X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/52cdaca9b7b8e15871a3de8b5b571c18dcc580f8..0f9bd85aa42c06b55d7a4e1693981233d95c62ff:/mpx-ksqr.c

diff --git a/mpx-ksqr.c b/mpx-ksqr.c
index 25dbb70..ba7aa18 100644
--- a/mpx-ksqr.c
+++ b/mpx-ksqr.c
@@ -1,13 +1,13 @@
 /* -*-c-*-
  *
- * $Id: mpx-ksqr.c,v 1.6 2000/10/08 15:48:35 mdw Exp $
+ * $Id$
  *
  * Karatsuba-based squaring algorithm
  *
  * (c) 1999 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,43 +15,18 @@
  * it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
- * 
+ *
  * Catacomb is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Library General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Library General Public
  * License along with Catacomb; if not, write to the Free
  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: mpx-ksqr.c,v $
- * Revision 1.6  2000/10/08 15:48:35  mdw
- * Rename Karatsuba constants now that we have @gfx_kmul@ too.
- *
- * Revision 1.5  2000/10/08 12:11:01  mdw
- * Use @mpx_ueq@ instead of @MPX_UCMP@.
- *
- * Revision 1.4  2000/07/29 17:04:02  mdw
- * Remove useless header `mpscan.h'.
- *
- * Revision 1.3  2000/06/17 11:42:54  mdw
- * Moved the Karatsuba macros into a separate file for better sharing.
- * Fixed some comments.  Use an improved technique so that all the
- * operations are squarings.
- *
- * 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>
@@ -64,7 +39,7 @@
 
 #ifdef TEST_RIG
 #  undef MPK_THRESH
-#  define MPK_THRESH 2
+#  define MPK_THRESH 4
 #endif
 
 /*----- Main code ---------------------------------------------------------*/
@@ -83,9 +58,9 @@
  *		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,
@@ -126,11 +101,6 @@ 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 --- */
 
   {
@@ -138,6 +108,8 @@ void mpx_ksqr(mpw *dv, mpw *dvl,
     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);
@@ -151,7 +123,7 @@ void mpx_ksqr(mpw *dv, mpw *dvl,
     MPX_COPY(rdv + m + 1, dvl, svm + 1, svn);
     UADD(rdv, sv, svm + 1);
     USUB(tdv, sv, svn);
-    
+
     if (m > MPK_THRESH)
       mpx_ksqr(sv, ssv, av, avm, ssv, svl);
     else
@@ -169,21 +141,21 @@ void mpx_ksqr(mpw *dv, mpw *dvl,
 #include <mLib/alloc.h>
 #include <mLib/testrig.h>
 
-#define ALLOC(v, vl, sz) do {                                           \
-  size_t _sz = (sz);                                                    \
-  mpw *_vv = xmalloc(MPWS(_sz));                                        \
-  mpw *_vvl = _vv + _sz;                                                \
-  (v) = _vv;                                                            \
-  (vl) = _vvl;                                                          \
+#define ALLOC(v, vl, sz) do {						\
+  size_t _sz = (sz);							\
+  mpw *_vv = xmalloc(MPWS(_sz));					\
+  mpw *_vvl = _vv + _sz;						\
+  (v) = _vv;								\
+  (vl) = _vvl;								\
 } while (0)
 
-#define LOAD(v, vl, d) do {                                             \
-  const dstr *_d = (d);                                                 \
-  mpw *_v, *_vl;                                                        \
-  ALLOC(_v, _vl, MPW_RQ(_d->len));                                      \
-  mpx_loadb(_v, _vl, _d->buf, _d->len);                                 \
-  (v) = _v;                                                             \
-  (vl) = _vl;                                                           \
+#define LOAD(v, vl, d) do {						\
+  const dstr *_d = (d);							\
+  mpw *_v, *_vl;							\
+  ALLOC(_v, _vl, MPW_RQ(_d->len));					\
+  mpx_loadb(_v, _vl, _d->buf, _d->len);					\
+  (v) = _v;								\
+  (vl) = _vl;								\
 } while (0)
 
 #define MAX(x, y) ((x) > (y) ? (x) : (y))
@@ -209,19 +181,19 @@ static int usqr(dstr *v)
   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)) {
     fprintf(stderr, "\n*** usqr failed\n");
-    dumpmp("       a", a, al);
+    dumpmp("	   a", a, al);
     dumpmp("expected", c, cl);
     dumpmp("  result", d, dl);
     ok = 0;
   }
 
-  free(a); free(c); free(d); free(s);
+  xfree(a); xfree(c); xfree(d); xfree(s);
   return (ok);
 }