https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120895
David C. Partridge <david.partridge at perdrix dot co.uk> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |UNCONFIRMED Resolution|INVALID |--- --- Comment #28 from David C. Partridge <david.partridge at perdrix dot co.uk> --- Microsoft recognised this as a BUG ages ago and fixed it. https://developercommunity.visualstudio.com/t/avx512-types-are-not-aligned-to-64-bytes/107143 Your comments above merely reiterate the INCORRECT behaviour of g++ - there is ONLY one alignment for this data type and it is 64 bytes, to set other values for this based on some compiler option or your whim is simply WRONG.