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From: "Petr Vandrovec" <VANDROVE@vc.cvut.cz>
To: Florian Weimer <Florian.Weimer@RUS.Uni-Stuttgart.DE>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gcc-3.0.1 and 2.4.7-ac1
Date: Fri, 27 Jul 2001 18:14:15 MET-1	[thread overview]
Message-ID: <9D6DD5713F9@vcnet.vc.cvut.cz> (raw)

On 27 Jul 01 at 18:03, Florian Weimer wrote:
> "Petr Vandrovec" <VANDROVE@vc.cvut.cz> writes:
> 
> > Just adding '-finline-limit=150' fixes all of them
> 
> This is not a fix, this is a workaround which is suitable for some
> specific GCC release(s).  The optimization decisions surrounding
> inlining are likely to change again, so this will break almost
> certainly in the future.

I found that main problem is in __constant_memcpy. This is very large
in internal representation (~70 'units'), so any kernel function which 
contains two memcpy calls with constant length cannot be inlined with 
current settings because of it contains 140+ internal operations - although
if compiler then generates static function (instead of inlined), it is ~10 
i386 operations long, from which 4 are push %edi/%esi and pop %esi/%edi...

                                            Best regards,
                                                    Petr Vandrovec
                                                    vandrove@vc.cvut.cz
                                                    

             reply	other threads:[~2001-07-27 16:14 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-07-27 18:14 Petr Vandrovec [this message]
  -- strict thread matches above, loose matches on Subject: below --
2001-07-26 20:28 [PATCH] gcc-3.0.1 and 2.4.7-ac1 Petr Vandrovec
2001-07-27  0:57 ` Richard Henderson
2001-07-27  3:12   ` Linus Torvalds
2001-07-27  6:44     ` Wayne Whitney
2001-07-27 16:03 ` Florian Weimer
2001-07-26 17:48 Petr Vandrovec
2001-07-26 17:52 ` Alan Cox
2001-07-26 20:12   ` Linus Torvalds
2001-07-27  6:55     ` Niels Kristian Bech Jensen
2001-07-27  8:34       ` Robert Schiele
2001-07-26 17:55 ` Alan Cox

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