APPENDIX A MIPS III INSTRUCTION SET DETAILS
Preliminary Users Manual S15543EJ1V0UM 439
ADDU Add Unsigned ADDU

rs

SPECIAL

0 0 0 0 0 0 rt rd 0

0 0 0 0 0

ADDU

1 0 0 0 0 1

31 26 25 21 20 16 15 11 10 6 5 0
6 5555 6
Format:
ADDU rd, rs, rt
Description:
The contents of general register
rs
and the contents of general register
rt
are added to form the result. The result
is placed into general register
rd
. No integer overflow exception occurs under any circumstances. In 64-bit mode,
the operands must be valid sign-extended, 32-bit values.
The only difference between this instruction and the ADD instruction is that ADDU never causes an integer
overflow exception.
Operation:
32 T: GPR [rd] GPR [ rs] + GPR [rt]
64 T: temp GPR [ rs] + GPR [rt]
GPR [rd] (temp31)32 || temp31...0
Exceptions:
None