From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 1FFAB3858C53; Fri, 2 Dec 2022 15:27:27 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1FFAB3858C53 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1669994847; bh=5+iRws1rTCpzctXNr5awSfDeX7tOQSzloukJ9R+uP+k=; h=From:To:Subject:Date:In-Reply-To:References:From; b=xNs9RuVHE0KGC5uN60yCRqHSlMcq5frtD4QrYmkl08TrnKFbH6IwXhDwJrXY0+Hrt ZDURfquh+wwIw4rAEUyJdGkEPPmng9r/TEb77+URK8fi4hiE77NGtnk7vKtvzV7qX7 QZ80rdSXgzr59+nfN9U/Ub8DoA4RWPajSPLiTodI= From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/107767] [13 Regression] switch to table conversion happening even though using btq is better Date: Fri, 02 Dec 2022 15:27:26 +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: 13.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal 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: 13.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: 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=3D107767 --- Comment #10 from Richard Biener --- Looks like a general CFG optimization if we have N forwarders to a PHI with= the same value then we can merge them to one (it's enough to have a single forwarder which we can use as the remaining one even). Note that's kind-of= a reverse mergephi for same values. PHI -> forwarder | PHI CFG cleanup will then eventually elide forwarders into the added forwarder.=