modernize get_int()

1 files changed, 23 insertions, 15 deletions

diff --git a/big.c b/big.c
index 72842fc..022b49d 100644
--- a/big.c
+++ b/big.c
@@ -14,7 +14,11 @@
 #include "big.h"
 #include <errno.h>
 
-static double logIBASE, log10IBASE;
+#define MAX_INT_BITS		60
+#define LONG_LONG_OVERFLOW	(1ll<<MAX_INT_BITS)
+
+static double logIBASE;
+static double log10IBASE;
 word big_one;
 
 static word big_plus(word, word, int);
@@ -59,26 +63,30 @@ word sto_int(long long i)
   }
 
   return x;
-}				/* change to long long, DT Oct 2019 */
-
-#define maxval (1ll<<60)
+}
 
-long long get_int(x)		/* mira bigint to C long long */
-word x;
+/* mira bigint to C long long */
+long long get_int(word x)
 {
   long long n = digit0(x);
   word sign = big_is_negative(x);
-  if (!(x = rest(x)))
-    return (sign ? -n : n);
-  {
-    word w = DIGITWIDTH;
-    while (x && w < 60)
-      n += (long long)digit(x) << w, w += DIGITWIDTH, x = rest(x);
-    if (x)
-      n = maxval;		/* overflow, return large value */
+  if (!(x = rest(x))) {
     return (sign ? -n : n);
   }
-}				/* change to long long, DT Oct 2019 */
+
+  word w = DIGITWIDTH;
+  while (x && w < MAX_INT_BITS) {
+    n += (long long)digit(x) << w;
+    w += DIGITWIDTH;
+    x = rest(x);
+  }
+
+  if (x) {
+    n = LONG_LONG_OVERFLOW;
+  }
+
+  return (sign ? -n : n);
+}
 
 word bignegate(x)
 word x;