// 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"
// cacheLineSize is used to prevent false sharing of cache lines.
// We choose 128 because Apple Silicon, a.k.a. M1, has 128-byte cache line size.
// It doesn't cost much and is much more future-proof.
const cacheLineSize = 128
func initOptions() {
options = []option{
{Name: "fp", Feature: &ARM64.HasFP},
{Name: "asimd", Feature: &ARM64.HasASIMD},
{Name: "evstrm", Feature: &ARM64.HasEVTSTRM},
{Name: "aes", Feature: &ARM64.HasAES},
{Name: "fphp", Feature: &ARM64.HasFPHP},
{Name: "jscvt", Feature: &ARM64.HasJSCVT},
{Name: "lrcpc", Feature: &ARM64.HasLRCPC},
{Name: "pmull", Feature: &ARM64.HasPMULL},
{Name: "sha1", Feature: &ARM64.HasSHA1},
{Name: "sha2", Feature: &ARM64.HasSHA2},
{Name: "sha3", Feature: &ARM64.HasSHA3},
{Name: "sha512", Feature: &ARM64.HasSHA512},
{Name: "sm3", Feature: &ARM64.HasSM3},
{Name: "sm4", Feature: &ARM64.HasSM4},
{Name: "sve", Feature: &ARM64.HasSVE},
{Name: "sve2", Feature: &ARM64.HasSVE2},
{Name: "crc32", Feature: &ARM64.HasCRC32},
{Name: "atomics", Feature: &ARM64.HasATOMICS},
{Name: "asimdhp", Feature: &ARM64.HasASIMDHP},
{Name: "cpuid", Feature: &ARM64.HasCPUID},
{Name: "asimrdm", Feature: &ARM64.HasASIMDRDM},
{Name: "fcma", Feature: &ARM64.HasFCMA},
{Name: "dcpop", Feature: &ARM64.HasDCPOP},
{Name: "asimddp", Feature: &ARM64.HasASIMDDP},
{Name: "asimdfhm", Feature: &ARM64.HasASIMDFHM},
{Name: "dit", Feature: &ARM64.HasDIT},
{Name: "i8mm", Feature: &ARM64.HasI8MM},
}
}
func archInit() {
switch runtime.GOOS {
case "freebsd":
readARM64Registers()
case "linux", "netbsd", "openbsd":
doinit()
default:
// Many platforms don't seem to allow reading these registers.
setMinimalFeatures()
}
}
// setMinimalFeatures fakes the minimal ARM64 features expected by
// TestARM64minimalFeatures.
func setMinimalFeatures() {
ARM64.HasASIMD = true
ARM64.HasFP = true
}
func readARM64Registers() {
Initialized = true
parseARM64SystemRegisters(getisar0(), getisar1(), getpfr0())
}
func parseARM64SystemRegisters(isar0, isar1, pfr0 uint64) {
// ID_AA64ISAR0_EL1
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
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
}
switch extractBits(isar1, 52, 55) {
case 1:
ARM64.HasI8MM = true
}
// ID_AA64PFR0_EL1
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
parseARM64SVERegister(getzfr0())
}
switch extractBits(pfr0, 48, 51) {
case 1:
ARM64.HasDIT = true
}
}
func parseARM64SVERegister(zfr0 uint64) {
switch extractBits(zfr0, 0, 3) {
case 1:
ARM64.HasSVE2 = true
}
}
func extractBits(data uint64, start, end uint) uint {
return (uint)(data>>start) & ((1 << (end - start + 1)) - 1)
}