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authorEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
committerEric Andersen <andersen@codepoet.org>2001-11-22 14:04:29 +0000
commit7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 (patch)
tree3a7e8476e868ae15f4da1b7ce26b2db6f434468c /libm/w_gamma.c
parentc117dd5fb183afb1a4790a6f6110d88704be6bf8 (diff)
Totally rework the math library, this time based on the MacOs X
math library (which is itself based on the math lib from FreeBSD). -Erik
Diffstat (limited to 'libm/w_gamma.c')
-rw-r--r--libm/w_gamma.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/libm/w_gamma.c b/libm/w_gamma.c
new file mode 100644
index 000000000..59fe8f640
--- /dev/null
+++ b/libm/w_gamma.c
@@ -0,0 +1,49 @@
+/* @(#)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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: w_gamma.c,v 1.7 1995/11/20 22:06:43 jtc Exp $";
+#endif
+
+/* double gamma(double x)
+ * Return the logarithm of the Gamma function of x.
+ *
+ * Method: call gamma_r
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+extern int signgam;
+
+#ifdef __STDC__
+ double gamma(double x)
+#else
+ double gamma(x)
+ double x;
+#endif
+{
+#ifdef _IEEE_LIBM
+ return __ieee754_lgamma_r(x,&signgam);
+#else
+ double y;
+ y = __ieee754_lgamma_r(x,&signgam);
+ if(_LIB_VERSION == _IEEE_) return y;
+ if(!finite(y)&&finite(x)) {
+ if(floor(x)==x&&x<=0.0)
+ return __kernel_standard(x,x,41); /* gamma pole */
+ else
+ return __kernel_standard(x,x,40); /* gamma overflow */
+ } else
+ return y;
+#endif
+}