fetestexcept(3p) [posix man page]
FETESTEXCEPT(3P) POSIX Programmer's Manual FETESTEXCEPT(3P) PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
fetestexcept -- test floating-point exception flags SYNOPSIS
#include <fenv.h> int fetestexcept(int excepts); DESCRIPTION
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.1-2008 defers to the ISO C standard. The fetestexcept() function shall determine which of a specified subset of the floating-point exception flags are currently set. The excepts argument specifies the floating-point status flags to be queried. RETURN VALUE
The fetestexcept() function shall return the value of the bitwise-inclusive OR of the floating-point exception macros corresponding to the currently set floating-point exceptions included in excepts. ERRORS
No errors are defined. The following sections are informative. EXAMPLES
The following example calls function f() if an invalid exception is set, and then function g() if an overflow exception is set: #include <fenv.h> /* ... */ { #pragma STDC FENV_ACCESS ON int set_excepts; feclearexcept(FE_INVALID | FE_OVERFLOW); // maybe raise exceptions set_excepts = fetestexcept(FE_INVALID | FE_OVERFLOW); if (set_excepts & FE_INVALID) f(); if (set_excepts & FE_OVERFLOW) g(); /* ... */ } APPLICATION USAGE
None. RATIONALE
None. FUTURE DIRECTIONS
None. SEE ALSO
feclearexcept(), fegetexceptflag(), feraiseexcept() The Base Definitions volume of POSIX.1-2008, <fenv.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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 Stan- dard is the referee document. The original Standard can be obtained online at http://www.unix.org/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 2013 FETESTEXCEPT(3P)
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FERAISEEXCEPT(3P) POSIX Programmer's Manual FERAISEEXCEPT(3P) PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the correspond- ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. NAME
feraiseexcept -- raise floating-point exception SYNOPSIS
#include <fenv.h> int feraiseexcept(int excepts); DESCRIPTION
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.1-2008 defers to the ISO C standard. The feraiseexcept() function shall attempt to raise the supported floating-point exceptions represented by the argument excepts. The order in which these floating-point exceptions are raised is unspecified. Whether the feraiseexcept() function additionally raises the inexact floating-point exception whenever it raises the overflow or underflow floating-point exception is implementation-defined. RETURN VALUE
If the argument is zero or if all the specified exceptions were successfully raised, feraiseexcept() shall return zero. Otherwise, it shall return a non-zero value. ERRORS
No errors are defined. The following sections are informative. EXAMPLES
None. APPLICATION USAGE
The effect is intended to be similar to that of floating-point exceptions raised by arithmetic operations. Hence, enabled traps for float- ing-point exceptions raised by this function are taken. RATIONALE
Raising overflow or underflow is allowed to also raise inexact because on some architectures the only practical way to raise an exception is to execute an instruction that has the exception as a side-effect. The function is not restricted to accept only valid coincident expressions for atomic operations, so the function can be used to raise exceptions accrued over several operations. FUTURE DIRECTIONS
None. SEE ALSO
feclearexcept(), fegetexceptflag(), fetestexcept() The Base Definitions volume of POSIX.1-2008, <fenv.h> COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol- ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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 Stan- dard is the referee document. The original Standard can be obtained online at http://www.unix.org/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 2013 FERAISEEXCEPT(3P)