[Bug c++/102228] lookup_anon_field is quadratic

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102228

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
I do have a functional patch which improves the -fsyntax-only compile-time for
the PR101555 testcase from 14s to 2s.

After lookup_anon_field is gone PR83309 pops up of course:

Samples: 6K of event 'cycles', Event count (approx.): 6523483993                
Overhead       Samples  Command  Shared Object     Symbol                       
  20.96%          1375  cc1plus  cc1plus           [.] get_class_binding_direct
  11.83%           776  cc1plus  cc1plus           [.] fields_linear_search
   7.63%           501  cc1plus  cc1plus           [.] cp_fold

I wonder if we should delay duplicate decl diagnostics until after the class
is completed so we have the CLASSTYPE_MEMBER_VEC populated.