This content has not been validated; it was AI-generated following the x86-64 ISA Documentation generation process to maintain high quality. However, as no human has verified this data, errors may exist. If the accuracy of this data is critical, please consult the Intel SDM. The model used to generate this is gemma4:31b

PBLENDVB

Blends bytes from two YMM or ZMM registers based on a mask provided in a third register. For each byte in the source registers, if the corresponding mask bit is set, the byte from the second source register is selected; otherwise, the byte from the first source register is selected.

The table after the description covers what the source and destinations can be.

DO NOT support LOCK

This instruction is available only in 64-bit mode and 32-bit mode. It requires the AVX extension for YMM registers and AVX-512 for ZMM registers.

To avoid unexpected behavior, ensure that the mask register is properly initialized; bits in the mask register that do not correspond to the vector length of the operands are ignored. When using AVX-512, the behavior depends on the specific foundation or extension used to define the register width (e.g., EVEX prefixing).