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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>
</conbody><related-links>
<link href="GUID-D525B9A9-6B32-535B-A282-60C85A48D3FB.dita"><linktext>Floating
point                 support</linktext></link>
<link href="GUID-3046453A-AB3A-5491-87A0-00F3514D4768.dita"><linktext>Vector Floating
Point Implementation Tutorial</linktext></link>
</related-links></concept>