From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 3853E3858CDB; Thu, 18 Jan 2024 05:15:37 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3853E3858CDB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1705554937; bh=H+1yvJ3S2iy+dBTDtvKcfpPSSPmpzOmtrHcYApbS/kw=; h=From:To:Subject:Date:In-Reply-To:References:From; b=hC8xeAY3BrHkiBe2Iv9GSQJvQqkPPuDOcd2CIoGSgn2m1V2Utf6BeEHLKQgafxZ1N T1FGZ1FL/AjQISYGR7R3Prc51iKowEAjFWepoIhOuPsMTO/o+Mt0qNnhZbsIxEKQHt fJGn6BGf2Ayqh4vsmXZPO/wNd7LpLseOaGBZGJe0= From: "linkw at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/112980] 64-bit powerpc ELFv2 does not allow nops to be generated before function global entry point Date: Thu, 18 Jan 2024 05:15:36 +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: 13.2.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: linkw at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: linkw at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc cf_reconfirmed_on assigned_to everconfirmed see_also bug_status 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=3D112980 Kewen Lin changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |matz at gcc dot gnu.org Last reconfirmed| |2024-01-18 Assignee|unassigned at gcc dot gnu.org |linkw at gcc dot gn= u.org Ever confirmed|0 |1 See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=3D99888 Status|UNCONFIRMED |ASSIGNED --- Comment #1 from Kewen Lin --- [1] made me realize that I forgot to post some comments here. (I thought I = did but actually didn't). As Segher's review comments in [2], to support "before NOPs" before global entry and "after NOPs" after global entry, we need to introduce a separate command line option, I think it can be a target specific option, which is enabled by default and we should mention its default behavior and impact in= the current documentation for -fpatchable-function-entry. I don't have a good n= ame candidate, any suggestions? Considering that the current behavior aligning with consecutive NOPs looks useless (this request and [1]), an alternative is to aggressively change the current behavior to "before NOPs" before global entry and "after NOPs" after global entry. Any preference or other ideas? Any comments are highly appreciated. I think with either (any) proposal it's inevitable to make the current beha= vior of -fpatchable-function-entry on "before NOPs" change, we should also docum= ent this change in releases/changes.html. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99888#c15 [2] https://gcc.gnu.org/pipermail/gcc-patches/2022-August/600239.html=