From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 442A03858D20; Fri, 28 Jul 2023 13:41:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 442A03858D20 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1690551717; bh=CQkCPqy2S4IWRdoZooF8v9J6QDGwz+SeMh45LdWjbGY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=yeMi3kwntrL69JlUtv8bsO9LJq2eMH46xn3Q3H7CBW7FGzO1NJvSo2zOJ+mOdYng4 SNecchvzRFiGJ8TwwlV9aI31DJyR9beJcV4iOnw//Nx+APOdjlnI6j8Rpvful/3eti yQcZ7dKuOY+oVZJIZyiB49xvWYZSp/KmyiHgGaco= From: "ubizjak at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/110832] [14 Regression] 14% capacita -O2 regression between g:9fdbd7d6fa5e0a76 (2023-07-26 01:45) and g:ca912a39cccdd990 (2023-07-27 03:44) on zen3 and core Date: Fri, 28 Jul 2023 13:41:56 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Version: 14.0 X-Bugzilla-Keywords: missed-optimization, needs-bisection X-Bugzilla-Severity: normal X-Bugzilla-Who: ubizjak at gmail dot com 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: 14.0 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=3D110832 --- Comment #7 from Uro=C5=A1 Bizjak --- (In reply to Richard Biener from comment #6) > Do we know whether we could in theory improve the sanitizing by optimizat= ion > without -funsafe-math-optimizations (I think -fno-trapping-math, > -ffinite-math-only -fno-signalling-nans should be a better guard?)? I was looking at -funsafe-math-optimizations because the compiler links in crtfastmath.c which sets DAZ and FTZ flags, so eventual denormals won't bot= her us. -fu-m-o also enables -fno-trapping-math, which assumes masked FP exceptions, so we can still allow V2SF infinities and NaNs. FYI, clang enab= les this optimization by default, since it defaults to -fno-trapping-math. It s= eems to me that they don't care about denormals.=