Search code examples
iosarmneon

Improve code with NEON on iOS - use VCEQ then VBIT

I am writing a histogram like function which looks at vector data and then puts the elements in predefined "histogram" buckets based on which range they are closest to.

I can obviously do this using if condition but I am trying to improve it using NEON because these are image buffers.

One way to do this would be with VCEQ then VBIT but sadly enough I could not find VBIT in the header of neon. Alternatively I figured I could take the VCEQ results and do an exclusive AND with a vector of 1s and then use VBIF :-) but VBIF is not there either!

Any thoughts here? Thanks

Solution

  • VBIT, VBIF, and VBSL all do the same operation up to permutation of the sources; you can use the vbsl* intrinsics to get any of the three operations.