On Friday, 24 May 2019 at 12:24:02 UTC, Alex wrote:
If it truly is a 27x faster then then that is very relevant and
knowing why is important.
Of course, a lot of that might simply be due to LDC and I
wasn't able to determine this.
Just one more thing you really ought to consider:
It isn't obvious that a LUT using double will be more precise
than computing sin using single precision float.
So when I use single precision float with ldc and "-O3
-ffast-math" then I get roughly 300ms. So in that case the LUT is
only 3 times faster.
Perhaps not worth it then. You might as well just use float
instead of double.
The downside is that -ffast-math makes all your computations more
inaccurate.
It is also possible that recent processors can do multiple
sin/cos as simd.
Too many options… I know.
