/*

 *  Copyright 2011 The LibYuv Project Authors. All rights reserved.

 *

 *  Use of this source code is governed by a BSD-style license

 *  that can be found in the LICENSE file in the root of the source

 *  tree. An additional intellectual property rights grant can be found

 *  in the file PATENTS. All contributing project authors may

 *  be found in the AUTHORS file in the root of the source tree.

 */

#include "libyuv/cpu_id.h"

#if defined(_MSC_VER)

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

#endif

#if !defined(__pnacl__) && !defined(__CLR_VER) &&                           \

    !defined(__native_client__) && (defined(_M_IX86) || defined(_M_X64)) && \

    defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)

#include <immintrin.h>  // For _xgetbv()

#endif

// For ArmCpuCaps() but unittested on all platforms

#include <stdio.h>  // For fopen()

#include <string.h>

#if defined(__linux__) && (defined(__aarch64__) || defined(__loongarch__))

#include <sys/auxv.h>  // For getauxval()

#endif

#if defined(_WIN32) && defined(__aarch64__)

#undef WIN32_LEAN_AND_MEAN

#define WIN32_LEAN_AND_MEAN

#undef WIN32_EXTRA_LEAN

#define WIN32_EXTRA_LEAN

#include <windows.h>  // For IsProcessorFeaturePresent()

#endif

#if defined(__APPLE__) && defined(__aarch64__)

#include <sys/sysctl.h>  // For sysctlbyname()

#endif

#ifdef __cplusplus

namespace libyuv {

extern "C" {

#endif

// For functions that use the stack and have runtime checks for overflow,

// use SAFEBUFFERS to avoid additional check.

#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) && \

    !defined(__clang__)

#define SAFEBUFFERS __declspec(safebuffers)

#else

#define SAFEBUFFERS

#endif

// cpu_info_ variable for SIMD instruction sets detected.

LIBYUV_API int cpu_info_ = 0;

// Low level cpuid for X86.

#if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \

     defined(__x86_64__)) &&                                     \

    !defined(__pnacl__) && !defined(__CLR_VER)

LIBYUV_API

void CpuId(int info_eax, int info_ecx, int* cpu_info) {

#if defined(_MSC_VER)

// Visual C version uses intrinsic or inline x86 assembly.

#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)

  __cpuidex(cpu_info, info_eax, info_ecx);

#elif defined(_M_IX86)

  __asm {

    mov        eax, info_eax

    mov        ecx, info_ecx

    mov        edi, cpu_info

    cpuid

    mov        [edi], eax

    mov        [edi + 4], ebx

    mov        [edi + 8], ecx

    mov        [edi + 12], edx

  }

#else  // Visual C but not x86

  if (info_ecx == 0) {

    __cpuid(cpu_info, info_eax);

  } else {

    cpu_info[3] = cpu_info[2] = cpu_info[1] = cpu_info[0] = 0u;

  }

#endif

// GCC version uses inline x86 assembly.

#else  // defined(_MSC_VER)

  int info_ebx, info_edx;

  asm volatile(

#if defined(__i386__) && defined(__PIC__)

      // Preserve ebx for fpic 32 bit.

      "mov         %%ebx, %%edi                  \n"

      "cpuid                                     \n"

      "xchg        %%edi, %%ebx                  \n"

      : "=D"(info_ebx),

#else

      "cpuid                                     \n"

      : "=b"(info_ebx),

#endif  //  defined( __i386__) && defined(__PIC__)

        "+a"(info_eax), "+c"(info_ecx), "=d"(info_edx));

  cpu_info[0] = info_eax;

  cpu_info[1] = info_ebx;

  cpu_info[2] = info_ecx;

  cpu_info[3] = info_edx;

#endif  // defined(_MSC_VER)

}

#else  // (defined(_M_IX86) || defined(_M_X64) ...

LIBYUV_API

void CpuId(int eax, int ecx, int* cpu_info) {

  (void)eax;

  (void)ecx;

  cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0;

}

#endif

// For VS2010 and earlier emit can be used:

//   _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0  // For VS2010 and earlier.

//  __asm {

//    xor        ecx, ecx    // xcr 0

//    xgetbv

//    mov        xcr0, eax

//  }

// For VS2013 and earlier 32 bit, the _xgetbv(0) optimizer produces bad code.

// https://code.google.com/p/libyuv/issues/detail?id=529

#if defined(_M_IX86) && defined(_MSC_VER) && (_MSC_VER < 1900)

#pragma optimize("g", off)

#endif

#if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \

     defined(__x86_64__)) &&                                     \

    !defined(__pnacl__) && !defined(__CLR_VER) && !defined(__native_client__)

// X86 CPUs have xgetbv to detect OS saves high parts of ymm registers.

static int GetXCR0() {

  int xcr0 = 0;

#if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219)

  xcr0 = (int)_xgetbv(0);  // VS2010 SP1 required.  NOLINT

#elif defined(__i386__) || defined(__x86_64__)

  asm(".byte 0x0f, 0x01, 0xd0" : "=a"(xcr0) : "c"(0) : "%edx");

#endif  // defined(__i386__) || defined(__x86_64__)

  return xcr0;

}

#else

// xgetbv unavailable to query for OSSave support.  Return 0.

#define GetXCR0() 0

#endif  // defined(_M_IX86) || defined(_M_X64) ..

// Return optimization to previous setting.

#if defined(_M_IX86) && defined(_MSC_VER) && (_MSC_VER < 1900)

#pragma optimize("g", on)

#endif

static int cpuinfo_search(const char* cpuinfo_line,

                          const char* needle,

                          int needle_len) {

  const char* p = strstr(cpuinfo_line, needle);

  return p && (p[needle_len] == ' ' || p[needle_len] == '\n');

}

// Based on libvpx arm_cpudetect.c

// For Arm, but public to allow testing on any CPU

LIBYUV_API SAFEBUFFERS int ArmCpuCaps(const char* cpuinfo_name) {

  char cpuinfo_line[512];

  FILE* f = fopen(cpuinfo_name, "re");

  if (!f) {

    // Assume Neon if /proc/cpuinfo is unavailable.

    // This will occur for Chrome sandbox for Pepper or Render process.

    return kCpuHasNEON;

  }

  memset(cpuinfo_line, 0, sizeof(cpuinfo_line));

  int features = 0;

  while (fgets(cpuinfo_line, sizeof(cpuinfo_line), f)) {

    if (memcmp(cpuinfo_line, "Features", 8) == 0) {

      if (cpuinfo_search(cpuinfo_line, " neon", 5)) {

        features |= kCpuHasNEON;

      }

    }

  }

  fclose(f);

  return features;

}

#ifdef __aarch64__

#ifdef __linux__

// Define hwcap values ourselves: building with an old auxv header where these

// hwcap values are not defined should not prevent features from being enabled.

#define YUV_AARCH64_HWCAP_ASIMDDP (1UL << 20)

#define YUV_AARCH64_HWCAP_SVE (1UL << 22)

#define YUV_AARCH64_HWCAP2_SVE2 (1UL << 1)

#define YUV_AARCH64_HWCAP2_SVEF32MM (1UL << 10)

#define YUV_AARCH64_HWCAP2_I8MM (1UL << 13)

#define YUV_AARCH64_HWCAP2_SME (1UL << 23)

#define YUV_AARCH64_HWCAP2_SME2 (1UL << 37)

// For AArch64, but public to allow testing on any CPU.

LIBYUV_API SAFEBUFFERS int AArch64CpuCaps(unsigned long hwcap,

                                          unsigned long hwcap2) {

  // Neon is mandatory on AArch64, so enable regardless of hwcaps.

  int features = kCpuHasNEON;

  // Don't try to enable later extensions unless earlier extensions are also

  // reported available. Some of these constraints aren't strictly required by

  // the architecture, but are satisfied by all micro-architectures of

  // interest. This also avoids an issue on some emulators where true

  // architectural constraints are not satisfied, e.g. SVE2 may be reported as

  // available while SVE is not.

  if (hwcap & YUV_AARCH64_HWCAP_ASIMDDP) {

    features |= kCpuHasNeonDotProd;

    if (hwcap2 & YUV_AARCH64_HWCAP2_I8MM) {

      features |= kCpuHasNeonI8MM;

      if (hwcap & YUV_AARCH64_HWCAP_SVE) {

        features |= kCpuHasSVE;

        if (hwcap2 & YUV_AARCH64_HWCAP2_SVEF32MM) {

          features |= kCpuHasSVEF32MM;

        }

        if (hwcap2 & YUV_AARCH64_HWCAP2_SVE2) {

          features |= kCpuHasSVE2;

        }

      }

      // SME may be present without SVE

      if (hwcap2 & YUV_AARCH64_HWCAP2_SME) {

        features |= kCpuHasSME;

        if (hwcap2 & YUV_AARCH64_HWCAP2_SME2) {

          features |= kCpuHasSME2;

        }

      }

    }

  }

  return features;

}

#elif defined(_WIN32)

// For AArch64, but public to allow testing on any CPU.

LIBYUV_API SAFEBUFFERS int AArch64CpuCaps() {

  // Neon is mandatory on AArch64, so enable unconditionally.

  int features = kCpuHasNEON;

  // For more information on IsProcessorFeaturePresent(), see:

  // https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-isprocessorfeaturepresent#parameters

#ifdef PF_ARM_V82_DP_INSTRUCTIONS_AVAILABLE

  if (IsProcessorFeaturePresent(PF_ARM_V82_DP_INSTRUCTIONS_AVAILABLE)) {

    features |= kCpuHasNeonDotProd;

  }

#endif

  // No Neon I8MM or SVE feature detection available here at time of writing.

  return features;

}

#elif defined(__APPLE__)

static bool have_feature(const char* feature) {

  // For more information on sysctlbyname(), see:

  // https://developer.apple.com/documentation/kernel/1387446-sysctlbyname/determining_instruction_set_characteristics

  int64_t feature_present = 0;

  size_t size = sizeof(feature_present);

  if (sysctlbyname(feature, &feature_present, &size, NULL, 0) != 0) {

    return false;

  }

  return feature_present;

}

// For AArch64, but public to allow testing on any CPU.

LIBYUV_API SAFEBUFFERS int AArch64CpuCaps() {

  // Neon is mandatory on AArch64, so enable unconditionally.

  int features = kCpuHasNEON;

  if (have_feature("hw.optional.arm.FEAT_DotProd")) {

    features |= kCpuHasNeonDotProd;

    if (have_feature("hw.optional.arm.FEAT_I8MM")) {

      features |= kCpuHasNeonI8MM;

      if (have_feature("hw.optional.arm.FEAT_SME")) {

        features |= kCpuHasSME;

        if (have_feature("hw.optional.arm.FEAT_SME2")) {

          features |= kCpuHasSME2;

        }

      }

    }

  }

  // No SVE feature detection available here at time of writing.

  return features;

}

#else  // !defined(__linux__) && !defined(_WIN32) && !defined(__APPLE__)

// For AArch64, but public to allow testing on any CPU.

LIBYUV_API SAFEBUFFERS int AArch64CpuCaps() {

  // Neon is mandatory on AArch64, so enable unconditionally.

  int features = kCpuHasNEON;

  // TODO(libyuv:980) support feature detection on other platforms.

  return features;

}

#endif

#endif  // defined(__aarch64__)

LIBYUV_API SAFEBUFFERS int RiscvCpuCaps(const char* cpuinfo_name) {

  char cpuinfo_line[512];

  int flag = 0;

  FILE* f = fopen(cpuinfo_name, "re");

  if (!f) {

#if defined(__riscv_vector)

    // Assume RVV if /proc/cpuinfo is unavailable.

    // This will occur for Chrome sandbox for Pepper or Render process.

    return kCpuHasRVV;

#else

    return 0;

#endif

  }

  memset(cpuinfo_line, 0, sizeof(cpuinfo_line));

  while (fgets(cpuinfo_line, sizeof(cpuinfo_line), f)) {

    if (memcmp(cpuinfo_line, "isa", 3) == 0) {

      // ISA string must begin with rv64{i,e,g} for a 64-bit processor.

      char* isa = strstr(cpuinfo_line, "rv64");

      if (isa) {

        size_t isa_len = strlen(isa);

        char* extensions;

        size_t extensions_len = 0;

        size_t std_isa_len;

        // Remove the new-line character at the end of string

        if (isa[isa_len - 1] == '\n') {

          isa[--isa_len] = '\0';

        }

        // 5 ISA characters

        if (isa_len < 5) {

          fclose(f);

          return 0;

        }

        // Skip {i,e,g} canonical checking.

        // Skip rvxxx

        isa += 5;

        // Find the very first occurrence of 's', 'x' or 'z'.

        // To detect multi-letter standard, non-standard, and

        // supervisor-level extensions.

        extensions = strpbrk(isa, "zxs");

        if (extensions) {

          extensions_len = strlen(extensions);

          // Multi-letter extensions are seperated by a single underscore

          // as described in RISC-V User-Level ISA V2.2.

          char* ext = extensions;

          while (ext) {

            char* next = strchr(ext, '_');

            if (next) {

              *next = '\0';

              next++;

            }

            // Search for the ZVFH (Vector FP16) extension.

            if (!strcmp(ext, "zvfh")) {

              flag |= kCpuHasRVVZVFH;

            }

            ext = next;

          }

        }

        std_isa_len = isa_len - extensions_len - 5;

        // Detect the v in the standard single-letter extensions.

        if (memchr(isa, 'v', std_isa_len)) {

          // The RVV implied the F extension.

          flag |= kCpuHasRVV;

        }

      }

    }

#if defined(__riscv_vector)

    // Assume RVV if /proc/cpuinfo is from x86 host running QEMU.

    else if ((memcmp(cpuinfo_line, "vendor_id\t: GenuineIntel", 24) == 0) ||

             (memcmp(cpuinfo_line, "vendor_id\t: AuthenticAMD", 24) == 0)) {

      fclose(f);

      return kCpuHasRVV;

    }

#endif

  }

  fclose(f);

  return flag;

}

#if defined(__loongarch__) && defined(__linux__)

// Define hwcap values ourselves: building with an old auxv header where these

// hwcap values are not defined should not prevent features from being enabled.

#define YUV_LOONGARCH_HWCAP_LSX (1 << 4)

#define YUV_LOONGARCH_HWCAP_LASX (1 << 5)

LIBYUV_API SAFEBUFFERS int LoongArchCpuCaps(void) {

  int flag = 0;

  unsigned long hwcap = getauxval(AT_HWCAP);

  if (hwcap & YUV_LOONGARCH_HWCAP_LSX)

    flag |= kCpuHasLSX;

  if (hwcap & YUV_LOONGARCH_HWCAP_LASX)

    flag |= kCpuHasLASX;

  return flag;

}

#endif

static SAFEBUFFERS int GetCpuFlags(void) {

  int cpu_info = 0;

#if !defined(__pnacl__) && !defined(__CLR_VER) &&                   \

    (defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || \

     defined(_M_IX86))

  int cpu_info0[4] = {0, 0, 0, 0};

  int cpu_info1[4] = {0, 0, 0, 0};

  int cpu_info7[4] = {0, 0, 0, 0};

  int cpu_einfo7[4] = {0, 0, 0, 0};

  int cpu_info24[4] = {0, 0, 0, 0};

  int cpu_amdinfo21[4] = {0, 0, 0, 0};

  CpuId(0, 0, cpu_info0);

  CpuId(1, 0, cpu_info1);

  if (cpu_info0[0] >= 7) {

    CpuId(7, 0, cpu_info7);

    CpuId(7, 1, cpu_einfo7);

    CpuId(0x80000021, 0, cpu_amdinfo21);

  }

  if (cpu_info0[0] >= 0x24) {

    CpuId(0x24, 0, cpu_info24);

  }

  cpu_info = kCpuHasX86 | ((cpu_info1[3] & 0x04000000) ? kCpuHasSSE2 : 0) |

             ((cpu_info1[2] & 0x00000200) ? kCpuHasSSSE3 : 0) |

             ((cpu_info1[2] & 0x00080000) ? kCpuHasSSE41 : 0) |

             ((cpu_info1[2] & 0x00100000) ? kCpuHasSSE42 : 0) |

             ((cpu_info7[1] & 0x00000200) ? kCpuHasERMS : 0) |

             ((cpu_info7[3] & 0x00000010) ? kCpuHasFSMR : 0);

  // AVX requires OS saves YMM registers.

  if (((cpu_info1[2] & 0x1c000000) == 0x1c000000) &&  // AVX and OSXSave

      ((GetXCR0() & 6) == 6)) {  // Test OS saves YMM registers

    cpu_info |= kCpuHasAVX | ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) |

                ((cpu_info1[2] & 0x00001000) ? kCpuHasFMA3 : 0) |

                ((cpu_info1[2] & 0x20000000) ? kCpuHasF16C : 0) |

                ((cpu_einfo7[0] & 0x00000010) ? kCpuHasAVXVNNI : 0) |

                ((cpu_einfo7[3] & 0x00000010) ? kCpuHasAVXVNNIINT8 : 0);

    cpu_info |= ((cpu_amdinfo21[0] & 0x00008000) ? kCpuHasERMS : 0);

    // Detect AVX512bw

    if ((GetXCR0() & 0xe0) == 0xe0 && (cpu_info7[1] & 0x00010000)) {

      cpu_info |= ((cpu_info7[1] & 0x40000000) ? kCpuHasAVX512BW : 0) |

                  ((cpu_info7[1] & 0x80000000) ? kCpuHasAVX512VL : 0) |

                  ((cpu_info7[2] & 0x00000002) ? kCpuHasAVX512VBMI : 0) |

                  ((cpu_info7[2] & 0x00000040) ? kCpuHasAVX512VBMI2 : 0) |

                  ((cpu_info7[2] & 0x00000800) ? kCpuHasAVX512VNNI : 0) |

                  ((cpu_info7[2] & 0x00001000) ? kCpuHasAVX512VBITALG : 0) |

                  ((cpu_einfo7[3] & 0x00080000) ? kCpuHasAVX10 : 0) |

                  ((cpu_info7[3] & 0x02000000) ? kCpuHasAMXINT8 : 0);

      if (cpu_info0[0] >= 0x24 && (cpu_einfo7[3] & 0x00080000)) {

        cpu_info |= ((cpu_info24[1] & 0xFF) >= 2) ? kCpuHasAVX10_2 : 0;

      }

    }

  }

#endif

#if defined(__loongarch__) && defined(__linux__)

  cpu_info = LoongArchCpuCaps();

  cpu_info |= kCpuHasLOONGARCH;

#endif

#if defined(__aarch64__)

#if defined(__linux__)

  // getauxval is supported since Android SDK version 18, minimum at time of

  // writing is 21, so should be safe to always use this. If getauxval is

  // somehow disabled then getauxval returns 0, which will leave Neon enabled

  // since Neon is mandatory on AArch64.

  unsigned long hwcap = getauxval(AT_HWCAP);

  unsigned long hwcap2 = getauxval(AT_HWCAP2);

  cpu_info = AArch64CpuCaps(hwcap, hwcap2);

#else

  cpu_info = AArch64CpuCaps();

#endif

  cpu_info |= kCpuHasARM;

#endif  // __aarch64__

#if defined(__arm__)

  // gcc -mfpu=neon defines __ARM_NEON__

  // __ARM_NEON__ generates code that requires Neon.  NaCL also requires Neon.

  // For Linux, /proc/cpuinfo can be tested but without that assume Neon.

  // Linux arm parse text file for neon detect.

#if defined(__linux__)

  cpu_info = ArmCpuCaps("/proc/cpuinfo");

#elif defined(__ARM_NEON__)

  cpu_info = kCpuHasNEON;

#else

  cpu_info = 0;

#endif

  cpu_info |= kCpuHasARM;

#endif  // __arm__

#if defined(__riscv) && defined(__linux__)

  cpu_info = RiscvCpuCaps("/proc/cpuinfo");

  cpu_info |= kCpuHasRISCV;

#endif  // __riscv

  cpu_info |= kCpuInitialized;

  return cpu_info;

}

// Note that use of this function is not thread safe.

LIBYUV_API

int MaskCpuFlags(int enable_flags) {

  int cpu_info = GetCpuFlags() & enable_flags;

  SetCpuFlags(cpu_info);

  return cpu_info;

}

LIBYUV_API

int InitCpuFlags(void) {

  return MaskCpuFlags(-1);

}

#ifdef __cplusplus

}  // extern "C"

}  // namespace libyuv

#endif