core/cpu_caps.cpp

   1
   2 #include "config.h"
   3
   4 #include "cpu_caps.h"
   5
   6 #if defined(_WIN32) && (defined(_M_ARM) || defined(_M_ARM64))
   7 #define WIN32_LEAN_AND_MEAN
   8 #include <windows.h>
   9 #ifndef PF_ARM_NEON_INSTRUCTIONS_AVAILABLE
  10 #define PF_ARM_NEON_INSTRUCTIONS_AVAILABLE 19
  11 #endif
  12 #endif
  13
  14 #if defined(HAVE_CPUID_H)
  15 #include <cpuid.h>
  16 #elif defined(HAVE_INTRIN_H)
  17 #include <intrin.h>
  18 #endif
  19
  20 #include <algorithm>
  21 #include <array>
  22 #include <cctype>
  23 #include <string>
  24
  25
  26 int CPUCapFlags{0};
  27
  28 namespace {
  29
  30 #if defined(HAVE_GCC_GET_CPUID) \
  31     && (defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64))
  32 using reg_type = unsigned int;
  33 inline std::array<reg_type,4> get_cpuid(unsigned int f)
  34 {
  35     std::array<reg_type,4> ret{};
  36     __get_cpuid(f, ret.data(), &ret[1], &ret[2], &ret[3]);
  37     return ret;
  38 }
  39 #define CAN_GET_CPUID
  40 #elif defined(HAVE_CPUID_INTRINSIC) \
  41     && (defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64))
  42 using reg_type = int;
  43 inline std::array<reg_type,4> get_cpuid(unsigned int f)
  44 {
  45     std::array<reg_type,4> ret{};
  46     (__cpuid)(ret.data(), f);
  47     return ret;
  48 }
  49 #define CAN_GET_CPUID
  50 #endif
  51
  52 } // namespace
  53
  54 std::optional<CPUInfo> GetCPUInfo()
  55 {
  56     CPUInfo ret;
  57
  58 #ifdef CAN_GET_CPUID
  59     auto cpuregs = get_cpuid(0);
  60     if(cpuregs[0] == 0)
  61         return std::nullopt;
  62
  63     const reg_type maxfunc{cpuregs[0]};
  64
  65     cpuregs = get_cpuid(0x80000000);
  66     const reg_type maxextfunc{cpuregs[0]};
  67
  68     ret.mVendor.append(reinterpret_cast<char*>(&cpuregs[1]), 4);
  69     ret.mVendor.append(reinterpret_cast<char*>(&cpuregs[3]), 4);
  70     ret.mVendor.append(reinterpret_cast<char*>(&cpuregs[2]), 4);
  71     auto iter_end = std::remove(ret.mVendor.begin(), ret.mVendor.end(), '\0');
  72     iter_end = std::unique(ret.mVendor.begin(), iter_end,
  73         [](auto&& c0, auto&& c1) { return std::isspace(c0) && std::isspace(c1); });
  74     ret.mVendor.erase(iter_end, ret.mVendor.end());
  75     if(!ret.mVendor.empty() && std::isspace(ret.mVendor.back()))
  76         ret.mVendor.pop_back();
  77     if(!ret.mVendor.empty() && std::isspace(ret.mVendor.front()))
  78         ret.mVendor.erase(ret.mVendor.begin());
  79
  80     if(maxextfunc >= 0x80000004)
  81     {
  82         cpuregs = get_cpuid(0x80000002);
  83         ret.mName.append(reinterpret_cast<char*>(cpuregs.data()), 16);
  84         cpuregs = get_cpuid(0x80000003);
  85         ret.mName.append(reinterpret_cast<char*>(cpuregs.data()), 16);
  86         cpuregs = get_cpuid(0x80000004);
  87         ret.mName.append(reinterpret_cast<char*>(cpuregs.data()), 16);
  88         iter_end = std::remove(ret.mName.begin(), ret.mName.end(), '\0');
  89         iter_end = std::unique(ret.mName.begin(), iter_end,
  90             [](auto&& c0, auto&& c1) { return std::isspace(c0) && std::isspace(c1); });
  91         ret.mName.erase(iter_end, ret.mName.end());
  92         if(!ret.mName.empty() && std::isspace(ret.mName.back()))
  93             ret.mName.pop_back();
  94         if(!ret.mName.empty() && std::isspace(ret.mName.front()))
  95             ret.mName.erase(ret.mName.begin());
  96     }
  97
  98     if(maxfunc >= 1)
  99     {
 100         cpuregs = get_cpuid(1);
 101         if((cpuregs[3]&(1<<25)))
 102             ret.mCaps |= CPU_CAP_SSE;
 103         if((ret.mCaps&CPU_CAP_SSE) && (cpuregs[3]&(1<<26)))
 104             ret.mCaps |= CPU_CAP_SSE2;
 105         if((ret.mCaps&CPU_CAP_SSE2) && (cpuregs[2]&(1<<0)))
 106             ret.mCaps |= CPU_CAP_SSE3;
 107         if((ret.mCaps&CPU_CAP_SSE3) && (cpuregs[2]&(1<<19)))
 108             ret.mCaps |= CPU_CAP_SSE4_1;
 109     }
 110
 111 #else
 112
 113     /* Assume support for whatever's supported if we can't check for it */
 114 #if defined(HAVE_SSE4_1)
 115 #warning "Assuming SSE 4.1 run-time support!"
 116     ret.mCaps |= CPU_CAP_SSE | CPU_CAP_SSE2 | CPU_CAP_SSE3 | CPU_CAP_SSE4_1;
 117 #elif defined(HAVE_SSE3)
 118 #warning "Assuming SSE 3 run-time support!"
 119     ret.mCaps |= CPU_CAP_SSE | CPU_CAP_SSE2 | CPU_CAP_SSE3;
 120 #elif defined(HAVE_SSE2)
 121 #warning "Assuming SSE 2 run-time support!"
 122     ret.mCaps |= CPU_CAP_SSE | CPU_CAP_SSE2;
 123 #elif defined(HAVE_SSE)
 124 #warning "Assuming SSE run-time support!"
 125     ret.mCaps |= CPU_CAP_SSE;
 126 #endif
 127 #endif /* CAN_GET_CPUID */
 128
 129 #ifdef HAVE_NEON
 130 #ifdef __ARM_NEON
 131     ret.mCaps |= CPU_CAP_NEON;
 132 #elif defined(_WIN32) && (defined(_M_ARM) || defined(_M_ARM64))
 133     if(IsProcessorFeaturePresent(PF_ARM_NEON_INSTRUCTIONS_AVAILABLE))
 134         ret.mCaps |= CPU_CAP_NEON;
 135 #else
 136 #warning "Assuming NEON run-time support!"
 137     ret.mCaps |= CPU_CAP_NEON;
 138 #endif
 139 #endif
 140
 141     return ret;
 142 }