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Fix bounds on workspace for Karatsuba operations.
[u/mdw/catacomb]
/
mpx-ksqr.c
diff --git
a/mpx-ksqr.c
b/mpx-ksqr.c
index
25dbb70
..
8a0ad64
100644
(file)
--- a/
mpx-ksqr.c
+++ b/
mpx-ksqr.c
@@
-1,6
+1,6
@@
/* -*-c-*-
*
/* -*-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
*
*
* Karatsuba-based squaring algorithm
*
@@
-30,6
+30,9
@@
/*----- Revision history --------------------------------------------------*
*
* $Log: mpx-ksqr.c,v $
/*----- 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.
*
* Revision 1.6 2000/10/08 15:48:35 mdw
* Rename Karatsuba constants now that we have @gfx_kmul@ too.
*
@@
-64,7
+67,7
@@
#ifdef TEST_RIG
# undef MPK_THRESH
#ifdef TEST_RIG
# undef MPK_THRESH
-# define MPK_THRESH
2
+# define MPK_THRESH
4
#endif
/*----- Main code ---------------------------------------------------------*/
#endif
/*----- Main code ---------------------------------------------------------*/
@@
-83,9
+86,9
@@
* large numbers, although more expensive on small ones, and
* rather simpler than full-blown Karatsuba multiplication.
*
* large numbers, although more expensive on small ones, and
* rather simpler than full-blown Karatsuba multiplication.
*
- * The destination must be t
wice as large as the argument. The
- *
scratch space must be twice as large as the argument, plu
s
- * the
magic number @MPK_SLOP@
.
+ * The destination must be t
hree times as large as the larger
+ *
argument. The scratch space must be five times as large a
s
+ * the
larger argument
.
*/
void mpx_ksqr(mpw *dv, mpw *dvl,
*/
void mpx_ksqr(mpw *dv, mpw *dvl,
@@
-126,11
+129,6
@@
void mpx_ksqr(mpw *dv, mpw *dvl,
m = (avl - av + 1) >> 1;
avm = av + m;
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 --- */
{
/* --- Sort out everything --- */
{
@@
-138,6
+136,8
@@
void mpx_ksqr(mpw *dv, mpw *dvl,
mpw *tdv = dv + m;
mpw *rdv = tdv + m;
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);
UADD2(sv, svm, av, avm, avm, avl);
if (m > MPK_THRESH)
mpx_ksqr(tdv, rdv + m + 4, sv, svm + 1, ssv, svl);
@@
-209,8
+209,8
@@
static int usqr(dstr *v)
LOAD(a, al, &v[0]);
LOAD(c, cl, &v[1]);
m = al - a + 1;
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)) {
mpx_ksqr(d, dl, a, al, s, sl);
if (!mpx_ueq(d, dl, c, cl)) {