This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: xscale-elf-gcc and arm-elf-gcc
- From: Richard Earnshaw <rearnsha at arm dot com>
- To: Nick Clifton <nickc at cambridge dot redhat dot com>
- Cc: Arvind Krishnaswamy <arvind at CS dot Arizona dot EDU>, gcc at gcc dot gnu dot org, Richard dot Earnshaw at arm dot com
- Date: Fri, 18 Jan 2002 10:37:43 +0000
- Subject: Re: xscale-elf-gcc and arm-elf-gcc
- Organization: ARM Ltd.
- Reply-to: Richard dot Earnshaw at arm dot com
>
> > xscale-elf-gcc code seems to be more compact than arm-elf-gcc. What
> > enables this?
>
> Presumably the use of the extra, XScale instructions. Do you have a
> specific example in mind ?
No, most of the differences are due to the fact that XScale uses the ARM
architecture 5te (armv5te) instruction set, whereas the arm-elf-gcc
configuration will default to using the armv3 instruction set (as
implemented on the arm6).
You can enable most of the optimizations on the arm-elf-gcc configuration
by adding the command line option -march=armv4 when you compile your
source code.
A final note: most of the so-called XScale instructions that gcc adds with
-mcpu=xscale are nothing more than standard armv5te instructions; I will
be installing a fix sometime to correct this anomaly.
R.