Method and system for fast determination of sticky and guard bits

Abstract

A method and system for fast calculation of the sticky bit and a function of the guard bit is disclosed. A first aspect of the method and system provides a fast calculation of the sticky bit. A second aspect provides a fast calculation of a function of the guard bit. Both aspects comprise means for providing an intermediate result of a floating point mathematical operation involving at least a first and a second operand and means for providing a mask indicating a position of a leading one in a mantissa of the intermediate result. In the first aspect, means for aligning a first bit of the mask to an (n+2)nd bit of the intermediate result, where n is the number of bits in a mantissa of the first or second operand, are coupled to the intermediate result providing means. In the second aspect, means for aligning a first bit of the mask to an (n+1)st bit of the intermediate result are coupled to the intermediate result providing means. In both aspects, means for providing an output are coupled to the aligning means and intermediate result providing means. The output of the first aspect comprises the sticky bit. The output of the second aspect comprises a function of the guard bit. Thus, the method and system allow the sticky bit and a function of the guard bit to be calculated substantially simultaneously with normalization. Because the method and system allow fast determination of the sticky bit and a function of the guard bit, the overall speed of the calculation is increased and system performance is improved.