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Date: Mon, 20 Jun 2022 21:57:45 +0200
From: Jakub Jelinek <jakub@redhat.com>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,
 gcc-patches List <gcc-patches@gcc.gnu.org>,
 "Carlos O'Donell" <carlos@systemhalted.org>
Subject: Re: [PATCH v1] tree-optimization/95821 - Convert strlen + strchr to
 memchr
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On Mon, Jun 20, 2022 at 12:12:53PM -0700, Noah Goldstein wrote:
> Got it. Will have that in V2.

Thanks.
> 
> We could also make the initial:
> bool is_strchr_zerop = integer_zerop (chr);
> 
> Only check the lower 8 bits.

Sure.  Though, in that case it is just an optimization,
it is ok to not to optimize strchr (x, 256); as
strchr (x, 0);, but it is not ok to optimize strchr (x, 256);
into memchr (x, 256, strlen (x)); so for the strlen (x) vs. strlen (x) + 1
decision it is needed for correctness.

	Jakub