why gcc 2.95.3 generate different result with option -mips2 and -mips3 for the same code

["glame" <glchen@xxxxxxxxx>]

hi,
when i disassemble the code, the result is as the following

-ffffffff80010b8c:  01001021    move    $v0,$t0  (-mips2)
+ffffffff80010b8c:  0100102d    move    $v0,$t0  (-mips3)

why? 


best regards
　　　　　　　　glame