[U-Boot] [PATCH] ARM: Add comments why -msoft-float is used.

[Alexander Holler]

Am 20.02.2011 09:42, schrieb Wolfgang Denk:
> Dear Alexander Holler,
>
> In message<1298171532-5296-1-git-send-email-holler at ahsoftware.de>  you wrote:
>> Without -msoft-float the compiler would be allowed to use certain
>> floating-point instructions (VFP/NEON) e.g. for optimizations, which
>> would require additional code, for example to save contexts for
>> interrupts. Add a comment which describes this in short words.
>
> Hm... why do you see a need to explain this for ARM, but not so for
> the other architectrures, say for PowerPC?

I don't know how other the compiler behaves for other architectures and 
if those are having the need to save fp-contexts for irqs.

>
> If you really want to add this, then it should probably be somewhere
> in the REAME or another central place of documentation (instead of
> distributed over tons of Makefiles), and to make your message

I prefer comments where they are usefull. Hiding them somewhere is useless.

> understood you might want to add "additional code" may mean that
> additional function blocks in the respective SoC may need to be
> initialized and, for example, clocked, which may for example
> significantly increase the power dissipation of the system.
>
>> +# -msoft-float forces the compiler to not use any fp-related instructions.
>
> Well, now this is a commonplace that says about nothing and can be
> leftout as well.

# -msoft-float forces the compiler to avoid any fp-related instructions 
for optimizations.

Would that be better?

Regards,

Alexander