Approximate Reciprocal Square Root with Single - and Half-Precision Floats

  • Matheus M. Susin UNICAMP
  • Lucas Wanner UNICAMP


In this work, we compared the precision, speed, and power consumption of the reciprocal square root of a single-precision floating point number, using different approximation techniques. We also devised an equivalent approximation for half-precision floating point numbers, and evaluated its performance across the whole range of positive non-zero 16-bit floating point values.


IEEE 754-2008 (2008). IEEE Standard for Floating-Point Arithmetic. IEEE Std 754-2008.

Kushner, D. (2002). The wizardry of id. IEEE Spectrum, pages 42–47.

McEniry, C. (2007). The mathematics behind the fast inverse square root function code.

Rau, C. (accessed on 2017-11-16). IEEE 754-based half-precision floating point library.
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SUSIN, Matheus M.; WANNER, Lucas. Approximate Reciprocal Square Root with Single - and Half-Precision Floats. In: ESCOLA REGIONAL DE ALTO DESEMPENHO DE SÃO PAULO (ERAD-SP), 9. , 2018, São José dos Campos. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2018 . p. 49-52. DOI:

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