[patch] Improve symbol lookup performance noted in PR 15519

[Pedro Alves]

On 05/31/2013 12:27 AM, Doug Evans wrote:
> Hi.
> Here's the patch I intend to check in to "fix"
> http://sourceware.org/bugzilla/show_bug.cgi?id=15519
> [It's not a complete "fix", there's still some performance gains
> to be had, but I'm leaving that for a separate pass.  This gets
> us >95% of the way there, at least in the benchmarks I've been using,
> including the one in the PR.  Thanks Paul!]
> 
> No regressions on amd64-linux, with/without Fission.
> 
> I'll let it sit for a few days in case there are any more comments.
> I'd also like to commit this to the 7.6 branch.  Ok Joel?
> [I need to rerun the testsuite in that tree before committing there.]

Thanks!

Absolutely no objections, but for my own education, and for the archives,
could you describe the gist of it?  E.g., what is it that is slow, and what
is it that is being avoided to get the speedup?  (where's the win?)
It isn't super obvious to me from reading the patch.

-- 
Pedro Alves