Different Float64 sum on different architectures

[danielw2904]

See here for a simple example:

Different inner product if vector type is not set

I think you do, but you may be surprised to know that floating point addition is not associative (due to, essentially, rounding). julia> @show (-1e30+1e30)+1.0 -1e30+(1e30+1.0); (-1.0e30 + 1.0e30) + 1.0 = 1.0 -1.0e30 + (1.0e30 + 1.0) = 0.0

Basically, summation is not associative and there is no guarantee for the order of execution of the sum.