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Altera_Forum
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14 years ago

NIOS2 HW & DIV Instructions + FPU

Hello i am in charge of designing a system that does a lot of complex sin/cos/* instructions and i need them to be fast. I am using NIOS2-F at 100mhz in a Cyclone IV. I've enabled HW and DIV ...
Altera_Forum's avatar
Altera_Forum
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14 years ago

If you are manually passing in the flags for your builds make sure you keep them in sync with the hardware implementation (i.e. don't pass in the 60-1 or 60-2 flags if you don't have the FPU added to the Nios II core).

The Taylor series I remember finding was under the POSIX implementation in newlib and it wasn't long enough to give an accurate answer. I ended up hardware accelerating it and since it only used the first 3 terms of the series I would end up with things like sqrt(1) = 0.999999.