Re: PATCH: Fix the MIPS ISA ELF setting (Re: RedHat 7.1/mips update)

["H . J . Lu" <hjl at lucon dot org>]

On Sun, Nov 04, 2001 at 12:53:22PM +0100, Thiemo Seufer wrote:
> H . J . Lu wrote:
> [snip]
> > Well, we don't have solution for this one anyway. When you do
> > 
> > # as -march=4100
> > 
> > it will accept 4100, which is defined as MIPS 3. That means it will
> > take any MIPS 3 instructions. My proposal
> > 
> > # as -march=4100 -mipsN
> > 
> > allows you change the `isa' field in `struct mips_cpu_info' to a
> > compatible value at the runtime. It won't accept more instructions
> > than
> > 
> > # as -march=4100
> > 
> > I don't see anything wrong with that.
> 
> Unfortunately the current behaviour of -mipsX is to select an
> processor close to this ISA level. This is compatible with

I don't see that in the source code. It is only default to a particular
processor for certain things if -march/-mtune is not used.

> traditional MIPS assemblers and older gas. Giving it different
> semantics instead of deprecating it will make things worse.
> 

That is a news to me:

# as -help
...
-mips1                  generate MIPS ISA I instructions
-mips2                  generate MIPS ISA II instructions
-mips3                  generate MIPS ISA III instructions
-mips4                  generate MIPS ISA IV instructions
-mips5                  generate MIPS ISA V instructions
-mips32                 generate MIPS32 ISA instructions
-mips64                 generate MIPS64 ISA instructions
...


H.J.