If you mean malloc() by that: malloc will return aligned memory so that you can store all data types, i.e. it is 64-bit aligned at least (so you can store double) but probably has even higher granularity.
It's the downside of malloc not knowing the type you want and returning void*. It has to assume the worst alignment requirements.
Which actually happen to be 128 bytes for SSE instructions.
Is this guaranteed by the standard? worst seems platform dependent, does that mean it will vary with platform? what about x86 vs amd64? could it ever be more than 128 bytes?
It's the downside of malloc not knowing the type you want and returning void*. It has to assume the worst alignment requirements.
Which actually happen to be 128 bytes for SSE instructions.