/* -*-c-*-
*
- * $Id: mpx-ksqr.c,v 1.1 1999/12/11 10:57:43 mdw Exp $
+ * $Id: mpx-ksqr.c,v 1.2 1999/12/13 15:35:01 mdw Exp $
*
* Karatsuba-based squaring algorithm
*
/*----- Revision history --------------------------------------------------*
*
* $Log: mpx-ksqr.c,v $
+ * Revision 1.2 1999/12/13 15:35:01 mdw
+ * Simplify and improve.
+ *
* Revision 1.1 1999/12/11 10:57:43 mdw
* Karatsuba squaring algorithm.
*
/*----- Header files ------------------------------------------------------*/
+#include <assert.h>
#include <stdio.h>
#include "mpx.h"
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 *ssv = sv + 2 * m;
+ mpw *svm = sv + m, *svn = svm + m, *ssv = svn + 4;
mpw *tdv = dv + m;
mpw *rdv = tdv + m;
mpx_kmul(sv, ssv, av, avm, avm, avl, ssv, svl);
else
mpx_umul(sv, ssv, av, avm, avm, avl);
- ULSL1(tdv, sv, ssv);
- MPX_ZERO(dv, tdv);
- MPX_ZERO(rdv + m + 1, dvl);
+ ULSL1(tdv, sv, svn);
if (m > KARATSUBA_CUTOFF)
mpx_ksqr(sv, ssv, avm, avl, ssv, svl);
else
mpx_usqr(sv, ssv, avm, avl);
- UADD(rdv, sv, ssv);
+ MPX_COPY(rdv + m + 1, dvl, svm + 1, svn);
+ UADD(rdv, sv, svm + 1);
if (m > KARATSUBA_CUTOFF)
mpx_ksqr(sv, ssv, av, avm, ssv, svl);
else
mpx_usqr(sv, ssv, av, avm);
- UADD(dv, sv, ssv);
+ MPX_COPY(dv, tdv, sv, svm);
+ UADD(tdv, svm, svn);
}
}