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// Copyright 2019 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 cpu
import "runtime"
const cacheLineSize = 64
func init() {
switch runtime.GOOS {
case "android", "darwin", "netbsd":
// Android and iOS don't seem to allow reading these registers.
//
// NetBSD:
// ID_AA64ISAR0_EL1 is a privileged register and cannot be read from EL0.
// It can be read via sysctl(3). Example for future implementers:
// https://nxr.netbsd.org/xref/src/usr.sbin/cpuctl/arch/aarch64.c
//
// Fake the minimal features expected by
// TestARM64minimalFeatures.
ARM64.HasASIMD = true
ARM64.HasFP = true
case "linux":
doinit()
default:
readARM64Registers()
}
}
func readARM64Registers() {
Initialized = true
// ID_AA64ISAR0_EL1
isar0 := getisar0()
switch extractBits(isar0, 4, 7) {
case 1:
ARM64.HasAES = true
case 2:
ARM64.HasAES = true
ARM64.HasPMULL = true
}
switch extractBits(isar0, 8, 11) {
case 1:
ARM64.HasSHA1 = true
}
switch extractBits(isar0, 12, 15) {
case 1:
ARM64.HasSHA2 = true
case 2:
ARM64.HasSHA2 = true
ARM64.HasSHA512 = true
}
switch extractBits(isar0, 16, 19) {
case 1:
ARM64.HasCRC32 = true
}
switch extractBits(isar0, 20, 23) {
case 2:
ARM64.HasATOMICS = true
}
switch extractBits(isar0, 28, 31) {
case 1:
ARM64.HasASIMDRDM = true
}
switch extractBits(isar0, 32, 35) {
case 1:
ARM64.HasSHA3 = true
}
switch extractBits(isar0, 36, 39) {
case 1:
ARM64.HasSM3 = true
}
switch extractBits(isar0, 40, 43) {
case 1:
ARM64.HasSM4 = true
}
switch extractBits(isar0, 44, 47) {
case 1:
ARM64.HasASIMDDP = true
}
// ID_AA64ISAR1_EL1
isar1 := getisar1()
switch extractBits(isar1, 0, 3) {
case 1:
ARM64.HasDCPOP = true
}
switch extractBits(isar1, 12, 15) {
case 1:
ARM64.HasJSCVT = true
}
switch extractBits(isar1, 16, 19) {
case 1:
ARM64.HasFCMA = true
}
switch extractBits(isar1, 20, 23) {
case 1:
ARM64.HasLRCPC = true
}
// ID_AA64PFR0_EL1
pfr0 := getpfr0()
switch extractBits(pfr0, 16, 19) {
case 0:
ARM64.HasFP = true
case 1:
ARM64.HasFP = true
ARM64.HasFPHP = true
}
switch extractBits(pfr0, 20, 23) {
case 0:
ARM64.HasASIMD = true
case 1:
ARM64.HasASIMD = true
ARM64.HasASIMDHP = true
}
switch extractBits(pfr0, 32, 35) {
case 1:
ARM64.HasSVE = true
}
}
func extractBits(data uint64, start, end uint) uint {
return (uint)(data>>start) & ((1 << (end - start + 1)) - 1)
}
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