X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/f4535c6454395e6d56ce0091a07b6d4f7d54a47f..95d9246390251adba7e6e9f0cc70bf0ebe0b2e60:/mpreduce.c

diff --git a/mpreduce.c b/mpreduce.c
index d99ff16..5016f29 100644
--- a/mpreduce.c
+++ b/mpreduce.c
@@ -7,7 +7,7 @@
  * (c) 2004 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,12 +15,12 @@
  * 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,
@@ -60,7 +60,7 @@ int mpreduce_create(mpreduce *r, mp *p)
   instr_v iv = DA_INIT;
   unsigned long d, i;
   unsigned op;
-  size_t w, b;
+  size_t w, b, bb;
 
   /* --- Fill in the easy stuff --- */
 
@@ -94,31 +94,33 @@ int mpreduce_create(mpreduce *r, mp *p)
   for (i = 0, mp_scan(&sc, p); mp_step(&sc); i++) {
     switch (st | mp_bit(&sc)) {
       case  Z | 1: st = Z1; break;
-      case Z1 | 0: st =  Z; printf("+ %lu\n", i - 1); break;
-      case Z1 | 1: st =  X; printf("- %lu\n", i - 1); break;
+      case Z1 | 0: st =	 Z; printf("+ %lu\n", i - 1); break;
+      case Z1 | 1: st =	 X; printf("- %lu\n", i - 1); break;
       case  X | 0: st = X0; break;
-      case X0 | 1: st =  X; printf("- %lu\n", i - 1); break;
-      case X0 | 0: st =  Z; printf("+ %lu\n", i - 1); break;
+      case X0 | 1: st =	 X; printf("- %lu\n", i - 1); break;
+      case X0 | 0: st =	 Z; printf("+ %lu\n", i - 1); break;
     }
   }
-  if (st >= X) printf("+ %lu\n", i);
+  if (st >= X) printf("+ %lu\n", i - 1);
+  st = Z;
 #endif
 
-  for (i = 0, mp_scan(&sc, p); i < d  - 1 && mp_step(&sc); i++) {
+  bb = MPW_BITS - (d + 1)%MPW_BITS;
+  for (i = 0, mp_scan(&sc, p); i < d && mp_step(&sc); i++) {
     switch (st | mp_bit(&sc)) {
       case  Z | 1: st = Z1; break;
-      case Z1 | 0: st =  Z; op = MPRI_SUB; goto instr;
-      case Z1 | 1: st =  X; op = MPRI_ADD; goto instr;
+      case Z1 | 0: st =	 Z; op = MPRI_SUB; goto instr;
+      case Z1 | 1: st =	 X; op = MPRI_ADD; goto instr;
       case  X | 0: st = X0; break;
-      case X0 | 1: st =  X; op = MPRI_ADD; goto instr;
-      case X0 | 0: st =  Z; op = MPRI_SUB; goto instr;
+      case X0 | 1: st =	 X; op = MPRI_ADD; goto instr;
+      case X0 | 0: st =	 Z; op = MPRI_SUB; goto instr;
       instr:
 	w = (d - i)/MPW_BITS + 1;
-	b = (MPW_BITS + i - d - 1)%MPW_BITS;
+	b = (bb + i)%MPW_BITS;
 	INSTR(op | !!b, w, b);
     }
   }
-  if ((DA(&iv)[DA_LEN(&iv) - 1].op & ~1u) == MPRI_SUB) {
+  if (DA_LEN(&iv) && (DA(&iv)[DA_LEN(&iv) - 1].op & ~1u) == MPRI_SUB) {
     mp_drop(r->p);
     DA_DESTROY(&iv);
     return (-1);
@@ -129,7 +131,9 @@ int mpreduce_create(mpreduce *r, mp *p)
   /* --- Wrap up --- */
 
   r->in = DA_LEN(&iv);
-  if (!r->s) {
+  if (!r->in)
+    r->iv = 0;
+  else if (!r->s) {
     r->iv = xmalloc(r->in * sizeof(mpreduce_instr));
     memcpy(r->iv, DA(&iv), r->in * sizeof(mpreduce_instr));
   } else {
@@ -151,6 +155,10 @@ int mpreduce_create(mpreduce *r, mp *p)
     }
   }
   DA_DESTROY(&iv);
+
+#ifdef DEBUG
+  mpreduce_dump(r, stdout);
+#endif
   return (0);
 }
 
@@ -166,7 +174,7 @@ int mpreduce_create(mpreduce *r, mp *p)
 void mpreduce_destroy(mpreduce *r)
 {
   mp_drop(r->p);
-  xfree(r->iv);
+  if (r->iv) xfree(r->iv);
 }
 
 /* --- @mpreduce_dump@ --- *
@@ -285,9 +293,9 @@ mp *mpreduce_do(mpreduce *r, mp *d, mp *x)
 	*vl = 0;
 	run(r->iv, il, vl, z);
 #ifdef DEBUG
-  MP_PRINTX("x", x);
-  mp_div(0, &_rr, x, r->p);
-  assert(MP_EQ(_r, _rr));
+	MP_PRINTX("x", x);
+	mp_div(0, &_rr, x, r->p);
+	assert(MP_EQ(_r, _rr));
 #endif
       }
     }
@@ -297,9 +305,9 @@ mp *mpreduce_do(mpreduce *r, mp *d, mp *x)
 	*vl &= ((1 << r->s) - 1);
 	run(r->iv + r->in, il + r->in, vl, z);
 #ifdef DEBUG
-  MP_PRINTX("x", x);
-  mp_div(0, &_rr, x, r->p);
-  assert(MP_EQ(_r, _rr));
+	MP_PRINTX("x", x);
+	mp_div(0, &_rr, x, r->p);
+	assert(MP_EQ(_r, _rr));
 #endif
       }
     }
@@ -324,11 +332,11 @@ mp *mpreduce_do(mpreduce *r, mp *d, mp *x)
 /* --- @mpreduce_exp@ --- *
  *
  * Arguments:	@mpreduce *mr@ = pointer to reduction context
- *              @mp *d@ = fake destination
- *              @mp *a@ = base
- *              @mp *e@ = exponent
+ *		@mp *d@ = fake destination
+ *		@mp *a@ = base
+ *		@mp *e@ = exponent
  *
- * Returns:     Result, %$a^e \bmod m$%.
+ * Returns:	Result, %$a^e \bmod m$%.
  */
 
 mp *mpreduce_exp(mpreduce *mr, mp *d, mp *a, mp *e)