A.5.14 BOUND: Check Array Index against Bounds
BOUND reg16,mem ; o16 62 /r [186]
BOUND reg32,mem ; o32 62 /r [386]
BOUND expects its second operand to point to an area of memory
containing two signed values of the same size as its first operand (i.e.
two words for the 16-bit form; two doublewords for the 32-bit form). It
performs two signed comparisons: if the value in the register passed
as its first operand is less than the first of the in-memory values,
or is greater than or equal to the second, it throws a BR exception.
Otherwise, it does nothing.