From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26324 invoked by alias); 11 Feb 2013 14:43:04 -0000 Received: (qmail 26250 invoked by uid 48); 11 Feb 2013 14:42:46 -0000 From: "kcc at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug sanitizer/55309] gcc's address-sanitizer 66% slower than clang's Date: Mon, 11 Feb 2013 14:43:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: sanitizer X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: kcc at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2013-02/txt/msg01072.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55309 --- Comment #30 from Kostya Serebryany 2013-02-11 14:42:43 UTC --- > Could we on x86_64 think about mem_to_shadow(x) (x >> 3) + 0x7fff8000 Committed http://llvm.org/viewvc/llvm-project?rev=174886&view=rev which adds an optional flag -mllvm -asan-short-64bit-mapping-offset=1 On bzip2/train it gives us ~ 2/3 of the zero-base-offset benefits: orig 0x7fff8000 zero 401.bzip2, 68.80, 64.80, 62.70 Measuring the rest. Note that with clang this did not require any change in the run-time (since recently we switched to ASAN_FLEXIBLE_MAPPING_AND_OFFSET=1)