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<concept id="GUID-CBC1E46A-E254-5A01-86AE-F5EB6135E3E3" xml:lang="en"><title>Vector Floating Point (VFP)</title><shortdesc>ARM provide a hardware floating point coprocessor that

provides floating point computation that is fully compliant with IEEE

Std 754-1985.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p> When a phone has this hardware, the base port must be configured

to use it. </p>

<p>The ARM architecture is called the ARM Vector Floating Point Architecture

(VFPv2), and the coprocessor is also called the <i>VFP unit</i>. </p>

<p>Symbian platform supports the use of VFPv2 on platforms where the

required hardware is present in both <i>RunFast</i> mode and in <i>IEEE-without-exceptions</i> mode. See ARM's Vector Floating-point

Coprocessor Technical reference Manual for more details on the coprocessor,

its architecture, and its execution modes. </p>

<p>Applications and, in a more limited sense, kernel side code can

use VFP in one of two ways: </p>

<ul>

<li id="GUID-D74E3541-3D8F-5338-A488-E40385D1C293"><p>indirectly through

the use of floating point support (helper) functions generated by

the compiler. </p> </li>

<li id="GUID-7316F251-5292-510C-9496-30C0B7A7A25C"><p>directly, either

through instructions generated by the compiler, or hand-written instructions

written in assembler. </p> </li>

</ul>

<p>An application uses the <codeph>armfpu</codeph> statement in its <filepath>.mmp</filepath> file to specify how it wants floating point to be

handled. By choosing to use the floating point support functions,

an application does not need to know how they are implemented or even

whether these functions make use of a VFP unit. However, if a device

does have a VFP unit, then the base port needs to replace the default

floating point support functions with VFP-enabled functions if applications

are to take advantage of the hardware. </p>

<section id="GUID-C20C78B4-62E4-403B-82F1-416539B50DD0"><title>See also</title><p><ul>

<li><p>Floating point support in Symbian^3 Tools Guide

&gt; Building</p></li>

<li><p><xref href="GUID-3046453A-AB3A-5491-87A0-00F3514D4768.dita">Vector

Floating Point Implementation Tutorial</xref></p></li>

</ul></p></section>

</conbody></concept>