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PBLENDW

Selects 16-bit words from two XMM source operands based on a mask provided in a third XMM operand. For each word, if the corresponding mask bit is 1, the word is taken from the first source operand; otherwise, it is taken from the second source operand.

The table below covers what the source and destinations can be.

DO NOT support LOCK

This instruction is only available when the processor supports the SSE4.1 instruction set. It operates exclusively on XMM registers; memory operands are not supported.

To avoid undefined behavior or incorrect results, the mask operand MUST be treated as a bitmask where each bit corresponds to a 16-bit word. Ensure that the input registers are properly aligned to 128-bit boundaries to prevent performance degradation, although the instruction itself does not trigger alignment faults.