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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/100162] missed optimization for dead code elimination at -O3 (vs. -O2)
Date: Fri, 05 May 2023 10:16:56 +0000 [thread overview]
Message-ID: <bug-100162-4-3oebyybC8L@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-100162-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100162
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> FRE is no longer able to optimize _7 to 2 in GCC 13+:
> c[0][b.1_1] = 2;
> c[1][b.1_1] = 2;
> c[2][b.1_1] = 2;
> c[3][b.1_1] = 2;
> c[4][b.1_1] = 2;
> a = 5;
> _5 = b.1_1 != 0;
> _6 = (int) _5;
> _7 = c[0][0];
That's PR108355. The "magic" special-casing of single element arrays went
away (or rather now triggers more unreliably).
prev parent reply other threads:[~2023-05-05 10:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 19:20 [Bug tree-optimization/100162] New: " zhendong.su at inf dot ethz.ch
2021-04-21 8:35 ` [Bug tree-optimization/100162] " rguenth at gcc dot gnu.org
2023-05-05 8:07 ` pinskia at gcc dot gnu.org
2023-05-05 10:16 ` rguenth at gcc dot gnu.org [this message]
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