cache lab

struct cache
├── struct cacheSet
    ├── struct setLine
        ├── int valid
        ├── int tag
        ├── char* block
        └── (help) int timeStamp


typedef struct{
	// Three fundamental parameters in perline 
	int valid;
	unsigned long long tag;
	char *block;
	// choose which to evict in LRU
	int timeStamp;
} setLine;

//set struct
typedef struct{
	setLine *lines;
} cacheSet;

//cache struct
typedef struct{
	cacheSet *sets;
} cache;

ypedef struct{
	int s;//Number of set index bits (S = 2^s is the number of sets)
    int S;//S=2^s
    int b;//Number of block bits (B = 2^b is the block size)
    int B;//B=2^b
    int E;//Associativity (number of lines per set)
    int verbosity;//Optional verbose flag that displays trace info
    
    //LRU output
    int hitNum;
    int missNum;
    int evictionNum;
} cachePara;


int main(int argc, char** argv){
	//init cache structure
	cache LRUcache;
    cachePara parameters;
    parameters.verbosity=0;

    //use getopt.h to read data from terminal, store them in parameters(1)
    char input;
    char *trace;
    while( (input=getopt(argc,argv,"s:E:b:t:vh")) != -1){
        switch(input){
        case 's':
            parameters.s = atoi(optarg);
            break;
        case 'E':
            parameters.E = atoi(optarg);
            break;
        case 'b':
           parameters.b = atoi(optarg);
            break;
        case 't':
            trace = optarg;
            break;
        case 'v':
            parameters.verbosity = 1;
            break;
        // print parameter prototype
        case 'h':
            printUsage();
            exit(0);
        default:
            printUsage();
            exit(-1);
        }
    }

    //init parameters(2)
    parameters.S = pow(2.0,parameters.s);
    parameters.B = pow(2.0,parameters.b);
    parameters.missNum = 0;
    parameters.hitNum = 0;
    parameters.evictionNum = 0;

    //cache init
    LRUcache = initCache(parameters);

    //imput trace file while simulation
    char command;
    int size;
    unsigned long long address;
    FILE *file;
    file=fopen(trace,"r");
    while(fscanf(file," %c %llx,%d",&command,&address,&size)==3){
    	switch(command){
    		case 'I':
                break;
    		case 'L': //Load
                parameters = simulate(LRUcache, parameters, address);
                break;
            case 'S': //Store
                parameters = simulate(LRUcache, parameters, address);
                break;
            case 'M': //Modify
                parameters = simulate(LRUcache, parameters, address);
                parameters = simulate(LRUcache, parameters, address);	
                break;
            default: //ignore 'I'
                break;
    	}
    }
    printSummary(parameters.hitNum,parameters.missNum,parameters.evictionNum);
    fclose(file);

    return 0;
}


cachePara simulate(cache currentCache, cachePara parameters, unsigned long long address){
    //get the tag
	int tagSize = 64-(parameters.b + parameters.s); //64 bit system
    unsigned long long tag = address >> (parameters.s + parameters.b);
    //get the set index
    unsigned long long tmp = address << (tagSize);
    unsigned long long setIndex = tmp >> (tagSize + parameters.b);
    cacheSet set = currentCache.sets[setIndex];
    
    int flag=1;//1 to hit, 0 not;

    //simulation hit
    for(int i=0;i<parameters.E;i++){
    	setLine currentLine=set.lines[i];
    	if(checkHit(currentLine,tag)==1){
    		parameters.hitNum++;
            flag=0;
            int tail=checkTail(set, parameters);
            set.lines[i].timeStamp = set.lines[tail].timeStamp+1;
    	}
    }

    //simulation miss load
    if(flag && checkFull(set,parameters)){
    	parameters.missNum++;
    	int loadIndex= checkLoad(set,parameters);
    	set.lines[loadIndex].valid=1;
    	set.lines[loadIndex].tag=tag;
    	int tail=checkTail(set,parameters);
    	set.lines[loadIndex].timeStamp=set.lines[tail].timeStamp+1;
    }
    else if(flag){
        parameters.missNum++;
        parameters.evictionNum++;
        int evictIndex= checkEvict(set,parameters);
        set.lines[evictIndex].valid=1;
        set.lines[evictIndex].tag=tag;
        int tail= checkTail(set,parameters);
    	set.lines[evictIndex].timeStamp=set.lines[tail].timeStamp+1;
    }
    return parameters;
}