Performs an SIMD add of the packed unsigned integers from the source operand (second operand) and the destination operand (first operand), and stores the packed integer results in the destination operand. See Figure 9-4 in the IA-32 Intel Architecture Software Developer's Manual, Volume 1 for an illustration of an SIMD operation. Overflow is handled with unsigned saturation, as described in the following paragraphs.
These instructions can operate on either 64-bit or 128-bit operands. When operating on 64-bit operands, the destination operand must be an MMX technology register and the source operand can be either an MMX technology register or a 64-bit memory location. When operating on 128- bit operands, the destination operand must be an XMM register and the source operand can be either an XMM register or a 128-bit memory location.
The PADDUSB instruction adds packed unsigned byte integers. When an individual byte result is beyond the range of an unsigned byte integer (that is, greater than FFH), the saturated value of FFH is written to the destination operand.
The PADDUSW instruction adds packed unsigned word integers. When an individual word result is beyond the range of an unsigned word integer (that is, greater than FFFFH), the saturated value of FFFFH is written to the destination operand.