current OpenJPEG and SSE alignment

[Tim Mooney]

Hi!

I'm working on packaging openjpeg-2.3.1 for OpenIndiana, one of the distributions using the Illumos kernel.  OpenIndiana currently ships openjpeg-2.1.2, with a patch that's a modified version of this SSE patch from PDFium.  Our modified patch no longer applies cleanly to openjpeg 2.3.1, so I'm assessing whether to drop the patch or update it.

I'm not an expert on SSE.  PDFium no longer uses their original patch, and I found openjpeg issue #624 and openjpeg issue #625 which seem to imply that alignment to 16 bytes is now assured by the memory-handling functions.  It's not explicitly spelled-out, though.

I'm looking for some guidance on whether it is safe for the SSE code to assume that alignment will be correct.  If that is indeed the case, we'll be able to drop our patch and proceed with the update.

Thanks much!

Tim