Update dependencies (#975)

19 files changed, 410 insertions, 61 deletions

diff --git a/vendor/golang.org/x/sys/cpu/byteorder.go b/vendor/golang.org/x/sys/cpu/byteorder.go
index da6b9e43..ed8da8de 100644
--- a/vendor/golang.org/x/sys/cpu/byteorder.go
+++ b/vendor/golang.org/x/sys/cpu/byteorder.go
@@ -5,26 +5,56 @@
 package cpu
 
 import (
-	"encoding/binary"
 	"runtime"
 )
 
+// byteOrder is a subset of encoding/binary.ByteOrder.
+type byteOrder interface {
+	Uint32([]byte) uint32
+	Uint64([]byte) uint64
+}
+
+type littleEndian struct{}
+type bigEndian struct{}
+
+func (littleEndian) Uint32(b []byte) uint32 {
+	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+func (littleEndian) Uint64(b []byte) uint64 {
+	_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}
+
+func (bigEndian) Uint32(b []byte) uint32 {
+	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24
+}
+
+func (bigEndian) Uint64(b []byte) uint64 {
+	_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
+		uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
+}
+
 // hostByteOrder returns binary.LittleEndian on little-endian machines and
 // binary.BigEndian on big-endian machines.
-func hostByteOrder() binary.ByteOrder {
+func hostByteOrder() byteOrder {
 	switch runtime.GOARCH {
 	case "386", "amd64", "amd64p32",
 		"arm", "arm64",
 		"mipsle", "mips64le", "mips64p32le",
 		"ppc64le",
 		"riscv", "riscv64":
-		return binary.LittleEndian
+		return littleEndian{}
 	case "armbe", "arm64be",
 		"mips", "mips64", "mips64p32",
 		"ppc", "ppc64",
 		"s390", "s390x",
 		"sparc", "sparc64":
-		return binary.BigEndian
+		return bigEndian{}
 	}
 	panic("unknown architecture")
 }
diff --git a/vendor/golang.org/x/sys/cpu/cpu.go b/vendor/golang.org/x/sys/cpu/cpu.go
index 679e78c2..b4e6ecb2 100644
--- a/vendor/golang.org/x/sys/cpu/cpu.go
+++ b/vendor/golang.org/x/sys/cpu/cpu.go
@@ -78,6 +78,42 @@ var ARM64 struct {
 	_           CacheLinePad
 }
 
+// ARM contains the supported CPU features of the current ARM (32-bit) platform.
+// All feature flags are false if:
+//   1. the current platform is not arm, or
+//   2. the current operating system is not Linux.
+var ARM struct {
+	_           CacheLinePad
+	HasSWP      bool // SWP instruction support
+	HasHALF     bool // Half-word load and store support
+	HasTHUMB    bool // ARM Thumb instruction set
+	Has26BIT    bool // Address space limited to 26-bits
+	HasFASTMUL  bool // 32-bit operand, 64-bit result multiplication support
+	HasFPA      bool // Floating point arithmetic support
+	HasVFP      bool // Vector floating point support
+	HasEDSP     bool // DSP Extensions support
+	HasJAVA     bool // Java instruction set
+	HasIWMMXT   bool // Intel Wireless MMX technology support
+	HasCRUNCH   bool // MaverickCrunch context switching and handling
+	HasTHUMBEE  bool // Thumb EE instruction set
+	HasNEON     bool // NEON instruction set
+	HasVFPv3    bool // Vector floating point version 3 support
+	HasVFPv3D16 bool // Vector floating point version 3 D8-D15
+	HasTLS      bool // Thread local storage support
+	HasVFPv4    bool // Vector floating point version 4 support
+	HasIDIVA    bool // Integer divide instruction support in ARM mode
+	HasIDIVT    bool // Integer divide instruction support in Thumb mode
+	HasVFPD32   bool // Vector floating point version 3 D15-D31
+	HasLPAE     bool // Large Physical Address Extensions
+	HasEVTSTRM  bool // Event stream support
+	HasAES      bool // AES hardware implementation
+	HasPMULL    bool // Polynomial multiplication instruction set
+	HasSHA1     bool // SHA1 hardware implementation
+	HasSHA2     bool // SHA2 hardware implementation
+	HasCRC32    bool // CRC32 hardware implementation
+	_           CacheLinePad
+}
+
 // PPC64 contains the supported CPU features of the current ppc64/ppc64le platforms.
 // If the current platform is not ppc64/ppc64le then all feature flags are false.
 //
diff --git a/vendor/golang.org/x/sys/cpu/cpu_arm.go b/vendor/golang.org/x/sys/cpu/cpu_arm.go
index 7f2348b7..981af681 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_arm.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_arm.go
@@ -6,4 +6,35 @@ package cpu
 
 const cacheLineSize = 32
 
-func doinit() {}
+// HWCAP/HWCAP2 bits.
+// These are specific to Linux.
+const (
+	hwcap_SWP       = 1 << 0
+	hwcap_HALF      = 1 << 1
+	hwcap_THUMB     = 1 << 2
+	hwcap_26BIT     = 1 << 3
+	hwcap_FAST_MULT = 1 << 4
+	hwcap_FPA       = 1 << 5
+	hwcap_VFP       = 1 << 6
+	hwcap_EDSP      = 1 << 7
+	hwcap_JAVA      = 1 << 8
+	hwcap_IWMMXT    = 1 << 9
+	hwcap_CRUNCH    = 1 << 10
+	hwcap_THUMBEE   = 1 << 11
+	hwcap_NEON      = 1 << 12
+	hwcap_VFPv3     = 1 << 13
+	hwcap_VFPv3D16  = 1 << 14
+	hwcap_TLS       = 1 << 15
+	hwcap_VFPv4     = 1 << 16
+	hwcap_IDIVA     = 1 << 17
+	hwcap_IDIVT     = 1 << 18
+	hwcap_VFPD32    = 1 << 19
+	hwcap_LPAE      = 1 << 20
+	hwcap_EVTSTRM   = 1 << 21
+
+	hwcap2_AES   = 1 << 0
+	hwcap2_PMULL = 1 << 1
+	hwcap2_SHA1  = 1 << 2
+	hwcap2_SHA2  = 1 << 3
+	hwcap2_CRC32 = 1 << 4
+)
diff --git a/vendor/golang.org/x/sys/cpu/cpu_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_arm64.go
new file mode 100644
index 00000000..6ac0b353
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_arm64.go
@@ -0,0 +1,134 @@
+// 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 "darwin":
+		// iOS does not seem to allow reading these registers
+	case "android", "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)
+}
diff --git a/vendor/golang.org/x/sys/cpu/cpu_arm64.s b/vendor/golang.org/x/sys/cpu/cpu_arm64.s
new file mode 100644
index 00000000..a54436e3
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_arm64.s
@@ -0,0 +1,31 @@
+// 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.
+
+// +build !gccgo
+
+#include "textflag.h"
+
+// func getisar0() uint64
+TEXT ·getisar0(SB),NOSPLIT,$0-8
+	// get Instruction Set Attributes 0 into x0
+	// mrs x0, ID_AA64ISAR0_EL1 = d5380600
+	WORD	$0xd5380600
+	MOVD	R0, ret+0(FP)
+	RET
+
+// func getisar1() uint64
+TEXT ·getisar1(SB),NOSPLIT,$0-8
+	// get Instruction Set Attributes 1 into x0
+	// mrs x0, ID_AA64ISAR1_EL1 = d5380620
+	WORD	$0xd5380620
+	MOVD	R0, ret+0(FP)
+	RET
+
+// func getpfr0() uint64
+TEXT ·getpfr0(SB),NOSPLIT,$0-8
+	// get Processor Feature Register 0 into x0
+	// mrs x0, ID_AA64PFR0_EL1 = d5380400
+	WORD	$0xd5380400
+	MOVD	R0, ret+0(FP)
+	RET
diff --git a/vendor/golang.org/x/sys/cpu/cpu_gc_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_gc_arm64.go
new file mode 100644
index 00000000..7b88e865
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_gc_arm64.go
@@ -0,0 +1,11 @@
+// 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.
+
+// +build !gccgo
+
+package cpu
+
+func getisar0() uint64
+func getisar1() uint64
+func getpfr0() uint64
diff --git a/vendor/golang.org/x/sys/cpu/cpu_gccgo_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_gccgo_arm64.go
new file mode 100644
index 00000000..53ca8d65
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_gccgo_arm64.go
@@ -0,0 +1,11 @@
+// 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.
+
+// +build gccgo
+
+package cpu
+
+func getisar0() uint64 { return 0 }
+func getisar1() uint64 { return 0 }
+func getpfr0() uint64  { return 0 }
diff --git a/vendor/golang.org/x/sys/cpu/cpu_gccgo.c b/vendor/golang.org/x/sys/cpu/cpu_gccgo_x86.c
index e363c7d1..e363c7d1 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_gccgo.c
+++ b/vendor/golang.org/x/sys/cpu/cpu_gccgo_x86.c
diff --git a/vendor/golang.org/x/sys/cpu/cpu_gccgo.go b/vendor/golang.org/x/sys/cpu/cpu_gccgo_x86.go
index ba49b91b..ba49b91b 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_gccgo.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_gccgo_x86.go
diff --git a/vendor/golang.org/x/sys/cpu/cpu_linux.go b/vendor/golang.org/x/sys/cpu/cpu_linux.go
index 76b5f507..fe139182 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_linux.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_linux.go
@@ -2,58 +2,14 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//+build !amd64,!amd64p32,!386
+// +build !386,!amd64,!amd64p32,!arm64
 
 package cpu
 
-import (
-	"io/ioutil"
-)
-
-const (
-	_AT_HWCAP  = 16
-	_AT_HWCAP2 = 26
-
-	procAuxv = "/proc/self/auxv"
-
-	uintSize = int(32 << (^uint(0) >> 63))
-)
-
-// For those platforms don't have a 'cpuid' equivalent we use HWCAP/HWCAP2
-// These are initialized in cpu_$GOARCH.go
-// and should not be changed after they are initialized.
-var hwCap uint
-var hwCap2 uint
-
 func init() {
-	buf, err := ioutil.ReadFile(procAuxv)
-	if err != nil {
-		// e.g. on android /proc/self/auxv is not accessible, so silently
-		// ignore the error and leave Initialized = false
+	if err := readHWCAP(); err != nil {
 		return
 	}
-
-	bo := hostByteOrder()
-	for len(buf) >= 2*(uintSize/8) {
-		var tag, val uint
-		switch uintSize {
-		case 32:
-			tag = uint(bo.Uint32(buf[0:]))
-			val = uint(bo.Uint32(buf[4:]))
-			buf = buf[8:]
-		case 64:
-			tag = uint(bo.Uint64(buf[0:]))
-			val = uint(bo.Uint64(buf[8:]))
-			buf = buf[16:]
-		}
-		switch tag {
-		case _AT_HWCAP:
-			hwCap = val
-		case _AT_HWCAP2:
-			hwCap2 = val
-		}
-	}
 	doinit()
-
 	Initialized = true
 }
diff --git a/vendor/golang.org/x/sys/cpu/cpu_linux_arm.go b/vendor/golang.org/x/sys/cpu/cpu_linux_arm.go
new file mode 100644
index 00000000..2057006d
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_linux_arm.go
@@ -0,0 +1,39 @@
+// 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
+
+func doinit() {
+	ARM.HasSWP = isSet(hwCap, hwcap_SWP)
+	ARM.HasHALF = isSet(hwCap, hwcap_HALF)
+	ARM.HasTHUMB = isSet(hwCap, hwcap_THUMB)
+	ARM.Has26BIT = isSet(hwCap, hwcap_26BIT)
+	ARM.HasFASTMUL = isSet(hwCap, hwcap_FAST_MULT)
+	ARM.HasFPA = isSet(hwCap, hwcap_FPA)
+	ARM.HasVFP = isSet(hwCap, hwcap_VFP)
+	ARM.HasEDSP = isSet(hwCap, hwcap_EDSP)
+	ARM.HasJAVA = isSet(hwCap, hwcap_JAVA)
+	ARM.HasIWMMXT = isSet(hwCap, hwcap_IWMMXT)
+	ARM.HasCRUNCH = isSet(hwCap, hwcap_CRUNCH)
+	ARM.HasTHUMBEE = isSet(hwCap, hwcap_THUMBEE)
+	ARM.HasNEON = isSet(hwCap, hwcap_NEON)
+	ARM.HasVFPv3 = isSet(hwCap, hwcap_VFPv3)
+	ARM.HasVFPv3D16 = isSet(hwCap, hwcap_VFPv3D16)
+	ARM.HasTLS = isSet(hwCap, hwcap_TLS)
+	ARM.HasVFPv4 = isSet(hwCap, hwcap_VFPv4)
+	ARM.HasIDIVA = isSet(hwCap, hwcap_IDIVA)
+	ARM.HasIDIVT = isSet(hwCap, hwcap_IDIVT)
+	ARM.HasVFPD32 = isSet(hwCap, hwcap_VFPD32)
+	ARM.HasLPAE = isSet(hwCap, hwcap_LPAE)
+	ARM.HasEVTSTRM = isSet(hwCap, hwcap_EVTSTRM)
+	ARM.HasAES = isSet(hwCap2, hwcap2_AES)
+	ARM.HasPMULL = isSet(hwCap2, hwcap2_PMULL)
+	ARM.HasSHA1 = isSet(hwCap2, hwcap2_SHA1)
+	ARM.HasSHA2 = isSet(hwCap2, hwcap2_SHA2)
+	ARM.HasCRC32 = isSet(hwCap2, hwcap2_CRC32)
+}
+
+func isSet(hwc uint, value uint) bool {
+	return hwc&value != 0
+}
diff --git a/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
index fa7fb1bd..79a38a0b 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_linux_arm64.go
@@ -4,8 +4,6 @@
 
 package cpu
 
-const cacheLineSize = 64
-
 // HWCAP/HWCAP2 bits. These are exposed by Linux.
 const (
 	hwcap_FP       = 1 << 0
@@ -35,6 +33,12 @@ const (
 )
 
 func doinit() {
+	if err := readHWCAP(); err != nil {
+		// failed to read /proc/self/auxv, try reading registers directly
+		readARM64Registers()
+		return
+	}
+
 	// HWCAP feature bits
 	ARM64.HasFP = isSet(hwCap, hwcap_FP)
 	ARM64.HasASIMD = isSet(hwCap, hwcap_ASIMD)
diff --git a/vendor/golang.org/x/sys/cpu/cpu_linux_noinit.go b/vendor/golang.org/x/sys/cpu/cpu_linux_noinit.go
new file mode 100644
index 00000000..f65134f6
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_linux_noinit.go
@@ -0,0 +1,9 @@
+// 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.
+
+// +build linux,!arm,!arm64,!ppc64,!ppc64le,!s390x
+
+package cpu
+
+func doinit() {}
diff --git a/vendor/golang.org/x/sys/cpu/cpu_mips64x.go b/vendor/golang.org/x/sys/cpu/cpu_mips64x.go
index f55e0c82..6165f121 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_mips64x.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_mips64x.go
@@ -7,5 +7,3 @@
 package cpu
 
 const cacheLineSize = 32
-
-func doinit() {}
diff --git a/vendor/golang.org/x/sys/cpu/cpu_mipsx.go b/vendor/golang.org/x/sys/cpu/cpu_mipsx.go
index cda87b1a..1269eee8 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_mipsx.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_mipsx.go
@@ -7,5 +7,3 @@
 package cpu
 
 const cacheLineSize = 32
-
-func doinit() {}
diff --git a/vendor/golang.org/x/sys/cpu/cpu_other_arm64.go b/vendor/golang.org/x/sys/cpu/cpu_other_arm64.go
index dd1e76dc..3ffc4afa 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_other_arm64.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_other_arm64.go
@@ -6,6 +6,4 @@
 
 package cpu
 
-const cacheLineSize = 64
-
 func doinit() {}
diff --git a/vendor/golang.org/x/sys/cpu/cpu_riscv64.go b/vendor/golang.org/x/sys/cpu/cpu_riscv64.go
new file mode 100644
index 00000000..efe2b7a8
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu_riscv64.go
@@ -0,0 +1,9 @@
+// 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.
+
+// +build riscv64
+
+package cpu
+
+const cacheLineSize = 32
diff --git a/vendor/golang.org/x/sys/cpu/cpu_wasm.go b/vendor/golang.org/x/sys/cpu/cpu_wasm.go
index bd9bbda0..8681e876 100644
--- a/vendor/golang.org/x/sys/cpu/cpu_wasm.go
+++ b/vendor/golang.org/x/sys/cpu/cpu_wasm.go
@@ -11,5 +11,3 @@ package cpu
 // rules are good enough.
 
 const cacheLineSize = 0
-
-func doinit() {}
diff --git a/vendor/golang.org/x/sys/cpu/hwcap_linux.go b/vendor/golang.org/x/sys/cpu/hwcap_linux.go
new file mode 100644
index 00000000..f3baa379
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/hwcap_linux.go
@@ -0,0 +1,56 @@
+// 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 (
+	"io/ioutil"
+)
+
+const (
+	_AT_HWCAP  = 16
+	_AT_HWCAP2 = 26
+
+	procAuxv = "/proc/self/auxv"
+
+	uintSize = int(32 << (^uint(0) >> 63))
+)
+
+// For those platforms don't have a 'cpuid' equivalent we use HWCAP/HWCAP2
+// These are initialized in cpu_$GOARCH.go
+// and should not be changed after they are initialized.
+var hwCap uint
+var hwCap2 uint
+
+func readHWCAP() error {
+	buf, err := ioutil.ReadFile(procAuxv)
+	if err != nil {
+		// e.g. on android /proc/self/auxv is not accessible, so silently
+		// ignore the error and leave Initialized = false. On some
+		// architectures (e.g. arm64) doinit() implements a fallback
+		// readout and will set Initialized = true again.
+		return err
+	}
+	bo := hostByteOrder()
+	for len(buf) >= 2*(uintSize/8) {
+		var tag, val uint
+		switch uintSize {
+		case 32:
+			tag = uint(bo.Uint32(buf[0:]))
+			val = uint(bo.Uint32(buf[4:]))
+			buf = buf[8:]
+		case 64:
+			tag = uint(bo.Uint64(buf[0:]))
+			val = uint(bo.Uint64(buf[8:]))
+			buf = buf[16:]
+		}
+		switch tag {
+		case _AT_HWCAP:
+			hwCap = val
+		case _AT_HWCAP2:
+			hwCap2 = val
+		}
+	}
+	return nil
+}