libgo/go/runtime/os_linux_ppc64x.go

   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 ignore_for_gccgo
   6 // +build ppc64 ppc64le
   7
   8 package runtime
   9
  10 import (
  11         "runtime/internal/sys"
  12 )
  13
  14 const (
  15         // ISA level
  16         // Go currently requires POWER5 as a minimum for ppc64, so we need
  17         // to check for ISA 2.03 and beyond.
  18         _PPC_FEATURE_POWER5_PLUS = 0x00020000 // ISA 2.03 (POWER5+)
  19         _PPC_FEATURE_ARCH_2_05   = 0x00001000 // ISA 2.05 (POWER6)
  20         _PPC_FEATURE_POWER6_EXT  = 0x00000200 // mffgpr/mftgpr extension (POWER6x)
  21         _PPC_FEATURE_ARCH_2_06   = 0x00000100 // ISA 2.06 (POWER7)
  22         _PPC_FEATURE2_ARCH_2_07  = 0x80000000 // ISA 2.07 (POWER8)
  23
  24         // Standalone capabilities
  25         _PPC_FEATURE_HAS_ALTIVEC = 0x10000000 // SIMD/Vector unit
  26         _PPC_FEATURE_HAS_VSX     = 0x00000080 // Vector scalar unit
  27 )
  28
  29 type facilities struct {
  30         _         [sys.CacheLineSize]byte
  31         isPOWER5x bool // ISA 2.03
  32         isPOWER6  bool // ISA 2.05
  33         isPOWER6x bool // ISA 2.05 + mffgpr/mftgpr extension
  34         isPOWER7  bool // ISA 2.06
  35         isPOWER8  bool // ISA 2.07
  36         hasVMX    bool // Vector unit
  37         hasVSX    bool // Vector scalar unit
  38         _         [sys.CacheLineSize]byte
  39 }
  40
  41 // cpu can be tested at runtime in go assembler code to check for
  42 // a certain ISA level or hardware capability, for example:
  43 //        ·cpu+facilities_hasVSX(SB) for checking the availability of VSX
  44 //        or
  45 //        ·cpu+facilities_isPOWER7(SB) for checking if the processor implements
  46 //        ISA 2.06 instructions.
  47 var cpu facilities
  48
  49 func archauxv(tag, val uintptr) {
  50         switch tag {
  51         case _AT_HWCAP:
  52                 cpu.isPOWER5x = val&_PPC_FEATURE_POWER5_PLUS != 0
  53                 cpu.isPOWER6 = val&_PPC_FEATURE_ARCH_2_05 != 0
  54                 cpu.isPOWER6x = val&_PPC_FEATURE_POWER6_EXT != 0
  55                 cpu.isPOWER7 = val&_PPC_FEATURE_ARCH_2_06 != 0
  56                 cpu.hasVMX = val&_PPC_FEATURE_HAS_ALTIVEC != 0
  57                 cpu.hasVSX = val&_PPC_FEATURE_HAS_VSX != 0
  58         case _AT_HWCAP2:
  59                 cpu.isPOWER8 = val&_PPC_FEATURE2_ARCH_2_07 != 0
  60         }
  61 }