From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E9EB317556; Tue, 21 May 2024 16:35:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716309343; cv=none; b=WturC9cT0KHHwLtlK3h311sv13E4PLUxXpaYQtwF2lXl5wxydbYxaD00d5bL3EUnXM5jUwVxNdQv8YK9nV+m3mCVCHNwSuyv9i35Ptfs3JDiHMhhKcF5Ps7bNxh/zjZknHKlyToPjeMcATE6qxR7mbxxuqzZvDk2lxEBrMklcIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716309343; c=relaxed/simple; bh=flYhV7d20dQSVWKKG9xe6WN4b57IFP0PEYtYsZvhEgI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=TdeJ6eJqRIG2wKSZWLJctcfPWASXSr3cO29sHfWic51GwnWOJ6OCN6WM/7qHfVnnvfoEilLoxjYLX3GnPzIE9CN2tk3YKrKtkdXMD2gw8OgJTpUcvaEDMYRSvPckYAE3EfznH5cVPdFGn9+OtnBIBUP7VJc6grXG2IrWs/lXyNk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OSnDxMBv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OSnDxMBv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFA2AC2BD11; Tue, 21 May 2024 16:35:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716309342; bh=flYhV7d20dQSVWKKG9xe6WN4b57IFP0PEYtYsZvhEgI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=OSnDxMBvwuZmzw1tj9S4tW3PKxmd2QDDX5Hs9M+GREWOOeCuYO8A2o5lxdeMgcrBP HgpjrRpH2Fv2a9TgqbPZcKVK4ubavEPLcA2O0fHaLwzzIt6FohK6rbPtUmFiHRzZQ+ usIGPMVbj6Qg/P/fxj5GiHm/xqj0oa1XGLBu6bxhuTELspa5Cg+ZXtgLVzXogmv2el 5ohMQn2jiBrQTrk3P3s+/iX30+ZHyw+rFS3LLuM17nzzD+reEO+uUyW9rI6Mps3R/r nqtw9VqHOkG5XbMGosKQIYPtq3aKMxk4wwsKQwQxE7YyNLyD2lvSD+2MlDm6L+yrVk O4wvpONO9IlYw== From: =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= To: Xiao Wang , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, luke.r.nels@gmail.com, xi.wang@gmail.com Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, pulehui@huawei.com, haicheng.li@intel.com, Xiao Wang Subject: Re: [PATCH] riscv, bpf: try RVC for reg move within BPF_CMPXCHG JIT In-Reply-To: <20240519050507.2217791-1-xiao.w.wang@intel.com> References: <20240519050507.2217791-1-xiao.w.wang@intel.com> Date: Tue, 21 May 2024 18:35:39 +0200 Message-ID: <87a5kjdsx0.fsf@all.your.base.are.belong.to.us> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Xiao Wang writes: > We could try to emit compressed insn for reg move operation during CMPXCHG > JIT, the instruction compression has no impact on the jump offsets of > following forward and backward jump instructions. ...and at some point we should start supporting Zacas and friends, instead of lr/sc. > Signed-off-by: Xiao Wang Acked-by: Bj=C3=B6rn T=C3=B6pel