Date: Sun, 27 Mar 2005 16:28:39 +0200 From: Alexander Leidinger <Alexander@Leidinger.net> To: Avleen Vig <lists-freebsd@silverwraith.com> Cc: hackers@freebsd.org Subject: Re: 5-STABLE kernel build with icc broken Message-ID: <20050327162839.2fafa6aa@Magellan.Leidinger.net> In-Reply-To: <20050327134044.GM78512@silverwraith.com> References: <423C15C5.6040902@fsn.hu> <20050327133059.3d68a78c@Magellan.Leidinger.net> <20050327134044.GM78512@silverwraith.com>
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On Sun, 27 Mar 2005 05:40:44 -0800
Avleen Vig <lists-freebsd@silverwraith.com> wrote:
> On Sun, Mar 27, 2005 at 01:30:59PM +0200, Alexander Leidinger wrote:
> > > It seems to me that building kernel with icc is currently broken, at
> > > least in 5-STABLE. Could somebody investigate this?
> >
> > I don't have a problem to compile it with a recent -current and a recent
> > icc (-stable not tested), but the resulting kernel imediatly panics
> > (page fault in _mtx_...()).
>
> Without intending to start any compiler holy wars, what benefits does
> ICC provide over GCC for the end user?
Various:
- auto-vectorizer (no benefit for the kernel, since we can't use
FPU/SIMD instructions at any time... yet (interested hackers can
have a look how DragonFly handles it, I can provide the necessary
commit logs))
- optimizations for Intel CPUs direct from the manufacturer of the CPU
(they have a lot of interest to produce very fast code)
- a different set of compiler warnings
- better code quality (if is compilable by more than one compiler it
may be more portable)
Icc already pointed out some bad code (asm code in the IP checksumming
code... DragonFly changed it already), and the panic as noticed above
may also be an indication that we have some code in the tree which
smells bad.
Bye,
Alexander.
--
The dark ages were caused by the Y1K problem.
http://www.Leidinger.net Alexander @ Leidinger.net
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