[PATCH] D110422: [AIX] Enable PGO without LTO

[Jinsong Ji via Phabricator via cfe-commits]

jsji added a comment.

> In other binary formats the first weak definition is selected and other weak definitions are discarded.
> Do you mean that AIX ld doesn't pick the first weak definition?

No. I think this is exactly what is causing problem here.

eg: if we have two weak symbols （weak_func）, and we generate the weak counter/data as usual:

  __llvm_prf_cnts:
  
  __profc_weak_func(1):
  
  __profc_weak_func(2):
  
  __llvm_prf_data:
  
  __profd_weak func(1):
  
  Pos_Rel __profc_weak_func  <=== Relocation to calculate the relative pointer
  
  __profd_weak_func(2):
  
  Pos_Rel __profc_weak_func  <=== Relocation to calculate the relative pointer

The relative pointer calculation in __profd_weak_fun will be wrong after linking.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110422/new/

https://reviews.llvm.org/D110422