github.com/icodeface/tls@v0.0.0-20230910023335-34df9250cd12/internal/cpu/cpu_arm.go (about)

     1  // Copyright 2017 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package cpu
     6  
     7  const CacheLinePadSize = 32
     8  
     9  // arm doesn't have a 'cpuid' equivalent, so we rely on HWCAP/HWCAP2.
    10  // These are linknamed in runtime/os_(linux|freebsd)_arm.go and are
    11  // initialized by archauxv().
    12  // These should not be changed after they are initialized.
    13  var HWCap uint
    14  var HWCap2 uint
    15  
    16  // HWCAP/HWCAP2 bits. These are exposed by Linux and FreeBSD.
    17  const (
    18  	hwcap_VFPv4 = 1 << 16
    19  	hwcap_IDIVA = 1 << 17
    20  )
    21  
    22  func doinit() {
    23  	options = []option{
    24  		{Name: "vfpv4", Feature: &ARM.HasVFPv4},
    25  		{Name: "idiva", Feature: &ARM.HasIDIVA},
    26  	}
    27  
    28  	// HWCAP feature bits
    29  	ARM.HasVFPv4 = isSet(HWCap, hwcap_VFPv4)
    30  	ARM.HasIDIVA = isSet(HWCap, hwcap_IDIVA)
    31  }
    32  
    33  func isSet(hwc uint, value uint) bool {
    34  	return hwc&value != 0
    35  }