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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
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FEUPDATEENV(3P) POSIX Programmer's Manual FEUPDATEENV(3P)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
feupdateenv — update floating-point environment
#include <fenv.h>
int feupdateenv(const fenv_t *envp);
The functionality described on this reference page is aligned
with the ISO C standard. Any conflict between the requirements
described here and the ISO C standard is unintentional. This
volume of POSIX.1‐2017 defers to the ISO C standard.
The feupdateenv() function shall attempt to save the currently
raised floating-point exceptions in its automatic storage,
attempt to install the floating-point environment represented by
the object pointed to by envp, and then attempt to raise the
saved floating-point exceptions. The argument envp shall point to
an object set by a call to feholdexcept() or fegetenv(), or equal
a floating-point environment macro.
The feupdateenv() function shall return a zero value if and only
if all the required actions were successfully carried out.
No errors are defined.
The following sections are informative.
The following example shows sample code to hide spurious
underflow floating-point exceptions:
#include <fenv.h>
double f(double x)
{
#pragma STDC FENV_ACCESS ON
double result;
fenv_t save_env;
feholdexcept(&save_env);
// compute result
if (/* test spurious underflow */)
feclearexcept(FE_UNDERFLOW);
feupdateenv(&save_env);
return result;
}
None.
None.
None.
fegetenv(3p), feholdexcept(3p)
The Base Definitions volume of POSIX.1‐2017, fenv.h(0p)
Portions of this text are reprinted and reproduced in electronic
form from IEEE Std 1003.1-2017, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The
Open Group Base Specifications Issue 7, 2018 Edition, Copyright
(C) 2018 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any
discrepancy between this version and the original IEEE and The
Open Group Standard, the original IEEE and The Open Group
Standard is the referee document. The original Standard can be
obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page
are most likely to have been introduced during the conversion of
the source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2017 FEUPDATEENV(3P)
Pages that refer to this page: fenv.h(0p), fegetenv(3p), feholdexcept(3p)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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