[PATCH] D87448: [CodeGen] [WinException] Only produce handler data at the end of the function if needed

Tue Nov 3 04:12:47 PST 2020

hans added a comment.
Herald added a subscriber: pengfei.

Sorry for the late follow-up, but this caused big problems in Chromium.

This caused an explosion in ICF times during linking on Windows when libfuzzer
instrumentation is enabled. For a small binary we see ICF time go from ~0 to
~10 s. For a large binary it goes from ~1 s to forevert (I gave up after 30
minutes).

See https://bugs.chromium.org/p/chromium/issues/detail?id=1144476

I don't know if the real issue is with this commit, lld's icf code, or libfuzzer's instrumentation, but until that's figured out, I've reverted this patch in cbf25fbed5b46ec47e3ce2799ed9095f2f18ea8f <https://reviews.llvm.org/rGcbf25fbed5b46ec47e3ce2799ed9095f2f18ea8f> to bring things back to a working state.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87448/new/

https://reviews.llvm.org/D87448