From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753793AbeFDOLR (ORCPT ); Mon, 4 Jun 2018 10:11:17 -0400 Received: from ozlabs.org ([203.11.71.1]:58977 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753770AbeFDOLO (ORCPT ); Mon, 4 Jun 2018 10:11:14 -0400 X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 1c38976334c0efce1b285369a6037f205e196299 In-Reply-To: <20180528060834.72DE86F377@po14934vm.idsi0.si.c-s.fr> To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras From: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: powerpc/Makefile: set -mcpu=860 flag for the 8xx Message-Id: <40zxgL3MdHz9s7X@ozlabs.org> Date: Tue, 5 Jun 2018 00:11:07 +1000 (AEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-05-28 at 06:08:34 UTC, Christophe Leroy wrote: > When compiled with GCC 8.1, vmlinux is significantly bigger than > with GCC 4.8. > > When looking at the generated code with objdump, we notice that > all functions and loops when a 16 bytes alignment. This significantly > increases the size of the kernel. It is pointless and even > counterproductive as on the 8xx 'nop' also consumes one clock cycle. > > Size of vmlinux with GCC 4.8: > text data bss dec hex filename > 5801948 1626076 457796 7885820 7853fc vmlinux > > Size of vmlinux with GCC 8.1: > text data bss dec hex filename > 6764592 1630652 456476 8851720 871108 vmlinux > > Size of vmlinux with GCC 8.1 and this patch: > text data bss dec hex filename > 6331544 1631756 456476 8419776 8079c0 vmlinux > > Signed-off-by: Christophe Leroy Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/1c38976334c0efce1b285369a6037f cheers