v == q->vl)
+ if (MP_ZEROP(q))
break;
- if (q->f & MP_NEG) {
+ if (MP_NEGP(q)) {
r = mp_lsl(r, d, 1);
r->f |= MP_NEG;
- if (MP_CMP(q, <=, r))
+ if (MP_CMP(q, >=, r))
break;
}
mp_div(&r, &q, q, d);
/* --- Finished, at last --- */
+ mp_drop(a);
mp_drop(q);
- if (r)
- mp_drop(r);
+ mp_drop(r);
return (d);
}