modernize bigtimes()

1 files changed, 18 insertions, 13 deletions

diff --git a/big.c b/big.c
index 0ebd8fa..78049eb 100644
--- a/big.c
+++ b/big.c
@@ -296,29 +296,34 @@ int bigcmp(word x, word y)
   }
 }
 
-word bigtimes(x, y)		/* naive multiply - quadratic */
-word x, y;
+/* naive multiply - quadratic */
+word bigtimes(word x, word y)
 {
+  /* important optimisation */
   if (len(x) < len(y)) {
     word hold = x;
     x = y;
     y = hold;
-  }				/* important optimisation */
+  }
+
   word r = make(INT, 0, 0);
-  word d = digit0(y);
+
+  /* short cut */
+  if (bigzero(x)) {
+    return (r);
+  }
+
+  //word d = digit0(y);
   word s = big_is_negative(y);
-  word n = 0;
-  if (bigzero(x))
-    return (r);			/* short cut */
-  for (;;) {
-    if (d)
+  for (word n = 0, d = digit0(y); y; n++, d = digit(y)) {
+    if (d) {
       r = bigplus(r, shift(n, stimes(x, d)));
-    n++;
+    }
+
     y = rest(y);
-    if (!y)
-      return (s != big_is_negative(x) ? bignegate(r) : r);
-    d = digit(y);
+    //d = digit(y);
   }
+  return (s != big_is_negative(x) ? bignegate(r) : r);
 }
 
 word shift(n, x)		/* multiply big x by n'th power of IBASE */