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VMASKMOV

Moves a doubleword value from a memory location to a specific element of a SIMD register, or from a specific element of a SIMD register to a memory location, based on an immediate index.

The following table covers what the source and destinations can be:

DO NOT support LOCK

This instruction is only available in 64-bit mode or compatibility mode. It requires the processor to support the SSE2 instruction set.

The immediate operand MUST be a constant within the range of the target register's element indices (e.g., 0-3 for xmm). Providing an immediate value that exceeds the register's capacity SHALL result in an invalid operand encoding. Because this instruction accesses memory as a dword, any memory access that crosses a page boundary MAY trigger a general-protection exception (#GP) or a page fault.