Re: [boost] Going forward with Boost.SIMD

Subject: Re: [boost] Going forward with Boost.SIMD
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2013-04-22 11:03:32

On Mon, Apr 22, 2013 at 6:32 PM, Mathias Gaunard <
mathias.gaunard_at_[hidden]> wrote:

> On 21/04/13 14:01, Evgeny Panasyuk wrote:
>
>  And what is your point? Do you mean that we should rely on
>> auto-vectorizer?
>>
>
> This has nothing to do with auto-vectorization.
>

I think the argument was that in one regard you point out that we cannot
rely on compiler to optimize the code and in the other you suggest the
opposite.

Although I admit that expression transform to FMA is simpler for the
compiler to handle, I would still prefer to explicitly spell it out as a
function call. In general, when writing SIMD code, I would prefer to spell
out as much as possible and leave only lowest level optimizations to the
compiler (such as instruction scheduling, register allocation and spilling,
maybe CSE and DCE, things like that).