From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <cunming.liang@intel.com>
Received: from mga02.intel.com (mga02.intel.com [134.134.136.20])
 by dpdk.org (Postfix) with ESMTP id EBD2C11C5
 for <dev@dpdk.org>; Fri,  6 Mar 2015 08:36:31 +0100 (CET)
Received: from orsmga003.jf.intel.com ([10.7.209.27])
 by orsmga101.jf.intel.com with ESMTP; 05 Mar 2015 23:36:13 -0800
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.11,351,1422950400"; 
 d="scan'208,217";a="536949904"
Received: from shwdeisgchi017.ccr.corp.intel.com (HELO [10.239.66.47])
 ([10.239.66.47])
 by orsmga003.jf.intel.com with ESMTP; 05 Mar 2015 23:35:58 -0800
Message-ID: <54F958ED.4070800@intel.com>
Date: Fri, 06 Mar 2015 15:36:13 +0800
From: "Liang, Cunming" <cunming.liang@intel.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64;
 rv:31.0) Gecko/20100101 Thunderbird/31.5.0
MIME-Version: 1.0
To: zhihong.wang@intel.com, dev@dpdk.org
References: <1425287030-18225-1-git-send-email-zhihong.wang@intel.com>
In-Reply-To: <1425287030-18225-1-git-send-email-zhihong.wang@intel.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
X-Content-Filtered-By: Mailman/MimeDel 2.1.15
Subject: Re: [dpdk-dev] [PATCH] A fix to work around strict-aliasing rules
 breaking
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Fri, 06 Mar 2015 07:36:33 -0000

Hi,

On 3/2/2015 5:03 PM, zhihong.wang@intel.com wrote:
> Fixed strict-aliasing rules breaking errors for some GCC version.
>
> Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
> ---
>   .../common/include/arch/x86/rte_memcpy.h           | 44 ++++++++++++----------
>   1 file changed, 24 insertions(+), 20 deletions(-)
>
> diff --git a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
> index 69a5c6f..f412099 100644
> --- a/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
> +++ b/lib/librte_eal/common/include/arch/x86/rte_memcpy.h
> @@ -195,6 +195,8 @@ rte_mov256blocks(uint8_t *dst, const uint8_t *src, size_t n)
>   static inline void *
>   rte_memcpy(void *dst, const void *src, size_t n)
>   {
> +	uintptr_t dstu = (uintptr_t)dst;
> +	uintptr_t srcu = (uintptr_t)src;
>   	void *ret = dst;
>   	int dstofss;
>   	int bits;
> @@ -204,22 +206,22 @@ rte_memcpy(void *dst, const void *src, size_t n)
>   	 */
>   	if (n < 16) {
>   		if (n & 0x01) {
> -			*(uint8_t *)dst = *(const uint8_t *)src;
> -			src = (const uint8_t *)src + 1;
> -			dst = (uint8_t *)dst + 1;
> +			*(uint8_t *)dstu = *(const uint8_t *)srcu;
> +			srcu = (uintptr_t)((const uint8_t *)srcu + 1);
> +			dstu = (uintptr_t)((uint8_t *)dstu + 1);
>   		}
>   		if (n & 0x02) {
> -			*(uint16_t *)dst = *(const uint16_t *)src;
> -			src = (const uint16_t *)src + 1;
> -			dst = (uint16_t *)dst + 1;
> +			*(uint16_t *)dstu = *(const uint16_t *)srcu;
> +			srcu = (uintptr_t)((const uint16_t *)srcu + 1);
> +			dstu = (uintptr_t)((uint16_t *)dstu + 1);
>   		}
>   		if (n & 0x04) {
> -			*(uint32_t *)dst = *(const uint32_t *)src;
> -			src = (const uint32_t *)src + 1;
> -			dst = (uint32_t *)dst + 1;
> +			*(uint32_t *)dstu = *(const uint32_t *)srcu;
> +			srcu = (uintptr_t)((const uint32_t *)srcu + 1);
> +			dstu = (uintptr_t)((uint32_t *)dstu + 1);
>   		}
>   		if (n & 0x08) {
> -			*(uint64_t *)dst = *(const uint64_t *)src;
> +			*(uint64_t *)dstu = *(const uint64_t *)srcu;
>   		}
>   		return ret;
>   	}
> @@ -458,6 +460,8 @@ static inline void *
>   rte_memcpy(void *dst, const void *src, size_t n)
>   {
>   	__m128i xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6, xmm7, xmm8;
> +	uintptr_t dstu = (uintptr_t)dst;
> +	uintptr_t srcu = (uintptr_t)src;
>   	void *ret = dst;
>   	int dstofss;
>   	int srcofs;
> @@ -467,22 +471,22 @@ rte_memcpy(void *dst, const void *src, size_t n)
>   	 */
>   	if (n < 16) {
>   		if (n & 0x01) {
> -			*(uint8_t *)dst = *(const uint8_t *)src;
> -			src = (const uint8_t *)src + 1;
> -			dst = (uint8_t *)dst + 1;
> +			*(uint8_t *)dstu = *(const uint8_t *)srcu;
> +			srcu = (uintptr_t)((const uint8_t *)srcu + 1);
> +			dstu = (uintptr_t)((uint8_t *)dstu + 1);
>   		}
>   		if (n & 0x02) {
> -			*(uint16_t *)dst = *(const uint16_t *)src;
> -			src = (const uint16_t *)src + 1;
> -			dst = (uint16_t *)dst + 1;
> +			*(uint16_t *)dstu = *(const uint16_t *)srcu;
> +			srcu = (uintptr_t)((const uint16_t *)srcu + 1);
> +			dstu = (uintptr_t)((uint16_t *)dstu + 1);
>   		}
>   		if (n & 0x04) {
> -			*(uint32_t *)dst = *(const uint32_t *)src;
> -			src = (const uint32_t *)src + 1;
> -			dst = (uint32_t *)dst + 1;
> +			*(uint32_t *)dstu = *(const uint32_t *)srcu;
> +			srcu = (uintptr_t)((const uint32_t *)srcu + 1);
> +			dstu = (uintptr_t)((uint32_t *)dstu + 1);
>   		}
>   		if (n & 0x08) {
> -			*(uint64_t *)dst = *(const uint64_t *)src;
> +			*(uint64_t *)dstu = *(const uint64_t *)srcu;
>   		}
>   		return ret;
>   	}

Acked-by:Cunming Liang <cunming.liang@intel.com 
<mailto:cunming.liang@intel.com>>