Function CanAccelerateCRC32C

src/leveldb/util/crc32c.cc:267–274

Determine if the CPU running this program can accelerate the CRC32C calculation.

// Determine if the CPU running this program can accelerate the CRC32C
// calculation.
static bool CanAccelerateCRC32C() {
  // port::AcceleretedCRC32C returns zero when unable to accelerate.
  static const char kTestCRCBuffer[] = "TestCRCBuffer";
  static const char kBufSize = sizeof(kTestCRCBuffer) - 1;
  static const uint32_t kTestCRCValue = 0xdcbc59fa;

  return port::AcceleratedCRC32C(0, kTestCRCBuffer, kBufSize) == kTestCRCValue;
}

uint32_t Extend(uint32_t crc, const char* data, size_t n) {
  static bool accelerate = CanAccelerateCRC32C();