instruments.md

typedef struct Type {
  uint32_t v[2];
} Type;

memcpy1(){
  ...
  for(...) {
    b[i].v[0] = a[i].v[0];
    b[i].v[1] = a[i].v[1];
    b[i+1].v[0] = a[i+1].v[0];
    b[i+1].v[1] = a[i+1].v[1];
  }
  ...
}

memcpy2() {
  ...
  for(...) {
    uint32_t v1 = a[i].v[0];
    uint32_t v2 = a[i].v[1];
    uint32_t v3 = a[i+1].v[0];
    uint32_t v4 = a[i+1].v[1];

    b[i].v[0] = v1;
    b[i].v[1] = v2;
    b[i+1].v[0] = v3;
    b[i+1].v[1] = v4;
  }
  ...
}    

Instrumentsを使った計測での比較

TIME	time	L2_RQSTS.ALL_DEMAND_MISS	MEM_LOAD_RETIRED.L1_MISS	MEM_LOAD_RETIRED.L2_MISS
memcpy1	5365ms	13,478,515	218,870	572,849,861
memcpy2	3604ms	1,730,475	80,561	3,698,854