[LLVMdev] Recent compile time performance regressions

[Tobias Grosser]

On 01/08/2014 22:07, Chandler Carruth wrote:
> Note that I've fixed one bad compile time regression quite recently, and
> we're bisecting to another one. We benchmarked the multithreading stuff
> pretty carefully, so I doubt its that. Have you tried reverting locally and
> reproducing?

Not really. It just saw this passing by and was wondering if it raised 
some bells.

The reason I pointed this patch out is that the pattern in which 
performance changes matches precisely the pattern this patch was applied 
and reverted, with the set of patches between subsequent performance 
runs being rather small.

Note, this patch is actually the smaller culprit, around 209801 there is 
another performance regression, but I have no idea if/where this is 
coming from or if this for some reason is a false positive.

I unfortunately currently don't have the time to investigate this, but 
thought I at least mention it on the mailing list.

Cheers,
Tobias

P.S: Until the last performance build at juli 31st the performance 
regression still existed, so I don't think your fix applied to this one.