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      1 /*
      2  *  Copyright (c) 2011 The LibYuv project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #include "libyuv/cpu_id.h"
     12 #include "libyuv/basic_types.h"  // for CPU_X86
     13 
     14 #ifdef _MSC_VER
     15 #include <intrin.h>
     16 #endif
     17 
     18 // TODO(fbarchard): Use cpuid.h when gcc 4.4 is used on OSX and Linux.
     19 #if (defined(__pic__) || defined(__APPLE__)) && defined(__i386__)
     20 static inline void __cpuid(int cpu_info[4], int info_type) {
     21   __asm__ volatile (
     22     "mov %%ebx, %%edi\n"
     23     "cpuid\n"
     24     "xchg %%edi, %%ebx\n"
     25     : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
     26     : "a"(info_type)
     27   );
     28 }
     29 #elif defined(__i386__) || defined(__x86_64__)
     30 static inline void __cpuid(int cpu_info[4], int info_type) {
     31   __asm__ volatile (
     32     "cpuid\n"
     33     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
     34     : "a"(info_type)
     35   );
     36 }
     37 #endif
     38 
     39 namespace libyuv {
     40 
     41 // CPU detect function for SIMD instruction sets.
     42 static int cpu_info_ = 0;
     43 
     44 // TODO(fbarchard): (cpu_info[2] & 0x10000000 ? kCpuHasAVX : 0)
     45 static void InitCpuFlags() {
     46 #ifdef CPU_X86
     47   int cpu_info[4];
     48   __cpuid(cpu_info, 1);
     49   cpu_info_ = (cpu_info[3] & 0x04000000 ? kCpuHasSSE2 : 0) |
     50               (cpu_info[2] & 0x00000200 ? kCpuHasSSSE3 : 0) |
     51               kCpuInitialized;
     52 #elif defined(__ARM_NEON__)
     53   // gcc -mfpu=neon defines __ARM_NEON__
     54   // Enable Neon if you want support for Neon and Arm, and use MaskCpuFlags
     55   // to disable Neon on devices that do not have it.
     56   cpu_info_ = kCpuHasNEON | kCpuInitialized;
     57 #else
     58   cpu_info_ = kCpuInitialized;
     59 #endif
     60 }
     61 
     62 void MaskCpuFlags(int enable_flags) {
     63   InitCpuFlags();
     64   cpu_info_ &= enable_flags;
     65 }
     66 
     67 bool TestCpuFlag(int flag) {
     68   if (0 == cpu_info_) {
     69     InitCpuFlags();
     70   }
     71   return cpu_info_ & flag ? true : false;
     72 }
     73 
     74 }  // namespace libyuv
     75