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-rw-r--r--math/w_tgamma_compat.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/math/w_tgamma_compat.c b/math/w_tgamma_compat.c
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+/* @(#)w_gamma.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* double gamma(double x)
+ * Return  the logarithm of the Gamma function of x or the Gamma function of x,
+ * depending on the library mode.
+ */
+
+#include <errno.h>
+#include <math.h>
+#include <math_private.h>
+
+double
+__tgamma(double x)
+{
+	int local_signgam;
+	double y = __ieee754_gamma_r(x,&local_signgam);
+
+	if(__glibc_unlikely (!isfinite (y) || y == 0)
+	   && (isfinite (x) || (isinf (x) && x < 0.0))
+	   && _LIB_VERSION != _IEEE_) {
+	  if (x == 0.0)
+	    return __kernel_standard(x,x,50); /* tgamma pole */
+	  else if(__floor(x)==x&&x<0.0)
+	    return __kernel_standard(x,x,41); /* tgamma domain */
+	  else if (y == 0)
+	    __set_errno (ERANGE); /* tgamma underflow */
+	  else
+	    return __kernel_standard(x,x,40); /* tgamma overflow */
+	}
+	return local_signgam < 0 ? -y : y;
+}
+weak_alias (__tgamma, tgamma)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__tgamma, __tgammal)
+weak_alias (__tgamma, tgammal)
+#endif