Re: rtlopt merge part 8 - webizer pass

[Jan Hubicka <jh at suse dot cz>]

> Jan Hubicka <jh@suse.cz> writes:
> 
> > + Simple optimization pass that splits independent uses of each
> > + pseudo increasing effect of other optimizations.  This can improve
> > + effect of the other transformation, such as CSE or register
> > + allocation.  Its source files are @file{web.c}.
> 
> You have some English grammar problems here.  The first sentence has
> no main verb.  The second sentence largely duplicates the first, but
> with problematic number agreement.
> 
> I would write this paragraph as
> 
>   Web construction is a simple pass that splits up independent uses of
>   each pseudo register.  This allows other passes, such as CSE and
>   hard register allocation, to do a better job.
> 
> > + The option @option{-dZ} causes a debugging dump of the RTL code
> > + after this pass.  This dump file's name is made by appending
> > + @samp{.web} to the input file name.
> 
> This paragraph is fine.
> 
> >   Optimize yet more.  @option{-O3} turns on all optimizations specified by
> > ! @option{-O2} and also turns on the @option{-finline-functions}, @option{-fweb}
> > ! and @option{-frename-registers} options.
> 
> Needs word wrapping.
> 
> Why is this optimization only enabled at -O3?

Because at the moment it makes debugging dificult by moving user
variables to different places.  Josef and Daniel is working on the
location list part that should allow us to enable it at -O2, together
with register renaming.

Thanks!

Honza
> 
> zw