X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/106b481c4fb7790f93944c6f40ef39a1f1b3058e..7eaaecf58694345b4e40db9981c0c2ac0f728378:/mpreduce.c

diff --git a/mpreduce.c b/mpreduce.c
index 0f20ed8..bc41f60 100644
--- a/mpreduce.c
+++ b/mpreduce.c
@@ -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 --- */
 
@@ -101,10 +101,12 @@ int mpreduce_create(mpreduce *r, mp *p)
       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;
@@ -114,11 +116,11 @@ int mpreduce_create(mpreduce *r, mp *p)
       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@ --- *