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authorWaldemar Brodkorb <wbx@uclibc-ng.org>2017-12-03 21:12:34 +0100
committerWaldemar Brodkorb <wbx@uclibc-ng.org>2017-12-03 21:12:34 +0100
commitedce88cfef2f2a62647c2ab9536ca29694fab292 (patch)
tree5cfc13c44a91bb8b983ee137de38e136289db81e /libm/x86_64/fegetround.c
parentc69db851309995c525b3993a10dc13dabdeb7b33 (diff)
x86_64: add fenv support from glibc
Diffstat (limited to 'libm/x86_64/fegetround.c')
-rw-r--r--libm/x86_64/fegetround.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/libm/x86_64/fegetround.c b/libm/x86_64/fegetround.c
new file mode 100644
index 000000000..d0ca106e9
--- /dev/null
+++ b/libm/x86_64/fegetround.c
@@ -0,0 +1,31 @@
+/* Return current rounding direction.
+ Copyright (C) 1997-2017 Free Software Foundation, Inc.
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <fenv.h>
+
+int
+fegetround (void)
+{
+ int cw;
+ /* We only check the x87 FPU unit. The SSE unit should be the same
+ - and if it's not the same there's no way to signal it. */
+
+ __asm__ ("fnstcw %0" : "=m" (*&cw));
+
+ return cw & 0xc00;
+}