Performance (i)FFT on PXA270

[ja9]

Hello,

I want to improve the performance of a caculation with a lot of 4k ffts and iffts on the PXA270 with Window CE 5.0

.

My own written (i)fft is an inplace normalized function written in C that works on 32bit integer complex data (one array for real and one for imaginair part) that has been tuned for an ARM7 core.

Now I am trying to use the intel ippsFFTFwd_CToC_32s_ISfs and ippsFFTInv_CToC_32s_ISfs, with an extern pBuffer, noscaling and after the following initialisation:

ippsFFTInitAlloc_C_32s( &pFFTStruc12Fwd, 12, IPP_FFT_DIV_FWD_BY_N, ippAlgHintFast );
ippsFFTInitAlloc_C_32s( &pFFTStruc12Inv, 12, IPP_FFT_DIV_INV_BY_N, ippAlgHintFast );
ippsFFTGetBufSize_C_32s(pFFTStruc12NoNorm, &sizeBuf);
pBuffer = (Ipp8u*)malloc( sizeBuf);

I am using the ippcorel.lib and ippss2l.lib linked static. I should think the library tuned for MMX instruction of the PXAwouldbe (much) faster than my ownwritten routine. However it'salmost equal or even a little bit slower.

Does anyone has a hintof what Imight do wrong?

[ja9]

I found the following in the intel site:

Signal Processing: Includes signal processing features for the following: Digital Filtering
Fourier Transformation
Windowing
Emphasis
Vector Statistics
Equalization
Signal Generation

Note: Not available on Intel PCA Processors

Does the remark "Not available on Intel PCA Processor" mean that the (I)FFT in the library ippss2l.lib of theipx package is not optimised for the IPX and PXA27x processors?

Is that the reason that the performance is dissapoints me?

[Ying_S_Intel]

Dear Customer,
The Intel IPP Signal Processing Functions are also supported for PXA27x processor, there was an errot statement info at our web site and we are working on the web content fix. We apologized for this inconvenience.

What you can do is to get the IPP 5.0 for PXA27x, ( although we support Microsoft Windows Mobile, it might work on Window CE 5.0).

Thecurrent versionis IPP 5.1.But for the package ofPXA27x, it remained 5.0.I attach the release notes of this package for your reference.

Hope it helps.
Thanks,
Ying S
Intel Corp.

[ja9]

Ok, that answer helps!

So I need to download the w_ipp_pca_wmmx_pu_5.0.012.exe instead of the w_ipp_ixp_p_5.1.017.exe

However where do I get the w_ipp_pca_wmmx_pu_5.0.012.exe? When I follow the page on the intel site I get only de first four of the five in the list...



w_ipp_ia32_p_5.1.017.exe

w_ipp_itanium_p_5.1.017.exe

w_ipp_em64t_p_5.1.017.exe

w_ipp_ixp_p_5.1.017.exe

w_ipp_pca_wmmx_pu_5.0.012.exe





...........?

Message Edited by ja9 on 05-29-200604:55 AM

[ja9]

Thanks again for the tip I found the w_ipp_pca_wmmx_pu_5.0.012.exe in the Intel Premier Support.

Message Edited by ja9 on 05-29-200609:55 AM