Add 64-bit optimized version lround.

1 files changed, 67 insertions, 0 deletions

diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c
new file mode 100644
index 0000000..2df169e
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c
@@ -0,0 +1,67 @@
+/* Round double value to long int.
+   Copyright (C) 1997, 2004, 2009 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 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 <math.h>
+
+#include "math_private.h"
+
+
+long int
+__lround (double x)
+{
+  int32_t j0;
+  int64_t i0;
+  long int result;
+  int sign;
+
+  EXTRACT_WORDS64 (i0, x);
+  j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
+  sign = i0 < 0 ? -1 : 1;
+  i0 &= UINT64_C(0xfffffffffffff);
+  i0 |= UINT64_C(0x10000000000000);
+
+  if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
+    {
+      if (j0 < 0)
+	return j0 < -1 ? 0 : sign;
+      else if (j0 >= 52)
+	result = i0 << (j0 - 52);
+      else
+	{
+	  i0 += UINT64_C(0x8000000000000) >> j0;
+
+	  result = i0 >> (52 - j0);
+	}
+    }
+  else
+    {
+      /* The number is too large.  It is left implementation defined
+	 what happens.  */
+      return (long int) x;
+    }
+
+  return sign * result;
+}
+
+weak_alias (__lround, lround)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__lround, __lroundl)
+weak_alias (__lround, lroundl)
+#endif