Add AVX2 detection

base/cpu.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_CPU_H_
 #define BASE_CPU_H_
 
 #include <string>
 
 #include "base/base_export.h"
 
 namespace base {
 
 // Query information about the processor.
 class BASE_EXPORT CPU {
  public:
   // Constructor
   CPU();
 
   enum IntelMicroArchitecture {
     PENTIUM,
     SSE,
     SSE2,
     SSE3,
     SSSE3,
     SSE41,
     SSE42,
     AVX,
+    AVX2,
     MAX_INTEL_MICRO_ARCHITECTURE
   };
 
   // Accessors for CPU information.
   const std::string& vendor_name() const { return cpu_vendor_; }
   int signature() const { return signature_; }
   int stepping() const { return stepping_; }
   int model() const { return model_; }
   int family() const { return family_; }
   int type() const { return type_; }
   int extended_model() const { return ext_model_; }
   int extended_family() const { return ext_family_; }
   bool has_mmx() const { return has_mmx_; }
   bool has_sse() const { return has_sse_; }
   bool has_sse2() const { return has_sse2_; }
   bool has_sse3() const { return has_sse3_; }
   bool has_ssse3() const { return has_ssse3_; }
   bool has_sse41() const { return has_sse41_; }
   bool has_sse42() const { return has_sse42_; }
   bool has_avx() const { return has_avx_; }
+  bool has_avx2() const { return has_avx2_; }
   // has_avx_hardware returns true when AVX is present in the CPU. This might
   // differ from the value of |has_avx()| because |has_avx()| also tests for
   // operating system support needed to actually call AVX instuctions.
   // Note: you should never need to call this function. It was added in order
   // to workaround a bug in NSS but |has_avx()| is what you want.
   bool has_avx_hardware() const { return has_avx_hardware_; }
   bool has_aesni() const { return has_aesni_; }
   bool has_non_stop_time_stamp_counter() const {
     return has_non_stop_time_stamp_counter_;
   }
@@ skipping 18 matching lines @@
   int ext_family_;
   bool has_mmx_;
   bool has_sse_;
   bool has_sse2_;
   bool has_sse3_;
   bool has_ssse3_;
   bool has_sse41_;
   bool has_sse42_;
   bool has_avx_;
   bool has_avx_hardware_;
+  bool has_avx2_;
   bool has_aesni_;
   bool has_non_stop_time_stamp_counter_;
   bool has_broken_neon_;
   std::string cpu_vendor_;
   std::string cpu_brand_;
 };
 
 }  // namespace base
 
 #endif  // BASE_CPU_H_