ARM iwmmxt CFLAGS

Matt Turner mattst88@gmail.com
Fri Jul 15 20:39:00 GMT 2011


On Thu, Jul 14, 2011 at 1:39 PM, Matt Turner <mattst88@gmail.com> wrote:
> Hi,
>
> I'm a bit confused about how CFLAGS related to ARM's iwmmxt
> instruction set extensions are handled.
>
> On x86 to enable SSEx instructions, one would do something like
> -march=... -msse3, but on ARM I must do something like -march=iwmmxt
> (where I'd have expected -march=armv7 -miwmmxt).
>
> What flags would I use to optimize code for armv7 while enabling
> iwmmxt instructions? -march=armv7 -mcpu=iwmmxt?
>
> Also, do I need to do anything with -mabi=iwmmxt? I think not, but..
>
> Thanks,
> Matt
>
> http://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html

There seems to be work in the direction of making this less insane.

http://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg08522.html

Matt



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