src/cpuinfo_x86.c

// Copyright 2017 Google Inc.
// Copyright 2020 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "cpuinfo_x86.h"

#include <stdbool.h>
#include <string.h>

#include "internal/bit_utils.h"
#include "internal/cpuid_x86.h"

#if !defined(CPU_FEATURES_ARCH_X86)
#error "Cannot compile cpuinfo_x86 on a non x86 platform."
#endif

////////////////////////////////////////////////////////////////////////////////
// Definitions for CpuId and GetXCR0Eax.
////////////////////////////////////////////////////////////////////////////////

#if defined(CPU_FEATURES_MOCK_CPUID_X86)
// Implementation will be provided by test/cpuinfo_x86_test.cc.
#elif defined(CPU_FEATURES_COMPILER_CLANG) || defined(CPU_FEATURES_COMPILER_GCC)

#include <cpuid.h>

Leaf CpuIdEx(uint32_t leaf_id, int ecx) {
  Leaf leaf;
  __cpuid_count(leaf_id, ecx, leaf.eax, leaf.ebx, leaf.ecx, leaf.edx);
  return leaf;
}

uint32_t GetXCR0Eax(void) {
  uint32_t eax, edx;
  /* named form of xgetbv not supported on OSX, so must use byte form, see:
     https://github.com/asmjit/asmjit/issues/78
   */
  __asm(".byte 0x0F, 0x01, 0xd0" : "=a"(eax), "=d"(edx) : "c"(0));
  return eax;
}

#elif defined(CPU_FEATURES_COMPILER_MSC)

#include <immintrin.h>
#include <intrin.h>  // For __cpuidex()

Leaf CpuIdEx(uint32_t leaf_id, int ecx) {
  Leaf leaf;
  int data[4];
  __cpuidex(data, leaf_id, ecx);
  leaf.eax = data[0];
  leaf.ebx = data[1];
  leaf.ecx = data[2];
  leaf.edx = data[3];
  return leaf;
}

uint32_t GetXCR0Eax(void) { return (uint32_t)_xgetbv(0); }

#else
#error "Unsupported compiler, x86 cpuid requires either GCC, Clang or MSVC."
#endif

static Leaf CpuId(uint32_t leaf_id) { return CpuIdEx(leaf_id, 0); }

static const Leaf kEmptyLeaf;

static Leaf SafeCpuIdEx(uint32_t max_cpuid_leaf, uint32_t leaf_id, int ecx) {
  if (leaf_id <= max_cpuid_leaf) {
    return CpuIdEx(leaf_id, ecx);
  } else {
    return kEmptyLeaf;
  }
}

static Leaf SafeCpuId(uint32_t max_cpuid_leaf, uint32_t leaf_id) {
  return SafeCpuIdEx(max_cpuid_leaf, leaf_id, 0);
}

#define MASK_XMM 0x2
#define MASK_YMM 0x4
#define MASK_MASKREG 0x20
#define MASK_ZMM0_15 0x40
#define MASK_ZMM16_31 0x80
#define MASK_XTILECFG 0x20000
#define MASK_XTILEDATA 0x40000

static bool HasMask(uint32_t value, uint32_t mask) {
  return (value & mask) == mask;
}

// Checks that operating system saves and restores xmm registers during context
// switches.
static bool HasXmmOsXSave(uint32_t xcr0_eax) {
  return HasMask(xcr0_eax, MASK_XMM);
}

// Checks that operating system saves and restores ymm registers during context
// switches.
static bool HasYmmOsXSave(uint32_t xcr0_eax) {
  return HasMask(xcr0_eax, MASK_XMM | MASK_YMM);
}

// Checks that operating system saves and restores zmm registers during context
// switches.
static bool HasZmmOsXSave(uint32_t xcr0_eax) {
  return HasMask(xcr0_eax, MASK_XMM | MASK_YMM | MASK_MASKREG | MASK_ZMM0_15 |
                               MASK_ZMM16_31);
}

// Checks that operating system saves and restores AMX/TMUL state during context
// switches.
static bool HasTmmOsXSave(uint32_t xcr0_eax) {
  return HasMask(xcr0_eax, MASK_XMM | MASK_YMM | MASK_MASKREG | MASK_ZMM0_15 |
                               MASK_ZMM16_31 | MASK_XTILECFG | MASK_XTILEDATA);
}

static bool HasSecondFMA(uint32_t model) {
  // Skylake server
  if (model == 0x55) {
    char proc_name[49] = {0};
    FillX86BrandString(proc_name);
    // detect Xeon
    if (proc_name[9] == 'X') {
      // detect Silver or Bronze
      if (proc_name[17] == 'S' || proc_name[17] == 'B') return false;
      // detect Gold 5_20 and below, except for Gold 53__
      if (proc_name[17] == 'G' && proc_name[22] == '5')
        return ((proc_name[23] == '3') ||
                (proc_name[24] == '2' && proc_name[25] == '2'));
      // detect Xeon W 210x
      if (proc_name[17] == 'W' && proc_name[21] == '0') return false;
      // detect Xeon D 2xxx
      if (proc_name[17] == 'D' && proc_name[19] == '2' && proc_name[20] == '1')
        return false;
    }
    return true;
  }
  // Cannon Lake client
  if (model == 0x66) return false;
  // Ice Lake client
  if (model == 0x7d || model == 0x7e) return false;
  // This is the right default...
  return true;
}

static void SetVendor(const Leaf leaf, char* const vendor) {
  *(uint32_t*)(vendor) = leaf.ebx;
  *(uint32_t*)(vendor + 4) = leaf.edx;
  *(uint32_t*)(vendor + 8) = leaf.ecx;
  vendor[12] = '\0';
}

static int IsVendor(const Leaf leaf, const char* const name) {
  const uint32_t ebx = *(const uint32_t*)(name);
  const uint32_t edx = *(const uint32_t*)(name + 4);
  const uint32_t ecx = *(const uint32_t*)(name + 8);
  return leaf.ebx == ebx && leaf.ecx == ecx && leaf.edx == edx;
}

static const CacheLevelInfo kEmptyCacheLevelInfo;

static CacheLevelInfo GetCacheLevelInfo(const uint32_t reg) {
  const int UNDEF = -1;
  const int KiB = 1024;
  const int MiB = 1024 * KiB;
  switch (reg) {
    case 0x01:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 32,
                              .partitioning = 0};
    case 0x02:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * MiB,
                              .ways = 0xFF,
                              .line_size = UNDEF,
                              .tlb_entries = 2,
                              .partitioning = 0};
    case 0x03:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 64,
                              .partitioning = 0};
    case 0x04:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 8,
                              .partitioning = 0};
    case 0x05:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 32,
                              .partitioning = 0};
    case 0x06:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 8 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x08:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 16 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x09:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 32 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x0A:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 8 * KiB,
                              .ways = 2,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x0B:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 4,
                              .partitioning = 0};
    case 0x0C:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 16 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x0D:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 16 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x0E:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 24 * KiB,
                              .ways = 6,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x1D:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 128 * KiB,
                              .ways = 2,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x21:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 256 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x22:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x23:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x24:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x25:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x29:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 4 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x2C:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 32 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x30:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 32 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x40:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = UNDEF,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x41:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 128 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x42:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 256 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x43:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x44:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x45:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x46:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 4 * MiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x47:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 8 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x48:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 3 * MiB,
                              .ways = 12,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x49:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 4 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case (0x49 | (1 << 8)):
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 4 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x4A:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 6 * MiB,
                              .ways = 12,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x4B:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 8 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x4C:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 12 * MiB,
                              .ways = 12,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x4D:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 16 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x4E:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 6 * MiB,
                              .ways = 24,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x4F:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 32,
                              .partitioning = 0};
    case 0x50:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 64,
                              .partitioning = 0};
    case 0x51:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 128,
                              .partitioning = 0};
    case 0x52:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 256,
                              .partitioning = 0};
    case 0x55:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 2 * MiB,
                              .ways = 0xFF,
                              .line_size = UNDEF,
                              .tlb_entries = 7,
                              .partitioning = 0};
    case 0x56:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 16,
                              .partitioning = 0};
    case 0x57:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 16,
                              .partitioning = 0};
    case 0x59:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 0xFF,
                              .line_size = UNDEF,
                              .tlb_entries = 16,
                              .partitioning = 0};
    case 0x5A:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 2 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 32,
                              .partitioning = 0};
    case 0x5B:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 64,
                              .partitioning = 0};
    case 0x5C:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 128,
                              .partitioning = 0};
    case 0x5D:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = 256,
                              .partitioning = 0};
    case 0x60:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 16 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x61:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 0xFF,
                              .line_size = UNDEF,
                              .tlb_entries = 48,
                              .partitioning = 0};
    case 0x63:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 2 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 4,
                              .partitioning = 0};
    case 0x66:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 8 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x67:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 16 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x68:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 32 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x70:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 12 * KiB,
                              .ways = 8,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x71:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 16 * KiB,
                              .ways = 8,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x72:
      return (CacheLevelInfo){.level = 1,
                              .cache_type = CPU_FEATURE_CACHE_INSTRUCTION,
                              .cache_size = 32 * KiB,
                              .ways = 8,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x76:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 2 * MiB,
                              .ways = 0xFF,
                              .line_size = UNDEF,
                              .tlb_entries = 8,
                              .partitioning = 0};
    case 0x78:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x79:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 128 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x7A:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 256 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x7B:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x7C:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 2};
    case 0x7D:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x7F:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 2,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x80:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x82:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 256 * KiB,
                              .ways = 8,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x83:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 8,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x84:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 8,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x85:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 8,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x86:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 4,
                              .line_size = 32,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0x87:
      return (CacheLevelInfo){.level = 2,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xA0:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_DTLB,
                              .cache_size = 4 * KiB,
                              .ways = 0xFF,
                              .line_size = UNDEF,
                              .tlb_entries = 32,
                              .partitioning = 0};
    case 0xB0:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 128,
                              .partitioning = 0};
    case 0xB1:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 2 * MiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 8,
                              .partitioning = 0};
    case 0xB2:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 64,
                              .partitioning = 0};
    case 0xB3:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 128,
                              .partitioning = 0};
    case 0xB4:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 256,
                              .partitioning = 0};
    case 0xB5:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 8,
                              .line_size = UNDEF,
                              .tlb_entries = 64,
                              .partitioning = 0};
    case 0xB6:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 8,
                              .line_size = UNDEF,
                              .tlb_entries = 128,
                              .partitioning = 0};
    case 0xBA:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 64,
                              .partitioning = 0};
    case 0xC0:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_TLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 8,
                              .partitioning = 0};
    case 0xC1:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_STLB,
                              .cache_size = 4 * KiB,
                              .ways = 8,
                              .line_size = UNDEF,
                              .tlb_entries = 1024,
                              .partitioning = 0};
    case 0xC2:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_DTLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 16,
                              .partitioning = 0};
    case 0xC3:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_STLB,
                              .cache_size = 4 * KiB,
                              .ways = 6,
                              .line_size = UNDEF,
                              .tlb_entries = 1536,
                              .partitioning = 0};
    case 0xCA:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_STLB,
                              .cache_size = 4 * KiB,
                              .ways = 4,
                              .line_size = UNDEF,
                              .tlb_entries = 512,
                              .partitioning = 0};
    case 0xD0:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 512 * KiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xD1:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xD2:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 4,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xD6:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xD7:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xD8:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 4 * MiB,
                              .ways = 8,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xDC:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 1 * 1536 * KiB,
                              .ways = 12,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xDD:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 3 * MiB,
                              .ways = 12,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xDE:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 6 * MiB,
                              .ways = 12,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xE2:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 2 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xE3:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 4 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xE4:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 8 * MiB,
                              .ways = 16,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xEA:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 12 * MiB,
                              .ways = 24,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xEB:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 18 * MiB,
                              .ways = 24,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xEC:
      return (CacheLevelInfo){.level = 3,
                              .cache_type = CPU_FEATURE_CACHE_DATA,
                              .cache_size = 24 * MiB,
                              .ways = 24,
                              .line_size = 64,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xF0:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_PREFETCH,
                              .cache_size = 64 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xF1:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_PREFETCH,
                              .cache_size = 128 * KiB,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    case 0xFF:
      return (CacheLevelInfo){.level = UNDEF,
                              .cache_type = CPU_FEATURE_CACHE_NULL,
                              .cache_size = UNDEF,
                              .ways = UNDEF,
                              .line_size = UNDEF,
                              .tlb_entries = UNDEF,
                              .partitioning = 0};
    default:
      return kEmptyCacheLevelInfo;
  }
}

static void GetByteArrayFromRegister(uint32_t result[4], const uint32_t reg) {
  for (int i = 0; i < 4; ++i) {
    result[i] = ExtractBitRange(reg, (i + 1) * 8, i * 8);
  }
}

static void ParseLeaf2(const int max_cpuid_leaf, CacheInfo* info) {
  Leaf leaf = SafeCpuId(max_cpuid_leaf, 2);
  uint32_t registers[] = {leaf.eax, leaf.ebx, leaf.ecx, leaf.edx};
  for (int i = 0; i < 4; ++i) {
    if (registers[i] & (1U << 31)) {
      continue;  // register does not contains valid information
    }
    uint32_t bytes[4];
    GetByteArrayFromRegister(bytes, registers[i]);
    for (int j = 0; j < 4; ++j) {
      if (bytes[j] == 0xFF)
        break;  // leaf 4 should be used to fetch cache information
      info->levels[info->size] = GetCacheLevelInfo(bytes[j]);
    }
    info->size++;
  }
}

static void ParseLeaf4(const int max_cpuid_leaf, CacheInfo* info) {
  info->size = 0;
  for (int cache_id = 0; cache_id < CPU_FEATURES_MAX_CACHE_LEVEL; cache_id++) {
    const Leaf leaf = SafeCpuIdEx(max_cpuid_leaf, 4, cache_id);
    CacheType cache_type = ExtractBitRange(leaf.eax, 4, 0);
    if (cache_type == CPU_FEATURE_CACHE_NULL) {
      info->levels[cache_id] = kEmptyCacheLevelInfo;
      continue;
    }
    int level = ExtractBitRange(leaf.eax, 7, 5);
    int line_size = ExtractBitRange(leaf.ebx, 11, 0) + 1;
    int partitioning = ExtractBitRange(leaf.ebx, 21, 12) + 1;
    int ways = ExtractBitRange(leaf.ebx, 31, 22) + 1;
    int tlb_entries = leaf.ecx + 1;
    int cache_size = (ways * partitioning * line_size * (tlb_entries));
    info->levels[cache_id] = (CacheLevelInfo){.level = level,
                                              .cache_type = cache_type,
                                              .cache_size = cache_size,
                                              .ways = ways,
                                              .line_size = line_size,
                                              .tlb_entries = tlb_entries,
                                              .partitioning = partitioning};
    info->size++;
  }
}

// Internal structure to hold the OS support for vector operations.
// Avoid to recompute them since each call to cpuid is ~100 cycles.
typedef struct {
  bool have_sse;
  bool have_avx;
  bool have_avx512;
  bool have_amx;
} OsSupport;

// Reference https://en.wikipedia.org/wiki/CPUID.
static void ParseCpuId(const uint32_t max_cpuid_leaf, X86Info* info,
                       OsSupport* os_support) {
  const Leaf leaf_1 = SafeCpuId(max_cpuid_leaf, 1);
  const Leaf leaf_7 = SafeCpuId(max_cpuid_leaf, 7);
  const Leaf leaf_7_1 = SafeCpuIdEx(max_cpuid_leaf, 7, 1);

  const bool have_xsave = IsBitSet(leaf_1.ecx, 26);
  const bool have_osxsave = IsBitSet(leaf_1.ecx, 27);
  const uint32_t xcr0_eax = (have_xsave && have_osxsave) ? GetXCR0Eax() : 0;
  os_support->have_sse = HasXmmOsXSave(xcr0_eax);
  os_support->have_avx = HasYmmOsXSave(xcr0_eax);
  os_support->have_avx512 = HasZmmOsXSave(xcr0_eax);
  os_support->have_amx = HasTmmOsXSave(xcr0_eax);

  const uint32_t family = ExtractBitRange(leaf_1.eax, 11, 8);
  const uint32_t extended_family = ExtractBitRange(leaf_1.eax, 27, 20);
  const uint32_t model = ExtractBitRange(leaf_1.eax, 7, 4);
  const uint32_t extended_model = ExtractBitRange(leaf_1.eax, 19, 16);

  X86Features* const features = &info->features;

  info->family = extended_family + family;
  info->model = (extended_model << 4) + model;
  info->stepping = ExtractBitRange(leaf_1.eax, 3, 0);

  features->fpu = IsBitSet(leaf_1.edx, 0);
  features->tsc = IsBitSet(leaf_1.edx, 4);
  features->cx8 = IsBitSet(leaf_1.edx, 8);
  features->clfsh = IsBitSet(leaf_1.edx, 19);
  features->mmx = IsBitSet(leaf_1.edx, 23);
  features->ss = IsBitSet(leaf_1.edx, 27);
  features->pclmulqdq = IsBitSet(leaf_1.ecx, 1);
  features->smx = IsBitSet(leaf_1.ecx, 6);
  features->cx16 = IsBitSet(leaf_1.ecx, 13);
  features->dca = IsBitSet(leaf_1.ecx, 18);
  features->movbe = IsBitSet(leaf_1.ecx, 22);
  features->popcnt = IsBitSet(leaf_1.ecx, 23);
  features->aes = IsBitSet(leaf_1.ecx, 25);
  features->f16c = IsBitSet(leaf_1.ecx, 29);
  features->rdrnd = IsBitSet(leaf_1.ecx, 30);
  features->sgx = IsBitSet(leaf_7.ebx, 2);
  features->bmi1 = IsBitSet(leaf_7.ebx, 3);
  features->hle = IsBitSet(leaf_7.ebx, 4);
  features->bmi2 = IsBitSet(leaf_7.ebx, 8);
  features->erms = IsBitSet(leaf_7.ebx, 9);
  features->rtm = IsBitSet(leaf_7.ebx, 11);
  features->rdseed = IsBitSet(leaf_7.ebx, 18);
  features->clflushopt = IsBitSet(leaf_7.ebx, 23);
  features->clwb = IsBitSet(leaf_7.ebx, 24);
  features->sha = IsBitSet(leaf_7.ebx, 29);
  features->vaes = IsBitSet(leaf_7.ecx, 9);
  features->vpclmulqdq = IsBitSet(leaf_7.ecx, 10);

  if (os_support->have_sse) {
    features->sse = IsBitSet(leaf_1.edx, 25);
    features->sse2 = IsBitSet(leaf_1.edx, 26);
    features->sse3 = IsBitSet(leaf_1.ecx, 0);
    features->ssse3 = IsBitSet(leaf_1.ecx, 9);
    features->sse4_1 = IsBitSet(leaf_1.ecx, 19);
    features->sse4_2 = IsBitSet(leaf_1.ecx, 20);
  }

  if (os_support->have_avx) {
    features->fma3 = IsBitSet(leaf_1.ecx, 12);
    features->avx = IsBitSet(leaf_1.ecx, 28);
    features->avx2 = IsBitSet(leaf_7.ebx, 5);
  }

  if (os_support->have_avx512) {
    features->avx512f = IsBitSet(leaf_7.ebx, 16);
    features->avx512cd = IsBitSet(leaf_7.ebx, 28);
    features->avx512er = IsBitSet(leaf_7.ebx, 27);
    features->avx512pf = IsBitSet(leaf_7.ebx, 26);
    features->avx512bw = IsBitSet(leaf_7.ebx, 30);
    features->avx512dq = IsBitSet(leaf_7.ebx, 17);
    features->avx512vl = IsBitSet(leaf_7.ebx, 31);
    features->avx512ifma = IsBitSet(leaf_7.ebx, 21);
    features->avx512vbmi = IsBitSet(leaf_7.ecx, 1);
    features->avx512vbmi2 = IsBitSet(leaf_7.ecx, 6);
    features->avx512vnni = IsBitSet(leaf_7.ecx, 11);
    features->avx512bitalg = IsBitSet(leaf_7.ecx, 12);
    features->avx512vpopcntdq = IsBitSet(leaf_7.ecx, 14);
    features->avx512_4vnniw = IsBitSet(leaf_7.edx, 2);
    features->avx512_4vbmi2 = IsBitSet(leaf_7.edx, 3);
    features->avx512_second_fma = HasSecondFMA(info->model);
    features->avx512_4fmaps = IsBitSet(leaf_7.edx, 3);
    features->avx512_bf16 = IsBitSet(leaf_7_1.eax, 5);
    features->avx512_vp2intersect = IsBitSet(leaf_7.edx, 8);
  }

  if (os_support->have_amx) {
    features->amx_bf16 = IsBitSet(leaf_7.edx, 22);
    features->amx_tile = IsBitSet(leaf_7.edx, 24);
    features->amx_int8 = IsBitSet(leaf_7.edx, 25);
  }
}

// Reference
// https://en.wikipedia.org/wiki/CPUID#EAX=80000000h:_Get_Highest_Extended_Function_Implemented.
static void ParseExtraAMDCpuId(X86Info* info, OsSupport os_support) {
  const Leaf leaf_80000000 = CpuId(0x80000000);
  const uint32_t max_extended_cpuid_leaf = leaf_80000000.eax;
  const Leaf leaf_80000001 = SafeCpuId(max_extended_cpuid_leaf, 0x80000001);

  X86Features* const features = &info->features;

  if (os_support.have_sse) {
    features->sse4a = IsBitSet(leaf_80000001.ecx, 6);
  }

  if (os_support.have_avx) {
    features->fma4 = IsBitSet(leaf_80000001.ecx, 16);
  }
}

static const X86Info kEmptyX86Info;
static const OsSupport kEmptyOsSupport;
static const CacheInfo kEmptyCacheInfo;

X86Info GetX86Info(void) {
  X86Info info = kEmptyX86Info;
  OsSupport os_support = kEmptyOsSupport;
  const Leaf leaf_0 = CpuId(0);
  const bool is_intel = IsVendor(leaf_0, "GenuineIntel");
  const bool is_amd = IsVendor(leaf_0, "AuthenticAMD");
  SetVendor(leaf_0, info.vendor);
  if (is_intel || is_amd) {
    const uint32_t max_cpuid_leaf = leaf_0.eax;
    ParseCpuId(max_cpuid_leaf, &info, &os_support);
  }
  if (is_amd) {
    ParseExtraAMDCpuId(&info, os_support);
  }
  return info;
}

CacheInfo GetX86CacheInfo(void) {
  CacheInfo info = kEmptyCacheInfo;
  const Leaf leaf_0 = CpuId(0);
  const uint32_t max_cpuid_leaf = leaf_0.eax;
  if (IsVendor(leaf_0, "GenuineIntel")) {
    ParseLeaf2(max_cpuid_leaf, &info);
    ParseLeaf4(max_cpuid_leaf, &info);
  }
  return info;
}

#define CPUID(FAMILY, MODEL) ((((FAMILY)&0xFF) << 8) | ((MODEL)&0xFF))

X86Microarchitecture GetX86Microarchitecture(const X86Info* info) {
  if (memcmp(info->vendor, "GenuineIntel", sizeof(info->vendor)) == 0) {
    switch (CPUID(info->family, info->model)) {
      case CPUID(0x06, 0x35):
      case CPUID(0x06, 0x36):
        // https://en.wikipedia.org/wiki/Bonnell_(microarchitecture)
        return INTEL_ATOM_BNL;
      case CPUID(0x06, 0x37):
      case CPUID(0x06, 0x4C):
        // https://en.wikipedia.org/wiki/Silvermont
        return INTEL_ATOM_SMT;
      case CPUID(0x06, 0x5C):
        // https://en.wikipedia.org/wiki/Goldmont
        return INTEL_ATOM_GMT;
      case CPUID(0x06, 0x0F):
      case CPUID(0x06, 0x16):
        // https://en.wikipedia.org/wiki/Intel_Core_(microarchitecture)
        return INTEL_CORE;
      case CPUID(0x06, 0x17):
      case CPUID(0x06, 0x1D):
        // https://en.wikipedia.org/wiki/Penryn_(microarchitecture)
        return INTEL_PNR;
      case CPUID(0x06, 0x1A):
      case CPUID(0x06, 0x1E):
      case CPUID(0x06, 0x1F):
      case CPUID(0x06, 0x2E):
        // https://en.wikipedia.org/wiki/Nehalem_(microarchitecture)
        return INTEL_NHM;
      case CPUID(0x06, 0x25):
      case CPUID(0x06, 0x2C):
      case CPUID(0x06, 0x2F):
        // https://en.wikipedia.org/wiki/Westmere_(microarchitecture)
        return INTEL_WSM;
      case CPUID(0x06, 0x2A):
      case CPUID(0x06, 0x2D):
        // https://en.wikipedia.org/wiki/Sandy_Bridge#Models_and_steppings
        return INTEL_SNB;
      case CPUID(0x06, 0x3A):
      case CPUID(0x06, 0x3E):
        // https://en.wikipedia.org/wiki/Ivy_Bridge_(microarchitecture)#Models_and_steppings
        return INTEL_IVB;
      case CPUID(0x06, 0x3C):
      case CPUID(0x06, 0x3F):
      case CPUID(0x06, 0x45):
      case CPUID(0x06, 0x46):
        // https://en.wikipedia.org/wiki/Haswell_(microarchitecture)
        return INTEL_HSW;
      case CPUID(0x06, 0x3D):
      case CPUID(0x06, 0x47):
      case CPUID(0x06, 0x4F):
      case CPUID(0x06, 0x56):
        // https://en.wikipedia.org/wiki/Broadwell_(microarchitecture)
        return INTEL_BDW;
      case CPUID(0x06, 0x4E):
      case CPUID(0x06, 0x55):
      case CPUID(0x06, 0x5E):
        // https://en.wikipedia.org/wiki/Skylake_(microarchitecture)
        return INTEL_SKL;
      case CPUID(0x06, 0x66):
        // https://en.wikipedia.org/wiki/Cannon_Lake_(microarchitecture)
        return INTEL_CNL;
      case CPUID(0x06, 0x7D):  // client
      case CPUID(0x06, 0x7E):  // client
      case CPUID(0x06, 0x9D):  // NNP-I
      case CPUID(0x06, 0x6A):  // server
      case CPUID(0x06, 0x6C):  // server
        // https://en.wikipedia.org/wiki/Ice_Lake_(microprocessor)
        return INTEL_ICL;
      case CPUID(0x06, 0x8C):
      case CPUID(0x06, 0x8D):
        // https://en.wikipedia.org/wiki/Tiger_Lake_(microarchitecture)
        return INTEL_TGL;
      case CPUID(0x06, 0x8F):
        // https://en.wikipedia.org/wiki/Sapphire_Rapids
        return INTEL_SPR;
      case CPUID(0x06, 0x8E):
        switch (info->stepping) {
          case 9:
            return INTEL_KBL;  // https://en.wikipedia.org/wiki/Kaby_Lake
          case 10:
            return INTEL_CFL;  // https://en.wikipedia.org/wiki/Coffee_Lake
          case 11:
            return INTEL_WHL;  // https://en.wikipedia.org/wiki/Whiskey_Lake_(microarchitecture)
          default:
            return X86_UNKNOWN;
        }
      case CPUID(0x06, 0x9E):
        if (info->stepping > 9) {
          // https://en.wikipedia.org/wiki/Coffee_Lake
          return INTEL_CFL;
        } else {
          // https://en.wikipedia.org/wiki/Kaby_Lake
          return INTEL_KBL;
        }
      default:
        return X86_UNKNOWN;
    }
  }
  if (memcmp(info->vendor, "AuthenticAMD", sizeof(info->vendor)) == 0) {
    switch (info->family) {
        // https://en.wikipedia.org/wiki/List_of_AMD_CPU_microarchitectures
      case 0x0F:
        return AMD_HAMMER;
      case 0x10:
        return AMD_K10;
      case 0x14:
        return AMD_BOBCAT;
      case 0x15:
        return AMD_BULLDOZER;
      case 0x16:
        return AMD_JAGUAR;
      case 0x17:
        return AMD_ZEN;
      default:
        return X86_UNKNOWN;
    }
  }
  return X86_UNKNOWN;
}

static void SetString(const uint32_t max_cpuid_ext_leaf, const uint32_t leaf_id,
                      char* buffer) {
  const Leaf leaf = SafeCpuId(max_cpuid_ext_leaf, leaf_id);
  // We allow calling memcpy from SetString which is only called when requesting
  // X86BrandString.
  memcpy(buffer, &leaf, sizeof(Leaf));
}

void FillX86BrandString(char brand_string[49]) {
  const Leaf leaf_ext_0 = CpuId(0x80000000);
  const uint32_t max_cpuid_leaf_ext = leaf_ext_0.eax;
  SetString(max_cpuid_leaf_ext, 0x80000002, brand_string);
  SetString(max_cpuid_leaf_ext, 0x80000003, brand_string + 16);
  SetString(max_cpuid_leaf_ext, 0x80000004, brand_string + 32);
  brand_string[48] = '\0';
}

////////////////////////////////////////////////////////////////////////////////
// Introspection functions

int GetX86FeaturesEnumValue(const X86Features* features,
                            X86FeaturesEnum value) {
  switch (value) {
    case X86_FPU:
      return features->fpu;
    case X86_TSC:
      return features->tsc;
    case X86_CX8:
      return features->cx8;
    case X86_CLFSH:
      return features->clfsh;
    case X86_MMX:
      return features->mmx;
    case X86_AES:
      return features->aes;
    case X86_ERMS:
      return features->erms;
    case X86_F16C:
      return features->f16c;
    case X86_FMA4:
      return features->fma4;
    case X86_FMA3:
      return features->fma3;
    case X86_VAES:
      return features->vaes;
    case X86_VPCLMULQDQ:
      return features->vpclmulqdq;
    case X86_BMI1:
      return features->bmi1;
    case X86_HLE:
      return features->hle;
    case X86_BMI2:
      return features->bmi2;
    case X86_RTM:
      return features->rtm;
    case X86_RDSEED:
      return features->rdseed;
    case X86_CLFLUSHOPT:
      return features->clflushopt;
    case X86_CLWB:
      return features->clwb;
    case X86_SSE:
      return features->sse;
    case X86_SSE2:
      return features->sse2;
    case X86_SSE3:
      return features->sse3;
    case X86_SSSE3:
      return features->ssse3;
    case X86_SSE4_1:
      return features->sse4_1;
    case X86_SSE4_2:
      return features->sse4_2;
    case X86_SSE4A:
      return features->sse4a;
    case X86_AVX:
      return features->avx;
    case X86_AVX2:
      return features->avx2;
    case X86_AVX512F:
      return features->avx512f;
    case X86_AVX512CD:
      return features->avx512cd;
    case X86_AVX512ER:
      return features->avx512er;
    case X86_AVX512PF:
      return features->avx512pf;
    case X86_AVX512BW:
      return features->avx512bw;
    case X86_AVX512DQ:
      return features->avx512dq;
    case X86_AVX512VL:
      return features->avx512vl;
    case X86_AVX512IFMA:
      return features->avx512ifma;
    case X86_AVX512VBMI:
      return features->avx512vbmi;
    case X86_AVX512VBMI2:
      return features->avx512vbmi2;
    case X86_AVX512VNNI:
      return features->avx512vnni;
    case X86_AVX512BITALG:
      return features->avx512bitalg;
    case X86_AVX512VPOPCNTDQ:
      return features->avx512vpopcntdq;
    case X86_AVX512_4VNNIW:
      return features->avx512_4vnniw;
    case X86_AVX512_4VBMI2:
      return features->avx512_4vbmi2;
    case X86_AVX512_SECOND_FMA:
      return features->avx512_second_fma;
    case X86_AVX512_4FMAPS:
      return features->avx512_4fmaps;
    case X86_AVX512_BF16:
      return features->avx512_bf16;
    case X86_AVX512_VP2INTERSECT:
      return features->avx512_vp2intersect;
    case X86_AMX_BF16:
      return features->amx_bf16;
    case X86_AMX_TILE:
      return features->amx_tile;
    case X86_AMX_INT8:
      return features->amx_int8;
    case X86_PCLMULQDQ:
      return features->pclmulqdq;
    case X86_SMX:
      return features->smx;
    case X86_SGX:
      return features->sgx;
    case X86_CX16:
      return features->cx16;
    case X86_SHA:
      return features->sha;
    case X86_POPCNT:
      return features->popcnt;
    case X86_MOVBE:
      return features->movbe;
    case X86_RDRND:
      return features->rdrnd;
    case X86_DCA:
      return features->dca;
    case X86_SS:
      return features->ss;
    case X86_LAST_:
      break;
  }
  return false;
}

const char* GetX86FeaturesEnumName(X86FeaturesEnum value) {
  switch (value) {
    case X86_FPU:
      return "fpu";
    case X86_TSC:
      return "tsc";
    case X86_CX8:
      return "cx8";
    case X86_CLFSH:
      return "clfsh";
    case X86_MMX:
      return "mmx";
    case X86_AES:
      return "aes";
    case X86_ERMS:
      return "erms";
    case X86_F16C:
      return "f16c";
    case X86_FMA4:
      return "fma4";
    case X86_FMA3:
      return "fma3";
    case X86_VAES:
      return "vaes";
    case X86_VPCLMULQDQ:
      return "vpclmulqdq";
    case X86_BMI1:
      return "bmi1";
    case X86_HLE:
      return "hle";
    case X86_BMI2:
      return "bmi2";
    case X86_RTM:
      return "rtm";
    case X86_RDSEED:
      return "rdseed";
    case X86_CLFLUSHOPT:
      return "clflushopt";
    case X86_CLWB:
      return "clwb";
    case X86_SSE:
      return "sse";
    case X86_SSE2:
      return "sse2";
    case X86_SSE3:
      return "sse3";
    case X86_SSSE3:
      return "ssse3";
    case X86_SSE4_1:
      return "sse4_1";
    case X86_SSE4_2:
      return "sse4_2";
    case X86_SSE4A:
      return "sse4a";
    case X86_AVX:
      return "avx";
    case X86_AVX2:
      return "avx2";
    case X86_AVX512F:
      return "avx512f";
    case X86_AVX512CD:
      return "avx512cd";
    case X86_AVX512ER:
      return "avx512er";
    case X86_AVX512PF:
      return "avx512pf";
    case X86_AVX512BW:
      return "avx512bw";
    case X86_AVX512DQ:
      return "avx512dq";
    case X86_AVX512VL:
      return "avx512vl";
    case X86_AVX512IFMA:
      return "avx512ifma";
    case X86_AVX512VBMI:
      return "avx512vbmi";
    case X86_AVX512VBMI2:
      return "avx512vbmi2";
    case X86_AVX512VNNI:
      return "avx512vnni";
    case X86_AVX512BITALG:
      return "avx512bitalg";
    case X86_AVX512VPOPCNTDQ:
      return "avx512vpopcntdq";
    case X86_AVX512_4VNNIW:
      return "avx512_4vnniw";
    case X86_AVX512_4VBMI2:
      return "avx512_4vbmi2";
    case X86_AVX512_SECOND_FMA:
      return "avx512_second_fma";
    case X86_AVX512_4FMAPS:
      return "avx512_4fmaps";
    case X86_AVX512_BF16:
      return "avx512_bf16";
    case X86_AVX512_VP2INTERSECT:
      return "avx512_vp2intersect";
    case X86_AMX_BF16:
      return "amx_bf16";
    case X86_AMX_TILE:
      return "amx_tile";
    case X86_AMX_INT8:
      return "amx_int8";
    case X86_PCLMULQDQ:
      return "pclmulqdq";
    case X86_SMX:
      return "smx";
    case X86_SGX:
      return "sgx";
    case X86_CX16:
      return "cx16";
    case X86_SHA:
      return "sha";
    case X86_POPCNT:
      return "popcnt";
    case X86_MOVBE:
      return "movbe";
    case X86_RDRND:
      return "rdrnd";
    case X86_DCA:
      return "dca";
    case X86_SS:
      return "ss";
    case X86_LAST_:
      break;
  }
  return "unknown_feature";
}

const char* GetX86MicroarchitectureName(X86Microarchitecture uarch) {
  switch (uarch) {
    case X86_UNKNOWN:
      return "X86_UNKNOWN";
    case INTEL_CORE:
      return "INTEL_CORE";
    case INTEL_PNR:
      return "INTEL_PNR";
    case INTEL_NHM:
      return "INTEL_NHM";
    case INTEL_ATOM_BNL:
      return "INTEL_ATOM_BNL";
    case INTEL_WSM:
      return "INTEL_WSM";
    case INTEL_SNB:
      return "INTEL_SNB";
    case INTEL_IVB:
      return "INTEL_IVB";
    case INTEL_ATOM_SMT:
      return "INTEL_ATOM_SMT";
    case INTEL_HSW:
      return "INTEL_HSW";
    case INTEL_BDW:
      return "INTEL_BDW";
    case INTEL_SKL:
      return "INTEL_SKL";
    case INTEL_ATOM_GMT:
      return "INTEL_ATOM_GMT";
    case INTEL_KBL:
      return "INTEL_KBL";
    case INTEL_CFL:
      return "INTEL_CFL";
    case INTEL_WHL:
      return "INTEL_WHL";
    case INTEL_CNL:
      return "INTEL_CNL";
    case INTEL_ICL:
      return "INTEL_ICL";
    case INTEL_TGL:
      return "INTEL_TGL";
    case INTEL_SPR:
      return "INTEL_SPR";
    case AMD_HAMMER:
      return "AMD_HAMMER";
    case AMD_K10:
      return "AMD_K10";
    case AMD_BOBCAT:
      return "AMD_BOBCAT";
    case AMD_BULLDOZER:
      return "AMD_BULLDOZER";
    case AMD_JAGUAR:
      return "AMD_JAGUAR";
    case AMD_ZEN:
      return "AMD_ZEN";
  }
  return "unknown microarchitecture";
}