update upstream sources

[clinton/guile-figl.git] / upstream-doc / manglsl / fma.xml

<?xml version="1.0" encoding="UTF-8"?>\r
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r
              "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r
<refentry id="fma">\r
    <refmeta>\r
        <refmetainfo>\r
            <copyright>\r
                <year>2011</year>\r
                <holder>Khronos Group</holder>\r
            </copyright>\r
        </refmetainfo>\r
        <refentrytitle>fma</refentrytitle>\r
        <manvolnum>3G</manvolnum>\r
    </refmeta>\r
    <refnamediv>\r
        <refname>fma</refname>\r
        <refpurpose>perform a fused multiply-add operation</refpurpose>\r
    </refnamediv>\r
    <refsynopsisdiv><title>Declaration</title>\r
        <funcsynopsis>\r
            <funcprototype>\r
                <funcdef>genType <function>fma</function></funcdef>\r
                <paramdef>genType <parameter>a</parameter></paramdef>\r
                <paramdef>genType <parameter>b</parameter></paramdef>\r
                <paramdef>genType <parameter>c</parameter></paramdef>\r
            </funcprototype>\r
            <funcprototype>\r
                <funcdef>genDType <function>fma</function></funcdef>\r
                <paramdef>genDType <parameter>a</parameter></paramdef>\r
                <paramdef>genDType <parameter>b</parameter></paramdef>\r
                <paramdef>genDType <parameter>c</parameter></paramdef>\r
            </funcprototype>\r
        </funcsynopsis>\r
    </refsynopsisdiv>\r
    <refsect1 id="parameters"><title>Parameters</title>\r
        <variablelist>\r
        <varlistentry>\r
            <term><parameter>a</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the first multiplicand.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>b</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the second multiplicand.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        <varlistentry>\r
            <term><parameter>c</parameter></term>\r
            <listitem>\r
                <para>\r
                    Specifies the value to be added to the result.\r
                </para>\r
            </listitem>\r
        </varlistentry>\r
        </variablelist>\r
    </refsect1>\r
    <refsect1 id="description"><title>Description</title>\r
        <para>\r
            <function>fma</function> performs, where possible, a fused multiply-add operation,\r
            returning <code>a * b + c</code>.\r
            In use cases where the return value is eventually consumed by a variable declared as\r
            <code>precise</code>:\r
            <itemizedlist>\r
                <listitem><function>fma</function>() is considered a single operation, whereas the\r
                expression <code>a * b + c</code> consumed by a variable declared as <code>precise</code>\r
                is considered two operations.</listitem>\r
                <listitem>The precision of <function>fma</function>() can differ from the precision\r
                of the expression <code>a * b + c</code>.</listitem>\r
                <listitem><function>fma</function>() will be computed with the same precision as any\r
                other <function>fma</function>() consumed by a <code>precise</code> variable,\r
                giving invariant results for the same input values of <parameter>a</parameter>,\r
                <parameter>b</parameter> and <parameter>c</parameter>.</listitem>\r
            </itemizedlist>\r
            Otherwise, in the absense of <code>precise</code> consumption, there are no\r
            special constraints on the number of operations or difference in precision between\r
            <function>fma</function>() and the expression <code>a * b + c</code>.\r
        </para>\r
    </refsect1>\r
    <refsect1 id="versions"><title>Version Support</title>\r
        <informaltable frame="topbot">\r
            #VARTABLECOLS#\r
                <thead>\r
                    #FUNCTABLEHEADER#\r
                    <row>\r
                        <entry>fma (genType)</entry>#newin40#\r
                    </row>\r
                    <row>\r
                        <entry>fma (genDType)</entry>#newin40#\r
                    </row>\r
                </thead>\r
            </tgroup>\r
        </informaltable>\r
    </refsect1>\r
    <refsect1 id="Copyright"><title>Copyright</title>\r
        <para>\r
            Copyright <trademark class="copyright"></trademark> 2011-2013 Khronos Group. \r
            This material may be distributed subject to the terms and conditions set forth in \r
            the Open Publication License, v 1.0, 8 June 1999.\r
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r
        </para>\r
    </refsect1>\r
</refentry>\r