github.com/corona10/go@v0.0.0-20180224231303-7a218942be57/src/internal/cpu/cpu.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 implements processor feature detection
     6  // used by the Go standard library.
     7  package cpu
     8  
     9  var X86 x86
    10  
    11  // The booleans in x86 contain the correspondingly named cpuid feature bit.
    12  // HasAVX and HasAVX2 are only set if the OS does support XMM and YMM registers
    13  // in addition to the cpuid feature bit being set.
    14  // The struct is padded to avoid false sharing.
    15  type x86 struct {
    16  	_            [CacheLineSize]byte
    17  	HasAES       bool
    18  	HasADX       bool
    19  	HasAVX       bool
    20  	HasAVX2      bool
    21  	HasBMI1      bool
    22  	HasBMI2      bool
    23  	HasERMS      bool
    24  	HasFMA       bool
    25  	HasOSXSAVE   bool
    26  	HasPCLMULQDQ bool
    27  	HasPOPCNT    bool
    28  	HasSSE2      bool
    29  	HasSSE3      bool
    30  	HasSSSE3     bool
    31  	HasSSE41     bool
    32  	HasSSE42     bool
    33  	_            [CacheLineSize]byte
    34  }
    35  
    36  var PPC64 ppc64
    37  
    38  // For ppc64x, it is safe to check only for ISA level starting on ISA v3.00,
    39  // since there are no optional categories. There are some exceptions that also
    40  // require kernel support to work (darn, scv), so there are capability bits for
    41  // those as well. The minimum processor requirement is POWER8 (ISA 2.07), so we
    42  // maintain some of the old capability checks for optional categories for
    43  // safety.
    44  // The struct is padded to avoid false sharing.
    45  type ppc64 struct {
    46  	_          [CacheLineSize]byte
    47  	HasVMX     bool // Vector unit (Altivec)
    48  	HasDFP     bool // Decimal Floating Point unit
    49  	HasVSX     bool // Vector-scalar unit
    50  	HasHTM     bool // Hardware Transactional Memory
    51  	HasISEL    bool // Integer select
    52  	HasVCRYPTO bool // Vector cryptography
    53  	HasHTMNOSC bool // HTM: kernel-aborted transaction in syscalls
    54  	HasDARN    bool // Hardware random number generator (requires kernel enablement)
    55  	HasSCV     bool // Syscall vectored (requires kernel enablement)
    56  	IsPOWER8   bool // ISA v2.07 (POWER8)
    57  	IsPOWER9   bool // ISA v3.00 (POWER9)
    58  	_          [CacheLineSize]byte
    59  }
    60  
    61  var ARM64 arm64
    62  
    63  // The booleans in arm64 contain the correspondingly named cpu feature bit.
    64  // The struct is padded to avoid false sharing.
    65  type arm64 struct {
    66  	_          [CacheLineSize]byte
    67  	HasFP      bool
    68  	HasASIMD   bool
    69  	HasEVTSTRM bool
    70  	HasAES     bool
    71  	HasPMULL   bool
    72  	HasSHA1    bool
    73  	HasSHA2    bool
    74  	HasCRC32   bool
    75  	HasATOMICS bool
    76  	_          [CacheLineSize]byte
    77  }