nlpodyssey/spago

// 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 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: "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},
    }
}

func archInit() {
    switch runtime.GOOS {
    case "freebsd":
        readARM64Registers()
    case "linux", "netbsd":
        doinit()
    default:
        // Most platforms don't seem to allow reading these registers.
        //
        // OpenBSD:
        // See https://golang.org/issue/31746
        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
    }

    // 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
    }
}

func extractBits(data uint64, start, end uint) uint {
    return (uint)(data>>start) & ((1 << (end - start + 1)) - 1)
}