base/cpu.cc

   1 // Copyright (c) 2011 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 #if defined(ARCH_CPU_X86_FAMILY)
   8 #if defined(_MSC_VER)
   9 #include <intrin.h>
  10 #endif
  11 #endif
  12
  13 #include <string.h>
  14
  15 namespace base {
  16
  17 CPU::CPU()
  18   : type_(0),
  19     family_(0),
  20     model_(0),
  21     stepping_(0),
  22     ext_model_(0),
  23     ext_family_(0),
  24     has_mmx_(false),
  25     has_sse_(false),
  26     has_sse2_(false),
  27     has_sse3_(false),
  28     has_ssse3_(false),
  29     has_sse41_(false),
  30     has_sse42_(false),
  31     cpu_vendor_("unknown") {
  32   Initialize();
  33 }
  34
  35 #if defined(ARCH_CPU_X86_FAMILY)
  36 #ifndef _MSC_VER
  37
  38 #if defined(__pic__) && defined(__i386__)
  39
  40 void __cpuid(int cpu_info[4], int info_type) {
  41   __asm__ volatile (
  42     "mov %%ebx, %%edi\n"
  43     "cpuid\n"
  44     "xchg %%edi, %%ebx\n"
  45     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  46     : "a"(info_type)
  47   );
  48 }
  49
  50 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  51   __asm__ volatile (
  52     "mov %%ebx, %%edi\n"
  53     "cpuid\n"
  54     "xchg %%edi, %%ebx\n"
  55     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  56     : "a"(info_type), "c"(info_index)
  57   );
  58 }
  59
  60 #else
  61
  62 void __cpuid(int cpu_info[4], int info_type) {
  63   __asm__ volatile (
  64     "cpuid \n\t"
  65     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  66     : "a"(info_type)
  67   );
  68 }
  69
  70 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  71   __asm__ volatile (
  72     "cpuid \n\t"
  73     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  74     : "a"(info_type), "c"(info_index)
  75   );
  76 }
  77
  78 #endif
  79 #endif  // _MSC_VER
  80 #endif  // ARCH_CPU_X86_FAMILY
  81
  82 void CPU::Initialize() {
  83 #if defined(ARCH_CPU_X86_FAMILY)
  84   int cpu_info[4] = {-1};
  85   char cpu_string[0x20];
  86
  87   // __cpuid with an InfoType argument of 0 returns the number of
  88   // valid Ids in CPUInfo[0] and the CPU identification string in
  89   // the other three array elements. The CPU identification string is
  90   // not in linear order. The code below arranges the information
  91   // in a human readable form.
  92   //
  93   // More info can be found here:
  94   // http://msdn.microsoft.com/en-us/library/hskdteyh.aspx
  95   __cpuid(cpu_info, 0);
  96   int num_ids = cpu_info[0];
  97   memset(cpu_string, 0, sizeof(cpu_string));
  98   *(reinterpret_cast<int*>(cpu_string)) = cpu_info[1];
  99   *(reinterpret_cast<int*>(cpu_string+4)) = cpu_info[3];
 100   *(reinterpret_cast<int*>(cpu_string+8)) = cpu_info[2];
 101
 102   // Interpret CPU feature information.
 103   if (num_ids > 0) {
 104     __cpuid(cpu_info, 1);
 105     stepping_ = cpu_info[0] & 0xf;
 106     model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0);
 107     family_ = (cpu_info[0] >> 8) & 0xf;
 108     type_ = (cpu_info[0] >> 12) & 0x3;
 109     ext_model_ = (cpu_info[0] >> 16) & 0xf;
 110     ext_family_ = (cpu_info[0] >> 20) & 0xff;
 111     cpu_vendor_ = cpu_string;
 112     has_mmx_ = (cpu_info[3] & 0x00800000) != 0;
 113     has_sse_ = (cpu_info[3] & 0x02000000) != 0;
 114     has_sse2_ = (cpu_info[3] & 0x04000000) != 0;
 115     has_sse3_ = (cpu_info[2] & 0x00000001) != 0;
 116     has_ssse3_ = (cpu_info[2] & 0x00000200) != 0;
 117     has_sse41_ = (cpu_info[2] & 0x00080000) != 0;
 118     has_sse42_ = (cpu_info[2] & 0x00100000) != 0;
 119   }
 120 #endif
 121 }
 122
 123 }  // namespace base