Intel Extensible Firmware Interface - Manual (Page 816)

Extensible Firmware Interface Specification
19-42 12/01/02 Version 1.10
BEHAVIORS AND RESTRICTIONS:
• If an index is specified for Operand 2, and Operand 2 register is direct, then the Operand 2
index value is added to the register contents such that Operand 2 = (UINTN)(R
2
+ Index).
• If an index is specified for Operand 1, and Operand 1 is direct, then an instruction encoding
exception is generated.
• If Operand 1 is direct, then the Operand 2 value will be 0-extended to 64 bits on a 32-bit
machine before storing to the Operand 1 register.