Algorithm 722: Functions to support the IEEE standard for binary floating-point arithmetic

ABSTRACT

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.

REFERENCES

• 1: COHEN, D. 1990. On holy wars and a plea for peace. Computer 14 (Oct. 1981), 48-54. Draft 0.94a of a Proposed Standard for a Genertc Package of Primttwe Functions for Ada. 1990 Unpublished working paper, ACM SIGAda Numerics Working Group.
• 2: Internatzonal Standard, Programming Languages--C. 1990. ISO/IEC 9899:1990, ISO, 1990.
• 3: IEEE Standard for Blnaly Floaang-Point Arlthmetw 1985. ANSI/IEEE Std 754-1985, IEEE, New York.
• 4: IEEE Standard for Ra&x-Independent Floating-Point Arithmetic. 1987. ANSI/IEEE Std 854- 1987, IEEE, New York.
• 5: Advance Information, 80387 80-bit CHMOS III Numeric Processor Extension. 1987. Intel Corp., Santa Clara, Calif.
• 6: i860T M 64-Bit Microprocessor Programmer's Reference Manual. 1990. Intel Corp., Santa Clara, Calif.
• 7: METCALF, M., AND REIn, J. 1985. Fortran 90 Explamed. Oxford University Press, Oxford.
• 8: MC68881 Floating-Point Coprocessor User's Manual. 1985. MC68881UM/AD, Motorola Inc.
• 9: PALMER, J. F., AND MORSE, S.P. 1984. The 8087 Prtmer. Wiley, New York.
• 10: Preliminary Data WTL1064 /1065 Htgh-Speed 64-Btt IEEE Floating Potnt Multiplter/ALU. 1984. Weitek Corp., Sunnyvale.

INDEX TERMS

Primary Classification:
  G. Mathematics of Computing
  G.1 NUMERICAL ANALYSIS
      G.1.0 General
          Subjects: Numerical algorithms

Additional Classification:
  G. Mathematics of Computing
  G.4 MATHEMATICAL SOFTWARE
      Subjects: Certification and testing

General Terms:
Algorithms

Keywords:
copysign, finite, isnan, logb, manipulative functions, nextafter, scalb