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From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/109811] libjxl 0.7 is a lot slower in GCC 13.1 vs Clang 16
Date: Wed, 17 May 2023 14:58:18 +0000	[thread overview]
Message-ID: <bug-109811-4-kb3AOrj0xb@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-109811-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109811

--- Comment #10 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Actually vectorization hurts on both compilers and bit more with clang.
It seems that all important loops are hand vectorized and since register
pressure is a problem, vectorizing other loops causes enough of collateral
damage to register allocation to regress performance.

I believe the core of the problem (or at least one of them) is simply way we
compile loops popping data from std::vector based stack. See PR109849
We keep updating stack datastructure in the innermost loop becuase in not too
common case reallocation needs to be done and that is done by offlined code.

  parent reply	other threads:[~2023-05-17 14:58 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-11 14:24 [Bug tree-optimization/109811] New: libxjl " aros at gmx dot com
2023-05-11 15:30 ` [Bug target/109811] " xry111 at gcc dot gnu.org
2023-05-11 15:49 ` aros at gmx dot com
2023-05-12  6:59 ` rguenth at gcc dot gnu.org
2023-05-17  8:42 ` hubicka at gcc dot gnu.org
2023-05-17  9:08 ` hubicka at gcc dot gnu.org
2023-05-17 12:35 ` [Bug target/109811] libjxl " hubicka at gcc dot gnu.org
2023-05-17 13:59 ` juzhe.zhong at rivai dot ai
2023-05-17 14:04 ` hubicka at gcc dot gnu.org
2023-05-17 14:10 ` jakub at gcc dot gnu.org
2023-05-17 14:58 ` hubicka at gcc dot gnu.org [this message]
2023-05-18 13:40 ` hubicka at gcc dot gnu.org
2023-06-19 16:28 ` cvs-commit at gcc dot gnu.org
2023-11-02 14:12 ` hubicka at gcc dot gnu.org
2023-11-21 14:17 ` cvs-commit at gcc dot gnu.org
2023-11-24 23:13 ` hubicka at gcc dot gnu.org
2023-11-24 23:23 ` sjames at gcc dot gnu.org
2023-11-25  6:22 ` aros at gmx dot com
2023-11-25 13:31 ` hubicka at gcc dot gnu.org
2024-01-05 21:31 ` hubicka at gcc dot gnu.org
2024-01-20 17:23 ` pinskia at gcc dot gnu.org

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