check_cxx_source_compiles("
#include <arm_neon.h>
#include <stdint.h>
int main() {
  uint8_t val = 3, dup[8];
  uint8x16_t v1 = vld1q_dup_u8(&val);
  uint8x16_t v2 = vqtbl1q_u8(v1, v1);
  vst1q_u8(dup, v1);
  vst1q_u8(dup, v2);
  return 0;
}" SNAPPY_HAVE_NEON)