libm/x86_64: implement some fenv functions

from glibc

Posted to uclibc:
http://lists.busybox.net/pipermail/uclibc/2010-December/044523.html

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/libm/x86_64/ftestexcept.c b/libm/x86_64/ftestexcept.c
new file mode 100644
index 000000000..091c25157
--- /dev/null
+++ b/libm/x86_64/ftestexcept.c
@@ -0,0 +1,33 @@
+/* Test exception in current environment.
+   Copyright (C) 2001 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <fenv.h>
+
+int
+fetestexcept (int excepts)
+{
+  int temp;
+  unsigned int mxscr;
+
+  /* Get current exceptions.  */
+  __asm__ ("fnstsw %0\n"
+	   "stmxcsr %1" : "=m" (*&temp), "=m" (*&mxscr));
+
+  return (temp | mxscr) & excepts & FE_ALL_EXCEPT;
+}