It's been a really long time since I last worked with fixed point arithmetic, so I decided to first do a little refresher on that:

https://www.youtube.com/watch?v=S12qx1DwjVk
https://www.youtube.com/watch?v=npQF28g6s_k
https://www.youtube.com/watch?v=7pkXlcapNB4

[download]

... and now I've run out of time and will have to get back to playing with it later :-/ But the above essentially confirms what I was thinking earlier: convert your floats in the range -4 to 4 into 128-bit ints with a scale of something like 1/2**124; addition and subtraction remain trivial, multiplication either requires a 256-bit output, or you'll have to shift your two multiplicands first and lose some precision.

Your approach is certainly different from that fixed-point approach, but mostly due to lack of time in comprehending it I'm not yet sure that I see where you are going with it other than implementing your own 128-bit floating point numbers?

BTW, in my research I also came across Math::Decimal128 and Math::Float128, although I'm not sure if those will help you in MSVC...

In reply to Re^9: Need more precision. (Updated.) by Anonymous Monk
in thread Need more precision. by BrowserUk

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