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From: Nathan Sidwell <nathan@acm.org>
To: gcc-patches@gcc.gnu.org
Subject: Re: [C++ PATCH] Reimplement ADL
Date: Thu, 25 May 2017 19:42:00 -0000	[thread overview]
Message-ID: <ba694a5c-35d8-93dc-d5cd-25d78b387200@acm.org> (raw)
In-Reply-To: <CADzB+2n=CR+t1BzGhFtYABc8XM4bUp7H=H3Fx0LkcA+OuB3qvA@mail.gmail.com>

On 05/25/2017 03:07 PM, Jason Merrill wrote:

>> The recursion is a rare event, so we optimize the non-recursive case.
> 
> Sounds like it would make sense to use a hash_set rather than flags on
> the decls.

I don't think that would be a win.  Although both are O(1), the constant 
factor is greater for the hash_set.  As I said, it is rare -- I think 
there was only once instance in building libstdc++ or in its testsuite, 
I can't recall which.

The cost of fixing it up is pretty cheap anyway -- iterate over the 
vector of seen scopes.

nathan

-- 
Nathan Sidwell

  reply	other threads:[~2017-05-25 19:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-25 13:26 Nathan Sidwell
2017-05-25 19:17 ` Jason Merrill
2017-05-25 19:42   ` Nathan Sidwell [this message]
2017-05-26  8:08 ` Jakub Jelinek
2017-05-26 11:38   ` Nathan Sidwell
2017-05-26 11:50     ` Jakub Jelinek

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