[PATCH] D23488: ThinLTO: add early "dead-stripping" on the Index

[Mehdi AMINI via Phabricator via llvm-commits]

mehdi_amini added inline comments.


================
Comment at: lib/LTO/LTO.cpp:341
+  GlobalRes.VisibleToRegularLTOPartition |=
+      (Partition == GlobalResolution::RegularLTO);
 }
----------------
mehdi_amini wrote:
> tejohnson wrote:
> > mehdi_amini wrote:
> > > It is not clear to me how the `VisibleToRegularLTOPartition` is computed here, it seems that for partition to be 0 (RegularLTO) the symbol has to be used or defined in LTO but not used or defined in ThinLTO?
> > This will be called for each partition it is referenced from. Partition 0 is always regular LTO, ThinLTO modules are partitions 1 and higher. So if this is ever called for Partition 0 then we have a reference in regular LTO. See the callsites in add*LTO
> I misread the assignment as `=` instead of `|=`.
Also technically to be only "visible" to the RegularLTO partition, it should be referenced from LTO but not defined there with a prevailing resolution.


https://reviews.llvm.org/D23488