mips instructions

[Eric Christopher]

> I have a vague recollection that MIPS took the bit definitions for
> these coprocessor instructions and defined them as new instructions.
> Take a look at the bit patterns for the new instructions, and see if
> they overlap with these.
> 

Ok.  That makes sense.

> Your patch is wrong.  The comment in mips.h may be misleading.  A `v'
> means that if the instruction is used with only two registers, the
> source register operand should be used as the destination register.
> That is, it permits writing `mul $2,$4'; this is equivalent to `mul
> $2,$2,$4'.  The `r', `w', `V', and `W' operand specifiers are
> similar.

Ok.  The comment is a bit misleading.  I'll see if I can fix that.

-eric