newlib-cygwin/newlib/libm/mathfp/sf_tgamma.c

/* w_gammaf.c -- float version of w_gamma.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#include <math.h>
#include <errno.h>

#ifdef __STDC__
	float tgammaf(float x)
#else
	float tgammaf(x)
	float x;
#endif
{
        float y;
	int local_signgam;
	y = gammaf_r(x,&local_signgam);
	if (local_signgam < 0) y = -y;
#ifdef _IEEE_LIBM
	return y;
#else
	if(_LIB_VERSION == _IEEE_) return y;

	if(!finitef(y)&&finitef(x)) {
	  if(floorf(x)==x&&x<=(float)0.0)
            {
              /* tgammaf pole */
              errno = EDOM;
              return HUGE_VAL;
            }
	  else
            {
              /* tgammaf overflow */
              errno = ERANGE;
              return HUGE_VAL;
            }
	}
	return y;
#endif
}