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 50DFE3858D28; Sun, 18 Jun 2023 19:24:55 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 50DFE3858D28
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1687116295;
	bh=bQVbiG5Xw+wVhGGDJDLOYd3X3Dlo2p7TX8BD6gks688=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=tMCojZ+QI1pmU0ba8CXR/EtDZJEGJnrxl/lqgCcGd0PG9SBIFIGWW24vOK+lOwNq/
	 /SfHOYz4gIimKYAcsJL1KwmsbPKb/OTueaZ3qvaIKupYQTmVVCEHXWQL8kHawPyyJ2
	 03WMsffoCdgA1MobLupsbyeyX/1Ngb45z6yRI9+s=
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/95185] Failure to optimize specific kind of
 sign comparison check
Date: Sun, 18 Jun 2023 19:24:54 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: easyhack, missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: pinskia at gcc dot gnu.org
X-Bugzilla-Status: NEW
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: 
Message-ID: <bug-95185-4-Z6ujrVKfwy@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-95185-4@http.gcc.gnu.org/bugzilla/>
References: <bug-95185-4@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=3D95185

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
  _1 =3D x_4(D) >=3D 0;
  _2 =3D y_5(D) <=3D 0;
  _3 =3D _1 =3D=3D _2;

Something like:
Prefer ^ over =3D=3D
```
(for cmp
(for cmpN
(for neeq
 (simplify
  (neeq:c (cmp @0 @1) @3
  (if (cmpN =3D=3D inverseof(cmp, TREE_TYPE (type))
   (bit_xor (cmpN @0 @1) @3)
  )
 )
)))
```

This is what clang seems to do rather than any magic around =3D=3D really.

I do wonder if we should try to expand bool =3D=3D bool as bool^bool^1 .=