xref: /dpdk/lib/distributor/rte_distributor_match_sse.c (revision 30a1de105a5f40d77b344a891c4a68f79e815c43)
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
find_match_vec(struct rte_distributor * d,uint16_t * data_ptr,uint16_t * output_ptr)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 }
85