Re: PING^2: resubmitted IRA improvement patches

[Vladimir Makarov <vmakarov at redhat dot com>]

On 12/06/2010 11:12 AM, Kenneth Zadeck wrote:
> sorry, for taking so long.   i have been temporarily put on another 
> project.
>
> i applied all of your patches to the trunk, and then reread all of the 
> ira files looking for parts that i did not understand.    many of them 
> relate to the patches at hand but some are things that should have 
> been documented in earlier rounds that were just missed.  When these 
> comments are properly addressed, you can check in your patches.
Kenny, thanks for pointing this out.  I'll address all your proposals.  
Many of them are for the code which is on the trunk.  That makes them 
even more valuable.
> ira.c:
>
>   setup_pressure_classes:
>
>     you should describe how you find/compute the set of pressure
>     classes here.
>
>   setup_allocno_and_important_classes:
>
>     there are no globals defined above.
>
>   setup_class_translate_array and setup_class_translate
>
>     what do these translators translate?
>
>   reorder_important_classes:
>
>     what makes a class "important"?  is it just that it is non empty?
>     what purpose do empty classes serve? (i.e. why were they just not
>     deleted to start with? and are some more important
>     than others?  is this why you reorder them?
>
>   setup_reg_class_relations
>
>     what "above" relations?  A line or two describing each relation as 
> it is
>     setup would be useful here.
>
>
> ira-color.c
>
>   assign_hard_reg
>
>     what criteria do you use to select a hard register to assign?
>
>   improve_allocation
>
>     what criteria do you use to improve the allocation?
I already added a lot of comments for this function.  They are now on 
the branch.
> ira-costs.c
>
>   setup_cost_classes and setup_regno_cost_classes_by_aclass
>
>     what are the costs based on?
>
>   ira-emit
>
>     a few extra comments would be appreciated here to describe what is
>     going on.