diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/feenablxcpt.c')
-rw-r--r-- | sysdeps/x86_64/fpu/feenablxcpt.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/sysdeps/x86_64/fpu/feenablxcpt.c b/sysdeps/x86_64/fpu/feenablxcpt.c new file mode 100644 index 0000000000..43259d0cfb --- /dev/null +++ b/sysdeps/x86_64/fpu/feenablxcpt.c @@ -0,0 +1,49 @@ +/* Enable floating-point exceptions. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <fenv.h> + +int +feenableexcept (int excepts) +{ + unsigned short int new_exc, old_exc; + unsigned int new, old; + + 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. */ + old = (~new) & (FE_ALL_EXCEPT << 7); + + new &= ~(excepts << 7); + __asm__ ("ldmxcsr %0" : : "m" (*&new)); + + return old_exc; +} |