From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 85907383907A; Tue, 30 Aug 2022 14:16:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 85907383907A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1661869000; bh=j2Y3b77lq2agSVZO6zaywIGVw+o9PUZSQxonx9v2wBc=; h=From:To:Subject:Date:In-Reply-To:References:From; b=deabz7TeGjVwRmmu90Jkqr/UThG9gMg+h7rk6qBV0Hmvw01QD9Fj7hcuecPVs9R36 1JmFb81D7T61qPTrqRyHT1XQAPWTXqN2nqmpja1yTofwq/1cdS+x3T0G1+kMhJ6RHG ymwSnxDeldbrSQLe1G5fdyjT/xp6M8aSGwYoxfU0= From: "rearnsha at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/106763] Armv8.2 vmov.f16 instruction sometimes causes SIGILL Date: Tue, 30 Aug 2022 14:16:40 +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: 12.2.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: rearnsha at gcc dot gnu.org 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: --- 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=3D106763 --- Comment #5 from Richard Earnshaw --- My guess (and it's only a guess because I'm not a kernel expert) is that th= e OS has disabled the FP/SIMD unit because of something like a context switch and then is failing, somehow, to recognize that the instruction is part of the = VFP extension, so not re-enabling it. That's plausible because this instruction was added as later extension. I note that your kernel is from the linux 4 series, which is pretty ancient these days.=