base/cpu.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/cpu.h"
   6
   7 #include <string.h>
   8
   9 #include "build/build_config.h"
  10
  11 #if defined(ARCH_CPU_X86_FAMILY)
  12 #if defined(_MSC_VER)
  13 #include <intrin.h>
  14 #endif
  15 #endif
  16
  17 namespace base {
  18
  19 CPU::CPU()
  20   : type_(0),
  21     family_(0),
  22     model_(0),
  23     stepping_(0),
  24     ext_model_(0),
  25     ext_family_(0),
  26     has_mmx_(false),
  27     has_sse_(false),
  28     has_sse2_(false),
  29     has_sse3_(false),
  30     has_ssse3_(false),
  31     has_sse41_(false),
  32     has_sse42_(false),
  33     cpu_vendor_("unknown") {
  34   Initialize();
  35 }
  36
  37 #if defined(ARCH_CPU_X86_FAMILY)
  38 #ifndef _MSC_VER
  39
  40 #if defined(__pic__) && defined(__i386__)
  41
  42 void __cpuid(int cpu_info[4], int info_type) {
  43   __asm__ volatile (
  44     "mov %%ebx, %%edi\n"
  45     "cpuid\n"
  46     "xchg %%edi, %%ebx\n"
  47     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  48     : "a"(info_type)
  49   );
  50 }
  51
  52 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  53   __asm__ volatile (
  54     "mov %%ebx, %%edi\n"
  55     "cpuid\n"
  56     "xchg %%edi, %%ebx\n"
  57     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  58     : "a"(info_type), "c"(info_index)
  59   );
  60 }
  61
  62 #else
  63
  64 void __cpuid(int cpu_info[4], int info_type) {
  65   __asm__ volatile (
  66     "cpuid \n\t"
  67     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  68     : "a"(info_type)
  69   );
  70 }
  71
  72 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  73   __asm__ volatile (
  74     "cpuid \n\t"
  75     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  76     : "a"(info_type), "c"(info_index)
  77   );
  78 }
  79
  80 #endif
  81 #endif  // _MSC_VER
  82 #endif  // ARCH_CPU_X86_FAMILY
  83
  84 void CPU::Initialize() {
  85 #if defined(ARCH_CPU_X86_FAMILY)
  86   int cpu_info[4] = {-1};
  87   char cpu_string[0x20];
  88
  89   // __cpuid with an InfoType argument of 0 returns the number of
  90   // valid Ids in CPUInfo[0] and the CPU identification string in
  91   // the other three array elements. The CPU identification string is
  92   // not in linear order. The code below arranges the information
  93   // in a human readable form.
  94   //
  95   // More info can be found here:
  96   // http://msdn.microsoft.com/en-us/library/hskdteyh.aspx
  97   __cpuid(cpu_info, 0);
  98   int num_ids = cpu_info[0];
  99   memset(cpu_string, 0, sizeof(cpu_string));
 100   *(reinterpret_cast<int*>(cpu_string)) = cpu_info[1];
 101   *(reinterpret_cast<int*>(cpu_string+4)) = cpu_info[3];
 102   *(reinterpret_cast<int*>(cpu_string+8)) = cpu_info[2];
 103
 104   // Interpret CPU feature information.
 105   if (num_ids > 0) {
 106     __cpuid(cpu_info, 1);
 107     stepping_ = cpu_info[0] & 0xf;
 108     model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0);
 109     family_ = (cpu_info[0] >> 8) & 0xf;
 110     type_ = (cpu_info[0] >> 12) & 0x3;
 111     ext_model_ = (cpu_info[0] >> 16) & 0xf;
 112     ext_family_ = (cpu_info[0] >> 20) & 0xff;
 113     cpu_vendor_ = cpu_string;
 114     has_mmx_ = (cpu_info[3] & 0x00800000) != 0;
 115     has_sse_ = (cpu_info[3] & 0x02000000) != 0;
 116     has_sse2_ = (cpu_info[3] & 0x04000000) != 0;
 117     has_sse3_ = (cpu_info[2] & 0x00000001) != 0;
 118     has_ssse3_ = (cpu_info[2] & 0x00000200) != 0;
 119     has_sse41_ = (cpu_info[2] & 0x00080000) != 0;
 120     has_sse42_ = (cpu_info[2] & 0x00100000) != 0;
 121   }
 122 #endif
 123 }
 124
 125 }  // namespace base