xref: /aosp_15_r20/external/zlib/crc_folding.c (revision 86ee64e75fa5f8bce2c8c356138035642429cd05)
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   <[email protected]>
11  * 	Jim Guilford    <[email protected]>
12  * 	Vinodh Gopal    <[email protected]>
13  * 	Erdinc Ozturk   <[email protected]>
14  * 	Jim Kukunas     <[email protected]>
15  *
16  * For conditions of distribution and use, see copyright notice in zlib.h
17  */
18 
19 #include "deflate.h"
20 
21 #ifdef CRC32_SIMD_SSE42_PCLMUL
22 
23 #include <inttypes.h>
24 #include <emmintrin.h>
25 #include <immintrin.h>
26 #include <wmmintrin.h>
27 
28 #define CRC_LOAD(s) \
29     do { \
30         __m128i xmm_crc0 = _mm_loadu_si128((__m128i *)s->crc0 + 0);\
31         __m128i xmm_crc1 = _mm_loadu_si128((__m128i *)s->crc0 + 1);\
32         __m128i xmm_crc2 = _mm_loadu_si128((__m128i *)s->crc0 + 2);\
33         __m128i xmm_crc3 = _mm_loadu_si128((__m128i *)s->crc0 + 3);\
34         __m128i xmm_crc_part = _mm_loadu_si128((__m128i *)s->crc0 + 4);
35 
36 #define CRC_SAVE(s) \
37         _mm_storeu_si128((__m128i *)s->crc0 + 0, xmm_crc0);\
38         _mm_storeu_si128((__m128i *)s->crc0 + 1, xmm_crc1);\
39         _mm_storeu_si128((__m128i *)s->crc0 + 2, xmm_crc2);\
40         _mm_storeu_si128((__m128i *)s->crc0 + 3, xmm_crc3);\
41         _mm_storeu_si128((__m128i *)s->crc0 + 4, xmm_crc_part);\
42     } while (0);
43 
crc_fold_init(deflate_state * const s)44 ZLIB_INTERNAL void crc_fold_init(deflate_state *const s)
45 {
46     CRC_LOAD(s)
47 
48     xmm_crc0 = _mm_cvtsi32_si128(0x9db42487);
49     xmm_crc1 = _mm_setzero_si128();
50     xmm_crc2 = _mm_setzero_si128();
51     xmm_crc3 = _mm_setzero_si128();
52 
53     CRC_SAVE(s)
54 
55     s->strm->adler = 0;
56 }
57 
fold_1(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)58 local void fold_1(deflate_state *const s,
59         __m128i *xmm_crc0, __m128i *xmm_crc1,
60         __m128i *xmm_crc2, __m128i *xmm_crc3)
61 {
62     const __m128i xmm_fold4 = _mm_set_epi32(
63             0x00000001, 0x54442bd4,
64             0x00000001, 0xc6e41596);
65 
66     __m128i x_tmp3;
67     __m128 ps_crc0, ps_crc3, ps_res;
68 
69     x_tmp3 = *xmm_crc3;
70 
71     *xmm_crc3 = *xmm_crc0;
72     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
73     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x10);
74     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
75     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
76     ps_res = _mm_xor_ps(ps_crc0, ps_crc3);
77 
78     *xmm_crc0 = *xmm_crc1;
79     *xmm_crc1 = *xmm_crc2;
80     *xmm_crc2 = x_tmp3;
81     *xmm_crc3 = _mm_castps_si128(ps_res);
82 }
83 
fold_2(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)84 local void fold_2(deflate_state *const s,
85         __m128i *xmm_crc0, __m128i *xmm_crc1,
86         __m128i *xmm_crc2, __m128i *xmm_crc3)
87 {
88     const __m128i xmm_fold4 = _mm_set_epi32(
89             0x00000001, 0x54442bd4,
90             0x00000001, 0xc6e41596);
91 
92     __m128i x_tmp3, x_tmp2;
93     __m128 ps_crc0, ps_crc1, ps_crc2, ps_crc3, ps_res31, ps_res20;
94 
95     x_tmp3 = *xmm_crc3;
96     x_tmp2 = *xmm_crc2;
97 
98     *xmm_crc3 = *xmm_crc1;
99     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x01);
100     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x10);
101     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
102     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
103     ps_res31= _mm_xor_ps(ps_crc3, ps_crc1);
104 
105     *xmm_crc2 = *xmm_crc0;
106     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
107     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x10);
108     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
109     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
110     ps_res20= _mm_xor_ps(ps_crc0, ps_crc2);
111 
112     *xmm_crc0 = x_tmp2;
113     *xmm_crc1 = x_tmp3;
114     *xmm_crc2 = _mm_castps_si128(ps_res20);
115     *xmm_crc3 = _mm_castps_si128(ps_res31);
116 }
117 
fold_3(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)118 local void fold_3(deflate_state *const s,
119         __m128i *xmm_crc0, __m128i *xmm_crc1,
120         __m128i *xmm_crc2, __m128i *xmm_crc3)
121 {
122     const __m128i xmm_fold4 = _mm_set_epi32(
123             0x00000001, 0x54442bd4,
124             0x00000001, 0xc6e41596);
125 
126     __m128i x_tmp3;
127     __m128 ps_crc0, ps_crc1, ps_crc2, ps_crc3, ps_res32, ps_res21, ps_res10;
128 
129     x_tmp3 = *xmm_crc3;
130 
131     *xmm_crc3 = *xmm_crc2;
132     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x01);
133     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x10);
134     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
135     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
136     ps_res32 = _mm_xor_ps(ps_crc2, ps_crc3);
137 
138     *xmm_crc2 = *xmm_crc1;
139     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x01);
140     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x10);
141     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
142     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
143     ps_res21= _mm_xor_ps(ps_crc1, ps_crc2);
144 
145     *xmm_crc1 = *xmm_crc0;
146     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
147     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x10);
148     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
149     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
150     ps_res10= _mm_xor_ps(ps_crc0, ps_crc1);
151 
152     *xmm_crc0 = x_tmp3;
153     *xmm_crc1 = _mm_castps_si128(ps_res10);
154     *xmm_crc2 = _mm_castps_si128(ps_res21);
155     *xmm_crc3 = _mm_castps_si128(ps_res32);
156 }
157 
fold_4(deflate_state * const s,__m128i * xmm_crc0,__m128i * xmm_crc1,__m128i * xmm_crc2,__m128i * xmm_crc3)158 local void fold_4(deflate_state *const s,
159         __m128i *xmm_crc0, __m128i *xmm_crc1,
160         __m128i *xmm_crc2, __m128i *xmm_crc3)
161 {
162     const __m128i xmm_fold4 = _mm_set_epi32(
163             0x00000001, 0x54442bd4,
164             0x00000001, 0xc6e41596);
165 
166     __m128i x_tmp0, x_tmp1, x_tmp2, x_tmp3;
167     __m128 ps_crc0, ps_crc1, ps_crc2, ps_crc3;
168     __m128 ps_t0, ps_t1, ps_t2, ps_t3;
169     __m128 ps_res0, ps_res1, ps_res2, ps_res3;
170 
171     x_tmp0 = *xmm_crc0;
172     x_tmp1 = *xmm_crc1;
173     x_tmp2 = *xmm_crc2;
174     x_tmp3 = *xmm_crc3;
175 
176     *xmm_crc0 = _mm_clmulepi64_si128(*xmm_crc0, xmm_fold4, 0x01);
177     x_tmp0 = _mm_clmulepi64_si128(x_tmp0, xmm_fold4, 0x10);
178     ps_crc0 = _mm_castsi128_ps(*xmm_crc0);
179     ps_t0 = _mm_castsi128_ps(x_tmp0);
180     ps_res0 = _mm_xor_ps(ps_crc0, ps_t0);
181 
182     *xmm_crc1 = _mm_clmulepi64_si128(*xmm_crc1, xmm_fold4, 0x01);
183     x_tmp1 = _mm_clmulepi64_si128(x_tmp1, xmm_fold4, 0x10);
184     ps_crc1 = _mm_castsi128_ps(*xmm_crc1);
185     ps_t1 = _mm_castsi128_ps(x_tmp1);
186     ps_res1 = _mm_xor_ps(ps_crc1, ps_t1);
187 
188     *xmm_crc2 = _mm_clmulepi64_si128(*xmm_crc2, xmm_fold4, 0x01);
189     x_tmp2 = _mm_clmulepi64_si128(x_tmp2, xmm_fold4, 0x10);
190     ps_crc2 = _mm_castsi128_ps(*xmm_crc2);
191     ps_t2 = _mm_castsi128_ps(x_tmp2);
192     ps_res2 = _mm_xor_ps(ps_crc2, ps_t2);
193 
194     *xmm_crc3 = _mm_clmulepi64_si128(*xmm_crc3, xmm_fold4, 0x01);
195     x_tmp3 = _mm_clmulepi64_si128(x_tmp3, xmm_fold4, 0x10);
196     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
197     ps_t3 = _mm_castsi128_ps(x_tmp3);
198     ps_res3 = _mm_xor_ps(ps_crc3, ps_t3);
199 
200     *xmm_crc0 = _mm_castps_si128(ps_res0);
201     *xmm_crc1 = _mm_castps_si128(ps_res1);
202     *xmm_crc2 = _mm_castps_si128(ps_res2);
203     *xmm_crc3 = _mm_castps_si128(ps_res3);
204 }
205 
206 local const unsigned zalign(32) pshufb_shf_table[60] = {
207 	0x84838281,0x88878685,0x8c8b8a89,0x008f8e8d, /* shl 15 (16 - 1)/shr1 */
208 	0x85848382,0x89888786,0x8d8c8b8a,0x01008f8e, /* shl 14 (16 - 3)/shr2 */
209 	0x86858483,0x8a898887,0x8e8d8c8b,0x0201008f, /* shl 13 (16 - 4)/shr3 */
210 	0x87868584,0x8b8a8988,0x8f8e8d8c,0x03020100, /* shl 12 (16 - 4)/shr4 */
211 	0x88878685,0x8c8b8a89,0x008f8e8d,0x04030201, /* shl 11 (16 - 5)/shr5 */
212 	0x89888786,0x8d8c8b8a,0x01008f8e,0x05040302, /* shl 10 (16 - 6)/shr6 */
213 	0x8a898887,0x8e8d8c8b,0x0201008f,0x06050403, /* shl  9 (16 - 7)/shr7 */
214 	0x8b8a8988,0x8f8e8d8c,0x03020100,0x07060504, /* shl  8 (16 - 8)/shr8 */
215 	0x8c8b8a89,0x008f8e8d,0x04030201,0x08070605, /* shl  7 (16 - 9)/shr9 */
216 	0x8d8c8b8a,0x01008f8e,0x05040302,0x09080706, /* shl  6 (16 -10)/shr10*/
217 	0x8e8d8c8b,0x0201008f,0x06050403,0x0a090807, /* shl  5 (16 -11)/shr11*/
218 	0x8f8e8d8c,0x03020100,0x07060504,0x0b0a0908, /* shl  4 (16 -12)/shr12*/
219 	0x008f8e8d,0x04030201,0x08070605,0x0c0b0a09, /* shl  3 (16 -13)/shr13*/
220 	0x01008f8e,0x05040302,0x09080706,0x0d0c0b0a, /* shl  2 (16 -14)/shr14*/
221 	0x0201008f,0x06050403,0x0a090807,0x0e0d0c0b  /* shl  1 (16 -15)/shr15*/
222 };
223 
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)224 local void partial_fold(deflate_state *const s, const size_t len,
225         __m128i *xmm_crc0, __m128i *xmm_crc1,
226         __m128i *xmm_crc2, __m128i *xmm_crc3,
227         __m128i *xmm_crc_part)
228 {
229 
230     const __m128i xmm_fold4 = _mm_set_epi32(
231             0x00000001, 0x54442bd4,
232             0x00000001, 0xc6e41596);
233     const __m128i xmm_mask3 = _mm_set1_epi32(0x80808080);
234 
235     __m128i xmm_shl, xmm_shr, xmm_tmp1, xmm_tmp2, xmm_tmp3;
236     __m128i xmm_a0_0, xmm_a0_1;
237     __m128 ps_crc3, psa0_0, psa0_1, ps_res;
238 
239     xmm_shl = _mm_load_si128((__m128i *)pshufb_shf_table + (len - 1));
240     xmm_shr = xmm_shl;
241     xmm_shr = _mm_xor_si128(xmm_shr, xmm_mask3);
242 
243     xmm_a0_0 = _mm_shuffle_epi8(*xmm_crc0, xmm_shl);
244 
245     *xmm_crc0 = _mm_shuffle_epi8(*xmm_crc0, xmm_shr);
246     xmm_tmp1 = _mm_shuffle_epi8(*xmm_crc1, xmm_shl);
247     *xmm_crc0 = _mm_or_si128(*xmm_crc0, xmm_tmp1);
248 
249     *xmm_crc1 = _mm_shuffle_epi8(*xmm_crc1, xmm_shr);
250     xmm_tmp2 = _mm_shuffle_epi8(*xmm_crc2, xmm_shl);
251     *xmm_crc1 = _mm_or_si128(*xmm_crc1, xmm_tmp2);
252 
253     *xmm_crc2 = _mm_shuffle_epi8(*xmm_crc2, xmm_shr);
254     xmm_tmp3 = _mm_shuffle_epi8(*xmm_crc3, xmm_shl);
255     *xmm_crc2 = _mm_or_si128(*xmm_crc2, xmm_tmp3);
256 
257     *xmm_crc3 = _mm_shuffle_epi8(*xmm_crc3, xmm_shr);
258     *xmm_crc_part = _mm_shuffle_epi8(*xmm_crc_part, xmm_shl);
259     *xmm_crc3 = _mm_or_si128(*xmm_crc3, *xmm_crc_part);
260 
261     xmm_a0_1 = _mm_clmulepi64_si128(xmm_a0_0, xmm_fold4, 0x10);
262     xmm_a0_0 = _mm_clmulepi64_si128(xmm_a0_0, xmm_fold4, 0x01);
263 
264     ps_crc3 = _mm_castsi128_ps(*xmm_crc3);
265     psa0_0 = _mm_castsi128_ps(xmm_a0_0);
266     psa0_1 = _mm_castsi128_ps(xmm_a0_1);
267 
268     ps_res = _mm_xor_ps(ps_crc3, psa0_0);
269     ps_res = _mm_xor_ps(ps_res, psa0_1);
270 
271     *xmm_crc3 = _mm_castps_si128(ps_res);
272 }
273 
crc_fold_copy(deflate_state * const s,unsigned char * dst,const unsigned char * src,long len)274 ZLIB_INTERNAL void crc_fold_copy(deflate_state *const s,
275         unsigned char *dst, const unsigned char *src, long len)
276 {
277     unsigned long algn_diff;
278     __m128i xmm_t0, xmm_t1, xmm_t2, xmm_t3;
279 
280     CRC_LOAD(s)
281 
282     if (len < 16) {
283         if (len == 0)
284             return;
285         goto partial;
286     }
287 
288     algn_diff = (0 - (uintptr_t)src) & 0xF;
289     if (algn_diff) {
290         xmm_crc_part = _mm_loadu_si128((__m128i *)src);
291         _mm_storeu_si128((__m128i *)dst, xmm_crc_part);
292 
293         dst += algn_diff;
294         src += algn_diff;
295         len -= algn_diff;
296 
297         partial_fold(s, algn_diff, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3,
298             &xmm_crc_part);
299     }
300 
301     while ((len -= 64) >= 0) {
302         xmm_t0 = _mm_load_si128((__m128i *)src);
303         xmm_t1 = _mm_load_si128((__m128i *)src + 1);
304         xmm_t2 = _mm_load_si128((__m128i *)src + 2);
305         xmm_t3 = _mm_load_si128((__m128i *)src + 3);
306 
307         fold_4(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
308 
309         _mm_storeu_si128((__m128i *)dst, xmm_t0);
310         _mm_storeu_si128((__m128i *)dst + 1, xmm_t1);
311         _mm_storeu_si128((__m128i *)dst + 2, xmm_t2);
312         _mm_storeu_si128((__m128i *)dst + 3, xmm_t3);
313 
314         xmm_crc0 = _mm_xor_si128(xmm_crc0, xmm_t0);
315         xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_t1);
316         xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_t2);
317         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t3);
318 
319         src += 64;
320         dst += 64;
321     }
322 
323     /*
324      * len = num bytes left - 64
325      */
326     if (len + 16 >= 0) {
327         len += 16;
328 
329         xmm_t0 = _mm_load_si128((__m128i *)src);
330         xmm_t1 = _mm_load_si128((__m128i *)src + 1);
331         xmm_t2 = _mm_load_si128((__m128i *)src + 2);
332 
333         fold_3(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
334 
335         _mm_storeu_si128((__m128i *)dst, xmm_t0);
336         _mm_storeu_si128((__m128i *)dst + 1, xmm_t1);
337         _mm_storeu_si128((__m128i *)dst + 2, xmm_t2);
338 
339         xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_t0);
340         xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_t1);
341         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t2);
342 
343         if (len == 0)
344             goto done;
345 
346         dst += 48;
347         src += 48;
348     } else if (len + 32 >= 0) {
349         len += 32;
350 
351         xmm_t0 = _mm_load_si128((__m128i *)src);
352         xmm_t1 = _mm_load_si128((__m128i *)src + 1);
353 
354         fold_2(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
355 
356         _mm_storeu_si128((__m128i *)dst, xmm_t0);
357         _mm_storeu_si128((__m128i *)dst + 1, xmm_t1);
358 
359         xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_t0);
360         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t1);
361 
362         if (len == 0)
363             goto done;
364 
365         dst += 32;
366         src += 32;
367     } else if (len + 48 >= 0) {
368         len += 48;
369 
370         xmm_t0 = _mm_load_si128((__m128i *)src);
371 
372         fold_1(s, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3);
373 
374         _mm_storeu_si128((__m128i *)dst, xmm_t0);
375 
376         xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_t0);
377 
378         if (len == 0)
379             goto done;
380 
381         dst += 16;
382         src += 16;
383     } else {
384         len += 64;
385         if (len == 0)
386             goto done;
387     }
388 
389 partial:
390 
391 #if defined(_MSC_VER)
392     /* VS does not permit the use of _mm_set_epi64x in 32-bit builds */
393     {
394         int32_t parts[4] = {0, 0, 0, 0};
395         memcpy(&parts, src, len);
396         xmm_crc_part = _mm_set_epi32(parts[3], parts[2], parts[1], parts[0]);
397     }
398 #else
399     {
400         int64_t parts[2] = {0, 0};
401         memcpy(&parts, src, len);
402         xmm_crc_part = _mm_set_epi64x(parts[1], parts[0]);
403     }
404 #endif
405 
406     zmemcpy(dst, src, len);  /* TODO: Possibly generate more efficient code. */
407     partial_fold(s, len, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3,
408         &xmm_crc_part);
409 done:
410     CRC_SAVE(s)
411 }
412 
413 local const unsigned zalign(16) crc_k[] = {
414     0xccaa009e, 0x00000000, /* rk1 */
415     0x751997d0, 0x00000001, /* rk2 */
416     0xccaa009e, 0x00000000, /* rk5 */
417     0x63cd6124, 0x00000001, /* rk6 */
418     0xf7011640, 0x00000001, /* rk7 */
419     0xdb710640, 0x00000001  /* rk8 */
420 };
421 
422 local const unsigned zalign(16) crc_mask[4] = {
423     0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000
424 };
425 
426 local const unsigned zalign(16) crc_mask2[4] = {
427     0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF
428 };
429 
crc_fold_512to32(deflate_state * const s)430 unsigned ZLIB_INTERNAL crc_fold_512to32(deflate_state *const s)
431 {
432     const __m128i xmm_mask  = _mm_load_si128((__m128i *)crc_mask);
433     const __m128i xmm_mask2 = _mm_load_si128((__m128i *)crc_mask2);
434 
435     unsigned crc;
436     __m128i x_tmp0, x_tmp1, x_tmp2, crc_fold;
437 
438     __m128i xmm_crc0 = _mm_loadu_si128((__m128i *)s->crc0 + 0);
439     __m128i xmm_crc1 = _mm_loadu_si128((__m128i *)s->crc0 + 1);
440     __m128i xmm_crc2 = _mm_loadu_si128((__m128i *)s->crc0 + 2);
441     __m128i xmm_crc3 = _mm_loadu_si128((__m128i *)s->crc0 + 3);
442 
443     /*
444      * k1
445      */
446     crc_fold = _mm_load_si128((__m128i *)crc_k);
447 
448     x_tmp0 = _mm_clmulepi64_si128(xmm_crc0, crc_fold, 0x10);
449     xmm_crc0 = _mm_clmulepi64_si128(xmm_crc0, crc_fold, 0x01);
450     xmm_crc1 = _mm_xor_si128(xmm_crc1, x_tmp0);
451     xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_crc0);
452 
453     x_tmp1 = _mm_clmulepi64_si128(xmm_crc1, crc_fold, 0x10);
454     xmm_crc1 = _mm_clmulepi64_si128(xmm_crc1, crc_fold, 0x01);
455     xmm_crc2 = _mm_xor_si128(xmm_crc2, x_tmp1);
456     xmm_crc2 = _mm_xor_si128(xmm_crc2, xmm_crc1);
457 
458     x_tmp2 = _mm_clmulepi64_si128(xmm_crc2, crc_fold, 0x10);
459     xmm_crc2 = _mm_clmulepi64_si128(xmm_crc2, crc_fold, 0x01);
460     xmm_crc3 = _mm_xor_si128(xmm_crc3, x_tmp2);
461     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
462 
463     /*
464      * k5
465      */
466     crc_fold = _mm_load_si128((__m128i *)crc_k + 1);
467 
468     xmm_crc0 = xmm_crc3;
469     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0);
470     xmm_crc0 = _mm_srli_si128(xmm_crc0, 8);
471     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc0);
472 
473     xmm_crc0 = xmm_crc3;
474     xmm_crc3 = _mm_slli_si128(xmm_crc3, 4);
475     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0x10);
476     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc0);
477     xmm_crc3 = _mm_and_si128(xmm_crc3, xmm_mask2);
478 
479     /*
480      * k7
481      */
482     xmm_crc1 = xmm_crc3;
483     xmm_crc2 = xmm_crc3;
484     crc_fold = _mm_load_si128((__m128i *)crc_k + 2);
485 
486     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0);
487     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
488     xmm_crc3 = _mm_and_si128(xmm_crc3, xmm_mask);
489 
490     xmm_crc2 = xmm_crc3;
491     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0x10);
492     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
493     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc1);
494 
495     crc = _mm_extract_epi32(xmm_crc3, 2);
496     return ~crc;
497 }
498 
499 #endif  /* CRC32_SIMD_SSE42_PCLMUL */
500