Re: macro FIXNUM_OVERFLOW_P in lisp.h is valid ?

[Toru TSUNEYOSHI]

I revised the macro.
(My former macro may be problematic on 64-bit platforms.)
Probably, the following is no problems in 64-bit platforms, I think.

/* citation from mktime.c ---> */

#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif

/* The extra casts work around common compiler bugs.  */
#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
/* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
   It is necessary at least when t == time_t.  */
#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
                              ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))

/* <--- citation from mktime.c */

#ifndef EMACS_INT_MIN
# define EMACS_INT_MIN TYPE_MINIMUM (EMACS_INT)
#endif
#ifndef EMACS_INT_MAX
# define EMACS_INT_MAX TYPE_MAXIMUM (EMACS_INT)
#endif

#define FIXNUM_OVERFLOW_P(i)                                      \
  ((i) < 0                                                        \
   ? (i) < EMACS_INT_MIN || (EMACS_INT)(i) < MOST_NEGATIVE_FIXNUM \
   : (i) > EMACS_INT_MAX || (EMACS_INT)(i) > MOST_POSITIVE_FIXNUM)