From owner-freebsd-toolchain@FreeBSD.ORG  Tue May 31 09:57:42 2011
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Date: Tue, 31 May 2011 09:57:42 +0000
From: Alexander Best <arundel@freebsd.org>
To: Bruce Cran <bruce@cran.org.uk>
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Cc: freebsd-hackers@FreeBSD.ORG, freebsd-toolchain@FreeBSD.ORG,
	Pan Tsu <inyaoo@gmail.com>
Subject: Re: [rfc] a few kern.mk and bsd.sys.mk related changes
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On Sat May 28 11, Bruce Cran wrote:
> On Sat, May 28, 2011 at 06:23:26PM +0000, Alexander Best wrote:
> > 
> > well i'm not an expert on this. but are we 100% sure that a kernel on amd64
> > compiled with -O2 frename-registers can be debugged the same way as one with
> > -O? if that is the case: sure...-O2 is fine. ;)
> > 
> > however i've often read messages - mostly by bruce evans - claiming that
> > anything greater than -O will in fact decrease a kernel's ability to be
> > debugged just as well as a kernel with -O.
> > 
> 
> The critical option when -O2 is used is -fno-omit-frame-pointers, since removing
> frame pointers makes debugging impossible (on i386). With -O2 code is moved around and
> removed, so debugging is more difficult, but can still provide useful
> information.

any reason we cannot use -O2 -fno-omit-frame-pointers -fno-strict-aliasing as
standard COPTFLAGS with debugging enabled for *all* archs?

> 
> -- 
> Bruce Cran

-- 
a13x