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From: Peter Mutsaers <plm@xs4all.nl>
Subject: Re: gcc optimizations for kernel
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References: <51d0eg$9uf@usenet4.interramp.com> <323A693E.7B4C@OntheNet.com.au>
Date: Sat, 14 Sep 1996 13:13:46 GMT
>> On Sat, 14 Sep 1996 18:13:50 +1000, Tony Griffiths
>> <tonyg@OntheNet.com.au> said:
TG> The higher levels of optimisation are "probably" OK for
TG> non-device driver code, but would almost certainly bring you
TG> undone in a driver. Re-arranging the order of 'bashing'
TG> device registers is generally not a good thing.
TG> If you feel brave enough to go through and modify the make
TG> file, then you might get a "-O3" kernel to work but it will be
TG> a LOT of work!!!
Hmm, I've been running for months with a kernel compiled with -O2,
without problems. I assume that the sections of device drivers that
depend on order are not reordered by gcc, or the makefiles force that
-O2 not be used for such files.
--
Peter Mutsaers | Abcoude (Utrecht),
plm@xs4all.nl | the Netherlands