...

Package cpu

import "vendor/golang.org/x/sys/cpu"
Overview
Index

Overview ▾

Package cpu implements processor feature detection for various CPU architectures.

Constants

IsBigEndian records whether the GOARCH's byte order is big endian.

const IsBigEndian = false

Variables

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 {
    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
    // contains filtered or unexported fields
}

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 {
    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
    // contains filtered or unexported fields
}

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

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 {
    HasMSA bool // MIPS SIMD architecture
    // contains filtered or unexported fields
}

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 {
    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
    // contains filtered or unexported fields
}

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 {
    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
    // contains filtered or unexported fields
}

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 {
    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
    // contains filtered or unexported fields
}

type CacheLinePad

CacheLinePad is used to pad structs to avoid false sharing.

type CacheLinePad struct {
    // contains filtered or unexported fields
}