Simplify, simdify, and speed up BitArray broadcasts with partitions

base/broadcast.jl

@@ -919,20 +919,19 @@ end
  length(dest) < 256 && return invoke(copyto!, Tuple{AbstractArray, Broadcasted{Nothing}}, dest, bc)
  tmp = Vector{Bool}(undef, bitcache_size)
  destc = dest.chunks
- ind = cind = 1
+ cind = 1
  bc′ = preprocess(dest, bc)
- @simd for I in eachindex(bc′)
- @inbounds tmp[ind] = bc′[I]
- ind += 1
- if ind > bitcache_size
- dumpbitcache(destc, cind, tmp)
- cind += bitcache_chunks
- ind = 1
+ for P in Iterators.partition(eachindex(bc′), bitcache_size)
+ ind = 1
+ @simd for I in P
+ @inbounds tmp[ind] = bc′[I]
+ ind += 1
+ end
+ @simd for i in ind:bitcache_size
+ @inbounds tmp[i] = false
  end
- end
- if ind > 1
- @inbounds tmp[ind:bitcache_size] .= false
  dumpbitcache(destc, cind, tmp)
+ cind += bitcache_chunks
  end
  return dest
 end