Re: [PD-dev] 64-bit (and/or ARM) Pd change default cosine table?

Hi,

On 26/05/2024 10:16, Miller Puckette wrote:

OK, so in a few years every new PC will probably have ARM or other RISC architecture.

I just made the interesting discovery that, on Mac ARMs, there is a difference, probably a slight decrease, in numerical accuracy in Pd's DSP objects.  So we've lost exact compatibliity and only have pretty-good-approximate compatibility.  On one piece I tested the divergence is about -100 dB relative to maximum amplitude and in another, which I think has unstable feedback paths, the results are further off.

I debugged something similar: https://post.lurk.org/@mathr/110760066818211577

TL;DR compile with -ffp-contract=off

Claude