mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2024-12-23 12:59:11 -05:00
91 lines
2.1 KiB
Go
91 lines
2.1 KiB
Go
// 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.
|
|
|
|
// +build s390x
|
|
|
|
package crc32
|
|
|
|
const (
|
|
vxMinLen = 64
|
|
vxAlignMask = 15 // align to 16 bytes
|
|
)
|
|
|
|
// hasVectorFacility reports whether the machine has the z/Architecture
|
|
// vector facility installed and enabled.
|
|
func hasVectorFacility() bool
|
|
|
|
var hasVX = hasVectorFacility()
|
|
|
|
// 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)
|
|
}
|