Re: thumb2 support

[Wermut <wermut@gmail.com>]

Hi

I have tested the patch from Stephen Thomas at least for gcc 4.6, 4.7
and 4.8. Seems to work. Would be nice if the 1.1.1 release will
include a fix.

Regards
Kevin

On Tue, Apr 29, 2014 at 3:14 AM, Stephen Thomas <scjthm@live.com> wrote:
>> On Tue, Apr 29, 2014 at 12:52:36AM +0100, Stephen Thomas wrote:
>> > I remember that the old thumb didn't support the conditional
>> > instructions and was quite slow. I only care about thumb2 and am
>> > currently using gcc, so I attach a patch for the thumb that will
>>
>> The code here is only used on armv6/v7. Do any such chips lack thumb2?
>> If there's any doubt, we could look at what gcc generates for the
>> __sync_* builtins in thumb mode.
>>
>> > only work for gcc .
>>
>> Why is it only for gcc?
>
> I have only tested with gcc. I don't know what llvm nor armcc do.  Is there
> an ASM standard like ther is for C/C++/fortran? There is some good info on
> thumb here, https://wiki.ubuntu.com/ARM/Thumb2 and the various ways of
> supporting ARM. I guess that the thumb2 could be replaced by a __thumb__.
>
>>
>> > I think that gcc builds two versions of atomic
>>
>> What do you mean by this?
>
> I am building the native toolchain as I would like to run this on an
> embedded platform. My understanding is that when you build the toolchain you
> need to provide somethings that end up going in libgcc_s.so such as
> threading if you are using openmp in C++. etc etc. That patch works for both
> the -marm and -mthumb or whatever the thumb targets are.
>
>>
>> > so the ugly #define was needed. I cannot remember what rvct/rvds or
>> > whatever it is branded as these days uses, but from memory old
>> > versions didn't support the gnu assebmly syntax.
>>
>> All asm in musl is gas syntax so this is nothing new.
>>
>> Rich