From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C66A8C3A5A1 for ; Wed, 28 Aug 2019 04:24:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BFDA23406 for ; Wed, 28 Aug 2019 04:24:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726237AbfH1EYy (ORCPT ); Wed, 28 Aug 2019 00:24:54 -0400 Received: from ozlabs.org ([203.11.71.1]:51451 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726146AbfH1EYw (ORCPT ); Wed, 28 Aug 2019 00:24:52 -0400 Received: by ozlabs.org (Postfix, from userid 1034) id 46JCM570Xkz9sP6; Wed, 28 Aug 2019 14:24:49 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: c691b4b83b6a348f7b9d13c36916e73c2e1d85e4 In-Reply-To: To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , segher@kernel.crashing.org From: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/3] powerpc: rewrite LOAD_REG_IMMEDIATE() as an intelligent macro Message-Id: <46JCM570Xkz9sP6@ozlabs.org> Date: Wed, 28 Aug 2019 14:24:49 +1000 (AEST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2019-08-20 at 14:34:12 UTC, Christophe Leroy wrote: > Today LOAD_REG_IMMEDIATE() is a basic #define which loads all > parts on a value into a register, including the parts that are NUL. > > This means always 2 instructions on PPC32 and always 5 instructions > on PPC64. And those instructions cannot run in parallele as they are > updating the same register. > > Ex: LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in: > > 3c 20 00 00 lis r1,0 > 60 21 00 00 ori r1,r1,0 > 78 21 07 c6 rldicr r1,r1,32,31 > 64 21 00 00 oris r1,r1,0 > 60 21 40 00 ori r1,r1,16384 > > Rewrite LOAD_REG_IMMEDIATE() with GAS macro in order to skip > the parts that are NUL. > > Rename existing LOAD_REG_IMMEDIATE() as LOAD_REG_IMMEDIATE_SYM() > and use that one for loading value of symbols which are not known > at compile time. > > Now LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in: > > 38 20 40 00 li r1,16384 > > Signed-off-by: Christophe Leroy Series applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/c691b4b83b6a348f7b9d13c36916e73c2e1d85e4 cheers