Detect register name

[Alexander Sviridenko]

Hi,

I have such gpr registers: a1,a2,...,aN and b1,b2,...,bN and "add
$src1, $src2" instruction, where src1 and src2 from h-gpr. The
question is, how can I detect where is in src1/src2 register aN and
where is bN.

Thanks.

-Alexander