lib/distributor/rte_distributor_match_sse.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2017 Intel Corporation
   3  */
   4
   5 #include <rte_mbuf.h>
   6 #include "distributor_private.h"
   7 #include "smmintrin.h"
   8
   9
  10 void
  11 find_match_vec(struct rte_distributor *d,
  12                         uint16_t *data_ptr,
  13                         uint16_t *output_ptr)
  14 {
  15         /* Setup */
  16         __m128i incoming_fids;
  17         __m128i inflight_fids;
  18         __m128i preflight_fids;
  19         __m128i wkr;
  20         __m128i mask1;
  21         __m128i mask2;
  22         __m128i output;
  23         struct rte_distributor_backlog *bl;
  24         uint16_t i;
  25
  26         /*
  27          * Function overview:
  28          * 2. Loop through all worker ID's
  29          *  2a. Load the current inflights for that worker into an xmm reg
  30          *  2b. Load the current backlog for that worker into an xmm reg
  31          *  2c. use cmpestrm to intersect flow_ids with backlog and inflights
  32          *  2d. Add any matches to the output
  33          * 3. Write the output xmm (matching worker ids).
  34          */
  35
  36
  37         output = _mm_set1_epi16(0);
  38         incoming_fids = _mm_load_si128((__m128i *)data_ptr);
  39
  40         for (i = 0; i < d->num_workers; i++) {
  41                 bl = &d->backlog[i];
  42
  43                 inflight_fids =
  44                         _mm_load_si128((__m128i *)&(d->in_flight_tags[i]));
  45                 preflight_fids =
  46                         _mm_load_si128((__m128i *)(bl->tags));
  47
  48                 /*
  49                  * Any incoming_fid that exists anywhere in inflight_fids will
  50                  * have 0xffff in same position of the mask as the incoming fid
  51                  * Example (shortened to bytes for brevity):
  52                  * incoming_fids   0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08
  53                  * inflight_fids   0x03 0x05 0x07 0x00 0x00 0x00 0x00 0x00
  54                  * mask            0x00 0x00 0xff 0x00 0xff 0x00 0xff 0x00
  55                  */
  56
  57                 mask1 = _mm_cmpestrm(inflight_fids, 8, incoming_fids, 8,
  58                         _SIDD_UWORD_OPS |
  59                         _SIDD_CMP_EQUAL_ANY |
  60                         _SIDD_UNIT_MASK);
  61                 mask2 = _mm_cmpestrm(preflight_fids, 8, incoming_fids, 8,
  62                         _SIDD_UWORD_OPS |
  63                         _SIDD_CMP_EQUAL_ANY |
  64                         _SIDD_UNIT_MASK);
  65
  66                 mask1 = _mm_or_si128(mask1, mask2);
  67                 /*
  68                  * Now mask contains 0xffff where there's a match.
  69                  * Next we need to store the worker_id in the relevant position
  70                  * in the output.
  71                  */
  72
  73                 wkr = _mm_set1_epi16(i+1);
  74                 mask1 = _mm_and_si128(mask1, wkr);
  75                 output = _mm_or_si128(mask1, output);
  76         }
  77
  78         /*
  79          * At this stage, the output 128-bit contains 8 16-bit values, with
  80          * each non-zero value containing the worker ID on which the
  81          * corresponding flow is pinned to.
  82          */
  83         _mm_store_si128((__m128i *)output_ptr, output);
  84 }