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Source file src/runtime/os_linux_ppc64x.go

Documentation: runtime

  // Copyright 2016 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 ppc64 ppc64le
  
  package runtime
  
  import (
  	"runtime/internal/sys"
  )
  
  const (
  	// ISA level
  	// Go currently requires POWER5 as a minimum for ppc64, so we need
  	// to check for ISA 2.03 and beyond.
  	_PPC_FEATURE_POWER5_PLUS = 0x00020000 // ISA 2.03 (POWER5+)
  	_PPC_FEATURE_ARCH_2_05   = 0x00001000 // ISA 2.05 (POWER6)
  	_PPC_FEATURE_POWER6_EXT  = 0x00000200 // mffgpr/mftgpr extension (POWER6x)
  	_PPC_FEATURE_ARCH_2_06   = 0x00000100 // ISA 2.06 (POWER7)
  	_PPC_FEATURE2_ARCH_2_07  = 0x80000000 // ISA 2.07 (POWER8)
  
  	// Standalone capabilities
  	_PPC_FEATURE_HAS_ALTIVEC = 0x10000000 // SIMD/Vector unit
  	_PPC_FEATURE_HAS_VSX     = 0x00000080 // Vector scalar unit
  )
  
  type facilities struct {
  	_         [sys.CacheLineSize]byte
  	isPOWER5x bool // ISA 2.03
  	isPOWER6  bool // ISA 2.05
  	isPOWER6x bool // ISA 2.05 + mffgpr/mftgpr extension
  	isPOWER7  bool // ISA 2.06
  	isPOWER8  bool // ISA 2.07
  	hasVMX    bool // Vector unit
  	hasVSX    bool // Vector scalar unit
  	_         [sys.CacheLineSize]byte
  }
  
  // cpu can be tested at runtime in go assembler code to check for
  // a certain ISA level or hardware capability, for example:
  //	  ·cpu+facilities_hasVSX(SB) for checking the availability of VSX
  //	  or
  //	  ·cpu+facilities_isPOWER7(SB) for checking if the processor implements
  //	  ISA 2.06 instructions.
  var cpu facilities
  
  func archauxv(tag, val uintptr) {
  	switch tag {
  	case _AT_HWCAP:
  		cpu.isPOWER5x = val&_PPC_FEATURE_POWER5_PLUS != 0
  		cpu.isPOWER6 = val&_PPC_FEATURE_ARCH_2_05 != 0
  		cpu.isPOWER6x = val&_PPC_FEATURE_POWER6_EXT != 0
  		cpu.isPOWER7 = val&_PPC_FEATURE_ARCH_2_06 != 0
  		cpu.hasVMX = val&_PPC_FEATURE_HAS_ALTIVEC != 0
  		cpu.hasVSX = val&_PPC_FEATURE_HAS_VSX != 0
  	case _AT_HWCAP2:
  		cpu.isPOWER8 = val&_PPC_FEATURE2_ARCH_2_07 != 0
  	}
  }
  

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