From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id BAC16385609A; Sat, 10 Sep 2022 19:07:59 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BAC16385609A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1662836879; bh=sscPTKGueVUsc8CA/5EOgJi+oYOaKCpuQI30RjjtMTY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=o33otbcJzY4Bio8PsuqDp4zgvReNpswzY+0iUJfeP6H6TlDFA0txpe3enE4iOBxwV zudnyxy/4AQOSpf4Df6ugpSGg6LbYyFBoT0Tyxa4lGWZ3lOM2frA6B3n6sEebyhisS 9DbkjG12ZG4crkFZeMxT7CkqKqIH+gqdRW6MQBy4= From: "pinskia at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/106902] Program compiled with -O3 -mfma produces different result Date: Sat, 10 Sep 2022 19:07:59 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 12.2.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal 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: 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=3D106902 --- Comment #1 from Andrew Pinski --- Note -mfma should only increase the precision of doing a multiple and add in infinite precision before a rounding step. So if you depend on exactly roun= ding after each operation then you need to use -ffp-contract=3Doff option.=