Subject: Re: Compiler timings on varous MVII NetBSDs etc.
To: NetBSD Bob <>
From: David Brownlee <>
List: port-vax
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		-- 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?
> Bob