craig.topper added a comment.

In D86488#2241176 <https://reviews.llvm.org/D86488#2241176>, @nikic wrote:

> This change has a 0.3% compile-time regression 
> (https://llvm-compile-time-tracker.com/compare.php?from=0c55889d809027136048a0d144209a2bc282e7fc&to=71f3169e1baeff262583b35ef88f8fb6df7be85e&stat=instructions)
>  and a 0.3% max-rss regression 
> (https://llvm-compile-time-tracker.com/compare.php?from=0c55889d809027136048a0d144209a2bc282e7fc&to=71f3169e1baeff262583b35ef88f8fb6df7be85e&stat=max-rss).
>
> Is that expected? The diff looks pretty harmless to me.

No it wasnt expected. There was already a comment on the commit about it. The 
settings it’s selecting should match the default we get with no -march on 
Linux. The only thing I’ve found so far is extra time to read the function 
attribute from getSubtargetImpl which happen every time getTTI is called. And 
extra time to add the function attribute in clang. The strange thing is it 
seems to have regressed O0 even so that rules out a lot of optimization related 
code. Any information you can provide would be helpful.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86488/new/

https://reviews.llvm.org/D86488

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to