From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v5 0/7] rte_hash_crc reworked to be platform-independent Date: Thu, 27 Nov 2014 22:04:41 +0100 Message-ID: <2858592.pE1d5roQkI@xps13> References: <1409724351-23786-1-git-send-email-e_zhumabekov@sts.kz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev-VfR2kkLFssw@public.gmane.org To: Yerden Zhumabekov Return-path: In-Reply-To: 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" 2014-11-20 11:15, Yerden Zhumabekov: > These patches bring a fallback mechanism to ensure that CRC32 hash is calculated regardless of hardware support from CPU (i.e. SSE4.2 intrinsics). > Performance is also improved by slicing data in 8 bytes. > > Patches were tested on machines either with and without SSE4.2 support. > > Software implementation seems to be about 4-5 times slower than SSE4.2-enabled one. Of course, they return identical results. > > Summary of changes: > * added CRC32 software implementation, which is used as a fallback in case SSE4.2 is not available, or if SSE4.2 is intentionally disabled. > * added rte_hash_crc_set_alg() function to control availability of SSE4.2. > * added rte_hash_crc_8byte() function to calculate CRC32 on 8-byte operand. > * reworked rte_hash_crc() function which leverages both versions of CRC32 hash calculation functions with 4 and 8-byte operands. > * removed compile-time checks from test_hash_perf and test_hash. > * setting default algorithm implementation as a constructor while application startup. > * SSE4.2 intrinsics are implemented through inline assembly code. > * added additional run-time check for 64-bit support. So you don't want to use the target attribute as suggested by Konstantin? Why the discussion ended without any acknowledgement? -- Thomas