I have a few of these boat anchors along with a few newer boxes. Is
there any easy way to set the arch and cpu options to default to
something every time I install something from pkgsrc or I recompile the
kernel and system?

Even a little optimization is significant on smaller machines.

- Pat

Rafal Boni wrote:
> 
> In message <Pine.WNT.4.30.0101221715350.-158195@tv>, tv@wasabisystems.com
> writes:
> 
> -> On Mon, 22 Jan 2001, Rafal Boni wrote:
> ->
> -> : -> It seems our gcc defines both "-mcpu=i386" and "-march=pentium" by defa
> -> ult.
> -> :
> -> : Given that we expect things to run on any x86 processor down to the '386,
> -> : maybe the defaults should be '-mcpu=pentium -march=i386' by default, in
> -> : other words the opposite of what we do now.
> ->
> -> You'd think so, but I've run on a Cyrix 6x86 (486 instruction set) as well
> -> as a 486DX-33 with the precompiled system binaries, so one of the following
> -> must be true:
> ->
> ->  1. -mcpu=i386 pulls down -march= to i386 at codegen time;
> 
> >From reading the gcc info page, I'd guess this is the correct answer...
> 
> What I meant to say is that the current set of default gcc flags makes it
> easy to say '-mcpu=pentium' expecting to get pentium-optimized but runnable
> on a '386 binaries and get binaries that won't run on a '386.
> 
> If we did '-mcpu=pentium -march=i386' (as opposed to '-mcpu=i386 -march=
> pentium') by default, users would get an experience closer to the one
> described by the gcc info page, is all.  Now, a user saying '-mcpu=i586'
> would still get binaries that ran on a '386, even if not optimally.
> 
> ->  2. gcc 2.91 (egcs 1.1) doesn't have many (or any) instruction definitions
> ->     for post-i386 machines;
> ->  3. the doc is wrong;
> ->  4. gcc does something Very Strange that makes the binaries just happen to
> ->     work.
> 
> --rafal
> 
> ----
> Rafal Boni                                                  rafal@mediaone.net

-- 

Pat Wendorf