[llvm-dev] RFC: PGO Late instrumentation for LLVM

[Philip Reames via llvm-dev]

On 08/11/2015 10:11 PM, Sean Silva wrote:
> Philip and Sanjoy, out of curiosity do you guys use your own 
> instrumentation placement for PGO? Is an IR-level PGO infrastructure 
> upstream something you guys would be interested in?
We have entirely separate infrastructure for this.  An IR-level PGO 
instrumentation infrastructure would be of no immediate benefit to me.  
Even in the long term, we'd have some restrictions on the profile 
collection points which are easy to reason about in the frontend, but 
would be hard in the middle end.

Philip