X86 Assembly Language and C Fundamentals

Chapter 9

Fixed-Point Arithmetic Instructions

In fixed-point operations, the radix point is in a fixed location in the operand. The radix point (or binary point for radix 2) is to the immediate right of the low-order bit for integers, or to the immediate left of the high-order bit for fractions. The operands in a computer can be expressed by any of the following number representations: unsigned, sign-magnitude, diminished-radix complement, or radix complement.

If the numbers are signed, then the sign bit can be extended to the left indefinitely without changing the value of the number. An n-bit signed number A is shown in Equation 9.1, where the leftmost digit an_1 is the sign bit. The sign bit for any radix is 0 for positive numbers and r -1 ...