github.com/panjjo/go@v0.0.0-20161104043856-d62b31386338/src/runtime/os_linux_ppc64x.go (about)

     1  // Copyright 2016 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  // +build ppc64 ppc64le
     6  
     7  package runtime
     8  
     9  import (
    10  	"runtime/internal/sys"
    11  )
    12  
    13  const (
    14  	// ISA level
    15  	// Go currently requires POWER5 as a minimum for ppc64, so we need
    16  	// to check for ISA 2.03 and beyond.
    17  	_PPC_FEATURE_POWER5_PLUS = 0x00020000 // ISA 2.03 (POWER5+)
    18  	_PPC_FEATURE_ARCH_2_05   = 0x00001000 // ISA 2.05 (POWER6)
    19  	_PPC_FEATURE_POWER6_EXT  = 0x00000200 // mffgpr/mftgpr extension (POWER6x)
    20  	_PPC_FEATURE_ARCH_2_06   = 0x00000100 // ISA 2.06 (POWER7)
    21  	_PPC_FEATURE2_ARCH_2_07  = 0x80000000 // ISA 2.07 (POWER8)
    22  
    23  	// Standalone capabilities
    24  	_PPC_FEATURE_HAS_ALTIVEC = 0x10000000 // SIMD/Vector unit
    25  	_PPC_FEATURE_HAS_VSX     = 0x00000080 // Vector scalar unit
    26  )
    27  
    28  type facilities struct {
    29  	_         [sys.CacheLineSize]byte
    30  	isPOWER5x bool // ISA 2.03
    31  	isPOWER6  bool // ISA 2.05
    32  	isPOWER6x bool // ISA 2.05 + mffgpr/mftgpr extension
    33  	isPOWER7  bool // ISA 2.06
    34  	isPOWER8  bool // ISA 2.07
    35  	hasVMX    bool // Vector unit
    36  	hasVSX    bool // Vector scalar unit
    37  	_         [sys.CacheLineSize]byte
    38  }
    39  
    40  // cpu can be tested at runtime in go assembler code to check for
    41  // a certain ISA level or hardware capability, for example:
    42  //	  ·cpu+facilities_hasVSX(SB) for checking the availability of VSX
    43  //	  or
    44  //	  ·cpu+facilities_isPOWER7(SB) for checking if the processor implements
    45  //	  ISA 2.06 instructions.
    46  var cpu facilities
    47  
    48  func archauxv(tag, val uintptr) {
    49  	switch tag {
    50  	case _AT_HWCAP:
    51  		cpu.isPOWER5x = val&_PPC_FEATURE_POWER5_PLUS != 0
    52  		cpu.isPOWER6 = val&_PPC_FEATURE_ARCH_2_05 != 0
    53  		cpu.isPOWER6x = val&_PPC_FEATURE_POWER6_EXT != 0
    54  		cpu.isPOWER7 = val&_PPC_FEATURE_ARCH_2_06 != 0
    55  		cpu.hasVMX = val&_PPC_FEATURE_HAS_ALTIVEC != 0
    56  		cpu.hasVSX = val&_PPC_FEATURE_HAS_VSX != 0
    57  	case _AT_HWCAP2:
    58  		cpu.isPOWER8 = val&_PPC_FEATURE2_ARCH_2_07 != 0
    59  	}
    60  }