From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 548D7A0547 for ; Fri, 23 Apr 2021 15:55:12 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 40D24416FF; Fri, 23 Apr 2021 15:55:12 +0200 (CEST) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by mails.dpdk.org (Postfix) with ESMTP id 8A37E410D8; Fri, 23 Apr 2021 15:55:08 +0200 (CEST) IronPort-SDR: +jjYhqtKZjb9C5VfY8z/vtuq+yVti0oI9nY0cmor4onWnDJw9qIWIijEHDhPEfrVEiBTtzxF4V j9DkJkCCfekA== X-IronPort-AV: E=McAfee;i="6200,9189,9963"; a="176192001" X-IronPort-AV: E=Sophos;i="5.82,245,1613462400"; d="scan'208";a="176192001" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Apr 2021 06:55:07 -0700 IronPort-SDR: m95sfaRIuAjifVKARvYdYF3b8OvVQmgB+52KtpRlX2wHifsuSkTcV0BcUQUiQY4P0Q01XxxNyT xsYLv/j5z85A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,245,1613462400"; d="scan'208";a="535549516" Received: from sivswdev08.ir.intel.com ([10.237.217.47]) by orsmga004.jf.intel.com with ESMTP; 23 Apr 2021 06:55:06 -0700 From: Konstantin Ananyev To: dev@dpdk.org Cc: alialnu@nvidia.com, Konstantin Ananyev , stable@dpdk.org Date: Fri, 23 Apr 2021 14:54:51 +0100 Message-Id: <20210423135451.11035-1-konstantin.ananyev@intel.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [dpdk-stable] [PATCH] acl: fix build with gcc 11 X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Sender: "stable" gcc 11 with '-O2' complains about some variables being used without being initialized: In file included from ../lib/librte_acl/acl_run_avx512x8.h:201, from ../lib/librte_acl/acl_run_avx512.c:110: In function ‘start_flow_avx512x8’, inlined from ‘search_trie_avx512x8.constprop’ at ../lib/librte_acl/acl_run_avx512_common.h:317:2: ../lib/librte_acl/acl_run_avx512_common.h:210:13: warning: ‘pdata’ is used uninitialized [-Wuninitialized] In file included from ../lib/librte_acl/acl_run_avx512x8.h:201, from ../lib/librte_acl/acl_run_avx512.c:110: ../lib/librte_acl/acl_run_avx512_common.h: In function ‘search_trie_avx512x8.constprop’: ../lib/librte_acl/acl_run_avx512_common.h:314:32: note: ‘pdata’ declared here In file included from ../lib/librte_acl/acl_run_avx512x8.h:201, from ../lib/librte_acl/acl_run_avx512.c:110: .... Indeed, these variables are not explicitly initialized, but this is done intentionally. We rely on constant mask value that we pass to start_flow*() functions as a parameter Note that gcc 11 with '-O3' and gcc 9/10 with both '-O2' and '-O3' doesn't produce this warning, same as clang. Which makes me think that they are able to successfully propagate this constant mask value though the code. Also even gcc 11 with '-O2' produces a warning, it is able to generate an output binary with properly propagated constant values. Anyway, to support clean build with gcc-11 this patch adds explicit initialization for these variables. I checked the output binary: with '-O3' both clang and gcc 10/11 generate no extra code for it. Also performance test didn't reveal any regressions. Bugzilla ID: 673 Fixes: b64c2295f7fc ("acl: add 256-bit AVX512 classify method") Fixes: 45da22e42ec3 ("acl: add 512-bit AVX512 classify method") Cc: stable@dpdk.org Reported-by: Ali Alnubani Signed-off-by: Konstantin Ananyev --- lib/acl/acl_run_avx512_common.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/lib/acl/acl_run_avx512_common.h b/lib/acl/acl_run_avx512_common.h index fafaf591e..fbad74d45 100644 --- a/lib/acl/acl_run_avx512_common.h +++ b/lib/acl/acl_run_avx512_common.h @@ -303,6 +303,28 @@ _F_(match_check_process)(struct acl_flow_avx512 *flow, uint32_t fm[2], } } +static inline void +_F_(reset_flow_vars)(_T_simd di[2], _T_simd idx[2], _T_simd pdata[4], + _T_simd tr_lo[2], _T_simd tr_hi[2]) +{ + di[0] = _M_SI_(setzero)(); + di[1] = _M_SI_(setzero)(); + + idx[0] = _M_SI_(setzero)(); + idx[1] = _M_SI_(setzero)(); + + pdata[0] = _M_SI_(setzero)(); + pdata[1] = _M_SI_(setzero)(); + pdata[2] = _M_SI_(setzero)(); + pdata[3] = _M_SI_(setzero)(); + + tr_lo[0] = _M_SI_(setzero)(); + tr_lo[1] = _M_SI_(setzero)(); + + tr_hi[0] = _M_SI_(setzero)(); + tr_hi[1] = _M_SI_(setzero)(); +} + /* * Perform search for up to (2 * _N_) flows in parallel. * Use two sets of metadata, each serves _N_ flows max. @@ -313,6 +335,8 @@ _F_(search_trie)(struct acl_flow_avx512 *flow) uint32_t fm[2]; _T_simd di[2], idx[2], in[2], pdata[4], tr_lo[2], tr_hi[2]; + _F_(reset_flow_vars)(di, idx, pdata, tr_lo, tr_hi); + /* first 1B load */ _F_(start_flow)(flow, _SIMD_MASK_BIT_, _SIMD_MASK_MAX_, &pdata[0], &idx[0], &di[0]); -- 2.26.3