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Separate preprocess and compile: some performance numbers
- From: Boris Kolpackov <boris at codesynthesis dot com>
- To: gcc at gcc dot gnu dot org
- Date: Thu, 18 May 2017 15:16:55 +0200
- Subject: Separate preprocess and compile: some performance numbers
- Authentication-results: sourceware.org; auth=none
I have implemented the separate preprocess and compile setup in build2.
For GCC it is using -fdirectives-only (thanks to everyone's suggestions
in the earlier thread). I've also done some benchmarking:
TL;DR for GCC:
Surprisingly, a separate preprocessor run is about 1% faster (probably
because of the time-localization of filesystem access). Overall, a
preprocessor run costs about 5% of a non-optimized C++ build.