From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 519F73858D1E; Thu, 10 Nov 2022 13:47:56 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 519F73858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1668088078; bh=LvboMC0R3PFhBDgqvunLabM1CjZr8HptXKBEr796sfQ=; h=From:To:Subject:Date:In-Reply-To:References:From; b=sSAwoFPnXpy4afEPtPeFxguCA/K0hEaNnYg9F3w4nHt8Xp3OSxueiRyytwEf7hCX1 jXF56+V6JzN/5EWqNi+ilzahajO41I3niGjXuVZUDhGdD/O8KctafYdoh2WTZRyTV7 6pbZ+ZBkSp4+wxme2OPGwigOshjcQJzuLXft0fXY= From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/107608] [13 Regression] Failure on fold-overflow-1.c Date: Thu, 10 Nov 2022 13:47:46 +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: X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 13.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc 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=3D107608 Richard Biener changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu.org --- Comment #2 from Richard Biener --- I think we are not properly preserving IEEE exceptions in DCE and friends. = We happily elide void foo(float x) { x + x; } even at -O0 - the above is elided in the gimplifier. With -fnon-call-exceptions we are a bit more careful (but the above is gone= in the gimplifier still). That said, as long as -ftrapping-math is default changing behavior isn't a = good idea IMHO. We very likely have very many lurking issues that would leave us with dead unused code around if we just fix DCE here. As you show it's not really a regression either.=