1 files changed, 50 insertions, 0 deletions
diff --git a/libquadmath/math/tgammaq.c b/libquadmath/math/tgammaq.c
new file mode 100644
index 000000000..3305b6484
--- /dev/null
+++ b/libquadmath/math/tgammaq.c
@@ -0,0 +1,50 @@
+/* Implementation of gamma function according to ISO C.
+   Copyright (C) 1997, 1999, 2002, 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
+   		  Jakub Jelinek <jj@ultra.linux.cz, 1999.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include "quadmath-imp.h"
+
+
+__float128
+tgammaq (__float128 x)
+{
+  /* 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.  */
+  int64_t hx;
+  uint64_t lx;
+
+  GET_FLT128_WORDS64 (hx, lx, x);
+
+  if (((hx & 0x7fffffffffffffffLL) | lx) == 0)
+    /* Return value for x == 0 is Inf with divide by zero exception.  */
+    return 1.0 / x;
+
+  if (hx < 0 && (uint64_t) hx < 0xffff000000000000ULL && rintq (x) == x)
+    /* Return value for integer x < 0 is NaN with invalid exception.  */
+    return (x - x) / (x - x);
+
+  if (hx == 0xffff000000000000ULL && lx == 0)
+    /* x == -Inf.  According to ISO this is NaN.  */
+    return x - x;
+
+  /* XXX FIXME.  */
+  return expq (lgammaq (x));
+}