From: Tom Lane <tgl@sss.pgh.pa.us>
To: Nathan Bossart <nathandbossart@gmail.com>
cc: pgsql-hackers@lists.postgresql.org
Subject: Re: Simplifying our Trap/Assert infrastructure
In-reply-to: <20221009212937.GC900071@nathanxps13>
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Comments: In-reply-to Nathan Bossart <nathandbossart@gmail.com>
	message dated "Sun, 09 Oct 2022 14:29:37 -0700"
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Date: Mon, 10 Oct 2022 15:20:08 -0400
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Nathan Bossart <nathandbossart@gmail.com> writes:
> On Sun, Oct 09, 2022 at 05:08:39PM -0400, Tom Lane wrote:
>> Something I thought about but forgot to mention in the initial email:
>> is it worth sprinkling these macros with "unlikely()"?

> I don't see why not.

I experimented with that, and found something that surprised me:
there's a noticeable code-bloat effect.  With the patch as given,

$ size src/backend/postgres 
   text    data     bss     dec     hex filename
9001199   86280  204496 9291975  8dc8c7 src/backend/postgres

but with unlikely(),

$ size src/backend/postgres 
   text    data     bss     dec     hex filename
9035423   86280  204496 9326199  8e4e77 src/backend/postgres

I don't quite understand why that's happening, but it seems to
show that this requires some investigation of its own.  So for
now I just pushed the patch as-is.

			regards, tom lane