x86_64: add fenv support from glibc

1 files changed, 31 insertions, 0 deletions

diff --git a/libm/x86_64/fegetenv.c b/libm/x86_64/fegetenv.c
new file mode 100644
index 000000000..1e362ccc0
--- /dev/null
+++ b/libm/x86_64/fegetenv.c
@@ -0,0 +1,31 @@
+/* Store current floating-point 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
+fegetenv (fenv_t *envp)
+{
+  __asm__ ("fnstenv %0\n"
+	   /* fnstenv changes the exception mask, so load back the
+	      stored environment.  */
+	   "fldenv %0\n"
+	   "stmxcsr %1" : "=m" (*envp), "=m" (envp->__mxcsr));
+
+  /* Success.  */
+  return 0;
+}