This is the mail archive of the
mailing list for the GCC project.
Re: [tree-ssa PATCH] Pick memory consumption low hanging fruit
- From: Diego Novillo <dnovillo at redhat dot com>
- To: Steven Bosscher <s dot bosscher at student dot tudelft dot nl>
- Cc: Andrew Macleod <amacleod at redhat dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 17 Nov 2003 13:25:50 -0500
- Subject: Re: [tree-ssa PATCH] Pick memory consumption low hanging fruit
- Organization: Red Hat Canada
- References: <email@example.com>
On Mon, 2003-11-17 at 12:55, Steven Bosscher wrote:
> Perhaps it's premature to you, IMHO it is _way_ overdue. To me it is a
> serious problem that tree ssa sucks up more memory than my machine has.
We're not feature-complete yet. We have been adding/removing fields
from the annotations all along. It's not even clear whether we want to
keep them long term. Some of them may become on-the-side hash-tables or
be moved into tree structures.
> I cannot even compile a decent C++ code because my machine goes out of memory
> and kills the compiler. And I bet I am not the only one with this problem.
> Now my machine has "only" 768MB of virtual memory, but no compiler should
> require that much to be able to compile a reasonable application. There are
> applications where tree-ssa eats up 5-10 times as much memory as, say,
> 2.95.3. To some people, it is completely unusable.
Yes. And this is another obvious merge criterion. But this memory
consumption problem is not one of the major problems we have right now
(at least, not in my radar).
Having said that, feel free to attack the problem. I don't think we
even know where our big memory problems are. We have some idea, but I
don't remember seeing a thorough analysis. To begin with, does PR 12524
represent all the memory problems we have? Are there other test cases
that show different problems? I know, for instance, that Gerald's
application kills my 256Mb box. I can't file a PR for it, but I'll get
to it eventually.