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