APPENDIX A MIPS III INSTRUCTION SET DETAILS
Preliminary Users Manual S15543EJ1V0UM 559
SUBU Subtract Unsigned SUBU
rs
SPECIAL
0 0 0 0 0 0 rt rd 0
0 0 0 0 0

SUBU

1 0 0 0 1 1

31 26 25 21 20 16 15 11 10 6 5 0
6 5555 6
Format:
SUBU rd, rs, rt
Description:
The contents of general register
rt
are subtracted from the contents of general register
rs
to form a result.
The result is placed into general register
rd
.
In 64-bit mode, the operands must be valid sign-extended, 32-bit values.
The only difference between this instruction and the SUB instruction is that SUBU never traps on overflow.
Operation:
32 T: GPR [rd] GPR [rs] - GPR [rt]
64 T: temp GPR [rs] - GPR [rt]
GPR [rd] (temp31)32 || temp31...0
Exceptions:
None