Refactor ARM NEON code

libpopcnt.h

@@ -680,39 +680,32 @@ static inline uint64_t popcnt(const void* data, uint64_t size)
  const uint8_t* ptr = (const uint8_t*) data;
  uint64_t cnt = 0;
  uint64_t tmp[2];
- uint64_t chunk_size = 128;
+ uint64_t chunk_size = 64;
  uint64_t n = size / chunk_size;
- uint64_t is_sum = 14;
+ uint64_t is_sum = 30;
  uint64_t i;
 
- uint8x16x4_t input0;
- uint8x16x4_t input1;
-
  uint64x2_t sum = vcombine_u64(vcreate_u64(0), vcreate_u64(0));
  uint8x16_t zero = vcombine_u8(vcreate_u8(0), vcreate_u8(0));
 
  uint8x16_t t0 = zero;
  uint8x16_t t1 = zero;
  uint8x16_t t2 = zero;
  uint8x16_t t3 = zero;
+ uint8x16x4_t input;
 
  for (i = 0; i < n; i++, ptr += chunk_size)
  {
- input0 = vld4q_u8(ptr);
- input1 = vld4q_u8(ptr + 64);
-
- t0 = vaddq_u8(t0, vcntq_u8(input0.val[0]));
- t1 = vaddq_u8(t1, vcntq_u8(input0.val[1]));
- t2 = vaddq_u8(t2, vcntq_u8(input0.val[2]));
- t3 = vaddq_u8(t3, vcntq_u8(input0.val[3]));
- t0 = vaddq_u8(t0, vcntq_u8(input1.val[0]));
- t1 = vaddq_u8(t1, vcntq_u8(input1.val[1]));
- t2 = vaddq_u8(t2, vcntq_u8(input1.val[2]));
- t3 = vaddq_u8(t3, vcntq_u8(input1.val[3]));
+ input = vld4q_u8(ptr);
+
+ t0 = vaddq_u8(t0, vcntq_u8(input.val[0]));
+ t1 = vaddq_u8(t1, vcntq_u8(input.val[1]));
+ t2 = vaddq_u8(t2, vcntq_u8(input.val[2]));
+ t3 = vaddq_u8(t3, vcntq_u8(input.val[3]));
 
  if (i == is_sum)
  {
- is_sum += 14;
+ is_sum += 30;
  sum = vpadalq(sum, t0);
  sum = vpadalq(sum, t1);
  sum = vpadalq(sum, t2);