Re: Proposal: Removing 32 bit support starting from PG17++

Hi,

On 2023-05-24 14:33:06 +0000, Hans Buschmann wrote:
> I recently stumbled over the following Intel proposal for dropping 32bit support in x86 processors. [1]

It's a proposal for something in the future. Which, even if implemented as is,
will affect future hardware, several years down the line. I don't think that's
a good reason for removing 32 bit support in postgres.

And postgres is used on non-x86 architectures...

> This inspired me to propose dropping 32bit support for PostgreSQL starting
> with PG17.
> ...
> Even if I am not a postgres hacker I suppose this could simplify things quite a lot.

There's some simplification, but I don't think it'd be that much.

I do think there are code removals and simplifications that would be bigger
than dropping 32bit support.

Dropping support for effectively-obsolete compilers like sun studio (requires
random environment variables to be exported to not run out of memory) and
AIX's xlc (requires a lot of extra compiler flags to be passed in for a sane
build) would remove a fair bit of code.

Dropping CPUs without native atomic operations / without a way to do tear-free
8 byte reads would make several substantial performance improvements easier,
while not really dropping any relevant platform.

Etc.

Greetings,

Andres Freund