From owner-cvs-all@FreeBSD.ORG  Wed Jun 27 14:47:35 2007
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Date: Wed, 27 Jun 2007 14:47:34 +0000
From: Andrey Chernov <ache@freebsd.org>
To: Xin LI <delphij@delphij.net>
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Subject: Re: cvs commit: src/share/mk sys.mk
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On Wed, Jun 27, 2007 at 09:47:56PM +0800, Xin LI wrote:
> Nitpicking: I think -O1 implies no strict-aliasing.  So -O1 -pipe might
> be just Ok.

It is for easy change-back.

> Well, I'd say that all these changes looks scary to me.
> 
> Is there any code in our base system to trigger tree-vrp bug?  Do we
> still have some time to have gcc fixed and tested rather than using
> band-aid like this?  IMHO fixing gcc sounds better than "fix"ing sys.mk
> if time permits us to fix and test a vendor solution.

It is hard to find such cases because of the silent nature of the bug:
basically any array usage inside loop, with array size smaller than 
the loop iterations can trigger that (premature exit from the loop).
I think this case is general enough to worry at the system level.

There is no vendor solution right now and will not be until gcc 4.2.1
I doubt it will be available as separate patch because of complexity of tree 
vrp optimization.

This change will be backed out right after fixing gcc in any way.

-- 
http://ache.pp.ru/