>vlad:~ 121> cc -mfp64 -c foo.c
>cc1: Only MIPS-III or MIPS-IV CPUs can support 64 bit fp registers
>vlad:~ 122> cc -mfp64 -mips3 -c foo.c
>vlad:~ 123> 

*That* is a bug.  Whether it's a documentation bug or a compiler bug
is up to Cygnus.     From the GCC info pages:


--------
`-mips3'
     Issue instructions from level 3 of the MIPS ISA (64 bit
     instructions).  `r4000' is the default CPU TYPE at this ISA level.
     This option does not change the sizes of any of the C data types.
[...]


`-mfp32'
     Assume that 32 32-bit floating point registers are available.
     This is the default.

`-mfp64'
     Assume that 32 64-bit floating point registers are available.
     This is the default when the `-mips3' option is used.

`-mgp32'
     Assume that 32 32-bit general purpose registers are available.
     This is the default.

`-mgp64'
     Assume that 32 64-bit general purpose registers are available.
     This is the default when the `-mips3' option is used.

`-mint64'
     Types long, int, and pointer are 64 bits.  This works only if
     `-mips3' is also specified.

`-mlong64'
     Types long and pointer are 64 bits, and type int is 32 bits.  This
     works only if `-mips3' is also specified.



--------

they should either sayeither say -mfp64 is available only with -mips3
(as for -mint64), or make -mfp64 availble for -mips1.

I suppose this might be a bug in the NetBSD tm config file, I haven't looked.


>Does anyone have experiance with 64-bit SGI systems?

Not I, the newest SGI I have an account on is a 4d/380:).