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diff --git a/libm/x86_64/fsetexcptflg.c b/libm/x86_64/fsetexcptflg.c
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+/* Set floating-point environment exception handling.
+ 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>
+#include <math.h>
+
+int
+fesetexceptflag (const fexcept_t *flagp, int excepts)
+{
+ fenv_t temp;
+ unsigned int mxcsr;
+
+ /* XXX: Do we really need to set both the exception in both units?
+ Shouldn't it be enough to set only the SSE unit? */
+
+ /* Get the current x87 FPU environment. We have to do this since we
+ cannot separately set the status word. */
+ __asm__ ("fnstenv %0" : "=m" (*&temp));
+
+ temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
+ temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;
+
+ /* Store the new status word (along with the rest of the environment.
+ Possibly new exceptions are set but they won't get executed unless
+ the next floating-point instruction. */
+ __asm__ ("fldenv %0" : : "m" (*&temp));
+
+ /* And now the same for SSE. */
+ __asm__ ("stmxcsr %0" : "=m" (*&mxcsr));
+
+ mxcsr &= ~(excepts & FE_ALL_EXCEPT);
+ mxcsr |= *flagp & excepts & FE_ALL_EXCEPT;
+
+ __asm__ ("ldmxcsr %0" : : "m" (*&mxcsr));
+
+ /* Success. */
+ return 0;
+}