[PATCH] D71261: [ThinLTO] upgrade IR symtab in parallel ahead of time

[Yuanfang Chen via Phabricator via llvm-commits]

ychen added a comment.

In D71261#2040732 <https://reviews.llvm.org/D71261#2040732>, @MaskRay wrote:

> Just to confirm. @ychen Do you have lots of bitcode files with different versions which require upgrade in LTO?


Yes. The number I collected was for cases for all files are bitcode and need upgrade.

> I tested with an internal program and there seems to be 1% improvement on time, minor cost on memory usage. I need to collect a bit more applications for benchmark.
>  Loading LazyObjFile and ArchiveFile eagerly may potentially accelerate "Parse input files". (Our Bazel builds use very file archives (we don't use `--nostart_end_lib`))
>  There is a proposal in 2019-04 http://lists.llvm.org/pipermail/llvm-dev/2019-April/131902.html making the scheme more generic.
> 
> @ruiu Is this proposal unfinished yet? I think we can at least add an option to opt in that mode (parsing LazyObjFile (and probably ArchiveFile) eagerly). This bitcode parsing may need a dependency on that mode.




Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D71261/new/

https://reviews.llvm.org/D71261