bearophile wrote:
> I have not found a quick way to let GCC vectorize this code, using two multiplications with one SSE instructions, I am not sure GCC is able to do this automatically.
> 
	Even with -ftree-vectorize? AFAIK it is considered experimental and
needs to be turned on explicitly. Don't know how good it is though...

		Jerome
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Jérôme M. Berger:

> 	Even with -ftree-vectorize?

Right.


> AFAIK it is considered experimental and
> needs to be turned on explicitly. Don't know how good it is though...

It's a very long lasting and complex experiment then :-) There is a lot of work behind that little switch. Modern compilers have a long way to go still, they need to compile little kernel loops better or much better.

Bye,
bearophile