x86_64: add fenv support from glibc

1 files changed, 31 insertions, 0 deletions

diff --git a/libm/x86_64/ftestexcept.c b/libm/x86_64/ftestexcept.c
new file mode 100644
index 000000000..a5a1080ec
--- /dev/null
+++ b/libm/x86_64/ftestexcept.c
@@ -0,0 +1,31 @@
+/* Test exception in current environment.
+   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+
+   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 <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;
+}