How is it possible to enable the usage of ARMv5T core DSP extensions in
AT91SAM9G20 at the gcc compiler level ?
Where can I find benchmarks about the processing efficiency of such
extensions ?
Thank you in advance for your attention.

Michele venturi Misha wrote:
> How is it possible to enable the usage of ARMv5T core DSP extensions in
> AT91SAM9G20 at the gcc compiler level ?

The DSP extensions are an intrinsic part of the ARM926EJ-S, so you will
at least have to set the -mcpu option to -mcpu=arm926ej-s (that much you
could get from the manual:
http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/ARM-Op...

Of course that is no guarantee that the compiler will use such
extensions, in fact I would say that it is unlikely, however it should
make the instructions available to the in-line assembler so you can
hand-optimise your code in assembler.

Clifford

Thanks for your prompt support.

Now the task is to check the different compilers.
Is someone knows some of them is actually using the ARMv5t extended
instructions please let me know.


Clifford Slocombe wrote:
> Michele venturi Misha wrote:
>> How is it possible to enable the usage of ARMv5T core DSP extensions in
>> AT91SAM9G20 at the gcc compiler level ?
>
> The DSP extensions are an intrinsic part of the ARM926EJ-S, so you will
> at least have to set the -mcpu option to -mcpu=arm926ej-s (that much you
> could get from the manual:
> http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/ARM-Op...
>
> Of course that is no guarantee that the compiler will use such
> extensions, in fact I would say that it is unlikely, however it should
> make the instructions available to the in-line assembler so you can
> hand-optimise your code in assembler.
>
> Clifford