[PATCH] D71263: AMDGPU: Don't run redundant GlobalDCE

Tue Dec 10 08:43:41 PST 2019

arsenm added a comment.

In D71263#1777570 <https://reviews.llvm.org/D71263#1777570>, @rampitec wrote:

> The idea to run it was to speedup compilation. After internalize we have an opportunity to remove some functions and do not spend time optimizing them. As far as I understand GlobalDCE is really cheap, unlike passes running before its next invocation.
>
> Did you make any compile time measurements to support it?

I found this patch lying around from 2017, and don't remember why I was looking at this. There aren't many passes run between the internalize here and GlobalOpt:

  Internalize Global Symbols
  Dead Global Elimination
  Interprocedural Sparse Conditional Constant Propagation
    FunctionPass Manager
      Dominator Tree Construction
  Called Value Propagation
  Deduce and propagate attributes
  Global Variable Optimizer

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D71263/new/

https://reviews.llvm.org/D71263