From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 56312 invoked by alias); 12 Sep 2018 14:12:50 -0000 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org Received: (qmail 56276 invoked by uid 48); 12 Sep 2018 14:12:48 -0000 From: "fche at redhat dot com" To: systemtap@sourceware.org Subject: [Bug translator/23634] WARNING: Can't parse SDT_V3 operand for x86_64 qemu tapset probe points Date: Wed, 12 Sep 2018 14:12:00 -0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: translator X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: fche at redhat dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- 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://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2018-q3/txt/msg00171.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=3D23634 Frank Ch. Eigler changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |fche at redhat dot com --- Comment #2 from Frank Ch. Eigler --- > Would there be a problem changing the default STAP_SDT_ARG_CONTRAINT from= "nor" to "nr"? Not so easy, unfortunately, or we would've done it already. "nr" forces the compiler to push nonliteral arguments into registers. There may not be many registers free at that point in the code, or in the processor generally, so there are performance costs. If we can satisfy a systemtap.apps testsuite run with "nr" on x86-64 (not so register-starved an architecture), then for that one perhaps we can switch = the default, and force people to accept the cost. The underlying problem here is that in gcc, there seems to be no code that corresponds to "public symbol relative offset" or "register-relative offset= ", both of which we could or do easily support in stap or other consumers. It= 's only this "local scratch symbol relative offset" case that's a loser. --=20 You are receiving this mail because: You are the assignee for the bug.