Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933302AbaLDXOz (ORCPT ); Thu, 4 Dec 2014 18:14:55 -0500 Received: from mail-ie0-f169.google.com ([209.85.223.169]:40906 "EHLO mail-ie0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753069AbaLDXOy (ORCPT ); Thu, 4 Dec 2014 18:14:54 -0500 Message-ID: <1417734891.22424.2.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: [PATCH] x86: bpf_jit_comp: Reduce is_ereg() code size From: Eric Dumazet To: Joe Perches Cc: Alexei Starovoitov , Quentin Lambert , "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Thu, 04 Dec 2014 15:14:51 -0800 In-Reply-To: <1417734048.2721.22.camel@perches.com> References: <1417734048.2721.22.camel@perches.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2014-12-04 at 15:00 -0800, Joe Perches wrote: > Use the (1 << reg) & mask trick to reduce code size. > > x86-64 size difference -O2 without profiling for various > gcc versions: > > Signed-off-by: Joe Perches > --- > > compiled, untested by me, but per Alexei Starovoitov this passes > the test_bpf suite Really, the root cause of this is the 'inline' abuse in non fast paths for non trivial functions. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/