In this paper we present Minibit+, an approach that optimizes the bit-widths of fixed-point and floating-point designs, while guaranteeing accuracy. Our approach adopts different levels of analysis giving the designer the opportunity to terminate it at any stage to obtain a result. Range analysis is achieved using a combined affine and interval arithmetic approach to reduce the number of bits. Precision analysis involves a coarse-grain and fine-grain analysis. The best representation, in fixed-point or floating-point, for the numbers is then chosen based on the range, precision and latency. Three case studies are used: discrete cosine transform, B–Splines and RGB to YCbCr color conversion. Our analysis can run over 200 times faster than current approaches to this problem while producing more accurate results, on average within 2–3% of an exhaustive search.
William G. Osborne, Ray C. C. Cheung, José