Re: [RFC] Remove -freorder-blocks-and-partition

[Xinliang David Li <davidxl@google.com>]

On Wed, Aug 3, 2011 at 2:06 PM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> In xalancbmk, with the partition option, most of object files have
>> nonzero size cold sections generated. The text size of the binary is
>> increased to 3572728 bytes from 3466790 bytes.  Profiling the program
>> using the training input shows the following differences. With
>> partitioning, number of executed branch instructions slightly
>> increases, but itlb misses and icache load misses are significantly
>> lower compared with the binary without partitioning.
>>
>>
>> David
>>
>> With partition:
>> -----------------
>>    53654937239  branches
>>       306751458  L1-icache-load-misses
>>         8146112  iTLB-load-misses
>
> Note that I was also planning for some time to introduce notion of provably cold
> stuff into our branch prediction heurstics. I.e. code leading to aborts, eh etc

no-return attribute is looked at by static profile estimation pass. Is
the attribute (definitely not returning) properly propagated to the
callers (wrappers of exit, etc)?

David

> that can be then offlined even w/o profile feedback and could perhaps help
> to large apps.
> (also the whole pass should be more effective with larger testcases, SPEC2k6 is slowly
> becoming a small one)
>
> Honza
>