blob: 4e50b56c6f9597bb7176006728049e1e7cf37ec4 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package crc32
import "internal/cpu"
const (
vxMinLen = 64
vxAlignMask = 15 // align to 16 bytes
)
// hasVX reports whether the machine has the z/Architecture
// vector facility installed and enabled.
var hasVX = cpu.S390X.HasVX
// vectorizedCastagnoli implements CRC32 using vector instructions.
// It is defined in crc32_s390x.s.
//
//go:noescape
func vectorizedCastagnoli(crc uint32, p []byte) uint32
// vectorizedIEEE implements CRC32 using vector instructions.
// It is defined in crc32_s390x.s.
//
//go:noescape
func vectorizedIEEE(crc uint32, p []byte) uint32
func archAvailableCastagnoli() bool {
return hasVX
}
var archCastagnoliTable8 *slicing8Table
func archInitCastagnoli() {
if !hasVX {
panic("not available")
}
// We still use slicing-by-8 for small buffers.
archCastagnoliTable8 = slicingMakeTable(Castagnoli)
}
// archUpdateCastagnoli calculates the checksum of p using
// vectorizedCastagnoli.
func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
if !hasVX {
panic("not available")
}
// Use vectorized function if data length is above threshold.
if len(p) >= vxMinLen {
aligned := len(p) & ^vxAlignMask
crc = vectorizedCastagnoli(crc, p[:aligned])
p = p[aligned:]
}
if len(p) == 0 {
return crc
}
return slicingUpdate(crc, archCastagnoliTable8, p)
}
func archAvailableIEEE() bool {
return hasVX
}
var archIeeeTable8 *slicing8Table
func archInitIEEE() {
if !hasVX {
panic("not available")
}
// We still use slicing-by-8 for small buffers.
archIeeeTable8 = slicingMakeTable(IEEE)
}
// archUpdateIEEE calculates the checksum of p using vectorizedIEEE.
func archUpdateIEEE(crc uint32, p []byte) uint32 {
if !hasVX {
panic("not available")
}
// Use vectorized function if data length is above threshold.
if len(p) >= vxMinLen {
aligned := len(p) & ^vxAlignMask
crc = vectorizedIEEE(crc, p[:aligned])
p = p[aligned:]
}
if len(p) == 0 {
return crc
}
return slicingUpdate(crc, archIeeeTable8, p)
}
|
