[LLVMdev] On LLD performance

[Rafael Espíndola]

> Here's an update.
>
> After http://reviews.llvm.org/D8372 , I updated the profiling data.
>
> https://people.freebsd.org/~davide/llvm/lld-03162015.svg
> It seems now 85% of CPU time is spent inside
> FileArchive::buildTableOfContents().
> In particular, 35% of the samples are spent inserting into
> unordered_map, so there's maybe something we can do differently there
> (e.g. , Rui's proposal of a concurrent map doesn't seem that bad).
>

Why do we even need to build the table from name to member?

Can't we just walk "archive->symbols()" and check for each symbol if
it is needed by the current link status?

Cheers,
Rafael