isinf.c

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/*-------------------------------------------------------------------------
 *
 * isinf.c
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/port/isinf.c
 *
 *-------------------------------------------------------------------------
 */

#include "c.h"

#include <float.h>
#include <math.h>

#if HAVE_FPCLASS                /* this is _not_ HAVE_FP_CLASS, and not typo */

#if HAVE_IEEEFP_H
#include <ieeefp.h>
#endif
int
isinf(double d)
{
    fpclass_t   type = fpclass(d);

    switch (type)
    {
        case FP_NINF:
        case FP_PINF:
            return 1;
        default:
            break;
    }
    return 0;
}
#else

#if defined(HAVE_FP_CLASS) || defined(HAVE_FP_CLASS_D)

#if HAVE_FP_CLASS_H
#include <fp_class.h>
#endif
int
isinf(x)
double      x;
{
#if HAVE_FP_CLASS
    int         fpclass = fp_class(x);
#else
    int         fpclass = fp_class_d(x);
#endif

    if (fpclass == FP_POS_INF)
        return 1;
    if (fpclass == FP_NEG_INF)
        return -1;
    return 0;
}
#elif defined(HAVE_CLASS)
int
isinf(double x)
{
    int         fpclass = class(x);

    if (fpclass == FP_PLUS_INF)
        return 1;
    if (fpclass == FP_MINUS_INF)
        return -1;
    return 0;
}
#endif

#endif