Encoding:

Format:

ADDIU ry, rx, immediate

Purpose:

Add Immediate Unsigned Word (3-Operand, Extended)

To add a constant to a 32-bit integer.

Description:

GPR[ry] = GPR[rx] + immediate

The 15-bit immediate is sign-extended and then added to the contents of GPR rx to form a 32-bit result. The result is placed into GPR ry.

No integer overfl w exception occurs under any circumstances.

Restrictions:

None

Operation:

temp = GPR[Xlat(rx)] + sign_extend(immediate)
GPR[Xlat(ry)] = temp

Exceptions:

None

Programming Notes:

The term "unsigned" in the instruction name is a misnomer;this operation is 32-bit modulo arithmetic that does not trap on overfl w. It is appropriate for unsigned arithmetic, such as address arithmetic, or integer arithmetic environments that ignore overfl w, such as C language arithmetic.