Date: Thu, 23 Sep 1999 21:28:15 +0200 (CEST) From: Oliver Fromme <olli@dorifer.heim3.tu-clausthal.de> To: freebsd-current@FreeBSD.ORG Subject: Re: gcc optimizer in -current system ... Message-ID: <199909231928.VAA01658@dorifer.heim3.tu-clausthal.de>
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bsd@picard.mandrakesoft.de wrote in list.freebsd-current:
> On Thu, 23 Sep 1999, The Hermit Hacker wrote:
> > just curious, but what is the max setting that can be used to compile the
> > kernel?
>
> Works rather nicely here with
>
> -O6 -mpentiumpro -march=pentiumpro -pipe -s -fexpensive-optimizations
> -ffast-math
-ffast-math shouldn't have any effect, because the kernel does
not contain floating-point code. -ffexp-opt is already included
in -O3 (which is the maximum -O value supported by the compiler),
so it is redundant, too.
The gcc optimizer is traditionally buggy. I wouldn't trust a
system compiled with anything more than -O (especially on
production servers). The higher optimization levels don't
provide much of a speed improvement anyway, sometimes they make
the code even slower. YMMV.
Regards
Oliver
--
Oliver Fromme, Leibnizstr. 18/61, 38678 Clausthal, Germany
(Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de)
"In jedem Stück Kohle wartet ein Diamant auf seine Geburt"
(Terry Pratchett)
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