1 /* adler32_sse42.c -- compute the Adler-32 checksum of a data stream
2  * Copyright (C) 1995-2011 Mark Adler
3  * Authors:
4  *   Adam Stylinski <[email protected]>
5  *   Brian Bockelman <[email protected]>
6  * For conditions of distribution and use, see copyright notice in zlib.h
7  */
8 
9 #include "../../zbuild.h"
10 #include "../../adler32_p.h"
11 #include "../../adler32_fold.h"
12 #include "adler32_ssse3_p.h"
13 #include <immintrin.h>
14 
15 #ifdef X86_SSE42_ADLER32
16 
adler32_fold_copy_sse42(uint32_t adler,uint8_t * dst,const uint8_t * src,size_t len)17 Z_INTERNAL uint32_t adler32_fold_copy_sse42(uint32_t adler, uint8_t *dst, const uint8_t *src, size_t len) {
18     uint32_t adler0, adler1;
19     adler1 = (adler >> 16) & 0xffff;
20     adler0 = adler & 0xffff;
21 
22 rem_peel:
23     if (len < 16) {
24        return adler32_copy_len_16(adler0, src, dst, len, adler1);
25     }
26 
27     __m128i vbuf, vbuf_0;
28     __m128i vs1_0, vs3, vs1, vs2, vs2_0, v_sad_sum1, v_short_sum2, v_short_sum2_0,
29             v_sad_sum2, vsum2, vsum2_0;
30     __m128i zero = _mm_setzero_si128();
31     const __m128i dot2v = _mm_setr_epi8(32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17);
32     const __m128i dot2v_0 = _mm_setr_epi8(16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1);
33     const __m128i dot3v = _mm_set1_epi16(1);
34     size_t k;
35 
36     while (len >= 16) {
37 
38         k = MIN(len, NMAX);
39         k -= k % 16;
40         len -= k;
41 
42         vs1 = _mm_cvtsi32_si128(adler0);
43         vs2 = _mm_cvtsi32_si128(adler1);
44 
45         vs3 = _mm_setzero_si128();
46         vs2_0 = _mm_setzero_si128();
47         vs1_0 = vs1;
48 
49         while (k >= 32) {
50             /*
51                vs1 = adler + sum(c[i])
52                vs2 = sum2 + 16 vs1 + sum( (16-i+1) c[i] )
53             */
54             vbuf = _mm_loadu_si128((__m128i*)src);
55             vbuf_0 = _mm_loadu_si128((__m128i*)(src + 16));
56             src += 32;
57             k -= 32;
58 
59             v_sad_sum1 = _mm_sad_epu8(vbuf, zero);
60             v_sad_sum2 = _mm_sad_epu8(vbuf_0, zero);
61             _mm_storeu_si128((__m128i*)dst, vbuf);
62             _mm_storeu_si128((__m128i*)(dst + 16), vbuf_0);
63             dst += 32;
64 
65             v_short_sum2 = _mm_maddubs_epi16(vbuf, dot2v);
66             v_short_sum2_0 = _mm_maddubs_epi16(vbuf_0, dot2v_0);
67 
68             vs1 = _mm_add_epi32(v_sad_sum1, vs1);
69             vs3 = _mm_add_epi32(vs1_0, vs3);
70 
71             vsum2 = _mm_madd_epi16(v_short_sum2, dot3v);
72             vsum2_0 = _mm_madd_epi16(v_short_sum2_0, dot3v);
73             vs1 = _mm_add_epi32(v_sad_sum2, vs1);
74             vs2 = _mm_add_epi32(vsum2, vs2);
75             vs2_0 = _mm_add_epi32(vsum2_0, vs2_0);
76             vs1_0 = vs1;
77         }
78 
79         vs2 = _mm_add_epi32(vs2_0, vs2);
80         vs3 = _mm_slli_epi32(vs3, 5);
81         vs2 = _mm_add_epi32(vs3, vs2);
82         vs3 = _mm_setzero_si128();
83 
84         while (k >= 16) {
85             /*
86                vs1 = adler + sum(c[i])
87                vs2 = sum2 + 16 vs1 + sum( (16-i+1) c[i] )
88             */
89             vbuf = _mm_loadu_si128((__m128i*)src);
90             src += 16;
91             k -= 16;
92 
93             v_sad_sum1 = _mm_sad_epu8(vbuf, zero);
94             v_short_sum2 = _mm_maddubs_epi16(vbuf, dot2v_0);
95 
96             vs1 = _mm_add_epi32(v_sad_sum1, vs1);
97             vs3 = _mm_add_epi32(vs1_0, vs3);
98             vsum2 = _mm_madd_epi16(v_short_sum2, dot3v);
99             vs2 = _mm_add_epi32(vsum2, vs2);
100             vs1_0 = vs1;
101 
102             _mm_storeu_si128((__m128i*)dst, vbuf);
103             dst += 16;
104         }
105 
106         vs3 = _mm_slli_epi32(vs3, 4);
107         vs2 = _mm_add_epi32(vs2, vs3);
108 
109         adler0 = partial_hsum(vs1) % BASE;
110         adler1 = hsum(vs2) % BASE;
111     }
112 
113     /* If this is true, there's fewer than 16 elements remaining */
114     if (len) {
115         goto rem_peel;
116     }
117 
118     return adler0 | (adler1 << 16);
119 }
120 
121 #endif
122