src/dsp/cpu.c

// Copyright 2011 Google Inc. All Rights Reserved.
//
// This code is licensed under the same terms as WebM:
//  Software License Agreement:  http://www.webmproject.org/license/software/
//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// CPU detection
//
// Author: Christian Duvivier (cduvivier@google.com)

#include "./dsp.h"

#if defined(__ANDROID__)
#include "./cpu-features.h"
#endif

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

//------------------------------------------------------------------------------
// SSE2 detection.
//

// apple/darwin gcc-4.0.1 defines __PIC__, but not __pic__ with -fPIC.
#if (defined(__pic__) || defined(__PIC__)) && defined(__i386__)
static WEBP_INLINE void GetCPUInfo(int cpu_info[4], int info_type) {
  __asm__ volatile (
    "mov %%ebx, %%edi\n"
    "cpuid\n"
    "xchg %%edi, %%ebx\n"
    : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
    : "a"(info_type));
}
#elif defined(__i386__) || defined(__x86_64__)
static WEBP_INLINE void GetCPUInfo(int cpu_info[4], int info_type) {
  __asm__ volatile (
    "cpuid\n"
    : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
    : "a"(info_type));
}
#elif defined(WEBP_MSC_SSE2)
#define GetCPUInfo __cpuid
#endif

#if defined(__i386__) || defined(__x86_64__) || defined(WEBP_MSC_SSE2)
static int x86CPUInfo(CPUFeature feature) {
  int cpu_info[4];
  GetCPUInfo(cpu_info, 1);
  if (feature == kSSE2) {
    return 0 != (cpu_info[3] & 0x04000000);
  }
  if (feature == kSSE3) {
    return 0 != (cpu_info[2] & 0x00000001);
  }
  return 0;
}
VP8CPUInfo VP8GetCPUInfo = x86CPUInfo;
#elif defined(WEBP_ANDROID_NEON)
static int AndroidCPUInfo(CPUFeature feature) {
  const AndroidCpuFamily cpu_family = android_getCpuFamily();
  const uint64_t cpu_features = android_getCpuFeatures();
  if (feature == kNEON) {
    return (cpu_family == ANDROID_CPU_FAMILY_ARM &&
            0 != (cpu_features & ANDROID_CPU_ARM_FEATURE_NEON));
  }
  return 0;
}
VP8CPUInfo VP8GetCPUInfo = AndroidCPUInfo;
#elif defined(__ARM_NEON__)
// define a dummy function to enable turning off NEON at runtime by setting
// VP8DecGetCPUInfo = NULL
static int armCPUInfo(CPUFeature feature) {
  (void)feature;
  return 1;
}
VP8CPUInfo VP8GetCPUInfo = armCPUInfo;
#else
VP8CPUInfo VP8GetCPUInfo = NULL;
#endif

#if defined(__cplusplus) || defined(c_plusplus)
}    // extern "C"
#endif