On 03/23/2015 07:34 PM, Joseph Myers wrote: > On Mon, 23 Mar 2015, Florian Weimer wrote: > >> __alignof__ (max_align_t) appears to be stuck at 16, even though some >> AVX512 operations require 512 byte alignment. >> >> Is this intentional? There are arguments for (more ABI compatibility) >> and against (max_align_t is misleading) this behavior. > > max_align_t is only about fundamental alignments. See > <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1892.htm#dr_445> for an > accepted cleanup of the alignment wording in C11. > > It doesn't seem useful to increase the alignment requirements for malloc > beyond this, especially as all allocations, even 1-byte ones, have the > same alignment requirements.
Ah, I should have looked at what max_align_t actually meant. With these semantics, the name is a bit confusing. I agree that requiring 64 byte alignment from malloc does not make much sense. Thanks. -- Florian Weimer / Red Hat Product Security
