142 lines
4.5 KiB
HTML
142 lines
4.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<!-- Copyright (c) 2001 The Open Group, All Rights Reserved -->
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<title>fegetround</title>
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<script type="text/javascript" language="JavaScript" src="../jscript/codes.js">
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<basefont size="3"> <a name="fegetround"></a> <a name="tag_03_150"></a><!-- fegetround -->
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<!--header start-->
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<center><font size="2">The Open Group Base Specifications Issue 6<br>
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IEEE Std 1003.1-2001<br>
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Copyright © 2001 The IEEE and The Open Group, All Rights reserved.</font></center>
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<!--header end-->
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<hr size="2" noshade>
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<h4><a name="tag_03_150_01"></a>NAME</h4>
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<blockquote>fegetround, fesetround - get and set current rounding direction</blockquote>
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<h4><a name="tag_03_150_02"></a>SYNOPSIS</h4>
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<blockquote class="synopsis">
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<p><code><tt>#include <<a href="../basedefs/fenv.h.html">fenv.h</a>><br>
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<br>
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int fegetround(void);<br>
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int fesetround(int</tt> <i>round</i><tt>);<br>
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</tt></code></p>
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</blockquote>
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<h4><a name="tag_03_150_03"></a>DESCRIPTION</h4>
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<blockquote>
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<div class="box"><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]"
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border="0"> The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the
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requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to
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the ISO C standard. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></div>
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<p>The <i>fegetround</i>() function shall get the current rounding direction.</p>
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<p>The <i>fesetround</i>() function shall establish the rounding direction represented by its argument <i>round</i>. If the
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argument is not equal to the value of a rounding direction macro, the rounding direction is not changed.</p>
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</blockquote>
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<h4><a name="tag_03_150_04"></a>RETURN VALUE</h4>
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<blockquote>
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<p>The <i>fegetround</i>() function shall return the value of the rounding direction macro representing the current rounding
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direction or a negative value if there is no such rounding direction macro or the current rounding direction is not
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determinable.</p>
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<p>The <i>fesetround</i>() function shall return a zero value if and only if the requested rounding direction was established.</p>
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</blockquote>
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<h4><a name="tag_03_150_05"></a>ERRORS</h4>
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<blockquote>
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<p>No errors are defined.</p>
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</blockquote>
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<hr>
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<div class="box"><em>The following sections are informative.</em></div>
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<h4><a name="tag_03_150_06"></a>EXAMPLES</h4>
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<blockquote>
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<p>The following example saves, sets, and restores the rounding direction, reporting an error and aborting if setting the rounding
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direction fails:</p>
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<pre>
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<tt>#include <fenv.h>
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#include <assert.h>
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void f(int round_dir)
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{
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#pragma STDC FENV_ACCESS ON
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int save_round;
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int setround_ok;
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save_round = fegetround();
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setround_ok = fesetround(round_dir);
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assert(setround_ok == 0);
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/* ... */
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fesetround(save_round);
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/* ... */
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}
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</tt>
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</pre>
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</blockquote>
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<h4><a name="tag_03_150_07"></a>APPLICATION USAGE</h4>
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<blockquote>
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<p>None.</p>
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</blockquote>
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<h4><a name="tag_03_150_08"></a>RATIONALE</h4>
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<blockquote>
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<p>None.</p>
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</blockquote>
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<h4><a name="tag_03_150_09"></a>FUTURE DIRECTIONS</h4>
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<blockquote>
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<p>None.</p>
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</blockquote>
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<h4><a name="tag_03_150_10"></a>SEE ALSO</h4>
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<blockquote>
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<p>The Base Definitions volume of IEEE Std 1003.1-2001, <a href="../basedefs/fenv.h.html"><i><fenv.h></i></a></p>
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</blockquote>
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<h4><a name="tag_03_150_11"></a>CHANGE HISTORY</h4>
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<blockquote>
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<p>First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.</p>
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<p>ISO/IEC 9899:1999 standard, Technical Corrigendum No. 1 is incorporated.</p>
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</blockquote>
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<div class="box"><em>End of informative text.</em></div>
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