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50 lines
1.7 KiB
C
50 lines
1.7 KiB
C
/* Store current floating-point environment and clear exceptions.
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Copyright (C) 1997-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <fenv_libc.h>
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#include <fpu_control.h>
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#define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_XM | _FPU_MASK_IM)
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int
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feholdexcept (fenv_t *envp)
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{
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fenv_union_t old, new;
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/* Save the currently set exceptions. */
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old.fenv = *envp = fegetenv_register ();
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/* Clear everything except for the rounding modes and non-IEEE arithmetic
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flag. */
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new.l = old.l & 0xffffffff00000007LL;
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if (new.l == old.l)
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return 0;
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/* If the old env had any enabled exceptions, then mask SIGFPE in the
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MSR FE0/FE1 bits. This may allow the FPU to run faster because it
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always takes the default action and can not generate SIGFPE. */
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if ((old.l & _FPU_MASK_ALL) != 0)
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(void)__fe_mask_env ();
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/* Put the new state in effect. */
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fesetenv_register (new.fenv);
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return 0;
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}
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libm_hidden_def (feholdexcept)
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