cpu_id.h 4.1 KB

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  1. /*
  2. * Copyright 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. #ifndef INCLUDE_LIBYUV_CPU_ID_H_
  11. #define INCLUDE_LIBYUV_CPU_ID_H_
  12. #include "libyuv/basic_types.h"
  13. #ifdef __cplusplus
  14. namespace libyuv {
  15. extern "C" {
  16. #endif
  17. // Internal flag to indicate cpuid requires initialization.
  18. static const int kCpuInitialized = 0x1;
  19. // These flags are only valid on ARM processors.
  20. static const int kCpuHasARM = 0x2;
  21. static const int kCpuHasNEON = 0x4;
  22. // 0x8 reserved for future ARM flag.
  23. // These flags are only valid on x86 processors.
  24. static const int kCpuHasX86 = 0x10;
  25. static const int kCpuHasSSE2 = 0x20;
  26. static const int kCpuHasSSSE3 = 0x40;
  27. static const int kCpuHasSSE41 = 0x80;
  28. static const int kCpuHasSSE42 = 0x100; // unused at this time.
  29. static const int kCpuHasAVX = 0x200;
  30. static const int kCpuHasAVX2 = 0x400;
  31. static const int kCpuHasERMS = 0x800;
  32. static const int kCpuHasFMA3 = 0x1000;
  33. static const int kCpuHasF16C = 0x2000;
  34. static const int kCpuHasGFNI = 0x4000;
  35. static const int kCpuHasAVX512BW = 0x8000;
  36. static const int kCpuHasAVX512VL = 0x10000;
  37. static const int kCpuHasAVX512VBMI = 0x20000;
  38. static const int kCpuHasAVX512VBMI2 = 0x40000;
  39. static const int kCpuHasAVX512VBITALG = 0x80000;
  40. static const int kCpuHasAVX512VPOPCNTDQ = 0x100000;
  41. // These flags are only valid on MIPS processors.
  42. static const int kCpuHasMIPS = 0x200000;
  43. static const int kCpuHasMSA = 0x400000;
  44. static const int kCpuHasMMI = 0x800000;
  45. // Optional init function. TestCpuFlag does an auto-init.
  46. // Returns cpu_info flags.
  47. LIBYUV_API
  48. int InitCpuFlags(void);
  49. // Detect CPU has SSE2 etc.
  50. // Test_flag parameter should be one of kCpuHas constants above.
  51. // Returns non-zero if instruction set is detected
  52. static __inline int TestCpuFlag(int test_flag) {
  53. LIBYUV_API extern int cpu_info_;
  54. #ifdef __ATOMIC_RELAXED
  55. int cpu_info = __atomic_load_n(&cpu_info_, __ATOMIC_RELAXED);
  56. #else
  57. int cpu_info = cpu_info_;
  58. #endif
  59. return (!cpu_info ? InitCpuFlags() : cpu_info) & test_flag;
  60. }
  61. // Internal function for parsing /proc/cpuinfo.
  62. LIBYUV_API
  63. int ArmCpuCaps(const char* cpuinfo_name);
  64. // For testing, allow CPU flags to be disabled.
  65. // ie MaskCpuFlags(~kCpuHasSSSE3) to disable SSSE3.
  66. // MaskCpuFlags(-1) to enable all cpu specific optimizations.
  67. // MaskCpuFlags(1) to disable all cpu specific optimizations.
  68. // MaskCpuFlags(0) to reset state so next call will auto init.
  69. // Returns cpu_info flags.
  70. LIBYUV_API
  71. int MaskCpuFlags(int enable_flags);
  72. // Sets the CPU flags to |cpu_flags|, bypassing the detection code. |cpu_flags|
  73. // should be a valid combination of the kCpuHas constants above and include
  74. // kCpuInitialized. Use this method when running in a sandboxed process where
  75. // the detection code might fail (as it might access /proc/cpuinfo). In such
  76. // cases the cpu_info can be obtained from a non sandboxed process by calling
  77. // InitCpuFlags() and passed to the sandboxed process (via command line
  78. // parameters, IPC...) which can then call this method to initialize the CPU
  79. // flags.
  80. // Notes:
  81. // - when specifying 0 for |cpu_flags|, the auto initialization is enabled
  82. // again.
  83. // - enabling CPU features that are not supported by the CPU will result in
  84. // undefined behavior.
  85. // TODO(fbarchard): consider writing a helper function that translates from
  86. // other library CPU info to libyuv CPU info and add a .md doc that explains
  87. // CPU detection.
  88. static __inline void SetCpuFlags(int cpu_flags) {
  89. LIBYUV_API extern int cpu_info_;
  90. #ifdef __ATOMIC_RELAXED
  91. __atomic_store_n(&cpu_info_, cpu_flags, __ATOMIC_RELAXED);
  92. #else
  93. cpu_info_ = cpu_flags;
  94. #endif
  95. }
  96. // Low level cpuid for X86. Returns zeros on other CPUs.
  97. // eax is the info type that you want.
  98. // ecx is typically the cpu number, and should normally be zero.
  99. LIBYUV_API
  100. void CpuId(int info_eax, int info_ecx, int* cpu_info);
  101. #ifdef __cplusplus
  102. } // extern "C"
  103. } // namespace libyuv
  104. #endif
  105. #endif // INCLUDE_LIBYUV_CPU_ID_H_