Good dotProduct

[bearophile]

Andrei Alexandrescu:
> You already have a loop at the end that takes care of the stray 
> elements. Why not move it to the beginning to take care of the stray 
> elements _and_ unaligned elements in one shot?

Unfortunately things aren't that simple, you need a pre-loop and a post-loop. That asm block can process only aligned values in groups of 8 floats. So if you have an unaligned array of N items, that starts and ends before and after a block of processable items, you need to process both head and tail separately.

a floats:           ** **** **** **** **** ***
Loop blocks: xxxxxxxxx xxxxxxxxx xxxxxxxxx xxxxxxxxx
16b aligned: ____ ____ ____ ____ ____ ____ ____ ____

if you don't understand still, I can create an example.

Bye,
bearophile