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Honored Contributor
Honored ContributorNIOS2 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_ForumHonored Contributor
Honored Contributor --- Quote Start --- Well if those instructions are called with no implementation then it'll probably result in one cycle per instruction but the results would be incorrect. Also you are not adding those flags manually are you? In your earlier post I see two usages of "mcustom-fpu-cfg" which shouldn't be happening since you are either using 60-1 (+, -, *) or 60-2 (+, -, *, /) and I'm not sure what happens when both are specified. This flag should have been passed in automatically for you. --- Quote End --- Humm when both are specified the last one is valid i guess, and yes i am adding those flags manually, what other way can i do it? I am compiling my aplication from Linux --- Quote Start --- I'm not sure which functions are in 'newlib' (libc), but for speed you'd want the sin/cos functions that act on float (not double) and have compiled newlib itself to use the FP custom instructions. --- Quote End --- How can i do this?
