From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 14A373858413; Fri, 12 Jan 2024 01:25:38 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 14A373858413 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1705022739; bh=HNOtbU2iob0csOeaZhB/RoX4xVImWfG9//BADEh1rUk=; h=From:To:Subject:Date:In-Reply-To:References:From; b=FmtmYYIcW+vQeE/usU4j2z7/Kq4aD+/ItvoaVGQOHiySxbN/hycwpFdW536aw5O12 Jmi/ZByvIq+atUrJlQB2V0VrzqVwye9MrFvB5zTSsXHU4dnaiz+wTbXRXRLf+vmXTe Itqm5I2hFcJCD/kGZiKt6mhnSTmOPS3dyzfHjV68= From: "hpa at zytor dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/113312] Update __attribute__((interrupt)) for Intel FRED Date: Fri, 12 Jan 2024 01:25:37 +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: 14.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: hpa at zytor dot com X-Bugzilla-Status: NEW 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=3D113312 --- Comment #15 from H. Peter Anvin --- That should be fine for this use case, obviously. I should add the following: the reason the assembly stub isn't a problem for FRED whereas it is a bit of a nuisance for IDT-style delivery is that with FRED, vector dispatch is done in software, not hardware. This is exactly because *most* operating systems do need some amount of common entry/exit c= ode anyway, and having to duplicate it is a severe nuisance. In the specific case of Linux, the full register set, including saved registers, are a required part of the exception frame in order for things l= ike ptrace() and fork() to work correctly, so relying on the compiler to save t= he "saved" registers doesn't work for us anyway. So since there is only *one* instance of the assembly stub needed, it means there isn't a whole separate stub needed for every handler.=