Question

我已经逐字地复制了这个video的代码并试图运行它，但是我收到了以下错误：

hw5.c:9:15: error: expected declaration specifiers or '...' before numeric constant hw5.c: In function 'print_hit_ratio': hw5.c:29:3: warning: unknown conversion type character 0xa in format [-Wformat] hw5.c: In function 'write_cache_table': hw5.c:59:10: error: 'cache_tag' undeclared (first use in this function) hw5.c:59:10: note: each undeclared identifier is reported only once for each function it appears in hw5.c: In function 'main': hw5.c:95:27: error: lvalue required as left operand of assignment hw5.c:105:31: error: 'cache_tag' undeclared (first use in this function) hw5.c:116:28: error: lvalue required as left operand of assignment1

我会发布整个代码。我看到有人问了一个关于第一个错误的类似问题，所以我接受了把它放在我的主要内部但没有做任何事情的建议。

#include <stdlib.h>
#include <stdio.h>

#define stream 1                //0 to run, 1 for cache.out
#define main_memory 1024
#define cache_line 10
#define cache_block_size 8      //8 wwords in each cache line

int cache_tag(cache_line);      //tag. if cache_tag[i] = 0 its a MISS

int total_memory_access = 0;    //amount of memory access or address request

int total_hit = 0;              //number of cache hits



//print the hit ratio



void print_hit_ratio(void){



float ratio;

  if (total_hit == 0)

    ratio = 0;

  else

   ratio = (float)total_hit / (float)total_memory_access;



//get percentage

  ratio *= 100;

  if(total_hit == 0)

   ratio = 0;



  printf("Hit ratio:%.2f%\n", ratio);

}



//print contents of the cache table

void write_cache_table(void){

  int i, j;

  FILE *ofp;            //output file pointer

  if (stream)

    ofp = fopen("cache.out", "w");

  else

    ofp = stdout;



  //print table header

  fprintf(ofp, "%6s|", "Lines ");

  for (i = 0; i < cache_block_size; i++){

    fprintf(ofp,"%6d|",i);

  }

  fprintf(ofp,"\n");



  for (i = -1; i<cache_block_size; i++){

    fprintf(ofp, "-------");

  }

  fprintf(ofp,"\n”);

//loop each each line

  for(i = 0; i<cache_line;i++){
    fprintf(ofp, "%6d|",i);
    for(j=0;j<cache_block_size;j++){
      //empty cache
      if(cache_tag[i]==0)
        fprintf(ofp,"%6d|",0);
      else
        fprintf(ofp,"%6d|",cache_tag[i]+j);
    }
    fprintf(ofp,"\n");
  }
  if(stream)
    fclose(ofp);
}

int usage(void){
  printf("Please pass a file\n");
  printf("Usage: cachesim <file>\n");
  return -1;
}

int main(int argc, char *argv[]){

  FILE *ifp;                            //input file
  int address_requested = 0;            //address requested

  if(argc != 2)
    exit(usage());

  //read input file from command line
  ifp = fopen(argv[1], "r");
  if(ifp == NULL) {
    printf("File does not exist\n", argv[1]);
    exit(usage());
  }

//CODE BEGINS HERE

  int i;
  for (i=0;i<cache_line;i++){
    cache_tag(cache_line) = 0;
  }

  int lastwrote = -1;

  //read input file and store CPU request in address_requested
  while(fscanf(ifp, "%d\n", &address_requested) != EOF){
    int done = 0;

    for(i = 0;i<cache_line;i++){

if(address_requested >= cache_tag[i] &&
      (address_requested - cache_tag[i] < cache_block_size)){

        total_hit++;
        done = 1;
        break;
      }
    }

    if(done == 0){
      lastwrote = (++lastwrote)%cache_line;
      cache_tag(lastwrote) = address_requested;
    }

    total_memory_access++;

  }
//END CODE

  print_hit_ratio();
  write_cache_table();
  fclose(ifp);
}

Answer 1

你困惑（）和[]。改变所有出现的

cache_tag(XX)

到

cache_tag[XX]

C错误中的缓存模拟器

1 个答案: