Subject: Re: Compiler timings on varous MVII NetBSDs etc.
To: NetBSD Bob <email@example.com>
From: David Brownlee <firstname.lastname@example.org>
Date: 01/25/2001 20:16:13
You would expect -O2 to produce faster, and sometimes larger code.
-O2 turns on additional 'expensive' optimisations which usually,
though not always benefit the code.
-Os turns on -O, plus any optimisation that reduces the size of
David/absolute -- www.netbsd.org: No hype required --
On Thu, 25 Jan 2001, NetBSD Bob wrote:
> > > These are all compiled on a stock stripped MVII kernel, using
> > > a stock stripped MVII config, basically all were identical to
> > > the 4.3BSD config.
> > The default gcc options changes from -O to -O2 on vax at some
> > point around 1.4. You might want to try all NetBSD compiles
> > with -O. (-O2 on earlier versions is likely to generate
> > incorrect code)
> Good to know. Would -O increase the size and/or affect the relative
> speeds compared to -O2?