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KSHIFTRW

Shifts the bits of a qword operand to the right by the count specified in a register or immediate. The operation is performed on a word-sized operand, where the value is shifted and the result is stored back.

The following table describes the supported source and destination operands.

DO NOT support LOCK

This instruction is only available in 64-bit mode. It SHALL NOT be used in compatibility mode.

Ensure that the shift count provided in the register or immediate is masked to 5 bits (0-31) for qword operations to avoid undefined behavior, as per standard x86-64 shift logic. Incorrectly calculating the shift count may lead to unexpected results if the value exceeds the register width.