Re: [boost] [gsoc] boost.simd news from the front.

Subject: Re: [boost] [gsoc] boost.simd news from the front.
From: David A. Greene (greened_at_[hidden])
Date: 2011-06-11 11:33:38

"Simonson, Lucanus J" <lucanus.j.simonson_at_[hidden]> writes:

> David A. Greene wrote:
>> For writing new code, I contend that a good compiler, with a few
>> directives here and there, can accomplish the same result as this
>> library and with less programmer effort.
>
> That's great, why don't you write one and then there will be one.  Let
> me know when you're done.  ;)

Already done.  :)

>>> MSVC does not, neither xlC ... neither clang ... so which compilers
>>> takes random crap C code and vectorize it automagically ?
>> 
>> Intel and PGI.
>
> Even the best vectorizing compilers for C++ are still terrible.  I
> think we should use "good" in an absolute rather than relative sense.

No compiler can vectorize things like pointer chasing on the SIMD
architectures because the hardware doesn't support it.  Likewise, no one
using boost.simd will be able to either.

If the algorithm is amenable to vectorization, the compiler should be
able to get it.

                          -Dave