From patchwork Wed Jun 1 11:28:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 9147205 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E5C2860761 for ; Wed, 1 Jun 2016 11:31:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D8AAD1FE7B for ; Wed, 1 Jun 2016 11:31:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CD2C02693F; Wed, 1 Jun 2016 11:31:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_HK_NAME_DR autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 525151FE7B for ; Wed, 1 Jun 2016 11:31:05 +0000 (UTC) Received: from localhost ([::1]:41829 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b84MZ-00024g-Lj for patchwork-qemu-devel@patchwork.kernel.org; Wed, 01 Jun 2016 07:31:03 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58859) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b84LI-0001q2-GM for qemu-devel@nongnu.org; Wed, 01 Jun 2016 07:30:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b84K1-0002y9-BA for qemu-devel@nongnu.org; Wed, 01 Jun 2016 07:29:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57370) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b84K1-0002xb-2g for qemu-devel@nongnu.org; Wed, 01 Jun 2016 07:28:25 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8977C8111B; Wed, 1 Jun 2016 11:28:24 +0000 (UTC) Received: from dgilbert-t530.redhat.com (ovpn-116-93.ams2.redhat.com [10.36.116.93]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u51BSLX4012356; Wed, 1 Jun 2016 07:28:23 -0400 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, liang.z.li@intel.com, pbonzini@redhat.com, peter.maydell@linaro.org Date: Wed, 1 Jun 2016 12:28:21 +0100 Message-Id: <1464780501-28080-1-git-send-email-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 01 Jun 2016 11:28:24 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] Improve avx2 configure test X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: amit.shah@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: "Dr. David Alan Gilbert" When configured with --extra-cflags=-O2 gcc optimised out the test and the readelf failed the check leaving avx2 disabled. The fix for that is to remove 'static' on 'foo'. At the same time, I thought it best to be more paranoid on checking whether both the compiler and assembler could actually use avx2, so make a couple of bogus calls to the the mm256 intrinsics. (I also wondered about trying to replicate the gcc4.9 test that's used in cutils.c - but I'd prefer to know the exact failure mode rather than test for the version). Signed-off-by: Dr. David Alan Gilbert --- configure | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/configure b/configure index b5aab72..13fabc3 100755 --- a/configure +++ b/configure @@ -1781,10 +1781,17 @@ fi # avx2 optimization requirement check cat > $TMPC << EOF -static void bar(void) {} +#pragma GCC push_options +#pragma GCC target("avx2") +#include +#include + +static int bar(void *a) { + return _mm256_movemask_epi8(_mm256_cmpeq_epi8(*(__m256i *)a, (__m256i){0})); +} static void *bar_ifunc(void) {return (void*) bar;} -static void foo(void) __attribute__((ifunc("bar_ifunc"))); -int main(void) { foo(); return 0; } +int foo(void *a) __attribute__((ifunc("bar_ifunc"))); +int main(int argc, char *argv[]) { return foo(argv[0]);} EOF if compile_prog "-mavx2" "" ; then if readelf --syms $TMPE |grep "IFUNC.*foo" >/dev/null 2>&1; then