|
1 <?xml version="1.0" encoding="utf-8"?> |
|
2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
|
3 <!-- This component and the accompanying materials are made available under the terms of the License |
|
4 "Eclipse Public License v1.0" which accompanies this distribution, |
|
5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
|
6 <!-- Initial Contributors: |
|
7 Nokia Corporation - initial contribution. |
|
8 Contributors: |
|
9 --> |
|
10 <!DOCTYPE concept |
|
11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
|
12 <concept id="GUID-947317B7-7E12-509B-9A16-F0604D7F8BA2" xml:lang="en"><title>armfpu</title><prolog><metadata><keywords/></metadata></prolog><conbody> |
|
13 <p> <codeph>armfpu [ vfpv2 | softvfp ]</codeph> </p> |
|
14 <p>Use the <codeph>armfpu</codeph> statement to specify how the compiler is |
|
15 to deal with floating point instructions. </p> |
|
16 <p>There are two ways in which floating point instructions can be handled |
|
17 on an ARM processor: </p> |
|
18 <ul> |
|
19 <li id="GUID-929D9EEB-1D4A-58DD-8E62-7E14EAB6566B"><p>through the use of floating |
|
20 point support functions. </p> </li> |
|
21 <li id="GUID-B28E550A-0785-50B5-B260-7F8C85F1CA2A"><p>directly on a hardware |
|
22 floating point co-processor, the Vector Floating Point (VFP) unit. </p> </li> |
|
23 </ul> |
|
24 <table id="GUID-A0C3733D-2744-5094-AF89-EF15737C68E9"> |
|
25 <tgroup cols="2"><colspec colname="col0"/><colspec colname="col1"/> |
|
26 <tbody> |
|
27 <row> |
|
28 <entry><p> <codeph>softvfp</codeph> </p> </entry> |
|
29 <entry><p>This keyword specifies that floating point instructions are handled |
|
30 by floating point support functions. </p> <p>On a device without a VFP unit, |
|
31 floating point support functions are implemented in software and operate slowly. |
|
32 On a device with a VFP unit, the floating point support functions are handled |
|
33 by the VFP unit, and operate faster than when implemented in software. </p> <p>Note |
|
34 that applications do not need to make any changes to take advantage of VFP-enabled |
|
35 floating point support functions, if they are provided in the device's ROM. |
|
36 Such functions are used automatically at run time. </p> <p>If <codeph>armfpu</codeph> is |
|
37 not specified in a <filepath>.mmp</filepath> file, then <codeph>armfpu softvfp</codeph> is |
|
38 assumed by default. </p> </entry> |
|
39 </row> |
|
40 <row> |
|
41 <entry><p> <codeph>vfpv2</codeph> </p> </entry> |
|
42 <entry><p>This keyword specifies that VFP specific code is to be generated |
|
43 at compile time whenever floating point instructions are used. </p> <p>On |
|
44 a device with a VFP unit, this option results in code that runs faster than |
|
45 the floating point support functions generated by <codeph>softvfp</codeph>. |
|
46 Note, however, that binaries produced with VFP specific code do not work on |
|
47 devices without a VFP unit. <i>Software Install</i> attempts to prevent their |
|
48 installation, but if any such binaries are installed onto a device in some |
|
49 other way, for example by inclusion into the ROM at device creation time, |
|
50 then a call to VFP specific code results in a KERN-EXEC 3 panic (see also <xref href="GUID-0AF47934-0A16-51A2-9254-992D7C6B322B.dita">Application Installation |
|
51 Guide</xref>). </p> </entry> |
|
52 </row> |
|
53 </tbody> |
|
54 </tgroup> |
|
55 </table></conbody></concept> |