* Greg A. Woods <woods@weird.com> [2004-09-30 13:15]:
> [ On Thursday, September 30, 2004 at 00:07:42 (+0200), Holger Weiss wrote: ]
> > AFAICS, "-mtune=" only defines a subset of what is defined via "-mcpu=".
[...]
> RTFM!  :-)

I did.

>   `-mcpu=CPU_TYPE'
>      Set the instruction set, register set, and instruction scheduling
>      parameters for machine type CPU_TYPE.
[...]
>   `-mtune=CPU_TYPE'
>      Set the instruction scheduling parameters for machine type
>      CPU_TYPE, but do not set the instruction set or register set that
>      the option `-mcpu='CPU_TYPE would.

That's what I was referring to. "-mcpu=" sets both the instruction set
and the scheduling parameters, "-mtune=" only sets the latter.

> Note that I specified "-mtune=supersparc", meaning I am choosing
> specific instruction scheduling parameters for a specific implementation
> of the SPARC v8 CPU.  :-)
[...]
> (I don't know if it makes any big difference or not though in any
> average use of a NetBSD system...  :-)

My point was that from reading the docs, I would have thought that
adding "-mtune=supersparc" to "-mcpu=supersparc" wouldn't make _any_
difference in the resulting code, but maybe I'm missing something?

Holger

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