aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/ieee754/ldbl-96/x2y2m1.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ieee754/ldbl-96/x2y2m1.c')
-rw-r--r--sysdeps/ieee754/ldbl-96/x2y2m1.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-96/x2y2m1.c b/sysdeps/ieee754/ldbl-96/x2y2m1.c
new file mode 100644
index 0000000000..3086fa2c80
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/x2y2m1.c
@@ -0,0 +1,39 @@
+/* Compute x^2 + y^2 - 1, without large cancellation error.
+ Copyright (C) 2012 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>
+#include <float.h>
+
+#if FLT_EVAL_METHOD == 0
+
+# include <sysdeps/ieee754/dbl-64/x2y2m1.c>
+
+#else
+
+/* Return X^2 + Y^2 - 1, computed without large cancellation error.
+ It is given that 1 > X >= Y >= epsilon / 2, and that either X >=
+ 0.75 or Y >= 0.5. */
+
+double
+__x2y2m1 (double x, double y)
+{
+ return (double) __x2y2m1l (x, y);
+}
+
+#endif