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 <algorithm>
  10
  11 #include "build/build_config.h"
  12
  13 #if defined(ARCH_CPU_X86_FAMILY)
  14 #if defined(_MSC_VER)
  15 #include <intrin.h>
  16 #endif
  17 #endif
  18
  19 namespace base {
  20
  21 CPU::CPU()
  22   : type_(0),
  23     family_(0),
  24     model_(0),
  25     stepping_(0),
  26     ext_model_(0),
  27     ext_family_(0),
  28     has_mmx_(false),
  29     has_sse_(false),
  30     has_sse2_(false),
  31     has_sse3_(false),
  32     has_ssse3_(false),
  33     has_sse41_(false),
  34     has_sse42_(false),
  35     cpu_vendor_("unknown") {
  36   Initialize();
  37 }
  38
  39 #if defined(ARCH_CPU_X86_FAMILY)
  40 #ifndef _MSC_VER
  41
  42 #if defined(__pic__) && defined(__i386__)
  43
  44 void __cpuid(int cpu_info[4], int info_type) {
  45   __asm__ volatile (
  46     "mov %%ebx, %%edi\n"
  47     "cpuid\n"
  48     "xchg %%edi, %%ebx\n"
  49     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  50     : "a"(info_type)
  51   );
  52 }
  53
  54 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  55   __asm__ volatile (
  56     "mov %%ebx, %%edi\n"
  57     "cpuid\n"
  58     "xchg %%edi, %%ebx\n"
  59     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  60     : "a"(info_type), "c"(info_index)
  61   );
  62 }
  63
  64 #else
  65
  66 void __cpuid(int cpu_info[4], int info_type) {
  67   __asm__ volatile (
  68     "cpuid \n\t"
  69     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  70     : "a"(info_type)
  71   );
  72 }
  73
  74 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  75   __asm__ volatile (
  76     "cpuid \n\t"
  77     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  78     : "a"(info_type), "c"(info_index)
  79   );
  80 }
  81
  82 #endif
  83 #endif  // _MSC_VER
  84 #endif  // ARCH_CPU_X86_FAMILY
  85
  86 void CPU::Initialize() {
  87 #if defined(ARCH_CPU_X86_FAMILY)
  88   int cpu_info[4] = {-1};
  89   char cpu_string[48];
  90
  91   // __cpuid with an InfoType argument of 0 returns the number of
  92   // valid Ids in CPUInfo[0] and the CPU identification string in
  93   // the other three array elements. The CPU identification string is
  94   // not in linear order. The code below arranges the information
  95   // in a human readable form. The human readable order is CPUInfo[1] |
  96   // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped
  97   // before using memcpy to copy these three array elements to cpu_string.
  98   __cpuid(cpu_info, 0);
  99   int num_ids = cpu_info[0];
 100   std::swap(cpu_info[2], cpu_info[3]);
 101   memcpy(cpu_string, &cpu_info[1], 3 * sizeof(cpu_info[1]));
 102   cpu_vendor_.assign(cpu_string, 3 * sizeof(cpu_info[1]));
 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     has_mmx_ = (cpu_info[3] & 0x00800000) != 0;
 114     has_sse_ = (cpu_info[3] & 0x02000000) != 0;
 115     has_sse2_ = (cpu_info[3] & 0x04000000) != 0;
 116     has_sse3_ = (cpu_info[2] & 0x00000001) != 0;
 117     has_ssse3_ = (cpu_info[2] & 0x00000200) != 0;
 118     has_sse41_ = (cpu_info[2] & 0x00080000) != 0;
 119     has_sse42_ = (cpu_info[2] & 0x00100000) != 0;
 120   }
 121
 122   // Get the brand string of the cpu.
 123   __cpuid(cpu_info, 0x80000000);
 124   const int parameter_end = 0x80000004;
 125
 126   if (cpu_info[0] >= parameter_end) {
 127     char* cpu_string_ptr = cpu_string;
 128
 129     for (int parameter = 0x80000002; parameter <= parameter_end &&
 130          cpu_string_ptr < &cpu_string[sizeof(cpu_string)]; parameter++) {
 131       __cpuid(cpu_info, parameter);
 132       memcpy(cpu_string_ptr, cpu_info, sizeof(cpu_info));
 133       cpu_string_ptr += sizeof(cpu_info);
 134     }
 135     cpu_brand_.assign(cpu_string, cpu_string_ptr - cpu_string);
 136   }
 137 #endif
 138 }
 139
 140 }  // namespace base