C语言 缓存模拟器
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时间：2020-09-02 11:00:45 来源:igfitidea点击:
Cache Simulator
提问by Lesha
I am writing a cache simulator. The idea is to given an input file with commands, trace the results of that input simulating cache functions so that we can keep track of cache hits and misses. I have written the following code but seem to be having trouble getting the proper output. I am posting my whole code because I dont want to make assumptions about where the problem may lie. Can anyone tell where I am making a mistake?
我正在编写一个缓存模拟器。这个想法是给一个带有命令的输入文件，跟踪该输入模拟缓存函数的结果，以便我们可以跟踪缓存命中和未命中。我编写了以下代码，但似乎无法获得正确的输出。我发布我的整个代码是因为我不想对问题可能出在哪里做出假设。谁能告诉我哪里出错了？
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include <strings.h>
#include "cachelab.h"
/* Always use a 64-bit variable to hold memory addresses*/
typedef unsigned long long int mem_addr_t;
/* a struct that groups cache parameters together */
typedef struct {
int s; /* 2**s cache sets */
int b; /* cacheline block size 2**b bytes */
int E; /* number of cachelines per set */
int S; /* number of sets, derived from S = 2**s */
int B; /* cacheline block size (bytes), derived from B = 2**b */
} cache_param_t;
int verbosity;
/*
* printUsage - Print usage info
*/
void printUsage(char* argv[])
{
printf("Usage: %s [-hv] -s <num> -E <num> -b <num> -t <file>\n", argv[0]);
printf("Options:\n");
printf(" -h Print this help message.\n");
printf(" -v Optional verbose flag.\n");
printf(" -s <num> Number of set index bits.\n");
printf(" -E <num> Number of lines per set.\n");
printf(" -b <num> Number of block offset bits.\n");
printf(" -t <file> Trace file.\n");
printf("\nExamples:\n");
printf(" %s -s 4 -E 1 -b 4 -t traces/yi.trace\n", argv[0]);
printf(" %s -v -s 8 -E 2 -b 4 -t traces/yi.trace\n", argv[0]);
exit(0);
}
int main(int argc, char **argv)
{
cache_param_t par;
bzero(&par, sizeof(par));
char *trace_file;
char c;
while( (c=getopt(argc,argv,"s:E:b:t:vh")) != -1){
switch(c){
case 's':
par.s = atoi(optarg);
break;
case 'E':
par.E = atoi(optarg);
break;
case 'b':
par.b = atoi(optarg);
break;
case 't':
trace_file = optarg;
break;
case 'v':
verbosity = 1;
break;
case 'h':
printUsage(argv);
exit(0);
default:
printUsage(argv);
exit(1);
}
}
if (par.s == 0 || par.E == 0 || par.b == 0 || trace_file == NULL) {
printf("%s: Missing required command line argument\n", argv[0]);
printUsage(argv);
exit(1);
}
/* TODO: Compute S and B based on information passed in */
//Compute S and B, 2^s and 2^b respectively
par.S = (1 << par.s);
par.B = (1 << par.b);
/* TODO: Initialize a cache */
//Structure for a line
typedef struct {
int valid;
mem_addr_t tag;
int timestamp;
} line_st;
//Structure for a set; a pointer to an array of lines
typedef struct {
line_st *lines;
} cache_set;
//Structure for a cache; a pointer to an array of sets
typedef struct {
cache_set *sets;
} cache_t;
//allocate space for sets and for lines
cache_t cache;
cache.sets = malloc(par.S * sizeof(cache_set));
for (int i = 0; i < par.S; i++) {
cache.sets[i].lines = malloc(sizeof(line_st) * par.E);
}
//counters
int hit_count = 0;
int miss_count = 0;
int eviction_count = 0;
/* TODO: Run the trace simulation */
char act; //L,S,M
int size; //size read in from file
int TSTAMP = 0; //value for LRU
int empty = -1; //index of empty space
int H = 0; //is there a hit
int E = 0; //is there an eviction
int toEvict = 0; //keeps track of what to evict
mem_addr_t addr;
//open the file and read it in
FILE * traceFile = fopen(trace_file, "r");
if (traceFile != NULL) {
//keep going while we have additional lines
//while(feof(traceFile) == 0) {
while(fscanf(traceFile, " %c %llx,%d", &act, &addr, &size) == 3){
if (act != 'I') {
//read the next line and look for string formated as " %c %llx,%d"
//sscanf(traceFile, " %c %llx,%d", &act, &addr, &size);
//fscanf(traceFile, " %c %llx,%d", &act, &addr, &size);
//calculate address tag and set index
mem_addr_t addr_tag = addr >> (par.s + par.b);
int tag_size = (64 - (par.s + par.b));
unsigned long long temp = addr << (tag_size);
unsigned long long setid = temp >> (tag_size + par.b);
//unsigned long long setid = ((addr >> par.b) & (par.S - 1));
cache_set set = cache.sets[setid];
int low = par.E + 1;
for(int e = 0; e < par.E; e++) {
if (set.lines[e].valid == 0) {
empty = e;
}
else if (set.lines[e].valid == 1){
if (TSTAMP < low) {
low = TSTAMP;
toEvict = e;
}
if (set.lines[e].tag == addr_tag) {
hit_count++;
H = 1;
set.lines[e].timestamp = TSTAMP;
TSTAMP++;
}
}
}
//if we have a miss
if (H != 1){
miss_count++;
//if we have an empty line
if (empty > -1) {
set.lines[empty].valid = 1;
set.lines[empty].tag = addr_tag;
set.lines[empty].timestamp = TSTAMP;
TSTAMP++;
}
//if the set is full we need to evict
else if (empty < 0) {
E = 1;
set.lines[toEvict].tag = addr_tag;
set.lines[toEvict].timestamp = TSTAMP;
eviction_count++;
}
}
//if the instruction is M, we will always get a hit
if (act == 'M') {
hit_count++;
}
//if the -v flag is set print out all debug information
if (verbosity == 1) {
printf("%c ", act);
//printf("%llx,%d ", addr_tag, setid);
printf("%llx,%d ", addr, size);
if (H == 1) {
printf("Hit ");
}
else if (H != 1) {
printf("Miss ");
}
if (E == 1) {
printf("Eviction ");
}
if (act == 'M') {
printf("Hit ");
}
printf("\n");
}
empty = -1;
H = 0;
E = 0;
}
}
}
/* TODO: Clean up cache resources */
/* TODO: Print out real results */
printSummary(hit_count, miss_count, eviction_count);
return 0;
}
I am running my code with the following sample input:
我正在使用以下示例输入运行我的代码：
S 00600aa0,1
S 7ff000384,4
L 7ff000384,4
L 7ff000384,4
L 00600a20,4
L 7ff000384,4
My code produces the following result:
我的代码产生以下结果：
./ -v -s 2 -E 2 -b 3 -t traces/test.trace
S 600aa0,1 Miss
S 7ff000384,4 Miss
L 7ff000384,4 Hit
L 7ff000384,4 Hit
L 600a20,4 Miss Eviction
L 7ff000384,4 Miss Eviction
hits:2 misses:4 evictions:2
but this is what it should be producing:
但这是它应该产生的：
./ -v -s 2 -E 2 -b 3 -t traces/test.trace
S 600aa0,1 miss
S 7ff000384,4 miss
L 7ff000384,4 hit
L 7ff000384,4 hit
L 600a20,4 miss eviction
L 7ff000384,4 hit
hits:3 misses:3 evictions:1
Can anyone tell what I am doing wrong?
谁能告诉我我做错了什么？
EDIT:
编辑：
Second test file:
第二个测试文件：
S 00600aa0,1
I 004005b6,5
I 004005bb,5
I 004005c0,5
S 7ff000398,8
I 0040051e,1
S 7ff000390,8
I 0040051f,3
I 00400522,4
S 7ff000378,8
I 00400526,4
S 7ff000370,8
I 0040052a,7
S 7ff000384,4
I 00400531,2
I 00400581,4
L 7ff000384,4
I 00400585,2
I 00400533,7
S 7ff000388,4
I 0040053a,2
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a20,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a60,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a24,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a70,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a28,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a80,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a2c,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a90,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040057d,4
M 7ff000384,4
I 00400581,4
L 7ff000384,4
I 00400585,2
I 00400533,7
S 7ff000388,4
I 0040053a,2
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a30,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a64,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a34,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a74,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a38,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a84,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a3c,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a94,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040057d,4
M 7ff000384,4
I 00400581,4
L 7ff000384,4
I 00400585,2
I 00400533,7
S 7ff000388,4
I 0040053a,2
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a40,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a68,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a44,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a78,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a48,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a88,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a4c,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a98,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040057d,4
M 7ff000384,4
I 00400581,4
L 7ff000384,4
I 00400585,2
I 00400533,7
S 7ff000388,4
I 0040053a,2
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a50,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a6c,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a54,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a7c,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a58,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a8c,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040053c,3
L 7ff000384,4
I 0040053f,2
I 00400541,4
I 00400545,3
I 00400548,4
L 7ff000378,8
I 0040054c,3
L 7ff000388,4
I 0040054f,2
I 00400551,3
L 00600a5c,4
I 00400554,3
S 7ff00038c,4
I 00400557,3
L 7ff000388,4
I 0040055a,2
I 0040055c,4
I 00400560,3
I 00400563,4
L 7ff000370,8
I 00400567,3
L 7ff000384,4
I 0040056a,3
I 0040056d,3
L 7ff00038c,4
I 00400570,3
S 00600a9c,4
I 00400573,4
M 7ff000388,4
I 00400577,4
L 7ff000388,4
I 0040057b,2
I 0040057d,4
M 7ff000384,4
I 00400581,4
L 7ff000384,4
I 00400585,2
I 00400587,1
L 7ff000390,8
I 00400588,1
L 7ff000398,8
I 004005c5,7
L 00600aa0,1
Expected Values:
预期值：
My simulator Reference simulator
(s,E,b) Hits Misses Evicts Hits Misses Evicts
(2,2,3) 196 42 34 201 37 29
(2,4,3) 208 30 14 212 26 10
采纳答案by JohnH
Tricky bug there. I changed the for-loop in the middle to only set emptyif it is already -1, so it will use the first empty spot found, then it won't change it again once it has found an empty spot. I also modified the initialization of lowto be INT_MAX and look for true least-recently used by changing the relevant elseconditions. I also re-ordered the code to look for a match BEFORE looking for eviction candidates, since finding a match freshens the cache timestamp. You also had forgotten to increment TSTAMP in the case of a Miss Eviction.
那里有棘手的错误。我将中间的 for 循环更改为仅empty在它已经是 -1时才设置，因此它将使用找到的第一个空位，然后一旦找到空位就不会再次更改它。我还修改了lowINT_MAX的初始化，并通过更改相关else条件来寻找真正的最近最少使用。我还重新排序了代码以在寻找驱逐候选之前寻找匹配，因为找到匹配会刷新缓存时间戳。您还忘记了在驱逐小姐的情况下增加 TSTAMP。
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>
#include <strings.h>
#include <limits.h>
//#include "cachelab.h"
/* Always use a 64-bit variable to hold memory addresses*/
typedef unsigned long long int mem_addr_t;
/* a struct that groups cache parameters together */
typedef struct
{
int s; /* 2**s cache sets */
int b; /* cacheline block size 2**b bytes */
int E; /* number of cachelines per set */
int S; /* number of sets, derived from S = 2**s */
int B; /* cacheline block size (bytes), derived from B = 2**b */
} cache_param_t;
int verbosity;
/* printUsage - Print usage info */
void printUsage( char *argv[] )
{
printf( "Usage: %s [-hv] -s <num> -E <num> -b <num> -t <file>\n", argv[0] );
printf( "Options:\n" );
printf( " -h Print this help message.\n" );
printf( " -v Optional verbose flag.\n" );
printf( " -s <num> Number of set index bits.\n" );
printf( " -E <num> Number of lines per set.\n" );
printf( " -b <num> Number of block offset bits.\n" );
printf( " -t <file> Trace file.\n" );
printf( "\nExamples:\n" );
printf( " %s -s 4 -E 1 -b 4 -t traces/yi.trace\n", argv[0] );
printf( " %s -v -s 8 -E 2 -b 4 -t traces/yi.trace\n", argv[0] );
exit( 0 );
}
void printSummary( int hit_count, int miss_count, int eviction_count )
{
printf( "hits: %d misses: %d evictions: %d\n", hit_count, miss_count, eviction_count );
}
int main( int argc, char **argv )
{
cache_param_t par;
bzero( &par, sizeof ( par ) );
char *trace_file;
char c;
while ( ( c = getopt( argc, argv, "s:E:b:t:vh" ) ) != -1 )
{
switch ( c )
{
case 's':
par.s = atoi( optarg );
break;
case 'E':
par.E = atoi( optarg );
break;
case 'b':
par.b = atoi( optarg );
break;
case 't':
trace_file = optarg;
break;
case 'v':
verbosity = 1;
break;
case 'h':
printUsage( argv );
exit( 0 );
default:
printUsage( argv );
exit( 1 );
}
}
if ( par.s == 0 || par.E == 0 || par.b == 0 || trace_file == NULL )
{
printf( "%s: Missing required command line argument\n", argv[0] );
printUsage( argv );
exit( 1 );
}
/* TODO: Compute S and B based on information passed in */
//Compute S and B, 2^s and 2^b respectively
par.S = ( 1 << par.s );
par.B = ( 1 << par.b );
/* TODO: Initialize a cache */
//Structure for a line
typedef struct
{
int valid;
mem_addr_t tag;
int timestamp;
} line_st;
//Structure for a set; a pointer to an array of lines
typedef struct
{
line_st *lines;
} cache_set;
//Structure for a cache; a pointer to an array of sets
typedef struct
{
cache_set *sets;
} cache_t;
//allocate space for sets and for lines
cache_t cache;
cache.sets = malloc( par.S * sizeof ( cache_set ) );
for ( int i = 0; i < par.S; i++ )
{
cache.sets[i].lines = malloc( sizeof ( line_st ) * par.E );
}
//counters
int hit_count = 0;
int miss_count = 0;
int eviction_count = 0;
/* TODO: Run the trace simulation */
char act; //L,S,M
int size; //size read in from file
int TSTAMP = 0; //value for LRU
int empty = -1; //index of empty space
int H = 0; //is there a hit
int E = 0; //is there an eviction
mem_addr_t addr;
//open the file and read it in
FILE *traceFile = fopen( trace_file, "r" );
if ( traceFile != NULL )
{
while ( fscanf( traceFile, " %c %llx,%d", &act, &addr, &size ) == 3 )
{
int toEvict = 0; //keeps track of what to evict
if ( act != 'I' )
{
//calculate address tag and set index
mem_addr_t addr_tag = addr >> ( par.s + par.b );
int tag_size = ( 64 - ( par.s + par.b ) );
unsigned long long temp = addr << ( tag_size );
unsigned long long setid = temp >> ( tag_size + par.b );
cache_set set = cache.sets[setid];
int low = INT_MAX; // CHANGED, also added #include <limits.h>
for ( int e = 0; e < par.E; e++ ) {
if ( set.lines[e].valid == 1 ) {
// CHANGED ORDER: look for hit before eviction candidates
if ( set.lines[e].tag == addr_tag ) {
hit_count++;
H = 1;
set.lines[e].timestamp = TSTAMP;
TSTAMP++;
}
// CHANGED WHOLE ELSE: look for oldest for eviction.
else if ( set.lines[e].timestamp < low ) {
low = set.lines[e].timestamp;
toEvict = e;
}
}
// CHANGED: if we haven't yet found an empty, mark one that we found.
else if( empty == -1 ) {
empty = e;
}
}
//if we have a miss
if ( H != 1 )
{
miss_count++;
//if we have an empty line
if ( empty > -1 )
{
set.lines[empty].valid = 1;
set.lines[empty].tag = addr_tag;
set.lines[empty].timestamp = TSTAMP;
TSTAMP++;
}
//if the set is full we need to evict
else if ( empty < 0 )
{
E = 1;
set.lines[toEvict].tag = addr_tag;
set.lines[toEvict].timestamp = TSTAMP;
TSTAMP++; // CHANGED: increment TSTAMP here too
eviction_count++;
}
}
//if the instruction is M, we will always get a hit
if ( act == 'M' )
{
hit_count++;
}
//if the -v flag is set print out all debug information
if ( verbosity == 1 )
{
printf( "%c ", act );
printf( "%llx,%d", addr, size );
if ( H == 1 )
{
printf( "Hit " );
}
else if ( H != 1 )
{
printf( "Miss " );
}
if ( E == 1 )
{
printf( "Eviction " );
}
// CHANGED: don't print Hit again since 'M' is always going to print Hit above.
printf( "\n" );
}
empty = -1;
H = 0;
E = 0;
}
}
}
/* TODO: Clean up cache resources */
/* TODO: Print out real results */
printSummary( hit_count, miss_count, eviction_count );
return 0;
}
My results:
我的结果：
$ ./ca2 -s 2 -E 2 -b 3 -t f2.trace
hits: 201 misses: 37 evictions: 29
$ ./ca2 -s 2 -E 4 -b 3 -t f2.trace
hits: 212 misses: 26 evictions: 10
