hashsum.c: Document `--progress' in the `--help' display.

[u/mdw/catacomb] / mpreduce.c

diff --git a/mpreduce.c b/mpreduce.c
index 13e705e..5016f29 100644 (file)
--- 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,
@@ -47,12 +47,12 @@ DA_DECL(instr_v, mpreduce_instr);
  * Arguments:  @gfreduce *r@ = structure to fill in
  *             @mp *x@ = an integer
  *
- * Returns:    ---
+ * Returns:    Zero if successful; nonzero on failure.
  *
  * Use:                Initializes a context structure for reduction.
  */
 
-void mpreduce_create(mpreduce *r, mp *p)
+int mpreduce_create(mpreduce *r, mp *p)
 {
   mpscan sc;
   enum { Z = 0, Z1 = 2, X = 4, X0 = 6 };
@@ -60,11 +60,12 @@ void 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 --- */
 
-  assert(MP_POSP(p));
+  if (!MP_POSP(p))
+    return (-1);
   d = mp_bits(p);
   r->lim = d/MPW_BITS;
   r->s = d%MPW_BITS;
@@ -93,34 +94,36 @@ void 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) {
-    fprintf(stderr,
-           "mpreduce can't handle moduli of the form 2^m + x\n");
-    abort();
+  if (DA_LEN(&iv) && (DA(&iv)[DA_LEN(&iv) - 1].op & ~1u) == MPRI_SUB) {
+    mp_drop(r->p);
+    DA_DESTROY(&iv);
+    return (-1);
   }
 
 #undef INSTR
@@ -128,7 +131,9 @@ void 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 {
@@ -149,7 +154,12 @@ void mpreduce_create(mpreduce *r, mp *p)
       r->iv[i + r->in].argy = b;
     }
   }
-  DA_DESTROY(&iv);  
+  DA_DESTROY(&iv);
+
+#ifdef DEBUG
+  mpreduce_dump(r, stdout);
+#endif
+  return (0);
 }
 
 /* --- @mpreduce_destroy@ --- *
@@ -164,7 +174,7 @@ void 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@ --- *
@@ -283,9 +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
       }
     }
@@ -295,9 +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
       }
     }
@@ -322,11 +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)