Re: Move MAXIMUM_ALIGNOF definition to c.h

Peter Eisentraut <peter(at)eisentraut(dot)org> writes:
> As suggested at [0], we can move the computation of MAXIMUM_ALIGNOF from
> configure.ac and meson.build to c.h. This eliminates code duplication.
> (For example, the AIX patch contemplates some changes, so it would be
> good to make those in only one place.)

I looked at this but am pretty underwhelmed. Yes, it replaces two
copies of that logic with one, but said logic is so trivial that
that's not a big win. Moreover, I'm finding it hard to believe
that we'll ever need to change that logic again --- the plain
max-of-two-alignment-measurements logic is the way it had been
for a long time and will be again after the AIX patch lands. I can't
foresee a future platform where it'd need to be any different.

In exchange for that simplification, we are taking a computation
that currently is done once per configure/meson-setup step, and
instead computing it during each .c file build. I imagine that
at least the autoconf implementation is more expensive than
what the C compiler would need to do, but repeating it over and
over again will surely end up costing more.

So this doesn't seem like a good change to me.

regards, tom lane