Re: Guile 1.5.8 beta available for testing.

[Lars J. Aas]

Marius Vollmer <address@hidden> wrote:
: "Lars J. Aas" <address@hidden> writes:
: 
: > : A fix would be to move the scm_t_signed_bits cast one level up, and
: > : also in SCM_MOST_NEGATIVE_FIXNUM.  We should do that and put a
: > : deriding comment about MS on the code.  OK?
: > 
: > Sounds reasonable.
: 
: However, in CVS HEAD, we use these definitions, to make them
: computable by the preprocessor:
: 
: #define SCM_I_FIXNUM_BIT         (SCM_LONG_BIT - 2)
: #define SCM_MOST_POSITIVE_FIXNUM ((SCM_T_SIGNED_BITS_MAX-3)/4)
: #define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
: 
: Does this work as well?

Yes, the following snippet works out of the box with no tweaks
necessary for the defines.

  Lars J

----------------------------------------------------------------------------

#include <stdio.h>
#include <limits.h>

typedef signed long scm_t_signed_bits;

#ifdef LONG_BIT
# define SCM_LONG_BIT LONG_BIT
#else
# define SCM_LONG_BIT (SCM_CHAR_BIT * sizeof (long) / sizeof (char))
#endif

#define SCM_T_SIGNED_BITS_MAX LONG_MAX

#define SCM_I_FIXNUM_BIT         (SCM_LONG_BIT - 2)
#define SCM_MOST_POSITIVE_FIXNUM ((SCM_T_SIGNED_BITS_MAX-3)/4)
#define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)

#define SCM_POSFIXABLE(n) ((n) <= SCM_MOST_POSITIVE_FIXNUM)

int
main(int argc, char ** argv)
{
  int val;
  fprintf(stderr, "test 1 - ");
  if ( SCM_POSFIXABLE(-1) ) fprintf(stderr, "success\n");
  else                      fprintf(stderr, "failure\n");
  fprintf(stderr, "test 2 - ");
  val = -1;
  if ( SCM_POSFIXABLE(val) ) fprintf(stderr, "success\n");
  else                       fprintf(stderr, "failure\n");
  return 0;
}