User Guide

128-Bit Media and Scientific Programming 155

24592—Rev. 3.15—November 2009 AMD64 Technology

In the above sequence, PCMPGTW, PAND, PANDN, and POR operate, in parallel, on all four

elements of the vectors.

Compare and Write Minimum or Maximum.

• PMAXUB—Packed Maximum Unsigned Bytes

• PMINUB—Packed Minimum Unsigned Bytes

• PMAXSW—Packed Maximum Signed Words

• PMINSW—Packed Minimum Signed Words

The PMAXUB and PMINUB instructions compare each of the 8-bit unsigned integer values in the

first operand with the corresponding 8-bit unsigned integer values in the second operand. The

instructions then write the maximum (PMAXUB) or minimum (PMINUB) of the two values for each

comparison into the corresponding byte of the destination.

The PMAXSW and PMINSW instructions perform operations analogous to the PMAXUB and

PMINUB instructions, except on 16-bit signed integer values.

4.5.8 Logical

The vector-logic instructions perform Boolean logic operations, including AND, OR, and exclusive

OR.

And

• PAND—Packed Logical Bitwise AND

• PANDN—Packed Logical Bitwise AND NOT

The PAND instruction performs a logical bitwise AND of the values in the first and second operands

and writes the result to the destination.

The PANDN instruction inverts the first operand (creating a ones-complement of the operand), ANDs

it with the second operand, and writes the result to the destination. Table 4-9 shows an example.

Table 4-9. Example PANDN Bit Values

Operand1 Bit

(Inverted)

Operand2 Bit

PANDN

Result Bit

1010

1000

0111

0100