2 * Implement fast Fletcher4 using superscalar pipelines.
4 * Use regular C code to compute
5 * Fletcher4 in two incremental 64-bit parallel accumulator streams,
6 * and then combine the streams to form the final four checksum words.
7 * This implementation is a derivative of the AVX SIMD implementation by
8 * James Guilford and Jinshan Xiong from Intel (see zfs_fletcher_intel.c).
10 * Copyright (C) 2016 Romain Dolbeau.
13 * Romain Dolbeau <romain.dolbeau@atos.net>
15 * This software is available to you under a choice of one of two
16 * licenses. You may choose to be licensed under the terms of the GNU
17 * General Public License (GPL) Version 2, available from the file
18 * COPYING in the main directory of this source tree, or the
19 * OpenIB.org BSD license below:
21 * Redistribution and use in source and binary forms, with or
22 * without modification, are permitted provided that the following
25 * - Redistributions of source code must retain the above
26 * copyright notice, this list of conditions and the following
29 * - Redistributions in binary form must reproduce the above
30 * copyright notice, this list of conditions and the following
31 * disclaimer in the documentation and/or other materials
32 * provided with the distribution.
34 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
35 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
36 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
37 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
38 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
39 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
40 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
44 #include <sys/byteorder.h>
45 #include <sys/spa_checksum.h>
46 #include <sys/strings.h>
47 #include <zfs_fletcher.h>
50 fletcher_4_superscalar_init(fletcher_4_ctx_t
*ctx
)
52 bzero(ctx
->superscalar
, 4 * sizeof (zfs_fletcher_superscalar_t
));
56 fletcher_4_superscalar_fini(fletcher_4_ctx_t
*ctx
, zio_cksum_t
*zcp
)
59 A
= ctx
->superscalar
[0].v
[0] + ctx
->superscalar
[0].v
[1];
60 B
= 2 * ctx
->superscalar
[1].v
[0] + 2 * ctx
->superscalar
[1].v
[1] -
61 ctx
->superscalar
[0].v
[1];
62 C
= 4 * ctx
->superscalar
[2].v
[0] - ctx
->superscalar
[1].v
[0] +
63 4 * ctx
->superscalar
[2].v
[1] - 3 * ctx
->superscalar
[1].v
[1];
64 D
= 8 * ctx
->superscalar
[3].v
[0] - 4 * ctx
->superscalar
[2].v
[0] +
65 8 * ctx
->superscalar
[3].v
[1] - 8 * ctx
->superscalar
[2].v
[1] +
66 ctx
->superscalar
[1].v
[1];
67 ZIO_SET_CHECKSUM(zcp
, A
, B
, C
, D
);
71 fletcher_4_superscalar_native(fletcher_4_ctx_t
*ctx
,
72 const void *buf
, uint64_t size
)
74 const uint32_t *ip
= buf
;
75 const uint32_t *ipend
= ip
+ (size
/ sizeof (uint32_t));
77 uint64_t a2
, b2
, c2
, d2
;
79 a
= ctx
->superscalar
[0].v
[0];
80 b
= ctx
->superscalar
[1].v
[0];
81 c
= ctx
->superscalar
[2].v
[0];
82 d
= ctx
->superscalar
[3].v
[0];
83 a2
= ctx
->superscalar
[0].v
[1];
84 b2
= ctx
->superscalar
[1].v
[1];
85 c2
= ctx
->superscalar
[2].v
[1];
86 d2
= ctx
->superscalar
[3].v
[1];
88 for (; ip
< ipend
; ip
+= 2) {
99 ctx
->superscalar
[0].v
[0] = a
;
100 ctx
->superscalar
[1].v
[0] = b
;
101 ctx
->superscalar
[2].v
[0] = c
;
102 ctx
->superscalar
[3].v
[0] = d
;
103 ctx
->superscalar
[0].v
[1] = a2
;
104 ctx
->superscalar
[1].v
[1] = b2
;
105 ctx
->superscalar
[2].v
[1] = c2
;
106 ctx
->superscalar
[3].v
[1] = d2
;
110 fletcher_4_superscalar_byteswap(fletcher_4_ctx_t
*ctx
,
111 const void *buf
, uint64_t size
)
113 const uint32_t *ip
= buf
;
114 const uint32_t *ipend
= ip
+ (size
/ sizeof (uint32_t));
116 uint64_t a2
, b2
, c2
, d2
;
118 a
= ctx
->superscalar
[0].v
[0];
119 b
= ctx
->superscalar
[1].v
[0];
120 c
= ctx
->superscalar
[2].v
[0];
121 d
= ctx
->superscalar
[3].v
[0];
122 a2
= ctx
->superscalar
[0].v
[1];
123 b2
= ctx
->superscalar
[1].v
[1];
124 c2
= ctx
->superscalar
[2].v
[1];
125 d2
= ctx
->superscalar
[3].v
[1];
127 for (; ip
< ipend
; ip
+= 2) {
128 a
+= BSWAP_32(ip
[0]);
129 a2
+= BSWAP_32(ip
[1]);
138 ctx
->superscalar
[0].v
[0] = a
;
139 ctx
->superscalar
[1].v
[0] = b
;
140 ctx
->superscalar
[2].v
[0] = c
;
141 ctx
->superscalar
[3].v
[0] = d
;
142 ctx
->superscalar
[0].v
[1] = a2
;
143 ctx
->superscalar
[1].v
[1] = b2
;
144 ctx
->superscalar
[2].v
[1] = c2
;
145 ctx
->superscalar
[3].v
[1] = d2
;
148 static boolean_t
fletcher_4_superscalar_valid(void)
153 const fletcher_4_ops_t fletcher_4_superscalar_ops
= {
154 .init_native
= fletcher_4_superscalar_init
,
155 .compute_native
= fletcher_4_superscalar_native
,
156 .fini_native
= fletcher_4_superscalar_fini
,
157 .init_byteswap
= fletcher_4_superscalar_init
,
158 .compute_byteswap
= fletcher_4_superscalar_byteswap
,
159 .fini_byteswap
= fletcher_4_superscalar_fini
,
160 .valid
= fletcher_4_superscalar_valid
,
161 .name
= "superscalar"