[PATCH] D52193: RFC: [clang] Multithreaded compilation support -- NOT FOR SUBMIT

[Angus Hewlett via Phabricator via cfe-commits]

angushewlett added a comment.

Having applied this patch to the clang latest (which took a bit of doing, and it's possible I messed up along the way) - all working in general, and a roughly 6x speed-up on my i7-7820X. However, PCH support does not seem to work correctly.

Specifically, it looks like when a file is set to build with /Yc (Create PCH), this is not executed serially with respect to the other jobs. Therefore it attempts to compile targets with /Yu (Use PCH) before the PCH has been generated, and fails.

When one or more files are passed with /Yc, PCH generation needs to execute to completion before the other jobs are started.

If I compile without using PCHs, it all works correctly (but clearly there's some performance hit).

Can anyone confirm if they've got /Yc & /Yu working correctly on their system?

Thanks,

  Angus.


Repository:
  rC Clang

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https://reviews.llvm.org/D52193