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From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/94779] Bad optimization of simple switch
Date: Mon, 27 Apr 2020 06:15:39 +0000	[thread overview]
Message-ID: <bug-94779-4-ar7PasNArF@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94779-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94779

--- Comment #6 from Gabriel Ravier <gabravier at gmail dot com> ---
There is another thing I realised : This code :

int f1(unsigned x)
{
    switch (x)
    {
        case 0:
            return 1;
        case 1:
            return 2;
        case 2:
            return 3;
    }
}

always gets optimized to `return x + 1;` with no problems. The switchconv pass
handles it. Maybe that pass should be doing the same optimisation on the code
from this issue, too. That seems like the simplest solution to this.

  parent reply	other threads:[~2020-04-27  6:15 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-27  0:40 [Bug tree-optimization/94779] New: " gabravier at gmail dot com
2020-04-27  4:31 ` [Bug tree-optimization/94779] " marxin at gcc dot gnu.org
2020-04-27  4:35 ` gabravier at gmail dot com
2020-04-27  4:38 ` gabravier at gmail dot com
2020-04-27  4:46 ` marxin at gcc dot gnu.org
2020-04-27  5:47 ` gabravier at gmail dot com
2020-04-27  6:15 ` gabravier at gmail dot com [this message]
2020-04-27  6:47 ` rguenth at gcc dot gnu.org
2020-04-27  6:51 ` gabravier at gmail dot com
2020-05-06 15:08 ` jakub at gcc dot gnu.org
2020-05-06 15:12 ` marxin at gcc dot gnu.org
2020-05-06 15:24 ` jakub at gcc dot gnu.org
2020-12-15 13:35 ` jakub at gcc dot gnu.org
2020-12-15 15:02 ` amacleod at redhat dot com
2020-12-17 13:36 ` marxin at gcc dot gnu.org
2020-12-17 13:41 ` jakub at gcc dot gnu.org
2020-12-17 13:57 ` marxin at gcc dot gnu.org
2020-12-17 14:07 ` jakub at gcc dot gnu.org
2020-12-17 16:38 ` amacleod at redhat dot com
2020-12-18 12:07 ` marxin at gcc dot gnu.org
2020-12-18 12:18 ` jakub at gcc dot gnu.org
2020-12-18 12:30 ` marxin at gcc dot gnu.org
2020-12-18 14:35 ` amacleod at redhat dot com
2021-08-16 12:39 ` marxin at gcc dot gnu.org

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