From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id D37683858427; Mon, 4 Dec 2023 06:57:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D37683858427 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1701673042; bh=8YQ4FeYCKxPwZXGy092PN3FV7gWr+DFTYcpewR77g88=; h=From:To:Subject:Date:In-Reply-To:References:From; b=Tz5Sy+sH+aLeVKXZWzPIBdpQSEFjcag+9YSFrQQ0SOB0IYRQOmhD9Jo64Xy3cvwF8 VRVvSTtf/Sw2JiZNgvvKDvQbIyhdwKcIDmPv1ymX/iltNusmJiFlEsKayiF+jp6PwE /e3Jn/+l/xgj6ncC3yuTBcmURAkcNv68NdKzrEbM= From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/112819] rearrange branches to improve code generation Date: Mon, 04 Dec 2023 06:57:22 +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: 14.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: rguenth 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: bug_status cc cf_reconfirmed_on everconfirmed Message-ID: In-Reply-To: References: 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: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112819 Richard Biener changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW CC| |fkastl at suse dot cz, | |hubicka at gcc dot gnu.org, | |rguenth at gcc dot gnu.org Last reconfirmed| |2023-12-04 Ever confirmed|0 |1 --- Comment #1 from Richard Biener --- We don't "re-associate" branches. But we might want to turn if-to-switch into sth that does (relaxing the restriction on the ifs testing the same va= r). We should have a PHI node with incoming vals predicated by the ifs, free to re-order otherwise. The *a deref might impose some limitations for re-ordering, but we can alwa= ys handle it last in this case. Might be also interesting to order branches which are predictable earlier. Related to switch-conversion/if-to-switch IMHO.=