aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/libm-ieee754/e_gammal_r.c')
-rw-r--r--sysdeps/libm-ieee754/e_gammal_r.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/e_gammal_r.c b/sysdeps/libm-ieee754/e_gammal_r.c
new file mode 100644
index 0000000000..4fd49886d1
--- /dev/null
+++ b/sysdeps/libm-ieee754/e_gammal_r.c
@@ -0,0 +1,46 @@
+/* Implementation of gamma function according to ISO C.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <math.h>
+#include <math_private.h>
+
+
+long double
+__ieee754_gammal_r (long double x, int *signgamp)
+{
+ /* We don't have a real gamma implementation now. We'll use lgamma
+ and the exp function. But due to the required boundary
+ conditions we must check some values separately. */
+ u_int32_t es, hx, lx;
+
+ GET_LDOUBLE_WORDS (es, hx, lx, x);
+
+ if (((es & 0x7fff) | hx | lx) == 0)
+ /* Return value for x == 0 is NaN with invalid exception. */
+ return x / x;
+ if ((hx & 0x8000) != 0 && (hx & 0x7fff) != 0x7fff && __rintl (x) == x)
+ {
+ /* Return value for integer x < 0 is NaN with invalid exception. */
+ return (x - x) / (x - x);
+ }
+
+ /* XXX FIXME. */
+ return __ieee754_expl (__ieee754_lgammal_r (x, signgamp));
+}