Re: Re[2]: [avr-gcc-list] Re: GCC-AVR Update (20082003)

[Joerg Wunsch]

As James Dabbs <address@hidden> wrote:

>> IAR can optimize RCALL vs. CALL in situations where it's clear that
>> an RCALL suffices, gcc currently can only use either of them.  (You
>> can force it to use RCALL even on > 8 KB devices, but that's
>> impractical.) This could perhaps also save a lot, where the
>> relative saving is most notable on 16 KB devices.

>That's a nice feature.  Out of curiosity, what would it take to get
>this into GCC?  Does the architecture allow this type of optimization
>(at the linker level)?

Nope, at the linker level it's sheer impossible.  If at all, it must
be done at the compiler level, i. e. it can only be applied to a
single compilation unit (aka., a single C source file).  That's
probably the same for IAR.

I don't know gcc's organization well enough, perhaps it can even only
be applied at the function level since each function is compiled
separately, i don't know.  This would render the idea pretty much
useless.  Maybe Denis or Marek can say something about whether it's
possible at all or not.
-- 
J"org Wunsch                                           Unix support engineer
address@hidden        http://www.interface-systems.de/~j/