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MCODE: Fastest way to multiply
04-15-2019, 07:50 PM
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RE: MCODE: Fastest way to multiply
Hi, PeterP, long time no see:

(04-15-2019 03:58 PM)PeterP Wrote:  For the MCODE gurus here, it seems one might be able to 'update' the OS routine for multiplication when doing large multiplications.

That's the key, large multiplications, because otherwise the overhead of calling a "*" in XROM would make it slower than the main "*" routine. I read many years ago an article (perhaps in CHHU) where someone coded addition "+" as XROM, to demonstrate the considerable overhead, and it executed way slower than using the main "+".

Quote:It was just generally a fascinating read to learn something as basic as multiplication can still be improved.

Yes, it is. For the record, I wrote an article titled Fantastic FOUR (which you can read/download in PDF format here) discussing FFT (Fast Fourier Transform) multiplication and including a 10-line subprogram for the HP-71B implementing it, with examples and timings.


All My Articles & other Materials here:  Valentin Albillo's HP Collection
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MCODE: Fastest way to multiply - PeterP - 04-15-2019, 03:58 PM
RE: MCODE: Fastest way to multiply - Valentin Albillo - 04-15-2019 07:50 PM

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