258 lines
4.8 KiB
HTML
258 lines
4.8 KiB
HTML
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<HTML><HEAD><TITLE>Man page of FMA</TITLE>
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</HEAD><BODY>
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<H1>FMA</H1>
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Section: Linux Programmer's Manual (3)<BR>Updated: 2017-09-15<BR><A HREF="#index">Index</A>
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<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
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<A NAME="lbAB"> </A>
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<H2>NAME</H2>
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fma, fmaf, fmal - floating-point multiply and add
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<A NAME="lbAC"> </A>
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<H2>SYNOPSIS</H2>
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<PRE>
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<B>#include <<A HREF="file:///usr/include/math.h">math.h</A>></B>
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<B>double fma(double </B><I>x</I><B>, double </B><I>y</I><B>, double </B><I>z</I><B>);</B>
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<B>float fmaf(float </B><I>x</I><B>, float </B><I>y</I><B>, float </B><I>z</I><B>);</B>
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<B>long double fmal(long double </B><I>x</I><B>, long double </B><I>y</I><B>, long double </B><I>z</I><B>);</B>
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</PRE>
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<P>
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Link with <I>-lm</I>.
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<P>
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Feature Test Macro Requirements for glibc (see
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<B><A HREF="/cgi-bin/man/man2html?7+feature_test_macros">feature_test_macros</A></B>(7)):
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<P>
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<B>fma</B>(),
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<B>fmaf</B>(),
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<B>fmal</B>():
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<DL COMPACT><DT id="1"><DD>
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_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
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</DL>
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<A NAME="lbAD"> </A>
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<H2>DESCRIPTION</H2>
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These functions compute
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<I>x</I> * <I>y</I> + <I>z</I>.
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The result is rounded as one ternary operation according to the
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current rounding mode (see
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<B><A HREF="/cgi-bin/man/man2html?3+fenv">fenv</A></B>(3)).
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<A NAME="lbAE"> </A>
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<H2>RETURN VALUE</H2>
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These functions return the value of
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<I>x</I> * <I>y</I> + <I>z</I>,
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rounded as one ternary operation.
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<P>
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If
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<I>x</I>
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or
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<I>y</I>
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is a NaN, a NaN is returned.
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<P>
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If
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<I>x</I>
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times
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<I>y</I>
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is an exact infinity, and
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<I>z</I>
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is an infinity with the opposite sign,
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a domain error occurs,
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and a NaN is returned.
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<P>
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If one of
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<I>x</I>
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or
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<I>y</I>
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is an infinity, the other is 0, and
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<I>z</I>
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is not a NaN,
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a domain error occurs, and
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a NaN is returned.
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<P>
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If one of
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<I>x</I>
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or
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<I>y</I>
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is an infinity, and the other is 0, and
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<I>z</I>
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is a NaN,
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a domain error occurs, and
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a NaN is returned.
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<P>
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If
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<I>x</I>
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times
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<I>y</I>
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is not an infinity times zero (or vice versa), and
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<I>z</I>
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is a NaN,
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a NaN is returned.
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<P>
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If the result overflows,
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a range error occurs, and
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an infinity with the correct sign is returned.
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<P>
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If the result underflows,
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a range error occurs, and
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a signed 0 is returned.
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<A NAME="lbAF"> </A>
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<H2>ERRORS</H2>
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See
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<B><A HREF="/cgi-bin/man/man2html?7+math_error">math_error</A></B>(7)
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for information on how to determine whether an error has occurred
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when calling these functions.
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<P>
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The following errors can occur:
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<DL COMPACT>
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<DT id="2">Domain error: <I>x</I> * <I>y</I> + <I>z</I>, or <I>x</I> * <I>y</I> is invalid and <I>z</I> is not a NaN<DD>
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An invalid floating-point exception
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(<B>FE_INVALID</B>)
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is raised.
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<DT id="3">Range error: result overflow<DD>
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An overflow floating-point exception
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(<B>FE_OVERFLOW</B>)
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is raised.
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<DT id="4">Range error: result underflow<DD>
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An underflow floating-point exception
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(<B>FE_UNDERFLOW</B>)
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is raised.
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</DL>
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<P>
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These functions do not set
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<I>errno</I>.
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<A NAME="lbAG"> </A>
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<H2>VERSIONS</H2>
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These functions first appeared in glibc in version 2.1.
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<A NAME="lbAH"> </A>
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<H2>ATTRIBUTES</H2>
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For an explanation of the terms used in this section, see
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<B><A HREF="/cgi-bin/man/man2html?7+attributes">attributes</A></B>(7).
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<TABLE BORDER>
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<TR VALIGN=top><TD><B>Interface</B></TD><TD><B>Attribute</B></TD><TD><B>Value</B><BR></TD></TR>
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<TR VALIGN=top><TD>
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<B>fma</B>(),
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<B>fmaf</B>(),
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<B>fmal</B>()
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</TD><TD>Thread safety</TD><TD>MT-Safe<BR></TD></TR>
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</TABLE>
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<A NAME="lbAI"> </A>
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<H2>CONFORMING TO</H2>
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C99, POSIX.1-2001, POSIX.1-2008.
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<A NAME="lbAJ"> </A>
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<H2>SEE ALSO</H2>
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<B><A HREF="/cgi-bin/man/man2html?3+remainder">remainder</A></B>(3),
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<B><A HREF="/cgi-bin/man/man2html?3+remquo">remquo</A></B>(3)
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<A NAME="lbAK"> </A>
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<H2>COLOPHON</H2>
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This page is part of release 5.05 of the Linux
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<I>man-pages</I>
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project.
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A description of the project,
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information about reporting bugs,
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and the latest version of this page,
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can be found at
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<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
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<P>
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<HR>
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<A NAME="index"> </A><H2>Index</H2>
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<DL>
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<DT id="5"><A HREF="#lbAB">NAME</A><DD>
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<DT id="6"><A HREF="#lbAC">SYNOPSIS</A><DD>
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<DT id="7"><A HREF="#lbAD">DESCRIPTION</A><DD>
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<DT id="8"><A HREF="#lbAE">RETURN VALUE</A><DD>
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<DT id="9"><A HREF="#lbAF">ERRORS</A><DD>
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<DT id="10"><A HREF="#lbAG">VERSIONS</A><DD>
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<DT id="11"><A HREF="#lbAH">ATTRIBUTES</A><DD>
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<DT id="12"><A HREF="#lbAI">CONFORMING TO</A><DD>
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<DT id="13"><A HREF="#lbAJ">SEE ALSO</A><DD>
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<DT id="14"><A HREF="#lbAK">COLOPHON</A><DD>
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</DL>
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<HR>
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This document was created by
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<A HREF="/cgi-bin/man/man2html">man2html</A>,
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using the manual pages.<BR>
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Time: 00:05:43 GMT, March 31, 2021
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</BODY>
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</HTML>
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