1 files changed, 8 insertions, 1 deletions
diff --git a/arith.c b/arith.c
index de8d782e..1d784a6e 100644
--- a/arith.c
+++ b/arith.c
@@ -51,7 +51,7 @@
 #define CNUM_BIT ((int) sizeof (cnum) * CHAR_BIT)
 #define ABS(A) ((A) < 0 ? -(A) : (A))
 
-static mp_int NUM_MAX_MP;
+static mp_int NUM_MAX_MP, INT_PTR_MAX_MP;
 
 val make_bignum(void)
 {
@@ -90,6 +90,11 @@ val normalize(val bignum)
   }
 }
 
+val in_int_ptr_range(val bignum)
+{
+  return (mp_cmp_mag(mp(bignum), &INT_PTR_MAX_MP) == MP_GT) ? nil : t;
+}
+
 int highest_bit(int_ptr_t n)
 {
 #if SIZEOF_PTR == 8
@@ -1487,4 +1492,6 @@ void arith_init(void)
 {
   mp_init(&NUM_MAX_MP);
   mp_set_intptr(&NUM_MAX_MP, NUM_MAX);
+  mp_init(&INT_PTR_MAX_MP);
+  mp_set_intptr(&INT_PTR_MAX_MP, INT_PTR_MAX);
 }