1 // Copyright (c) 2006-2008 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 #include <intrin.h> 7 #include <string> 8 9 namespace base { 10 11 CPU::CPU() 12 : type_(0), 13 family_(0), 14 model_(0), 15 stepping_(0), 16 ext_model_(0), 17 ext_family_(0), 18 cpu_vendor_("unknown") { 19 Initialize(); 20 } 21 22 void CPU::Initialize() { 23 int cpu_info[4] = {-1}; 24 char cpu_string[0x20]; 25 26 // __cpuid with an InfoType argument of 0 returns the number of 27 // valid Ids in CPUInfo[0] and the CPU identification string in 28 // the other three array elements. The CPU identification string is 29 // not in linear order. The code below arranges the information 30 // in a human readable form. 31 // 32 // More info can be found here: 33 // http://msdn.microsoft.com/en-us/library/hskdteyh.aspx 34 __cpuid(cpu_info, 0); 35 int num_ids = cpu_info[0]; 36 memset(cpu_string, 0, sizeof(cpu_string)); 37 *(reinterpret_cast<int*>(cpu_string)) = cpu_info[1]; 38 *(reinterpret_cast<int*>(cpu_string+4)) = cpu_info[3]; 39 *(reinterpret_cast<int*>(cpu_string+8)) = cpu_info[2]; 40 41 // Interpret CPU feature information. 42 if (num_ids > 0) { 43 __cpuid(cpu_info, 1); 44 stepping_ = cpu_info[0] & 0xf; 45 model_ = (cpu_info[0] >> 4) & 0xf; 46 family_ = (cpu_info[0] >> 8) & 0xf; 47 type_ = (cpu_info[0] >> 12) & 0x3; 48 ext_model_ = (cpu_info[0] >> 16) & 0xf; 49 ext_family_ = (cpu_info[0] >> 20) & 0xff; 50 cpu_vendor_ = cpu_string; 51 } 52 } 53 54 } // namespace base 55
