1 files changed, 99 insertions, 22 deletions

diff --git a/src/data.c b/src/data.c
index 78bd454056d..a41ffe7a1f6 100644
--- a/src/data.c
+++ b/src/data.c
@@ -2326,33 +2326,110 @@ DEFUN ("zerop", Fzerop, Szerop, 1, 1, 0,
   return Qnil;
 }
 
-/* Convert between long values and pairs of Lisp integers.
-   Note that long_to_cons returns a single Lisp integer
-   when the value fits in one.  */
+/* Convert the cons-of-integers, integer, or float value C to an
+   unsigned value with maximum value MAX.  Signal an error if C does not
+   have a valid format or is out of range.  */
+uintmax_t
+cons_to_unsigned (Lisp_Object c, uintmax_t max)
+{
+  int valid = 0;
+  uintmax_t val IF_LINT (= 0);
+  if (INTEGERP (c))
+    {
+      valid = 0 <= XINT (c);
+      val = XINT (c);
+    }
+  else if (FLOATP (c))
+    {
+      double d = XFLOAT_DATA (c);
+      if (0 <= d
+          && d < (max == UINTMAX_MAX ? (double) UINTMAX_MAX + 1 : max + 1))
+        {
+          val = d;
+          valid = 1;
+        }
+    }
+  else if (CONSP (c) && NATNUMP (XCAR (c)))
+    {
+      uintmax_t top = XFASTINT (XCAR (c));
+      Lisp_Object rest = XCDR (c);
+      if (top <= UINTMAX_MAX >> 24 >> 16
+          && CONSP (rest)
+          && NATNUMP (XCAR (rest)) && XFASTINT (XCAR (rest)) < 1 << 24
+          && NATNUMP (XCDR (rest)) && XFASTINT (XCDR (rest)) < 1 << 16)
+        {
+          uintmax_t mid = XFASTINT (XCAR (rest));
+          val = top << 24 << 16 | mid << 16 | XFASTINT (XCDR (rest));
+          valid = 1;
+        }
+      else if (top <= UINTMAX_MAX >> 16)
+        {
+          if (CONSP (rest))
+            rest = XCAR (rest);
+          if (NATNUMP (rest) && XFASTINT (rest) < 1 << 16)
+            {
+              val = top << 16 | XFASTINT (rest);
+              valid = 1;
+            }
+        }
+    }
 
-Lisp_Object
-long_to_cons (long unsigned int i)
-{
-  unsigned long top = i >> 16;
-  unsigned int bot = i & 0xFFFF;
-  if (top == 0)
-    return make_number (bot);
-  if (top == (unsigned long)-1 >> 16)
-    return Fcons (make_number (-1), make_number (bot));
-  return Fcons (make_number (top), make_number (bot));
+  if (! (valid && val <= max))
+    error ("Not an in-range integer, float, or cons of integers");
+  return val;
 }
 
-unsigned long
-cons_to_long (Lisp_Object c)
+/* Convert the cons-of-integers, integer, or float value C to a signed
+   value with extrema MIN and MAX.  Signal an error if C does not have
+   a valid format or is out of range.  */
+intmax_t
+cons_to_signed (Lisp_Object c, intmax_t min, intmax_t max)
 {
-  Lisp_Object top, bot;
+  int valid = 0;
+  intmax_t val IF_LINT (= 0);
   if (INTEGERP (c))
-    return XINT (c);
-  top = XCAR (c);
-  bot = XCDR (c);
-  if (CONSP (bot))
-    bot = XCAR (bot);
-  return ((XINT (top) << 16) | XINT (bot));
+    {
+      val = XINT (c);
+      valid = 1;
+    }
+  else if (FLOATP (c))
+    {
+      double d = XFLOAT_DATA (c);
+      if (min <= d
+          && d < (max == INTMAX_MAX ? (double) INTMAX_MAX + 1 : max + 1))
+        {
+          val = d;
+          valid = 1;
+        }
+    }
+  else if (CONSP (c) && INTEGERP (XCAR (c)))
+    {
+      intmax_t top = XINT (XCAR (c));
+      Lisp_Object rest = XCDR (c);
+      if (INTMAX_MIN >> 24 >> 16 <= top && top <= INTMAX_MAX >> 24 >> 16
+          && CONSP (rest)
+          && NATNUMP (XCAR (rest)) && XFASTINT (XCAR (rest)) < 1 << 24
+          && NATNUMP (XCDR (rest)) && XFASTINT (XCDR (rest)) < 1 << 16)
+        {
+          intmax_t mid = XFASTINT (XCAR (rest));
+          val = top << 24 << 16 | mid << 16 | XFASTINT (XCDR (rest));
+          valid = 1;
+        }
+      else if (INTMAX_MIN >> 16 <= top && top <= INTMAX_MAX >> 16)
+        {
+          if (CONSP (rest))
+            rest = XCAR (rest);
+          if (NATNUMP (rest) && XFASTINT (rest) < 1 << 16)
+            {
+              val = top << 16 | XFASTINT (rest);
+              valid = 1;
+            }
+        }
+    }
+
+  if (! (valid && min <= val && val <= max))
+    error ("Not an in-range integer, float, or cons of integers");
+  return val;
 }
 
 DEFUN ("number-to-string", Fnumber_to_string, Snumber_to_string, 1, 1, 0,