> > > pkgsrc collection, should therefore run on any 1.5/i386. You can build
> > 
> > all binaries compiled with -mpentiumpro RUNS on any i386!
> 
> So what?  All -mpentiumpro changes is the instruction scheduling.

yes. because of that it's good as default option - it runs still same fast
on 386 for example.
 
> If you compile stuff with -march=pentiumpro -mcpu=pentiumpro 
> (-mcpu=pentiumpro is equivalent to -mpentiumpro) the resulting binaries
> will use the extra instructions added in newer Intel processors but will 
> NOT run on processors that do not implement the entire P6 instruction set.
> 
> Notably, such code won't even run on the AMD K6, though it will run on the
> Athlon.  Around here, we compile most stuff -mcpu=pentiumpro -march=pentium
> for this exact reason.  -march=pentium or -march=pentiumpro can speed up
> some code a lot (e.g. certain ciphers) but the resulting code will not run
> on older processors.
nice... so to get binaries working on pentium I or anything better - what
options would be the best?

----------------------------
Microsoft is not an answer.
Microsoft is the question.
The answer is "NO".