about summary refs log tree commit diff
path: root/vendor/golang.org/x/sys/cpu/cpu.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/sys/cpu/cpu.go')
-rw-r--r--vendor/golang.org/x/sys/cpu/cpu.go293
1 files changed, 293 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/cpu/cpu.go b/vendor/golang.org/x/sys/cpu/cpu.go
new file mode 100644
index 0000000..ec07aab
--- /dev/null
+++ b/vendor/golang.org/x/sys/cpu/cpu.go
@@ -0,0 +1,293 @@
+// Copyright 2018 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 implements processor feature detection for
+// various CPU architectures.
+package cpu
+
+import (
+	"os"
+	"strings"
+)
+
+// Initialized reports whether the CPU features were initialized.
+//
+// For some GOOS/GOARCH combinations initialization of the CPU features depends
+// on reading an operating specific file, e.g. /proc/self/auxv on linux/arm
+// Initialized will report false if reading the file fails.
+var Initialized bool
+
+// CacheLinePad is used to pad structs to avoid false sharing.
+type CacheLinePad struct{ _ [cacheLineSize]byte }
+
+// X86 contains the supported CPU features of the
+// current X86/AMD64 platform. If the current platform
+// is not X86/AMD64 then all feature flags are false.
+//
+// X86 is padded to avoid false sharing. Further the HasAVX
+// and HasAVX2 are only set if the OS supports XMM and YMM
+// registers in addition to the CPUID feature bit being set.
+var X86 struct {
+	_                   CacheLinePad
+	HasAES              bool // AES hardware implementation (AES NI)
+	HasADX              bool // Multi-precision add-carry instruction extensions
+	HasAVX              bool // Advanced vector extension
+	HasAVX2             bool // Advanced vector extension 2
+	HasAVX512           bool // Advanced vector extension 512
+	HasAVX512F          bool // Advanced vector extension 512 Foundation Instructions
+	HasAVX512CD         bool // Advanced vector extension 512 Conflict Detection Instructions
+	HasAVX512ER         bool // Advanced vector extension 512 Exponential and Reciprocal Instructions
+	HasAVX512PF         bool // Advanced vector extension 512 Prefetch Instructions
+	HasAVX512VL         bool // Advanced vector extension 512 Vector Length Extensions
+	HasAVX512BW         bool // Advanced vector extension 512 Byte and Word Instructions
+	HasAVX512DQ         bool // Advanced vector extension 512 Doubleword and Quadword Instructions
+	HasAVX512IFMA       bool // Advanced vector extension 512 Integer Fused Multiply Add
+	HasAVX512VBMI       bool // Advanced vector extension 512 Vector Byte Manipulation Instructions
+	HasAVX5124VNNIW     bool // Advanced vector extension 512 Vector Neural Network Instructions Word variable precision
+	HasAVX5124FMAPS     bool // Advanced vector extension 512 Fused Multiply Accumulation Packed Single precision
+	HasAVX512VPOPCNTDQ  bool // Advanced vector extension 512 Double and quad word population count instructions
+	HasAVX512VPCLMULQDQ bool // Advanced vector extension 512 Vector carry-less multiply operations
+	HasAVX512VNNI       bool // Advanced vector extension 512 Vector Neural Network Instructions
+	HasAVX512GFNI       bool // Advanced vector extension 512 Galois field New Instructions
+	HasAVX512VAES       bool // Advanced vector extension 512 Vector AES instructions
+	HasAVX512VBMI2      bool // Advanced vector extension 512 Vector Byte Manipulation Instructions 2
+	HasAVX512BITALG     bool // Advanced vector extension 512 Bit Algorithms
+	HasAVX512BF16       bool // Advanced vector extension 512 BFloat16 Instructions
+	HasAMXTile          bool // Advanced Matrix Extension Tile instructions
+	HasAMXInt8          bool // Advanced Matrix Extension Int8 instructions
+	HasAMXBF16          bool // Advanced Matrix Extension BFloat16 instructions
+	HasBMI1             bool // Bit manipulation instruction set 1
+	HasBMI2             bool // Bit manipulation instruction set 2
+	HasCX16             bool // Compare and exchange 16 Bytes
+	HasERMS             bool // Enhanced REP for MOVSB and STOSB
+	HasFMA              bool // Fused-multiply-add instructions
+	HasOSXSAVE          bool // OS supports XSAVE/XRESTOR for saving/restoring XMM registers.
+	HasPCLMULQDQ        bool // PCLMULQDQ instruction - most often used for AES-GCM
+	HasPOPCNT           bool // Hamming weight instruction POPCNT.
+	HasRDRAND           bool // RDRAND instruction (on-chip random number generator)
+	HasRDSEED           bool // RDSEED instruction (on-chip random number generator)
+	HasSSE2             bool // Streaming SIMD extension 2 (always available on amd64)
+	HasSSE3             bool // Streaming SIMD extension 3
+	HasSSSE3            bool // Supplemental streaming SIMD extension 3
+	HasSSE41            bool // Streaming SIMD extension 4 and 4.1
+	HasSSE42            bool // Streaming SIMD extension 4 and 4.2
+	_                   CacheLinePad
+}
+
+// ARM64 contains the supported CPU features of the
+// current ARMv8(aarch64) platform. If the current platform
+// is not arm64 then all feature flags are false.
+var ARM64 struct {
+	_           CacheLinePad
+	HasFP       bool // Floating-point instruction set (always available)
+	HasASIMD    bool // Advanced SIMD (always available)
+	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
+	HasATOMICS  bool // Atomic memory operation instruction set
+	HasFPHP     bool // Half precision floating-point instruction set
+	HasASIMDHP  bool // Advanced SIMD half precision instruction set
+	HasCPUID    bool // CPUID identification scheme registers
+	HasASIMDRDM bool // Rounding double multiply add/subtract instruction set
+	HasJSCVT    bool // Javascript conversion from floating-point to integer
+	HasFCMA     bool // Floating-point multiplication and addition of complex numbers
+	HasLRCPC    bool // Release Consistent processor consistent support
+	HasDCPOP    bool // Persistent memory support
+	HasSHA3     bool // SHA3 hardware implementation
+	HasSM3      bool // SM3 hardware implementation
+	HasSM4      bool // SM4 hardware implementation
+	HasASIMDDP  bool // Advanced SIMD double precision instruction set
+	HasSHA512   bool // SHA512 hardware implementation
+	HasSVE      bool // Scalable Vector Extensions
+	HasSVE2     bool // Scalable Vector Extensions 2
+	HasASIMDFHM bool // Advanced SIMD multiplication FP16 to FP32
+	HasDIT      bool // Data Independent Timing support
+	HasI8MM     bool // Advanced SIMD Int8 matrix multiplication instructions
+	_           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
+}
+
+// MIPS64X contains the supported CPU features of the current mips64/mips64le
+// platforms. If the current platform is not mips64/mips64le or the current
+// operating system is not Linux then all feature flags are false.
+var MIPS64X struct {
+	_      CacheLinePad
+	HasMSA bool // MIPS SIMD architecture
+	_      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.
+//
+// For ppc64/ppc64le, it is safe to check only for ISA level starting on ISA v3.00,
+// since there are no optional categories. There are some exceptions that also
+// require kernel support to work (DARN, SCV), so there are feature bits for
+// those as well. The struct is padded to avoid false sharing.
+var PPC64 struct {
+	_        CacheLinePad
+	HasDARN  bool // Hardware random number generator (requires kernel enablement)
+	HasSCV   bool // Syscall vectored (requires kernel enablement)
+	IsPOWER8 bool // ISA v2.07 (POWER8)
+	IsPOWER9 bool // ISA v3.00 (POWER9), implies IsPOWER8
+	_        CacheLinePad
+}
+
+// S390X contains the supported CPU features of the current IBM Z
+// (s390x) platform. If the current platform is not IBM Z then all
+// feature flags are false.
+//
+// S390X is padded to avoid false sharing. Further HasVX is only set
+// if the OS supports vector registers in addition to the STFLE
+// feature bit being set.
+var S390X struct {
+	_         CacheLinePad
+	HasZARCH  bool // z/Architecture mode is active [mandatory]
+	HasSTFLE  bool // store facility list extended
+	HasLDISP  bool // long (20-bit) displacements
+	HasEIMM   bool // 32-bit immediates
+	HasDFP    bool // decimal floating point
+	HasETF3EH bool // ETF-3 enhanced
+	HasMSA    bool // message security assist (CPACF)
+	HasAES    bool // KM-AES{128,192,256} functions
+	HasAESCBC bool // KMC-AES{128,192,256} functions
+	HasAESCTR bool // KMCTR-AES{128,192,256} functions
+	HasAESGCM bool // KMA-GCM-AES{128,192,256} functions
+	HasGHASH  bool // KIMD-GHASH function
+	HasSHA1   bool // K{I,L}MD-SHA-1 functions
+	HasSHA256 bool // K{I,L}MD-SHA-256 functions
+	HasSHA512 bool // K{I,L}MD-SHA-512 functions
+	HasSHA3   bool // K{I,L}MD-SHA3-{224,256,384,512} and K{I,L}MD-SHAKE-{128,256} functions
+	HasVX     bool // vector facility
+	HasVXE    bool // vector-enhancements facility 1
+	_         CacheLinePad
+}
+
+func init() {
+	archInit()
+	initOptions()
+	processOptions()
+}
+
+// options contains the cpu debug options that can be used in GODEBUG.
+// Options are arch dependent and are added by the arch specific initOptions functions.
+// Features that are mandatory for the specific GOARCH should have the Required field set
+// (e.g. SSE2 on amd64).
+var options []option
+
+// Option names should be lower case. e.g. avx instead of AVX.
+type option struct {
+	Name      string
+	Feature   *bool
+	Specified bool // whether feature value was specified in GODEBUG
+	Enable    bool // whether feature should be enabled
+	Required  bool // whether feature is mandatory and can not be disabled
+}
+
+func processOptions() {
+	env := os.Getenv("GODEBUG")
+field:
+	for env != "" {
+		field := ""
+		i := strings.IndexByte(env, ',')
+		if i < 0 {
+			field, env = env, ""
+		} else {
+			field, env = env[:i], env[i+1:]
+		}
+		if len(field) < 4 || field[:4] != "cpu." {
+			continue
+		}
+		i = strings.IndexByte(field, '=')
+		if i < 0 {
+			print("GODEBUG sys/cpu: no value specified for \"", field, "\"\n")
+			continue
+		}
+		key, value := field[4:i], field[i+1:] // e.g. "SSE2", "on"
+
+		var enable bool
+		switch value {
+		case "on":
+			enable = true
+		case "off":
+			enable = false
+		default:
+			print("GODEBUG sys/cpu: value \"", value, "\" not supported for cpu option \"", key, "\"\n")
+			continue field
+		}
+
+		if key == "all" {
+			for i := range options {
+				options[i].Specified = true
+				options[i].Enable = enable || options[i].Required
+			}
+			continue field
+		}
+
+		for i := range options {
+			if options[i].Name == key {
+				options[i].Specified = true
+				options[i].Enable = enable
+				continue field
+			}
+		}
+
+		print("GODEBUG sys/cpu: unknown cpu feature \"", key, "\"\n")
+	}
+
+	for _, o := range options {
+		if !o.Specified {
+			continue
+		}
+
+		if o.Enable && !*o.Feature {
+			print("GODEBUG sys/cpu: can not enable \"", o.Name, "\", missing CPU support\n")
+			continue
+		}
+
+		if !o.Enable && o.Required {
+			print("GODEBUG sys/cpu: can not disable \"", o.Name, "\", required CPU feature\n")
+			continue
+		}
+
+		*o.Feature = o.Enable
+	}
+}