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ruby--ruby/missing/isinf.c
shyouhei 98d6f01de3 merge revision(s) 13914:13917:
* missing/isinf.c (isinf): don't define if the macro is defined.
	* numeric.c (flodivmod): work around for infinity.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_6@16935 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2008-06-07 18:49:52 +00:00

72 lines
1 KiB
C

/* public domain rewrite of isinf(3) */
#ifdef __osf__
#define _IEEE 1
#include <nan.h>
int
isinf(n)
double n;
{
if (IsNANorINF(n) && IsINF(n)) {
return 1;
}
else {
return 0;
}
}
#else
#include "config.h"
#if defined(HAVE_FINITE) && defined(HAVE_ISNAN)
#include <math.h>
#ifdef HAVE_IEEEFP_H
#include <ieeefp.h>
#endif
/*
* isinf may be provided only as a macro.
* ex. HP-UX, Solaris 10
* http://www.gnu.org/software/automake/manual/autoconf/Function-Portability.html
*/
#ifndef isinf
int
isinf(n)
double n;
{
return (!finite(n) && !isnan(n));
}
#endif
#else
#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
static double zero() { return 0.0; }
static double one() { return 1.0; }
static double inf() { return one() / zero(); }
int
isinf(n)
double n;
{
static double pinf = 0.0;
static double ninf = 0.0;
if (pinf == 0.0) {
pinf = inf();
ninf = -pinf;
}
return memcmp(&n, &pinf, sizeof n) == 0
|| memcmp(&n, &ninf, sizeof n) == 0;
}
#endif
#endif