Subject: Re: Compiler timings on varous MVII NetBSDs etc.
To: David Brownlee <abs@netbsd.org>
From: Lord Isildur <mrfusion@umbar.vaxpower.org>
List: port-vax
Date: 01/25/2001 15:30:58
one note about the libc growth- some of it has gotten a LOT slower. 
for example, on bob's machien he put up for testing yesterday, i ran some 
test program that among other things calledprintf a little under 300 
thousand time. compiled with dynamic linking, with -O2, it took the 
printfs about 980 seconds to run. Compiled statically, about 910 seconds. 
On the ka650 at home, with a much older libc, the same thing took about 
85 seconds. (the program did about 90 seconds of other work).. 

isildur

On Thu, 25 Jan 2001, David Brownlee wrote:

> On Thu, 25 Jan 2001, NetBSD Bob wrote:
> 
> > > > Offhand, can I compile a NetBSD-1.2 kernel on NetBSD-1.5
> > > > by unrolling into a separate tree, and not break anything?
> > >
> > > i dont know if things would work quite right- config has certainly
> > > changed betwen 1.3 and 1.4, and probably there some gcc idiosyncracies
> > > that will make it barf on the 1.2 stuff..
> >
> > But, I would expect the config from 1.5 to be backwards compatible
> > with 1.2, but, the reverse, touch and go.
> >
> 	We went around a similar loop a month or so ago - there
> 	have been many changes to the format. You would want to
> 	compile a 1.2 config on 1.5.
> 
> > That was exactly my thought.  It does not have to be all that great a
> > compile, but it just has to finish, and link into a completed kernel.
> > If there was no great size change, then gcc was doing its job and
> > a lot of misc gago has not crept in with gcc.  If it grew by
> > say more than 10%, then gcc is throwing in things, because the
> > code was the same.
> 
> 	You might be better of compiling some large application
> 	such as ghostscript or pine, then compare the final binary
> 	and sizes of all the .o files generated. Link it statically
> 	on 1.5 also.
> 
> 	I'd expect final binary to increase as libc has grown (locale
> 	support, extra features, etc), but the .o files should be
> 	pretty much the same. Smaller in -current with Matt's changes
> 	to gcc :)
> 
> 		David/absolute		-- www.netbsd.org: No hype required --
> 
> 
> 
> 
>