[lld] r286100 - [ELF] Make InputSection<ELFT>::writeTo virtual

[Rafael Espíndola via llvm-commits]

On 8 November 2016 at 05:44, Rafael Espíndola
<rafael.espindola at gmail.com> wrote:
> Why virtual and not a switch on Kind?
>
> It is odd to have two dispatch systems in the same type. This also
> adds a vtable pointer to a pretty common class. Have you benchmarked
> it?

Reverting your patch I get:


firefox
  master 7.076592678
  patch  7.045007685 1.00448331562x faster
firefox-gc
  master 7.272410408
  patch  7.255948085 1.00226880386x faster
chromium
  master 4.886548772
  patch  4.856506268 1.00618603217x faster
chromium fast
  master 1.817117752
  patch  1.798675043 1.01025349691x faster
the gold plugin
  master 0.334146085
  patch  0.334137857 1.00002462457x faster
clang
  master 0.566548508
  patch  0.564552724 1.00353515963x faster
llvm-as
  master 0.033392083
  patch  0.033195595 1.0059190986x faster
the gold plugin fsds
  master 0.363725583
  patch  0.361394799 1.00644941213x faster
clang fsds
  master 0.649312555
  patch  0.645128174 1.00648612348x faster
llvm-as fsds
  master 0.030836558
  patch  0.030612317 1.00732518875x faster
scylla
  master 3.139408801
  patch  3.143890138 1.00142744615x slower

So it does look like at least constraining the vtable to the synthetic
input classes would be a good thing. Can you take a look?

Cheers,
Rafael