From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id CA1D83858C36; Thu,  7 Mar 2024 17:20:53 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CA1D83858C36
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1709832053;
	bh=sDWFx6EuQzPKqUeR2pk9aLPEgKsYFbKNyVC6xj/kJ+o=;
	h=From:To:Subject:Date:From;
	b=NuUBnt75AbfKcAWnne3mdaNQuRO+JkZCsMyMYmrgAu/fXILbieIgiVR9+KjsaUZ5A
	 Qk2zVcFIiVOOZ6O/RHWJ7cjAvmGPiasuIVKxCbQgvBoYo9HP12AL3QfHhalj1RbGcM
	 UVXAr+whlLMH4ZdkmOAU8jOOTiPfBQhZRDgsqllU=
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/114273] New: `PHI(a, MIN(b, c)) < c` is not
 optimized to just `PHI(a,b) < c`
Date: Thu, 07 Mar 2024 17:20:53 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: pinskia at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 keywords bug_severity priority component assigned_to reporter
 target_milestone
Message-ID: <bug-114273-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114273

            Bug ID: 114273
           Summary: `PHI(a, MIN(b, c)) < c` is not optimized to just
                    `PHI(a,b) < c`
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
void dummy(void);
bool f(unsigned a, unsigned b, bool c)
{
        unsigned ind =3D b;
        if (c)
        {
                dummy();
                ind =3D a > 6 ? 6 : a;
        }
        return ind < 6;
}
bool f2(unsigned a, unsigned b, bool c)
{
        unsigned ind =3D b;
        if (c)
        {
                dummy();
                ind =3D a;
        }
        return ind < 6;
}
```

GCC should be able to remove the MIN_EXPR in f.
Note GCC is able to optimize `MIN_EXPR<a,b> < b`  since
r14-3922-g06bedc3860d3e6 .

This seems like PRE is the place for this kind of optimization but I am not
100% sure.=