Re: [PATCH v2] mem-pool: Don't assume uintmax_t is aligned enough for all types

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 23, 2022, 20:28 UTC
Message-ID: <xmqqo8428ae6.fsf@gitster.g>
In-Reply-To: <FD089F0E-C826-4A8E-BC16-F763E256B410@jrtc27.com>

Jessica Clarke <jrtc27@jrtc27.com> writes:

Show 5 quoted lines

> So, sizeof(X) does not always equal _Alignof(X), even for primitive
> types, _Alignof need only be a factor of sizeof. The two are the same
> on most architectures, and is a sensible ABI, but the exception is the
> m68k case I was referring to above. On m68k, sizeof(long long) == 8,
> but _Alignof(long long) == 2 (yes this is a real pain point of its ABI;

Ah, thanks. Having a variant of the above explanation in a comment next to the "union within a struct" would help future readers from asking the same question as I asked.