D vs VM-based platforms
Daniel Keep
daniel.keep.lists at gmail.com
Tue May 1 16:42:57 PDT 2007
Stephen Waits wrote:
> Daniel Keep wrote:
>>
>> Funny thing, turns out SSE is actually *slower* for doing a dot product
>> than regular old x87 code!
>
> You should qualify this - I'm guessing you mean for a single dot
> product? If so, this is the case in most vector coprocessors, as
> load/store overhead can easily outweigh the gains in vectorization.
>
> --Steve
Sorry; yes, you're right: it's for a single dot product.
I'm surprised at this because of the sheer number of articles I ran
across touting "faster" dot product functions using SSE. I have a
feeling these people have never bothered to actually *benchmark* their
"faster" functions :P
-- Daniel
--
int getRandomNumber()
{
return 4; // chosen by fair dice roll.
// guaranteed to be random.
}
http://xkcd.com/
v2sw5+8Yhw5ln4+5pr6OFPma8u6+7Lw4Tm6+7l6+7D
i28a2Xs3MSr2e4/6+7t4TNSMb6HTOp5en5g6RAHCP http://hackerkey.com/
More information about the Digitalmars-d
mailing list