From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pawel Wodkowski Subject: Re: [PATCH] A fix to work around strict-aliasing rules breaking Date: Mon, 02 Mar 2015 13:32:11 +0100 Message-ID: <54F4584B.5090507@intel.com> References: <1425287030-18225-1-git-send-email-zhihong.wang@intel.com> <20150302103224.GC8520@bricha3-MOBL3> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: dev-VfR2kkLFssw@public.gmane.org To: Bruce Richardson , zhihong.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Return-path: In-Reply-To: <20150302103224.GC8520@bricha3-MOBL3> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On 2015-03-02 11:32, Bruce Richardson wrote: > On Mon, Mar 02, 2015 at 05:03:50PM +0800, zhihong.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote: >> Fixed strict-aliasing rules breaking errors for some GCC version. >> > > This looks messy. Also, I believe the definition of memcpy should include > the "restrict" keyword to indicate that source and dest can't overlap. Might > that help fix the issue? > Is this error related with overlapping or casting 'void *' to 'uintXX_t *' that make compiler report aliasing rule breaking? > >> Signed-off-by: Zhihong Wang >> --- >> .../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; If so maybe using union here would be good solution or 'char *'. -- Pawel