ychen added a comment. In D69327#1719419 <https://reviews.llvm.org/D69327#1719419>, @steven_wu wrote:
> In D69327#1719411 <https://reviews.llvm.org/D69327#1719411>, @ychen wrote: > > > Thanks for the inputs @steven_wu @tejohnson. Totally agree with the points > > you brought up. One last thing I'm not quite sure is the caching of > > `-fthin-link-bitcode`. It is a `-cc1` option since it is a kind of > > implementation of ThinLTO, right? I'm a little hesitant to begin writing up > > patches to teach build system/caching tool (I could think of at least three > > for our workload) to recognize this option because of that. If there are > > any changes to the option, the same thing needs to be done again. Do you > > have any thoughts on that? Is the option in use for your workload and do > > you think it is stable enough to have build systems caching for it? > > (Another option is to produce `-fthin-link-bitcode` output post compile > > time which I assume having total build time impact to some degree). > > > `-fthin-link-bitcode` option is used to run distributed thin link. The format > is not stable but it is deterministic for a fixed compiler version. You > should be able to cache the thin-link-bitcode and expected it to be used only > by the same compiler version. > > For any build system that implements caching, it must take compiler version > into consideration because different compiler will produce different output. > I don't think the rule to cache thin-link-bitcode is any different from any > other output during the build. I tried ccache, it does not cache `-fthin-link-bitcode` output. From this link, it seems ccache only cares about "-o" output. https://github.com/ccache/ccache/blob/ac9911b47b8a3777d20a3c481f90f877e8f9a81d/src/ccache.cpp#L2616 Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D69327/new/ https://reviews.llvm.org/D69327 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
