This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: [C++ PATCH] Reimplement ADL

From: Nathan Sidwell <nathan at acm dot org>
To: gcc-patches at gcc dot gnu dot org
Date: Thu, 25 May 2017 15:17:09 -0400
Subject: Re: [C++ PATCH] Reimplement ADL
Authentication-results: sourceware.org; auth=none
References: <4f2b3ce9-7f06-6a10-f1c9-4542b3651bd0@acm.org> <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 constantfactor is greater for the hash_set. As I said, it is rare -- I thinkthere 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 thevector of seen scopes.


nathan

--
Nathan Sidwell

References:
- [C++ PATCH] Reimplement ADL
  - From: Nathan Sidwell
- Re: [C++ PATCH] Reimplement ADL
  - From: Jason Merrill

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]