Addu, Add unsigned – NEC Network Controller uPD98502 User Manual
Page 439
APPENDIX A MIPS III INSTRUCTION SET DETAILS
Preliminary User’s 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
5
5
5
5
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]
← (temp
31
)
32
|| temp
31...0
Exceptions:
None