Fix bug, and add a test rig.

[u/mdw/catacomb] / mpmul.c

diff --git a/mpmul.c b/mpmul.c
index 46f7b72..e5d6a4a 100644 (file)
--- a/mpmul.c
+++ b/mpmul.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mpmul.c,v 1.1 2000/07/01 11:21:39 mdw Exp $
+ * $Id: mpmul.c,v 1.2 2000/07/09 21:31:10 mdw Exp $
  *
  * Multiply many small numbers together
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: mpmul.c,v $
+ * Revision 1.2  2000/07/09 21:31:10  mdw
+ * Fix bug, and add a test rig.
+ *
  * Revision 1.1  2000/07/01 11:21:39  mdw
  * New interface for computing products of many (small) integers.
  *
@@ -86,14 +89,14 @@ void mpmul_add(mpmul *b, mp *x)
   }
 
   if (i > HWM) {
-    while (i > LWM) {
+    while (i > LWM || (i > 0 && MP_LEN(b->v[i - 1]) <= MP_LEN(x))) {
       i--;
       x = mp_mul(x, x, b->v[i]);
       MP_DROP(b->v[i]);
     }
   }
 
-  b->v[i] = x;
+  b->v[i++] = x;
   b->i = i;
 }
 
@@ -142,8 +145,46 @@ mp *mp_factorial(unsigned long i)
     x = mp_fromulong(x, j);
     mpmul_add(&b, x);
   }
-  mp_drop(x);
+  if (x)
+    mp_drop(x);
   return (mpmul_done(&b));
 }
 
+/*----- Test rig ----------------------------------------------------------*/
+
+#ifdef TEST_RIG
+
+#include <mLib/testrig.h>
+
+static int vfact(dstr *v)
+{
+  unsigned long x = *(unsigned long *)v[0].buf;
+  mp *fx = *(mp **)v[1].buf;
+  mp *y = mp_factorial(x);
+  int ok = 1;
+  if (MP_CMP(fx, !=, y)) {
+    fprintf(stderr, "factorial failed\n");
+    MP_FPRINTF(stderr, (stderr, "%lu! = ", x), fx);
+    MP_EPRINT("result", y);
+    ok = 0;
+  }
+  mp_drop(fx);
+  mp_drop(y);
+  assert(mparena_count(MPARENA_GLOBAL) == 0);
+  return (ok);
+}
+
+static test_chunk tests[] = {
+  { "factorial", vfact, { &type_ulong, &type_mp, 0 } },
+  { 0, 0, { 0 } }
+};
+
+int main(int argc, char *argv[])
+{
+  test_run(argc, argv, tests, SRCDIR "/tests/mp");
+  return (0);
+}
+
+#endif
+
 /*----- That's all, folks -------------------------------------------------*/