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1 /*
2  * Compute the CRC32 using a parallelized folding approach with the PCLMULQDQ
3  * instruction.
4  *
5  * A white paper describing this algorithm can be found at:
6  * http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
7  *
8  * Copyright (C) 2013 Intel Corporation. All rights reserved.
9  * Authors:
10  * 	Wajdi Feghali   <wajdi.k.feghali@intel.com>
11  * 	Jim Guilford    <james.guilford@intel.com>
12  * 	Vinodh Gopal    <vinodh.gopal@intel.com>
13  * 	Erdinc Ozturk   <erdinc.ozturk@intel.com>
14  * 	Jim Kukunas     <james.t.kukunas@linux.intel.com>
15  *
16  * For conditions of distribution and use, see copyright notice in zlib.h
17  */
18 
19 #include "deflate.h"
20 
21 #include <inttypes.h>
22 #include <emmintrin.h>
23 #include <immintrin.h>
24 #include <wmmintrin.h>
25 
26 #ifndef __GNUC__
27 #define __attribute__()
28 #endif
29 
30 #define CRC_LOAD(s) \
31     do { \
32         __m128i xmm_crc0 = _mm_loadu_si128((__m128i *)s->crc0 + 0);\
33         __m128i xmm_crc1 = _mm_loadu_si128((__m128i *)s->crc0 + 1);\
34         __m128i xmm_crc2 = _mm_loadu_si128((__m128i *)s->crc0 + 2);\
35         __m128i xmm_crc3 = _mm_loadu_si128((__m128i *)s->crc0 + 3);\
36         __m128i xmm_crc_part = _mm_loadu_si128((__m128i *)s->crc0 + 4);
37 
38 #define CRC_SAVE(s) \
39         _mm_storeu_si128((__m128i *)s->crc0 + 0, xmm_crc0);\
40         _mm_storeu_si128((__m128i *)s->crc0 + 1, xmm_crc1);\
41         _mm_storeu_si128((__m128i *)s->crc0 + 2, xmm_crc2);\
42         _mm_storeu_si128((__m128i *)s->crc0 + 3, xmm_crc3);\
43         _mm_storeu_si128((__m128i *)s->crc0 + 4, xmm_crc_part);\
44     } while (0);
45 
46 __attribute__((target("sse4.2,pclmul")))
crc_fold_init(deflate_state * const s)47 ZLIB_INTERNAL void crc_fold_init(deflate_state *const s)
48 {
49     CRC_LOAD(s)
50 
51     xmm_crc0 = _mm_cvtsi32_si128(0x9db42487);
52     xmm_crc1 = _mm_setzero_si128();
53     xmm_crc2 = _mm_setzero_si128();
54     xmm_crc3 = _mm_setzero_si128();
55 
56     CRC_SAVE(s)
57 
58     s->strm->adler = 0;
59 }
60 
61 __attribute__((target("sse4.2,pclmul")))
fold_1(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)62 local void fold_1(deflate_state *const s,
63         __m128i *xmm_crc0, __m128i *xmm_crc1,
64         __m128i *xmm_crc2, __m128i *xmm_crc3)
65 {
66     const __m128i xmm_fold4 = _mm_set_epi32(
67             0x00000001, 0x54442bd4,
68             0x00000001, 0xc6e41596);
69 
70     __m128i x_tmp3;
71     __m128 ps_crc0, ps_crc3, ps_res;
72 
73     x_tmp3 = *xmm_crc3;
74 
75     *xmm_crc3 = *xmm_crc0;
76     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
77     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x10);
78     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
79     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
80     ps_res = _mm_xor_ps(ps_crc0, ps_crc3);
81 
82     *xmm_crc0 = *xmm_crc1;
83     *xmm_crc1 = *xmm_crc2;
84     *xmm_crc2 = x_tmp3;
85     *xmm_crc3 = _mm_castps_si128(ps_res);
86 }
87 
88 __attribute__((target("sse4.2,pclmul")))
fold_2(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)89 local void fold_2(deflate_state *const s,
90         __m128i *xmm_crc0, __m128i *xmm_crc1,
91         __m128i *xmm_crc2, __m128i *xmm_crc3)
92 {
93     const __m128i xmm_fold4 = _mm_set_epi32(
94             0x00000001, 0x54442bd4,
95             0x00000001, 0xc6e41596);
96 
97     __m128i x_tmp3, x_tmp2;
98     __m128 ps_crc0, ps_crc1, ps_crc2, ps_crc3, ps_res31, ps_res20;
99 
100     x_tmp3 = *xmm_crc3;
101     x_tmp2 = *xmm_crc2;
102 
103     *xmm_crc3 = *xmm_crc1;
104     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x01);
105     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x10);
106     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
107     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
108     ps_res31= _mm_xor_ps(ps_crc3, ps_crc1);
109 
110     *xmm_crc2 = *xmm_crc0;
111     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
112     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x10);
113     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
114     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
115     ps_res20= _mm_xor_ps(ps_crc0, ps_crc2);
116 
117     *xmm_crc0 = x_tmp2;
118     *xmm_crc1 = x_tmp3;
119     *xmm_crc2 = _mm_castps_si128(ps_res20);
120     *xmm_crc3 = _mm_castps_si128(ps_res31);
121 }
122 
123 __attribute__((target("sse4.2,pclmul")))
fold_3(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)124 local void fold_3(deflate_state *const s,
125         __m128i *xmm_crc0, __m128i *xmm_crc1,
126         __m128i *xmm_crc2, __m128i *xmm_crc3)
127 {
128     const __m128i xmm_fold4 = _mm_set_epi32(
129             0x00000001, 0x54442bd4,
130             0x00000001, 0xc6e41596);
131 
132     __m128i x_tmp3;
133     __m128 ps_crc0, ps_crc1, ps_crc2, ps_crc3, ps_res32, ps_res21, ps_res10;
134 
135     x_tmp3 = *xmm_crc3;
136 
137     *xmm_crc3 = *xmm_crc2;
138     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x01);
139     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x10);
140     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
141     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
142     ps_res32 = _mm_xor_ps(ps_crc2, ps_crc3);
143 
144     *xmm_crc2 = *xmm_crc1;
145     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x01);
146     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x10);
147     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
148     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
149     ps_res21= _mm_xor_ps(ps_crc1, ps_crc2);
150 
151     *xmm_crc1 = *xmm_crc0;
152     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
153     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x10);
154     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
155     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
156     ps_res10= _mm_xor_ps(ps_crc0, ps_crc1);
157 
158     *xmm_crc0 = x_tmp3;
159     *xmm_crc1 = _mm_castps_si128(ps_res10);
160     *xmm_crc2 = _mm_castps_si128(ps_res21);
161     *xmm_crc3 = _mm_castps_si128(ps_res32);
162 }
163 
164 __attribute__((target("sse4.2,pclmul")))
fold_4(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)165 local void fold_4(deflate_state *const s,
166         __m128i *xmm_crc0, __m128i *xmm_crc1,
167         __m128i *xmm_crc2, __m128i *xmm_crc3)
168 {
169     const __m128i xmm_fold4 = _mm_set_epi32(
170             0x00000001, 0x54442bd4,
171             0x00000001, 0xc6e41596);
172 
173     __m128i x_tmp0, x_tmp1, x_tmp2, x_tmp3;
174     __m128 ps_crc0, ps_crc1, ps_crc2, ps_crc3;
175     __m128 ps_t0, ps_t1, ps_t2, ps_t3;
176     __m128 ps_res0, ps_res1, ps_res2, ps_res3;
177 
178     x_tmp0 = *xmm_crc0;
179     x_tmp1 = *xmm_crc1;
180     x_tmp2 = *xmm_crc2;
181     x_tmp3 = *xmm_crc3;
182 
183     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
184     x_tmp0 = _mm_clmulepi64_si128(x_tmp0, xmm_fold4, 0x10);
185     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
186     ps_t0 = _mm_castsi128_ps(x_tmp0);
187     ps_res0 = _mm_xor_ps(ps_crc0, ps_t0);
188 
189     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x01);
190     x_tmp1 = _mm_clmulepi64_si128(x_tmp1, xmm_fold4, 0x10);
191     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
192     ps_t1 = _mm_castsi128_ps(x_tmp1);
193     ps_res1 = _mm_xor_ps(ps_crc1, ps_t1);
194 
195     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x01);
196     x_tmp2 = _mm_clmulepi64_si128(x_tmp2, xmm_fold4, 0x10);
197     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
198     ps_t2 = _mm_castsi128_ps(x_tmp2);
199     ps_res2 = _mm_xor_ps(ps_crc2, ps_t2);
200 
201     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x01);
202     x_tmp3 = _mm_clmulepi64_si128(x_tmp3, xmm_fold4, 0x10);
203     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
204     ps_t3 = _mm_castsi128_ps(x_tmp3);
205     ps_res3 = _mm_xor_ps(ps_crc3, ps_t3);
206 
207     *xmm_crc0 = _mm_castps_si128(ps_res0);
208     *xmm_crc1 = _mm_castps_si128(ps_res1);
209     *xmm_crc2 = _mm_castps_si128(ps_res2);
210     *xmm_crc3 = _mm_castps_si128(ps_res3);
211 }
212 
213 local const unsigned zalign(32) pshufb_shf_table[60] = {
214 	0x84838281,0x88878685,0x8c8b8a89,0x008f8e8d, /* shl 15 (16 - 1)/shr1 */
215 	0x85848382,0x89888786,0x8d8c8b8a,0x01008f8e, /* shl 14 (16 - 3)/shr2 */
216 	0x86858483,0x8a898887,0x8e8d8c8b,0x0201008f, /* shl 13 (16 - 4)/shr3 */
217 	0x87868584,0x8b8a8988,0x8f8e8d8c,0x03020100, /* shl 12 (16 - 4)/shr4 */
218 	0x88878685,0x8c8b8a89,0x008f8e8d,0x04030201, /* shl 11 (16 - 5)/shr5 */
219 	0x89888786,0x8d8c8b8a,0x01008f8e,0x05040302, /* shl 10 (16 - 6)/shr6 */
220 	0x8a898887,0x8e8d8c8b,0x0201008f,0x06050403, /* shl  9 (16 - 7)/shr7 */
221 	0x8b8a8988,0x8f8e8d8c,0x03020100,0x07060504, /* shl  8 (16 - 8)/shr8 */
222 	0x8c8b8a89,0x008f8e8d,0x04030201,0x08070605, /* shl  7 (16 - 9)/shr9 */
223 	0x8d8c8b8a,0x01008f8e,0x05040302,0x09080706, /* shl  6 (16 -10)/shr10*/
224 	0x8e8d8c8b,0x0201008f,0x06050403,0x0a090807, /* shl  5 (16 -11)/shr11*/
225 	0x8f8e8d8c,0x03020100,0x07060504,0x0b0a0908, /* shl  4 (16 -12)/shr12*/
226 	0x008f8e8d,0x04030201,0x08070605,0x0c0b0a09, /* shl  3 (16 -13)/shr13*/
227 	0x01008f8e,0x05040302,0x09080706,0x0d0c0b0a, /* shl  2 (16 -14)/shr14*/
228 	0x0201008f,0x06050403,0x0a090807,0x0e0d0c0b  /* shl  1 (16 -15)/shr15*/
229 };
230 
231 __attribute__((target("sse4.2,pclmul")))
partial_fold(deflate_state * const s,const size_t len,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3,__m128i * xmm_crc_part)232 local void partial_fold(deflate_state *const s, const size_t len,
233         __m128i *xmm_crc0, __m128i *xmm_crc1,
234         __m128i *xmm_crc2, __m128i *xmm_crc3,
235         __m128i *xmm_crc_part)
236 {
237 
238     const __m128i xmm_fold4 = _mm_set_epi32(
239             0x00000001, 0x54442bd4,
240             0x00000001, 0xc6e41596);
241     const __m128i xmm_mask3 = _mm_set1_epi32(0x80808080);
242 
243     __m128i xmm_shl, xmm_shr, xmm_tmp1, xmm_tmp2, xmm_tmp3;
244     __m128i xmm_a0_0, xmm_a0_1;
245     __m128 ps_crc3, psa0_0, psa0_1, ps_res;
246 
247     xmm_shl = _mm_load_si128((__m128i *)pshufb_shf_table + (len - 1));
248     xmm_shr = xmm_shl;
249     xmm_shr = _mm_xor_si128(xmm_shr, xmm_mask3);
250 
251     xmm_a0_0 = _mm_shuffle_epi8(*xmm_crc0, xmm_shl);
252 
253     *xmm_crc0 = _mm_shuffle_epi8(*xmm_crc0, xmm_shr);
254     xmm_tmp1 = _mm_shuffle_epi8(*xmm_crc1, xmm_shl);
255     *xmm_crc0 = _mm_or_si128(*xmm_crc0, xmm_tmp1);
256 
257     *xmm_crc1 = _mm_shuffle_epi8(*xmm_crc1, xmm_shr);
258     xmm_tmp2 = _mm_shuffle_epi8(*xmm_crc2, xmm_shl);
259     *xmm_crc1 = _mm_or_si128(*xmm_crc1, xmm_tmp2);
260 
261     *xmm_crc2 = _mm_shuffle_epi8(*xmm_crc2, xmm_shr);
262     xmm_tmp3 = _mm_shuffle_epi8(*xmm_crc3, xmm_shl);
263     *xmm_crc2 = _mm_or_si128(*xmm_crc2, xmm_tmp3);
264 
265     *xmm_crc3 = _mm_shuffle_epi8(*xmm_crc3, xmm_shr);
266     *xmm_crc_part = _mm_shuffle_epi8(*xmm_crc_part, xmm_shl);
267     *xmm_crc3 = _mm_or_si128(*xmm_crc3, *xmm_crc_part);
268 
269     xmm_a0_1 = _mm_clmulepi64_si128(xmm_a0_0, xmm_fold4, 0x10);
270     xmm_a0_0 = _mm_clmulepi64_si128(xmm_a0_0, xmm_fold4, 0x01);
271 
272     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
273     psa0_0 = _mm_castsi128_ps(xmm_a0_0);
274     psa0_1 = _mm_castsi128_ps(xmm_a0_1);
275 
276     ps_res = _mm_xor_ps(ps_crc3, psa0_0);
277     ps_res = _mm_xor_ps(ps_res, psa0_1);
278 
279     *xmm_crc3 = _mm_castps_si128(ps_res);
280 }
281 
282 __attribute__((target("sse4.2,pclmul")))
crc_fold_copy(deflate_state * const s,unsigned char * dst,const unsigned char * src,long len)283 ZLIB_INTERNAL void crc_fold_copy(deflate_state *const s,
284         unsigned char *dst, const unsigned char *src, long len)
285 {
286     unsigned long algn_diff;
287     __m128i xmm_t0, xmm_t1, xmm_t2, xmm_t3;
288 
289     CRC_LOAD(s)
290 
291     if (len < 16) {
292         if (len == 0)
293             return;
294         goto partial;
295     }
296 
297     algn_diff = 0 - (uintptr_t)src & 0xF;
298     if (algn_diff) {
299         xmm_crc_part = _mm_loadu_si128((__m128i *)src);
300         _mm_storeu_si128((__m128i *)dst, xmm_crc_part);
301 
302         dst += algn_diff;
303         src += algn_diff;
304         len -= algn_diff;
305 
306         partial_fold(s, algn_diff, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3,
307             &xmm_crc_part);
308     }
309 
310     while ((len -= 64) >= 0) {
311         xmm_t0 = _mm_load_si128((__m128i *)src);
312         xmm_t1 = _mm_load_si128((__m128i *)src + 1);
313         xmm_t2 = _mm_load_si128((__m128i *)src + 2);
314         xmm_t3 = _mm_load_si128((__m128i *)src + 3);
315 
316         fold_4(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
317 
318         _mm_storeu_si128((__m128i *)dst, xmm_t0);
319         _mm_storeu_si128((__m128i *)dst + 1, xmm_t1);
320         _mm_storeu_si128((__m128i *)dst + 2, xmm_t2);
321         _mm_storeu_si128((__m128i *)dst + 3, xmm_t3);
322 
323         xmm_crc0 = _mm_xor_si128(xmm_crc0, xmm_t0);
324         xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_t1);
325         xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_t2);
326         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t3);
327 
328         src += 64;
329         dst += 64;
330     }
331 
332     /*
333      * len = num bytes left - 64
334      */
335     if (len + 16 >= 0) {
336         len += 16;
337 
338         xmm_t0 = _mm_load_si128((__m128i *)src);
339         xmm_t1 = _mm_load_si128((__m128i *)src + 1);
340         xmm_t2 = _mm_load_si128((__m128i *)src + 2);
341 
342         fold_3(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
343 
344         _mm_storeu_si128((__m128i *)dst, xmm_t0);
345         _mm_storeu_si128((__m128i *)dst + 1, xmm_t1);
346         _mm_storeu_si128((__m128i *)dst + 2, xmm_t2);
347 
348         xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_t0);
349         xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_t1);
350         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t2);
351 
352         if (len == 0)
353             goto done;
354 
355         dst += 48;
356         src += 48;
357     } else if (len + 32 >= 0) {
358         len += 32;
359 
360         xmm_t0 = _mm_load_si128((__m128i *)src);
361         xmm_t1 = _mm_load_si128((__m128i *)src + 1);
362 
363         fold_2(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
364 
365         _mm_storeu_si128((__m128i *)dst, xmm_t0);
366         _mm_storeu_si128((__m128i *)dst + 1, xmm_t1);
367 
368         xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_t0);
369         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t1);
370 
371         if (len == 0)
372             goto done;
373 
374         dst += 32;
375         src += 32;
376     } else if (len + 48 >= 0) {
377         len += 48;
378 
379         xmm_t0 = _mm_load_si128((__m128i *)src);
380 
381         fold_1(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
382 
383         _mm_storeu_si128((__m128i *)dst, xmm_t0);
384 
385         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t0);
386 
387         if (len == 0)
388             goto done;
389 
390         dst += 16;
391         src += 16;
392     } else {
393         len += 64;
394         if (len == 0)
395             goto done;
396     }
397 
398 partial:
399 
400 #if defined(_MSC_VER)
401     /* VS does not permit the use of _mm_set_epi64x in 32-bit builds */
402     {
403         int32_t parts[4] = {0, 0, 0, 0};
404         memcpy(&parts, src, len);
405         xmm_crc_part = _mm_set_epi32(parts[3], parts[2], parts[1], parts[0]);
406     }
407 #else
408     {
409         int64_t parts[2] = {0, 0};
410         memcpy(&parts, src, len);
411         xmm_crc_part = _mm_set_epi64x(parts[1], parts[0]);
412     }
413 #endif
414 
415     _mm_storeu_si128((__m128i *)dst, xmm_crc_part);
416     partial_fold(s, len, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3,
417         &xmm_crc_part);
418 done:
419     CRC_SAVE(s)
420 }
421 
422 local const unsigned zalign(16) crc_k[] = {
423     0xccaa009e, 0x00000000, /* rk1 */
424     0x751997d0, 0x00000001, /* rk2 */
425     0xccaa009e, 0x00000000, /* rk5 */
426     0x63cd6124, 0x00000001, /* rk6 */
427     0xf7011640, 0x00000001, /* rk7 */
428     0xdb710640, 0x00000001  /* rk8 */
429 };
430 
431 local const unsigned zalign(16) crc_mask[4] = {
432     0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000
433 };
434 
435 local const unsigned zalign(16) crc_mask2[4] = {
436     0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF
437 };
438 
439 __attribute__((target("sse4.2,pclmul")))
crc_fold_512to32(deflate_state * const s)440 unsigned ZLIB_INTERNAL crc_fold_512to32(deflate_state *const s)
441 {
442     const __m128i xmm_mask  = _mm_load_si128((__m128i *)crc_mask);
443     const __m128i xmm_mask2 = _mm_load_si128((__m128i *)crc_mask2);
444 
445     unsigned crc;
446     __m128i x_tmp0, x_tmp1, x_tmp2, crc_fold;
447 
448     CRC_LOAD(s)
449 
450     /*
451      * k1
452      */
453     crc_fold = _mm_load_si128((__m128i *)crc_k);
454 
455     x_tmp0 = _mm_clmulepi64_si128(xmm_crc0, crc_fold, 0x10);
456     xmm_crc0 = _mm_clmulepi64_si128(xmm_crc0, crc_fold, 0x01);
457     xmm_crc1 = _mm_xor_si128(xmm_crc1, x_tmp0);
458     xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_crc0);
459 
460     x_tmp1 = _mm_clmulepi64_si128(xmm_crc1, crc_fold, 0x10);
461     xmm_crc1 = _mm_clmulepi64_si128(xmm_crc1, crc_fold, 0x01);
462     xmm_crc2 = _mm_xor_si128(xmm_crc2, x_tmp1);
463     xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_crc1);
464 
465     x_tmp2 = _mm_clmulepi64_si128(xmm_crc2, crc_fold, 0x10);
466     xmm_crc2 = _mm_clmulepi64_si128(xmm_crc2, crc_fold, 0x01);
467     xmm_crc3 = _mm_xor_si128(xmm_crc3, x_tmp2);
468     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
469 
470     /*
471      * k5
472      */
473     crc_fold = _mm_load_si128((__m128i *)crc_k + 1);
474 
475     xmm_crc0 = xmm_crc3;
476     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0);
477     xmm_crc0 = _mm_srli_si128(xmm_crc0, 8);
478     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc0);
479 
480     xmm_crc0 = xmm_crc3;
481     xmm_crc3 = _mm_slli_si128(xmm_crc3, 4);
482     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0x10);
483     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc0);
484     xmm_crc3 = _mm_and_si128(xmm_crc3, xmm_mask2);
485 
486     /*
487      * k7
488      */
489     xmm_crc1 = xmm_crc3;
490     xmm_crc2 = xmm_crc3;
491     crc_fold = _mm_load_si128((__m128i *)crc_k + 2);
492 
493     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0);
494     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
495     xmm_crc3 = _mm_and_si128(xmm_crc3, xmm_mask);
496 
497     xmm_crc2 = xmm_crc3;
498     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0x10);
499     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
500     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc1);
501 
502     crc = _mm_extract_epi32(xmm_crc3, 2);
503     return ~crc;
504     CRC_SAVE(s)
505 }
506