Subject: How much of the Intel instruction set do we use?
To: None <port-i386@NetBSD.ORG>
From: Brian Stark <bstark@siemens-psc.com>
List: port-i386
Date: 04/01/1998 13:25:15
Hello,

This is a question for those who understand the differences between the 
different instruction sets used on the Intel 386/486/Pentium/etc...
platforms:

To what extent does NetBSD/i386 take advantage of the differences among
the available CPU types? I know about the different kernel configuration
options for the different CPU types, but if I build a kernel for a Pentium
system, is it really going to be that much better than say a kernel built
for a 386?

I would like to know that when a new version of an Intel CPU comes out,
are there people that look at the new features in the CPU and then try to
take advantage of those features in the NetBSD source code? 

For example, lately, Intel has been advertising the Pentium with MMX
technology. Does NetBSD take advantage of the new instructions on systems
with a Pentium with MMX?

Also, when it comes to taking advantage of the new features in a CPU,
where do we try to take advantage of that -- in the port-specific assembly
code, the GNU compiler, or both?


Thanks,


Brian

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