michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "base/cpu.h"
michael@0: #include <intrin.h>
michael@0: #include <string>
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: CPU::CPU()
michael@0:   : type_(0),
michael@0:     family_(0),
michael@0:     model_(0),
michael@0:     stepping_(0),
michael@0:     ext_model_(0),
michael@0:     ext_family_(0),
michael@0:     cpu_vendor_("unknown") {
michael@0:   Initialize();
michael@0: }
michael@0: 
michael@0: void CPU::Initialize() {
michael@0:   int cpu_info[4] = {-1};
michael@0:   char cpu_string[0x20];
michael@0: 
michael@0:   // __cpuid with an InfoType argument of 0 returns the number of
michael@0:   // valid Ids in CPUInfo[0] and the CPU identification string in
michael@0:   // the other three array elements. The CPU identification string is
michael@0:   // not in linear order. The code below arranges the information
michael@0:   // in a human readable form.
michael@0:   //
michael@0:   // More info can be found here:
michael@0:   // http://msdn.microsoft.com/en-us/library/hskdteyh.aspx
michael@0:   __cpuid(cpu_info, 0);
michael@0:   int num_ids = cpu_info[0];
michael@0:   memset(cpu_string, 0, sizeof(cpu_string));
michael@0:   *(reinterpret_cast<int*>(cpu_string)) = cpu_info[1];
michael@0:   *(reinterpret_cast<int*>(cpu_string+4)) = cpu_info[3];
michael@0:   *(reinterpret_cast<int*>(cpu_string+8)) = cpu_info[2];
michael@0: 
michael@0:   // Interpret CPU feature information.
michael@0:   if (num_ids > 0) {
michael@0:     __cpuid(cpu_info, 1);
michael@0:     stepping_ = cpu_info[0] & 0xf;
michael@0:     model_ = (cpu_info[0] >> 4) & 0xf;
michael@0:     family_ = (cpu_info[0] >> 8) & 0xf;
michael@0:     type_ = (cpu_info[0] >> 12) & 0x3;
michael@0:     ext_model_ = (cpu_info[0] >> 16) & 0xf;
michael@0:     ext_family_ = (cpu_info[0] >> 20) & 0xff;
michael@0:     cpu_vendor_ = cpu_string;
michael@0:   }
michael@0: }
michael@0: 
michael@0: }  // namespace base