/* -*-c-*-
*
- * $Id: mpx-ksqr.c,v 1.6 2000/10/08 15:48:35 mdw Exp $
+ * $Id: mpx-ksqr.c,v 1.7 2002/10/09 00:36:03 mdw Exp $
*
* Karatsuba-based squaring algorithm
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mpx-ksqr.c,v $
+ * Revision 1.7 2002/10/09 00:36:03 mdw
+ * Fix bounds on workspace for Karatsuba operations.
+ *
* Revision 1.6 2000/10/08 15:48:35 mdw
* Rename Karatsuba constants now that we have @gfx_kmul@ too.
*
#ifdef TEST_RIG
# undef MPK_THRESH
-# define MPK_THRESH 2
+# define MPK_THRESH 4
#endif
/*----- Main code ---------------------------------------------------------*/
* large numbers, although more expensive on small ones, and
* rather simpler than full-blown Karatsuba multiplication.
*
- * The destination must be twice as large as the argument. The
- * scratch space must be twice as large as the argument, plus
- * the magic number @MPK_SLOP@.
+ * The destination must be three times as large as the larger
+ * argument. The scratch space must be five times as large as
+ * the larger argument.
*/
void mpx_ksqr(mpw *dv, mpw *dvl,
m = (avl - av + 1) >> 1;
avm = av + m;
- assert(((void)"Destination too small for Karatsuba square",
- dvl - dv >= 4 * m));
- assert(((void)"Not enough workspace for Karatsuba square",
- svl - sv >= 4 * m));
-
/* --- Sort out everything --- */
{
mpw *tdv = dv + m;
mpw *rdv = tdv + m;
+ assert(rdv + m + 4 < dvl);
+ assert(ssv < svl);
UADD2(sv, svm, av, avm, avm, avl);
if (m > MPK_THRESH)
mpx_ksqr(tdv, rdv + m + 4, sv, svm + 1, ssv, svl);
LOAD(a, al, &v[0]);
LOAD(c, cl, &v[1]);
m = al - a + 1;
- ALLOC(d, dl, 2 * m);
- ALLOC(s, sl, 2 * m + 32);
+ ALLOC(d, dl, 3 * m);
+ ALLOC(s, sl, 5 * m);
mpx_ksqr(d, dl, a, al, s, sl);
if (!mpx_ueq(d, dl, c, cl)) {