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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/112324] New: phiopt fail to recog if (b < 0) max = MAX(-b, max); else max = MAX (b, max) into max = MAX (ABS(b), max)
Date: Wed, 01 Nov 2023 01:26:25 +0000	[thread overview]
Message-ID: <bug-112324-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112324

            Bug ID: 112324
           Summary: phiopt fail to recog if (b < 0) max = MAX(-b, max);
                    else max = MAX (b, max) into max = MAX (ABS(b), max)
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: crazylht at gmail dot com
  Target Milestone: ---

#define MAX(a, b) ((a) > (b) ? (a) : (b)) 
int
foo (int n, int* a)
{
    int max = 0;
    for (int i = 0; i != n; i++)
    {
        int tmp = a[i];
        if (tmp < 0)
          max = MAX (-tmp, max);
        else
          max = MAX (tmp, max);
    }
    return max;
}

int
foo1 (int n, int* a)
{
    int max = 0;
    for (int i = 0; i != n; i++)
    {
        int tmp = a[i];
        max = MAX ((tmp < 0 ? -tmp : tmp), max);
    }
    return max;
}

foo should be same as foo1, but gcc failed to recognize ABS_EXPR in foo.
It's from pr110015(originally from source code in openjpeg).

             reply	other threads:[~2023-11-01  1:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-01  1:26 crazylht at gmail dot com [this message]
2023-11-01  1:32 ` [Bug tree-optimization/112324] " pinskia at gcc dot gnu.org
2023-11-01  1:33 ` pinskia at gcc dot gnu.org
2023-11-06 17:27 ` pinskia at gcc dot gnu.org
2023-11-06 17:56 ` pinskia at gcc dot gnu.org
2023-11-06 20:23 ` pinskia at gcc dot gnu.org
2023-11-19 16:23 ` sjames at gcc dot gnu.org
2023-11-19 16:43 ` pinskia at gcc dot gnu.org
2023-11-19 17:13 ` pinskia at gcc dot gnu.org

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