1 files changed, 70 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_roundevenl.c b/sysdeps/ieee754/ldbl-128ibm/s_roundevenl.c
new file mode 100644
index 0000000000..84950e215f
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_roundevenl.c
@@ -0,0 +1,70 @@
+/* Round to nearest integer value, rounding halfway cases to even.
+   ldbl-128ibm version.
+   Copyright (C) 2016-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <math_private.h>
+
+long double
+__roundevenl (long double x)
+{
+  double xh, xl, hi;
+
+  ldbl_unpack (x, &xh, &xl);
+
+  if (xh != 0 && isfinite (xh))
+    {
+      hi = __roundeven (xh);
+      if (hi != xh)
+	{
+	  /* The high part is not an integer; the low part only
+	     affects the result if the high part is exactly half way
+	     between two integers and the low part is nonzero in the
+	     opposite direction to the rounding of the high part.  */
+	  double diff = hi - xh;
+	  if (fabs (diff) == 0.5)
+	    {
+	      if (xl < 0 && diff > 0)
+		xh = hi - 1;
+	      else if (xl > 0 && diff < 0)
+		xh = hi + 1;
+	      else
+		xh = hi;
+	    }
+	  else
+	    xh = hi;
+	  xl = 0;
+	}
+      else
+	{
+	  /* The high part is a nonzero integer.  Rounding the low
+	     part to nearest, ties round to even, is always correct,
+	     as a high part that is an odd integer together with a low
+	     part with magnitude 0.5 is not a valid long double.  */
+	  xl = __roundeven (xl);
+	  xh = hi;
+	  ldbl_canonicalize_int (&xh, &xl);
+	}
+    }
+  else
+    /* Quiet signaling NaN arguments.  */
+    xh += xh;
+
+  return ldbl_pack (xh, xl);
+}
+weak_alias (__roundevenl, roundevenl)