On Monday, 28 October 2013 at 02:30:53 UTC, Manu wrote:

GPU's also tend to deal with strict alignments of various buffers.

SIMD requires >= 16byte alignment, which is higher than the default 4-8
byte alignment of many allocators.

AFAIK the alignments for those cases are known a priori, the question was regarding alignments that are only known at runtime.