ippMalloc/ippsMalloc alignment size

[thomtek]

According to the IPP user manual, ippMalloc() and ippsMalloc_xxx() provide buffers aligned to 64-byte boundaries.  But an IPP web page says they align to 32-byte boundaries:  https://software.intel.com/en-us/articles/performance-tools-for-software-developers-memory-function-faq

We are going to use _aligned_malloc() for large buffer memory allocation and want to set the alignment paramter to give the same alignment as IPP does.  Should we use 32-byte or 64-byte alignment?

Tom

[Bjoern_B_Intel]

Hi Tom,

I will look into this.

Best,

Bjoern

[thomtek]

Hi,

Any answer to this question yet?

Tom

[Bjoern_B_Intel]

Hi Tom,

You are right, the documentation is inconsistent here. The article on the IPP web page is quite some years old while we changed the alignment to 64-byte. This is true for all kinds of ippMalloc functions as we also need to support AVX with 512-bit vectors which by nature has to be 64-byte aligned. We will change and update the ippMalloc article on the IPP web page accordingly.

So please use 64-byte alignment in your application to be aligned with the ippMalloc functions.

Thanks for reporting the issue so we can fixed the documentation.

Best,

Bjoern

[Bjoern_B_Intel]

Remark: Article Intel® IPP Memory Function ippMalloc/Free FAQ got updated. This request will get closed.

Thanks,

Bjoern