> -----Original Message----- > From: Thomas Monjalon [mailto:tho...@monjalon.net] > Sent: Friday, October 13, 2017 8:22 AM > To: Li, Xiaoyun <xiaoyun...@intel.com> > Cc: dev@dpdk.org; Ananyev, Konstantin <konstantin.anan...@intel.com>; > Richardson, Bruce <bruce.richard...@intel.com>; Lu, Wenzhuo > <wenzhuo...@intel.com>; Zhang, Helin <helin.zh...@intel.com> > Subject: Re: [dpdk-dev] [PATCH v7 1/3] eal/x86: run-time dispatch over memcpy > > 13/10/2017 03:06, Li, Xiaoyun: > > Hi > > Sorry for the late reply. I took AL last 3 days. > > > > From: Thomas Monjalon [mailto:tho...@monjalon.net] > > > 05/10/2017 14:33, Xiaoyun Li: > > > > +/** > > > > + * Macro for copying unaligned block from one location to another > > > > +with constant load offset, > > > > + * 47 bytes leftover maximum, > > > > + * locations should not overlap. > > > > + * Requirements: > > > > + * - Store is aligned > > > > + * - Load offset is <offset>, which must be immediate value within > > > > +[1, 15] > > > > + * - For <src>, make sure <offset> bit backwards & <16 - offset> bit > > > > +forwards are available for loading > > > > + * - <dst>, <src>, <len> must be variables > > > > + * - __m128i <xmm0> ~ <xmm8> must be pre-defined */ #define > > > > +MOVEUNALIGNED_LEFT47_IMM(dst, src, len, > > > > > > Naive question: > > > Is there a real benefit of using a macro compared to a static inline > > > function > > > optimized by a modern compiler? > > > > > The macro is in the existing DPDK codes. I didn't touch it. I just change > > the file name and the function name to rte_memcpy_internal. > > So I am not clear about if there is real benefit. > > In my opinion, I think it is the same as static inline function. > > > > Do I need to change them to inline function? > > In this patch, it appears as a new macro.
Ah no, it definitely been there before. All we did here - git mv rte_memcpy.h rte_memcpyu_interlan.h and then in rte_memcpy_internal.h renamed rte_memcpy() to rte_memcpy_internal(). > If you can, inline function is cleaner for the new one. I don't think it will be straightforward - one of the parameters is a constant value. My preference would be to keep original rte_memcpy() code intact as much as we can here (except probably cosmetic changes - indentation, line length fixing etc.). After all that patch is for adding architecture function selection at runtime only. If we like to improve our rte_memcpy() any furher - NP with that, but let it be a separate patch. Konstantin > > > > Anyway, if you are doing a new version, please reduce lines length and fix > > > the indent from spaces to tabs. > > > > > They are original DPDK codes so I didn't touch them. > > But in next version, I will fix them. > > Just to be sure: we are talking about fixing checkpatch warnings > only for the code added, changed or moved. > > Thanks
