[google] Add options to pattern match function name for hotness attributes

[Xinliang David Li]

On Sat, Jun 2, 2012 at 11:11 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> Actually Dehao also plans to teach the static predictor to understand
>> standard library functions more (e.g IO functions) and add more naming
>
> How this differ from annotating the library?

I find them more suitable to be compiler heuristic than being
function's attribute -- attribute is a much stronger assertion.

>
> There are indeed quite some possibilities to do about library calls....
>
> One thing I always wondered about is how to tell predictor that paths containing
> heavy IO functions don't need to be really opimized to death, since their execution
> time is dominated by the IO...
>

Yes -- if branch predictor does the right thing and if function
splitter is powerful enough, the IO code can be outlined and optimized
for size :)


>> based heuristics such as 'error, success, failure, fatal etc).
>
> yeah, this is also mentioned by some branch prediction papers. It is bit kludgy
> in nature (i.e. it won't understand programs written in Czech language) but it
> is an heuristics after all.
>

right.

thanks,

David

> Honza
>>
>> thanks,
>>
>> David
>>
>> > Honza
>> >>
>> >> thanks,
>> >>
>> >> David
>> >> > Honza