From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Rowley <dgrowleyml@gmail.com>
cc: Dmitry Mityugov <d.mityugov@postgrespro.ru>,
        Corey Huinker <corey.huinker@gmail.com>, pgsql-hackers@postgresql.org
Subject: Re: [PATCH] Use strchr() to search for a single character
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Comments: In-reply-to David Rowley <dgrowleyml@gmail.com>
	message dated "Wed, 23 Jul 2025 10:18:26 +1200"
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Date: Tue, 22 Jul 2025 18:36:24 -0400
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David Rowley <dgrowleyml@gmail.com> writes:
> Looking at [1], it seems even ancient versions of gcc and clang
> rewrite the strstr() into a strchr() call when the search term is a
> single char string. So it might not be worth doing to any trouble
> here.

I was wondering if that might be true.  However, your godbolt results
show that MSVC doesn't do this optimization, and the usage in
pgmkdirp.c is inside "#ifdef WIN32", so maybe it's worth fixing there.

I can't get excited about dmetaphone --- that's about as old and
crufty as anything in our tree.  If we were going to touch it the
first thing I'd want to do is get rid of its non-multibyte-safe
upcasing logic (MakeUpper).  The "WITZ" business is kind of
silly-looking, but the question it brings to my mind is whether
the algorithm was mistranscribed; so rather than just delete that
line we should do some research.  If we care, that is.

			regards, tom lane