diff options
Diffstat (limited to 'man3p/feupdateenv.3p')
-rw-r--r-- | man3p/feupdateenv.3p | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/man3p/feupdateenv.3p b/man3p/feupdateenv.3p new file mode 100644 index 000000000..c31aa0c7b --- /dev/null +++ b/man3p/feupdateenv.3p @@ -0,0 +1,80 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "FEUPDATEENV" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" feupdateenv +.SH NAME +feupdateenv \- update floating-point environment +.SH SYNOPSIS +.LP +\fB#include <fenv.h> +.br +.sp +int feupdateenv(const fenv_t *\fP\fIenvp\fP\fB); +.br +\fP +.SH DESCRIPTION +.LP +The \fIfeupdateenv\fP() 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 \fIenvp\fP, and then attempt to raise +the saved floating-point exceptions. The argument \fIenvp\fP shall +point to an object set by a call to \fIfeholdexcept\fP() or \fIfegetenv\fP(), +or equal +a floating-point environment macro. +.SH RETURN VALUE +.LP +The \fIfeupdateenv\fP() function shall return a zero value if and +only if all the required actions were successfully carried +out. +.SH ERRORS +.LP +No errors are defined. +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +The following example shows sample code to hide spurious underflow +floating-point exceptions: +.sp +.RS +.nf + +\fB#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; +} +\fP +.fi +.RE +.SH APPLICATION USAGE +.LP +None. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIfegetenv\fP() , \fIfeholdexcept\fP() , the Base Definitions +volume of IEEE\ Std\ 1003.1-2001, \fI<fenv.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 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 . |