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 67B4B46332; Mon, 3 Mar 2025 23:27:37 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 38E3C40156; Mon, 3 Mar 2025 23:27:37 +0100 (CET) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mails.dpdk.org (Postfix) with ESMTP id B477F40041 for ; Mon, 3 Mar 2025 23:27:35 +0100 (CET) Received: by linux.microsoft.com (Postfix, from userid 1213) id 165E12110488; Mon, 3 Mar 2025 14:27:35 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 165E12110488 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1741040855; bh=Yz3POLjQtdNH/EifP7P6DYMbu5yRb6nFW/Xa38xcZRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UGXpE6aUxyons5xSEpqDUDo6s2hWMWHRQL16bDa63jgafQ8fnFbpd4zcD/mwO1r/f uE7Qw0eYHJq2YVJbksvifgUDHxI0HAANm4IY3uN5PanjWmAftwXuocdDJfr6VeAcDI S6VocLuGxeykwhsBmXlysLMFWVdRVHxC2a1eRSWQ= Date: Mon, 3 Mar 2025 14:27:35 -0800 From: Andre Muezerie To: Yipeng Wang , Sameh Gobriel , Bruce Richardson , Vladimir Medvedkin Cc: dev@dpdk.org Subject: Re: [PATCH 1/2] lib/hash: initialize __m128i data type in a portable way Message-ID: <20250303222735.GA30522@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> References: <1732748278-14796-1-git-send-email-andremue@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1732748278-14796-1-git-send-email-andremue@linux.microsoft.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Wed, Nov 27, 2024 at 02:57:57PM -0800, Andre Muezerie wrote: > The mechanism used to initialize an __m128i data type in rte_thash.h is > non-portable and MSVC does not like it. It clearly is not doing what > is desired: > > ..\lib\hash\rte_thash.h(38): warning C4305: 'initializing': > truncation from 'unsigned __int64' to 'char' > ..\lib\hash\rte_thash.h(38): warning C4305: 'initializing': > truncation from 'unsigned __int64' to 'char' > > A more portable approach is to use compiler intrinsics to perform the > initialization. This patch uses a single compiler intrinsic to > initialize the data type using a sequence of 16 bytes stored in > memory. > > There should be no perf degradation due to this change. > > Signed-off-by: Andre Muezerie > --- > lib/hash/rte_thash.h | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/lib/hash/rte_thash.h b/lib/hash/rte_thash.h > index c0af5968df..3512639792 100644 > --- a/lib/hash/rte_thash.h > +++ b/lib/hash/rte_thash.h > @@ -34,8 +34,9 @@ extern "C" { > /* Byte swap mask used for converting IPv6 address > * 4-byte chunks to CPU byte order > */ > -static const __m128i rte_thash_ipv6_bswap_mask = { > - 0x0405060700010203ULL, 0x0C0D0E0F08090A0BULL}; > +static const uint8_t rte_thash_ipv6_bswap_mask[] = { > + 0x03, 0x02, 0x01, 0x00, 0x07, 0x06, 0x05, 0x04, > + 0x0B, 0x0A, 0x09, 0x08, 0x0F, 0x0E, 0x0D, 0x0C}; > #endif > > /** > @@ -152,12 +153,14 @@ rte_thash_load_v6_addrs(const struct rte_ipv6_hdr *orig, > union rte_thash_tuple *targ) > { > #ifdef RTE_ARCH_X86 > + const __m128i ipv6_bswap_mask = > + _mm_loadu_si128((const __m128i*)&rte_thash_ipv6_bswap_mask); > __m128i ipv6 = _mm_loadu_si128((const __m128i *)&orig->src_addr); > *(__m128i *)&targ->v6.src_addr = > - _mm_shuffle_epi8(ipv6, rte_thash_ipv6_bswap_mask); > + _mm_shuffle_epi8(ipv6, ipv6_bswap_mask); > ipv6 = _mm_loadu_si128((const __m128i *)&orig->dst_addr); > *(__m128i *)&targ->v6.dst_addr = > - _mm_shuffle_epi8(ipv6, rte_thash_ipv6_bswap_mask); > + _mm_shuffle_epi8(ipv6, ipv6_bswap_mask); > #elif defined(__ARM_NEON) > uint8x16_t ipv6 = vld1q_u8(orig->src_addr.a); > vst1q_u8(targ->v6.src_addr.a, vrev32q_u8(ipv6)); > -- > 2.34.1 Could someone please review this patch and let me know if there are changes to be made? I have other patches depending on this. Thanks, Andre Muezerie