1 /*
2  * AVX2 optimized hash slide, based on Intel's slide_sse implementation
3  *
4  * Copyright (C) 2017 Intel Corporation
5  * Authors:
6  *   Arjan van de Ven   <[email protected]>
7  *   Jim Kukunas        <[email protected]>
8  *   Mika T. Lindqvist  <[email protected]>
9  *
10  * For conditions of distribution and use, see copyright notice in zlib.h
11  */
12 #include "../../zbuild.h"
13 #include "../../deflate.h"
14 
15 #include <immintrin.h>
16 
slide_hash_chain(Pos * table,uint32_t entries,const __m256i wsize)17 static inline void slide_hash_chain(Pos *table, uint32_t entries, const __m256i wsize) {
18     table += entries;
19     table -= 16;
20 
21     do {
22         __m256i value, result;
23 
24         value = _mm256_loadu_si256((__m256i *)table);
25         result = _mm256_subs_epu16(value, wsize);
26         _mm256_storeu_si256((__m256i *)table, result);
27 
28         table -= 16;
29         entries -= 16;
30     } while (entries > 0);
31 }
32 
slide_hash_avx2(deflate_state * s)33 Z_INTERNAL void slide_hash_avx2(deflate_state *s) {
34     uint16_t wsize = (uint16_t)s->w_size;
35     const __m256i ymm_wsize = _mm256_set1_epi16((short)wsize);
36 
37     slide_hash_chain(s->head, HASH_SIZE, ymm_wsize);
38     slide_hash_chain(s->prev, wsize, ymm_wsize);
39 }
40