[llvm-dev] [PGO] Indirect call profiling of vtable pointers

Johan Engelen via llvm-dev llvm-dev at lists.llvm.org
Tue Apr 5 12:39:05 PDT 2016


I have implemented indirect call value profiling in LDC, using Clang's code
for inspiration, and it appears to work great. An often recurring indirect
call is nicely promoted to a comparison and a direct call (I am using a
modified LLVM with the indirect call promotion pass added).
However, I am wondering if I can go one step further: instead of indexing
into a vtable and doing the comparison on the function address, profile the
vtable pointer and do the comparison on the vtable pointer.
Does LLVM have support for this already, or do I have to code this myself?
Or perhaps I am dreaming and this doesn't make sense?

Kind regards,
  Johan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160405/6c021786/attachment.html>


More information about the llvm-dev mailing list