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     has_non_stop_time_stamp_counter_(false),
  36     cpu_vendor_("unknown") {
  37   Initialize();
  38 }
  39
  40 #if defined(ARCH_CPU_X86_FAMILY)
  41 #ifndef _MSC_VER
  42
  43 #if defined(__pic__) && defined(__i386__)
  44
  45 void __cpuid(int cpu_info[4], int info_type) {
  46   __asm__ volatile (
  47     "mov %%ebx, %%edi\n"
  48     "cpuid\n"
  49     "xchg %%edi, %%ebx\n"
  50     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  51     : "a"(info_type)
  52   );
  53 }
  54
  55 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  56   __asm__ volatile (
  57     "mov %%ebx, %%edi\n"
  58     "cpuid\n"
  59     "xchg %%edi, %%ebx\n"
  60     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  61     : "a"(info_type), "c"(info_index)
  62   );
  63 }
  64
  65 #else
  66
  67 void __cpuid(int cpu_info[4], int info_type) {
  68   __asm__ volatile (
  69     "cpuid \n\t"
  70     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  71     : "a"(info_type)
  72   );
  73 }
  74
  75 void __cpuidex(int cpu_info[4], int info_type, int info_index) {
  76   __asm__ volatile (
  77     "cpuid \n\t"
  78     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
  79     : "a"(info_type), "c"(info_index)
  80   );
  81 }
  82
  83 #endif
  84 #endif  // _MSC_VER
  85 #endif  // ARCH_CPU_X86_FAMILY
  86
  87 void CPU::Initialize() {
  88 #if defined(ARCH_CPU_X86_FAMILY)
  89   int cpu_info[4] = {-1};
  90   char cpu_string[48];
  91
  92   // __cpuid with an InfoType argument of 0 returns the number of
  93   // valid Ids in CPUInfo[0] and the CPU identification string in
  94   // the other three array elements. The CPU identification string is
  95   // not in linear order. The code below arranges the information
  96   // in a human readable form. The human readable order is CPUInfo[1] |
  97   // CPUInfo[3] | CPUInfo[2]. CPUInfo[2] and CPUInfo[3] are swapped
  98   // before using memcpy to copy these three array elements to cpu_string.
  99   __cpuid(cpu_info, 0);
 100   int num_ids = cpu_info[0];
 101   std::swap(cpu_info[2], cpu_info[3]);
 102   memcpy(cpu_string, &cpu_info[1], 3 * sizeof(cpu_info[1]));
 103   cpu_vendor_.assign(cpu_string, 3 * sizeof(cpu_info[1]));
 104
 105   // Interpret CPU feature information.
 106   if (num_ids > 0) {
 107     __cpuid(cpu_info, 1);
 108     stepping_ = cpu_info[0] & 0xf;
 109     model_ = ((cpu_info[0] >> 4) & 0xf) + ((cpu_info[0] >> 12) & 0xf0);
 110     family_ = (cpu_info[0] >> 8) & 0xf;
 111     type_ = (cpu_info[0] >> 12) & 0x3;
 112     ext_model_ = (cpu_info[0] >> 16) & 0xf;
 113     ext_family_ = (cpu_info[0] >> 20) & 0xff;
 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     has_avx_ = (cpu_info[2] & 0x10000000) != 0;
 122   }
 123
 124   // Get the brand string of the cpu.
 125   __cpuid(cpu_info, 0x80000000);
 126   const int parameter_end = 0x80000004;
 127   int max_parameter = cpu_info[0];
 128
 129   if (cpu_info[0] >= parameter_end) {
 130     char* cpu_string_ptr = cpu_string;
 131
 132     for (int parameter = 0x80000002; parameter <= parameter_end &&
 133          cpu_string_ptr < &cpu_string[sizeof(cpu_string)]; parameter++) {
 134       __cpuid(cpu_info, parameter);
 135       memcpy(cpu_string_ptr, cpu_info, sizeof(cpu_info));
 136       cpu_string_ptr += sizeof(cpu_info);
 137     }
 138     cpu_brand_.assign(cpu_string, cpu_string_ptr - cpu_string);
 139   }
 140
 141   const int parameter_containing_non_stop_time_stamp_counter = 0x80000007;
 142   if (max_parameter >= parameter_containing_non_stop_time_stamp_counter) {
 143     __cpuid(cpu_info, parameter_containing_non_stop_time_stamp_counter);
 144     has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0;
 145   }
 146 #endif
 147 }
 148
 149 CPU::IntelMicroArchitecture CPU::GetIntelMicroArchitecture() const {
 150   if (has_avx()) return AVX;
 151   if (has_sse42()) return SSE42;
 152   if (has_sse41()) return SSE41;
 153   if (has_ssse3()) return SSSE3;
 154   if (has_sse3()) return SSE3;
 155   if (has_sse2()) return SSE2;
 156   if (has_sse()) return SSE;
 157   return PENTIUM;
 158 }
 159
 160 }  // namespace base