1 /* compare256_avx2.c -- AVX2 version of compare256
2 * Copyright Mika T. Lindqvist <[email protected]>
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6 #include "../../zbuild.h"
7
8 #include "fallback_builtins.h"
9
10 #if defined(X86_AVX2) && defined(HAVE_BUILTIN_CTZ)
11
12 #include <immintrin.h>
13 #ifdef _MSC_VER
14 # include <nmmintrin.h>
15 #endif
16
compare256_avx2_static(const uint8_t * src0,const uint8_t * src1)17 static inline uint32_t compare256_avx2_static(const uint8_t *src0, const uint8_t *src1) {
18 uint32_t len = 0;
19
20 do {
21 __m256i ymm_src0, ymm_src1, ymm_cmp;
22 ymm_src0 = _mm256_loadu_si256((__m256i*)src0);
23 ymm_src1 = _mm256_loadu_si256((__m256i*)src1);
24 ymm_cmp = _mm256_cmpeq_epi8(ymm_src0, ymm_src1); /* non-identical bytes = 00, identical bytes = FF */
25 unsigned mask = (unsigned)_mm256_movemask_epi8(ymm_cmp);
26 if (mask != 0xFFFFFFFF) {
27 uint32_t match_byte = (uint32_t)__builtin_ctz(~mask); /* Invert bits so identical = 0 */
28 return len + match_byte;
29 }
30
31 src0 += 32, src1 += 32, len += 32;
32
33 ymm_src0 = _mm256_loadu_si256((__m256i*)src0);
34 ymm_src1 = _mm256_loadu_si256((__m256i*)src1);
35 ymm_cmp = _mm256_cmpeq_epi8(ymm_src0, ymm_src1);
36 mask = (unsigned)_mm256_movemask_epi8(ymm_cmp);
37 if (mask != 0xFFFFFFFF) {
38 uint32_t match_byte = (uint32_t)__builtin_ctz(~mask);
39 return len + match_byte;
40 }
41
42 src0 += 32, src1 += 32, len += 32;
43 } while (len < 256);
44
45 return 256;
46 }
47
compare256_avx2(const uint8_t * src0,const uint8_t * src1)48 Z_INTERNAL uint32_t compare256_avx2(const uint8_t *src0, const uint8_t *src1) {
49 return compare256_avx2_static(src0, src1);
50 }
51
52 #define LONGEST_MATCH longest_match_avx2
53 #define COMPARE256 compare256_avx2_static
54
55 #include "match_tpl.h"
56
57 #define LONGEST_MATCH_SLOW
58 #define LONGEST_MATCH longest_match_slow_avx2
59 #define COMPARE256 compare256_avx2_static
60
61 #include "match_tpl.h"
62
63 #endif
64