2004-11-03 13:51:07 +00:00
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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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2007-06-20 22:33:04 +00:00
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.TH "FEUPDATEENV" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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2004-11-03 13:51:07 +00:00
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.\" feupdateenv
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2007-09-20 06:03:25 +00:00
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.SH PROLOG
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This manual page is part of the POSIX Programmer's Manual.
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The Linux implementation of this interface may differ (consult
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the corresponding Linux manual page for details of Linux behavior),
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or the interface may not be implemented on Linux.
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2004-11-03 13:51:07 +00:00
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.SH NAME
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feupdateenv \- update floating-point environment
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.SH SYNOPSIS
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.LP
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\fB#include <fenv.h>
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.br
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.sp
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int feupdateenv(const fenv_t *\fP\fIenvp\fP\fB);
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIfeupdateenv\fP() function shall attempt to save the currently
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raised floating-point exceptions in its automatic storage,
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attempt to install the floating-point environment represented by the
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object pointed to by \fIenvp\fP, and then attempt to raise
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the saved floating-point exceptions. The argument \fIenvp\fP shall
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point to an object set by a call to \fIfeholdexcept\fP() or \fIfegetenv\fP(),
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or equal
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a floating-point environment macro.
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.SH RETURN VALUE
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.LP
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The \fIfeupdateenv\fP() function shall return a zero value if and
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only if all the required actions were successfully carried
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out.
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.SH ERRORS
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.LP
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No errors are defined.
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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The following example shows sample code to hide spurious underflow
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floating-point exceptions:
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.sp
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.RS
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.nf
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\fB#include <fenv.h>
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double f(double x)
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{
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#pragma STDC FENV_ACCESS ON
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double result;
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fenv_t save_env;
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feholdexcept(&save_env);
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// compute result
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if (/* test spurious underflow */)
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feclearexcept(FE_UNDERFLOW);
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feupdateenv(&save_env);
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return result;
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}
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\fP
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.fi
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.RE
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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2007-09-20 06:11:55 +00:00
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\fIfegetenv\fP(), \fIfeholdexcept\fP(), the Base Definitions
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2004-11-03 13:51:07 +00:00
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volume of IEEE\ Std\ 1003.1-2001, \fI<fenv.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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