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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/fedisblxcpt.c
parentc69db851309995c525b3993a10dc13dabdeb7b33 (diff)
x86_64: add fenv support from glibc
Diffstat (limited to 'libm/x86_64/fedisblxcpt.c')
-rw-r--r--libm/x86_64/fedisblxcpt.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/libm/x86_64/fedisblxcpt.c b/libm/x86_64/fedisblxcpt.c
new file mode 100644
index 000000000..16dd196e8
--- /dev/null
+++ b/libm/x86_64/fedisblxcpt.c
@@ -0,0 +1,45 @@
+/* Disable floating-point exceptions.
+ Copyright (C) 2001-2017 Free Software Foundation, Inc.
+ Contributed by Andreas Jaeger <aj@suse.de>, 2001.
+
+ 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
+fedisableexcept (int excepts)
+{
+ unsigned short int new_exc, old_exc;
+ unsigned int new;
+
+ excepts &= FE_ALL_EXCEPT;
+
+ /* Get the current control word of the x87 FPU. */
+ __asm__ ("fstcw %0" : "=m" (*&new_exc));
+
+ old_exc = (~new_exc) & FE_ALL_EXCEPT;
+
+ new_exc |= excepts;
+ __asm__ ("fldcw %0" : : "m" (*&new_exc));
+
+ /* And now the same for the SSE MXCSR register. */
+ __asm__ ("stmxcsr %0" : "=m" (*&new));
+
+ /* The SSE exception masks are shifted by 7 bits. */
+ new |= excepts << 7;
+ __asm__ ("ldmxcsr %0" : : "m" (*&new));
+
+ return old_exc;
+}