Need some opinions

[Jerry Quinn]

Jeff Law writes:

>   > > Another would be to rearrange the meaning of -O1, -O2, -O3, etc to make
>   > > space for a -O1 option which did just these simple optimizations.
>   > 
>   > No way. -O2 et al are widely entrenched by now (for better or worse).
> I suspect this is the case.  And it is definitely for the worse IMHO.
> 
>   > > A third would be to have it controlled by a flag which could be enabled
>   > > even when optimize == 0.
>   > 
>   > Reasonable too, but yet another flag that interacts with all the others in
>   > possibly weird ways?
> I don't see that many interactions.
> 
>   > Or you could add this to -O1 and up.
> -O1 already runs the full jump optimizer, so a dumb jump optimization pass
> would not be particularly useful (except to clean up the cfg for sibcall and
> tail recursion elimination)

Since -O2 is fairly hidebound we could take HP's way out and start using +Ox
to reorder the optimization levels.  This gives a new number range to work
with.

Howver, it can still lead to the same problem we have today with expectations
about how much is done at a certain level.

-- 
Jerry Quinn                             Tel: (514) 761-8737
jquinn@nortelnetworks.com               Fax: (514) 761-8505
Speech Recognition Research