Re: Improve a few appendStringInfo calls new to v18

On Fri, Apr 11, 2025 at 10:40:57AM +1200, David Rowley wrote:
> On Fri, 11 Apr 2025 at 02:51, Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
>> This probably isn't v18 material, but this reminds me of my idea to change
>> appendStringInfoString() into a macro for appendBinaryStringInfo() so that
>> the compiler can remove the runtime strlen() calls for string literals [0].
>> In most cases, the benefits are probably negligible, but StringInfo is
>> sometimes used in hot paths.
>
> That one has come up a few times. The most lengthy discussion I
> remember was in [1]. It didn't come to anything, but I don't think
> there were any objections to it, so maybe we should just do it.
>
> In the thread I did some measurements of binary size increases. For
> non-compile-time consts, it does mean putting the strlen() call in the
> calling function, which is a bit of overhead in terms of size. The
> macro trick I suggested should have fixed that, but I admit the macro
> is a bit ugly. The macro version also still has the overhead of having
> to pass the length of the string when it detects a compile-time const.

Thanks for the additional context.

--
nathan