From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 19 Feb 2016 15:23:16 +0100 Subject: [PATCH 1/3] [RESEND] ARM: pass -march=armv7-a when building NEON files with clang In-Reply-To: References: <1455815113-2562966-1-git-send-email-arnd@arndb.de> <1455815113-2562966-2-git-send-email-arnd@arndb.de> Message-ID: <3205167.CfekeqRXnt@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 18 February 2016 12:31:35 Nicolas Pitre wrote: > On Thu, 18 Feb 2016, Arnd Bergmann wrote: > > > clang ignores the -mfpu=neon flag when building with -march=armv6: > > > > In file included from lib/raid6/neon1.c:27: > > clang/3.8.0/include/arm_neon.h:28:2: error: "NEON support not enabled" > > > > There is no real need to build the file with -march=armv6 in a > > multi-CPU enabled kernel, as nothing in here will ever get called > > on an ARMv6 CPU. Adding -march=armv7 doesn't hurt and can only > > improve the code quality. > > Is this enough to override a previous -mfpu for gcc? I did not see any build failures on gcc with this, so I assume it has no effect. I could move the -march=armv7-a in front of -mfpu=neon if you think that would be safer though. Arnd