intrinsics performance vs. IPP perfromance

[andrewk88]

Hello All,

I'd be interested to find out more about performance of the Intel's intrinsics in the context of image and video processing and have few related questions:

1) any references to documentation/books/header fileslisting all available instrinsics with/without their description (incl. SSE4)

2) what would be a reccomended/allowedcompilers when using intrinsics - is it still possible to use MSFT VisualC then?

3)would ausage of intrinsics code be beneficial from perfromance point of view comparing to a functionally corresponding IPP callsin a typical operations like image convolution/interpolation and/or SADs computation in video motion estimation. As youmight imagine sometimes some extra performance benefits might be obtained by adaptation tospecial circumstances or when it's hard to find a functionally corresponding IPP call, which has to be achieved by a composition of multiple operations and for example involving multiple memory operations)

4) are actually intrinsics widely utilized in IPP implementation and are any particular situations when intrinsics usage would be explicitly discouraged?

5) reference to any available code examples with intrinsics?

Best regards,

AndrewK

[Vladimir_Dudnik]

Hi Andrew,

too many question:)

As Intel intrinsics is kind of compiler technology, I'd refer you to Intel Compiler documentation regarding the list of intrinsics and so on.

Usually, Intel compiler supports new architecture faster than Microsoft compiler, so if you are interested in utilization of the latest microarchitecture innovations Intel compiler should be your choice.

In IPP we use intrinsics, might be not so widely, because usually we start optimization for the next cpu generation before compiler available or stable enough.

As far as I know we do not provide sample how to use intrinsics in IPP samples. The reason is that IPP samples covers many architectures and there is no single set of intrinsics available for all arhitectures like IPP functions.

Regards,
Vladimir