Skip to main content

Basic Floating-Point Operators

  • Chapter
  • First Online:
Application-Specific Arithmetic

Abstract

This chapter shows how to build the operators for the basic operations (addition and subtraction, multiplication, division, and square root) in floating point. Specialized floating-point operators (such as squarers and constant multipliers) and fused floating-point operators (such as fused multiply-add, combined sum and difference, or sum of squares) will be reviewed in Chap. 15. For each operation, we start with the construction of simple but non-standard operators suitable for hidden application-specific datapaths. Then, refinements for improved standard compliance or improved performance are presented.

It makes me nervous to fly on airplanes since I know they are designed using floating-point arithmetic.Alston Householder

Relax. Today’s planes are piloted using floating-point arithmetic. The authors

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 139.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Hardcover Book
USD 179.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    The IEEE 754 standard [754-19] defines five exceptions (Invalid, Overflow, Underflow, DivideByZero, and Inexact) that can be trapped by software to manage the respective situations. Software may also ignore these exceptions, because the hardware returns a value in each of these situations (a NaN for Invalid, an infinity for Overflow and DivideByZero, a subnormal result for Underflow). In this book we assume that application-specific hardware will do without raising these exceptions. Our reader having a need for any of them should be aware that they have been well thought out in the IEEE 754 standard.

  2. 2.

    It may be the subtraction of two numbers with the same sign or the addition of numbers with different signs.

  3. 3.

    Mathematically, the equality of two infinities could be endlessly debated. At least this choice is consistent with a comparison of the concatenation of fraction and exponent field (when using IEEE 754 encoding).

References

  1. IEEE Standard for Floating-Point Arithmetic. also IEEE/ISO/IEC 60559-2020. 2019

    Google Scholar 

  2. Javier D. Bruguera. “Radix-64 Floating-Point Divider”. In: Symposium on Computer Arithmetic (ARITH). IEEE, 2018, pp. 87–94

    Google Scholar 

  3. Javier D. Bruguera. “Low-Latency and High-Bandwidth Pipelined Radix-64 Division and Square Root Unit”. In: Symposium on Computer Arithmetic (ARITH). IEEE, 2022

    Google Scholar 

  4. Marius Cornea, John Harrison, and Ping Tak Peter Tang. Scientific Computing on Itanium®-Based Systems. Intel Press, 2002

    Google Scholar 

  5. Florent de Dinechin, Mioara Joldeş, Bogdan Pasca, and Guil- laume Revy. “Multiplicative square root algorithms for FP-GAs”. In: International Conference on Field-Programmable Logic and Applications (FPL). IEEE, 2010, pp. 574–577

    Google Scholar 

  6. Pedro Echeverría and Marisa López-Vallejo. “Customizing floating-point units for FPGAs: Area-performance-standard trade-offs”. In: Microprocessors and Microsystems 35.6 (2011), pp. 535–546

    Google Scholar 

  7. David R. Lutz. “Optimized Leading Zero Anticipators for Faster Fused Multiply-Adds”. In: Asilomar Conference on Signals, Circuits and Systems. IEEE, 2017, pp. 741–744

    Google Scholar 

  8. David R. Lutz. “ARM Floating-Point 2019: Latency, Area, Power”. In: Symposium on Computer Arithmetic (ARITH). IEEE, 2019, pp. 69–76

    Google Scholar 

  9. Peter Markstein. IA-64 and Elementary Functions: Speed and Precision. Hewlett-Packard Professional Books. Prentice Hall, 2000

    Google Scholar 

  10. Jean-Michel Muller, Nicolas Brunie, Florent de Dinechin, Claude-Pierre Jeannerod, Mioara Joldeş, Vincent Lefèvre, Guillaume Melquiond, Nathalie Revol, and Serge Torres. Handbook of Floating-Point Arithmetic. 2nd ed. Birkhäuser Boston, 2018

    Google Scholar 

  11. Martin M. Schmookler and Kevin J. Nowka. “Leading Zero Anticipation and Detection - A comparison of methods”. In: Symposium on Computer Arithmetic (ARITH). IEEE, 2001, pp. 7–12

    Google Scholar 

  12. Jongwook Sohn, David K. Dean, Eric Quintana, and Wing Shek Wong. “Enhanced Floating-Point Adder with Full De-normal Support”. In: Symposium on Computer Arithmetic (ARITH). IEEE, 2022

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

Copyright information

© 2024 Springer Nature Switzerland AG

About this chapter

Check for updates. Verify currency and authenticity via CrossMark

Cite this chapter

de Dinechin, F., Kumm, M. (2024). Basic Floating-Point Operators. In: Application-Specific Arithmetic. Springer, Cham. https://doi.org/10.1007/978-3-031-42808-1_11

Download citation

  • DOI: https://doi.org/10.1007/978-3-031-42808-1_11

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-031-42807-4

  • Online ISBN: 978-3-031-42808-1

  • eBook Packages: EngineeringEngineering (R0)

Publish with us

Policies and ethics