HYBRID TYPE FUNCTION COMPUTING METHOD AND ARITHMETIC PROCESSING SYSTEM

PURPOSE:To calculate a strict solution of a square root with high efficiency by calculating an approximate solution by a Newton Raphson method, etc., correcting only the higher rank bit trains in order to restart the dichotomy when the accuracy of the approximate solution is not satisfactory. CONSTITUTION:An approximate solution of a square root is calculated by a Newton Raphson method, etc. and this bit train is corrected with use of an addition multiplier. If the accuracy of the approximate solution is satisfac tory, all bits are corrected with the correction processing of the approximate solution. If the accuracy of a strict solution is not satisfactory, only the higher rank bit trains are corrected and then the dichotomy is restarted there. Then the rounding processing is carried out lastly to any result. Thus, it is possible to calculate the strict solution of a square root with higher efficiency in a prescribed floating point format.