From: Richard Henderson <rth@redhat.com>
To: "Joseph S. Myers" <jsm@polyomino.org.uk>
Cc: "Kaveh R. Ghazi" <ghazi@caip.rutgers.edu>,
ian@wasabisystems.com, gcc@gcc.gnu.org
Subject: Re: Can we speed up the gcc_target structure?
Date: Sun, 18 Jan 2004 22:05:00 -0000 [thread overview]
Message-ID: <20040118220522.GA14767@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.58.0401182111570.9475@digraph.polyomino.org.uk>
On Sun, Jan 18, 2004 at 09:14:14PM +0000, Joseph S. Myers wrote:
> When --enable-intermodule is used, does (or should) the compiler manage to
> detect which parts of the target structure are in fact constant (even
> without constifying)?
I'm certain that it doesn't.
It's not inconcievable that a compiler could not that there are
never any writes to a structure, promote it to readonly, and then
constant propagate the values out of that structure.
However, that sort of optimization requires that you see the *entire*
program, not just large parts of it, as with the current intermodule
code. So I expect this sort of thing is relatively far away.
One possibility is a switch that says "except for main, nothing
outside these files reference any of the symbols herein defined."
That might get you the same effect as whole-program optimization
without having to have extra info about external runtime libraries.
r~
next prev parent reply other threads:[~2004-01-18 22:05 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-18 8:37 Ian Lance Taylor
2004-01-18 9:03 ` Zack Weinberg
2004-01-18 14:09 ` Ian Lance Taylor
2004-01-18 22:25 ` Zack Weinberg
2004-01-19 0:53 ` Ian Lance Taylor
2004-01-19 1:18 ` Geoff Keating
2004-01-18 11:30 ` Joseph S. Myers
2004-01-18 13:58 ` Kaveh R. Ghazi
2004-01-18 19:54 ` Ian Lance Taylor
2004-01-18 20:10 ` Richard Henderson
2004-01-18 20:17 ` Ian Lance Taylor
2004-01-18 21:14 ` Joseph S. Myers
2004-01-18 22:05 ` Richard Henderson [this message]
2004-01-18 22:22 ` Jan Hubicka
2004-01-18 22:37 ` Richard Henderson
2004-01-19 19:33 ` DJ Delorie
2004-01-19 20:41 ` Richard Henderson
2004-01-19 1:12 ` Geoff Keating
2004-01-19 13:51 ` Ian Lance Taylor
2004-01-18 22:18 Chris Lattner
2004-01-18 22:33 ` Jan Hubicka
2004-01-18 22:40 ` Chris Lattner
2004-01-18 22:48 ` Jan Hubicka
2004-01-18 22:50 ` Chris Lattner
2004-01-18 23:27 ` Jan Hubicka
2004-01-18 23:34 ` Jakub Jelinek
2004-01-19 1:36 ` Chris Lattner
2004-01-18 22:42 ` Joseph S. Myers
2004-01-18 22:44 ` Chris Lattner
2004-01-18 22:36 ` Richard Henderson
2004-01-18 22:42 ` Chris Lattner
2004-01-19 11:51 Richard Kenner
2004-01-19 12:01 ` Richard Guenther
2004-01-19 20:02 ` Richard Henderson
2004-01-19 14:16 ` Robert Dewar
2004-01-19 18:03 ` Zack Weinberg
2004-01-19 18:18 Richard Kenner
2004-01-19 18:26 ` Zack Weinberg
2004-01-19 19:05 Richard Kenner
2004-01-19 21:15 ` Zack Weinberg
2004-01-19 21:25 Richard Kenner
2004-01-19 23:36 ` Zack Weinberg
2004-01-19 23:42 Richard Kenner
2004-01-19 23:46 ` Zack Weinberg
2004-01-19 23:48 Richard Kenner
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