From: Zack Weinberg <zack@codesourcery.com>
To: "Dave Korn" <dk@artimi.com>
Cc: "'gcc_mailing_list'" <gcc@gcc.gnu.org>
Subject: Re: optimization issue about -O2 and -Os
Date: Fri, 30 Apr 2004 19:12:00 -0000 [thread overview]
Message-ID: <87y8odiepk.fsf@egil.codesourcery.com> (raw)
In-Reply-To: <NUTMEGQzBxhJTANZwwP0000010e@NUTMEG.CAM.ARTIMI.COM> (Dave Korn's message of "Fri, 30 Apr 2004 17:24:45 +0100")
"Dave Korn" <dk@artimi.com> writes:
>
> Ah, I stand corrected. Would it be accurate to say that they are _both_
> shorthand for a set of -f options _and_ _also_ control a set of other
> behaviours, which entail enabling, disabling, or fine-tuning the parameters
> of other optimisations that do not correspond directly to -f options ?
Yeah, that's pretty accurate. You can look through the source code
for instances of the global flags "optimize" and "optimize_size".
Anything you can do to improve the documentation in this regard would
be much appreciated. It would probably be a good move to deemphasize
all those -f switches; they tend not to be all that useful; I consider
their primary purpose to be working around bugs in specific
optimizations, using -On -fno-<buggy-pass>.
zw
next prev parent reply other threads:[~2004-04-30 16:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-29 10:33 Ebony Zhu
2004-04-30 0:37 ` Jim Wilson
2004-04-30 6:39 ` Ebony Zhu
2004-04-30 9:20 ` Jim Wilson
2004-04-30 13:23 ` Ebony Zhu
2004-04-30 16:06 ` Dave Korn
2004-04-30 16:42 ` Zack Weinberg
2004-04-30 18:09 ` Dave Korn
2004-04-30 19:12 ` Zack Weinberg [this message]
2004-04-30 19:45 ` Dave Korn
2004-04-30 20:05 ` Phil Edwards
2004-04-30 20:09 ` David Edelsohn
2004-04-30 21:02 ` llewelly
2004-04-30 18:29 ` Dale Johannesen
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