dot dot dot.jl

using Benchmarks
mydot{T<:BLAS.BlasReal, TI<:Integer}(x::Vector{T}, rx::Union{UnitRange{TI},Range{TI}}, y::Vector{T}, ry::Union{UnitRange{TI},Range{TI}}) =  BLAS.dot(sub(x, rx), sub(y, ry))
mydot{T<:BLAS.BlasComplex, TI<:Integer}(x::Vector{T}, rx::Union{UnitRange{TI},Range{TI}}, y::Vector{T}, ry::Union{UnitRange{TI},Range{TI}}) =  BLAS.dotc(sub(x, rx), sub(y, ry))

n = 1000
m = 20
step_size = 5
x = rand(n)
y = rand(n)
xc = rand(Complex128, n)
yc = rand(Complex128, n)

dot(x,1:m, y, 1:m) == mydot(x,1:m, y, 1:m) && dot(xc,1:m, yc, 1:m) == mydot(xc,1:m, yc, 1:m)

# Unit stride
@benchmark dot(x,1:m, y, 1:m)
@benchmark mydot(x,1:m, y, 1:m)
@benchmark dot(xc,1:m, yc, 1:m)
@benchmark mydot(xc,1:m, yc, 1:m)

# step_size stride
@benchmark dot(x,1:step_size:m, y, 1:step_size:m)
@benchmark mydot(x,1:step_size:m, y, 1:step_size:m)
@benchmark dot(xc,1:step_size:m, yc, 1:step_size:m)
@benchmark mydot(xc,1:step_size:m, yc, 1:step_size:m)