riccibruno added a comment. In https://reviews.llvm.org/D54166#1299230, @rjmccall wrote:
> In https://reviews.llvm.org/D54166#1299149, @riccibruno wrote: > > > In https://reviews.llvm.org/D54166#1298889, @rjmccall wrote: > > > > > IIRC, abbreviations just silently don't take effect if the record doesn't > > > conform; so things will appear to work, but the size on disk will be > > > bigger. > > > > > > I looked at where the abbreviations are defined, and it seems that the only > > abbreviations for > > statements/expressions are for `DeclRefExpr`, `IntegerLiteral`, > > `CharacterLiteral` > > and `ImplicitCastExpr` (grep for `EmitAbbrev` in `Serialization/`, > > for some reasons they are emitted in `WriteDeclAbbrev()`...). > > > > And indeed changing the serialization format of `CharacterLiteral` triggers > > various assertions > > because of the abbreviation. Therefore unless I am missing something no > > other statement/expression > > has currently an abbreviation. I suspect therefore that someone could go > > wild and cut the on-disk > > size of the serialization format significantly here. > > > > I looked at the size of the generated pch for all of Boost, and I am only > > seeing an increase of > > about 8k, which is entirely attributable to the fact that I am adding one > > field to the serialization > > format. I can rework it to remove this additional field if needed. > > > If you're generally interested in improving build times, working on the > serialization format would probably be really valuable. We don't generally > insist on a zero-regressions policy in other commits, though. I was planning to finish packing the other expression classes to minimize the in-memory footprint of the AST first. I will try to take a look at serialization if I have some time but no promise for now. Thanks for the review ! Repository: rC Clang https://reviews.llvm.org/D54166 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
