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Date: Fri, 26 Jul 2013 11:54:25 -0700
From: John-Mark Gurney <jmg@funkthat.com>
To: Andriy Gapon <avg@freebsd.org>
Subject: Re: amd64: -O2 even with DEBUG
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Andriy Gapon wrote this message on Fri, Jul 26, 2013 at 10:14 +0300:
> I wonder why amd64 is distinguished to have -O2 in COPTFLAGS even when DEBUG is
> defined.  For all other archs it's -O for that case.
> 
> Perhaps, this was discussed / explained in the past, but I would appreciate it
> being said again (or even written as a comment in kern.pre.mk).

It's probably because at least gcc produces terrible amd64 code w/o
it...  It will constantly reload the register it uses to do relative
loads w/ the same value even though nothing changed... makes performance
suck... 

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."