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charlietuna/inv_sqrt_rrrlog.c

Created April 9, 2014 05:52
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Improved (over John Carmack's) inverse square root hack from Řrřola - http://rrrola.wz.cz/inv_sqrt.html
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inv_sqrt_rrrlog.c
float inv_sqrt(float x)
{
union { float f; uint32 u; } y = {x};
y.u = 0x5F1FFFF9ul - (y.u >> 1);
return 0.703952253f * y.f * (2.38924456f - x * y.f * y.f);
}
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