Algorithm 722: Functions to support the IEEE standard for binary floating-point arithmetic
William J. Cody, Jerome T. Coonen · ACM Transactions on Mathematical Software · 1993
This paper describes C programs for the support functions copysign(x,y), logb(x), scalb(x,n), nextafter(x,y), finite(x), and isnan(x) recommended in the Appendix to the IEEE Standard for Binary Floating-Point Arithmetic. In the case of logb , the modified definition given in the later IEEE Standard for Radix-Independent Floating-Point Arithmetic is followed. These programs should run without modification on most systems conforming to the binary standard.