Hi Jerin, > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Jerin Jacob > Sent: Thursday, December 03, 2015 9:34 AM > To: Thomas Monjalon > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH 3/4] eal/arm: Enable lpm/table/pipeline libs > > On Wed, Dec 02, 2015 at 05:57:10PM +0100, Thomas Monjalon wrote: > > 2015-12-02 22:23, Jerin Jacob: > > > On Wed, Dec 02, 2015 at 05:40:13PM +0100, Thomas Monjalon wrote: > > > > 2015-12-02 20:04, Jerin Jacob: > > > > > On Wed, Dec 02, 2015 at 09:13:51PM +0800, Jianbo Liu wrote: > > > > > > On 2 December 2015 at 18:39, Jerin Jacob <jerin.jacob at > > > > > > caviumnetworks.com> wrote: > > > > > > > AND they include "rte_lpm.h"(it internally includes rte_vect.h) > > > > > > > that lead to multiple definition and its not good. > > > > > > > > > > > > > But you will have similar issue since "typedef int32x4_t __m128i" > > > > > > appears in both your patch and this header file. > > > > > > > > > > I just tested it, it won't break, back to back "typedef int32x4_t > > > > > __m128i" > > > > > is fine(unlike inline function). > > > > > > > > > > my intention to keep __m128i "as is" because changing the __m128i to > > > > > rte_??? > > > > > something would break the ABI. > > > > > > > > Isn't it already broken in 2.2? > > > > > > Does it mean, You would like to have rte_128i(or similar) kind of > > > abstraction to represent 128bit SIMD variable in DPDK? > > > > If you are convinced that it is the best way to write a generic code, yes. > > I grep-ed through DPDK API list to see the dependency with SIMD in API > definition.I see only rte_lpm_lookupx4 API has SIMD dependency in API > definition. > > I believe that's the root cause of the problem. IMO, The > better way to fix this would be to remove __m128i from API and have more > general representation to remove the architecture dependency from API > > something like this, > > rte_lpm_lookupx4(const struct rte_lpm *lpm, uint32_t *ip, uint16_t > hop[4], uint16_t defv) > > instead of > > rte_lpm_lookupx4(const struct rte_lpm *lpm, __m128i ip, uint16_t > hop[4], uint16_t defv)
The idea for that function was that rte_lpm_lookupx4() accepts 4 IPv4 addresses that are: 1. already in 128bit register 2. 'prepared' - byte swap is already done for them if needed. About ways to fix __m128i dependency: as I can see x86 and arm DPDK code already has xmm_t typedef: $ find lib -type f | xargs grep xmm_t | grep typedef lib/librte_eal/common/include/arch/x86/rte_vect.h:typedef __m128i xmm_t; lib/librte_eal/common/include/arch/arm/rte_vect.h:typedef int32x4_t xmm_t; Why not to change rte_lpm_lookupx4() to accept xmm_t as input parameter. As I understand it would solve the problem, and wouldn't introduce any API/ABI breakage, right? Konstantin > > Now I am not sure why this API was created like this, from l3fwd.c > example, it looks to accommodate the IPV4 byte swap[1]. If it's true, > maybe we can have eal byte swap abstraction for optimized byte swap on > memory for 4 IP address in one shot > > or > > Have rte_lpm_lookupx4 take an argument for byte swap or not ? > > or > > something similar? > > Thoughts ? > > [1] > const __m128i bswap_mask = _mm_set_epi8(12, 13, 14, 15, 8, 9, 10, 11, > 4, 5, 6, 7, 0, 1, 2, 3); > /* Byte swap 4 IPV4 addresses. */ > dip = _mm_shuffle_epi8(dip, bswap_mask); > > Jerin > > > I think the most important question is to know what is the best solution > > for performance and maintainability. The API/ABI questions will be > > considered > > after. > > > > Thanks for your involvement guys.
