add cpu caching tester.
All checks were successful
continuous-integration/drone/push Build is passing
All checks were successful
continuous-integration/drone/push Build is passing
This commit is contained in:
parent
5f339eaa55
commit
e6dfd24678
@ -21,4 +21,7 @@ steps:
|
||||
|
||||
- cd misc || exit
|
||||
- g++ sizeof.cpp -o sizeof && ./sizeof
|
||||
- g++ caching.cpp -o caching && ./caching
|
||||
- echo "following program fails to show the effect of 'likely' due to CPU branch predictor."
|
||||
- g++ likely.cpp -o likely && ./likely
|
||||
- cd -
|
53
misc/caching.cpp
Normal file
53
misc/caching.cpp
Normal file
@ -0,0 +1,53 @@
|
||||
#include <iostream>
|
||||
#include <sys/time.h>
|
||||
#include <random>
|
||||
|
||||
using namespace std;
|
||||
|
||||
const int SIZE = 256 * 1024 * 1024;
|
||||
const int pagenum = 16 * 1024;
|
||||
const int pagesize = SIZE / pagenum;
|
||||
|
||||
void xorsum_seq(int *data)
|
||||
{
|
||||
int xorsum = 0;
|
||||
timeval start, end;
|
||||
gettimeofday(&start, nullptr);
|
||||
for (int page = 0; page < pagenum; page++)
|
||||
{
|
||||
for (int idx = 0; idx < pagesize; idx++)
|
||||
xorsum ^= data[page * pagesize + idx];
|
||||
}
|
||||
|
||||
gettimeofday(&end, nullptr);
|
||||
double usec = (end.tv_sec - start.tv_sec) + (double)(end.tv_usec - start.tv_usec) / 1000000;
|
||||
cout << __func__ << " duration: " << usec << ", xorsum: " << xorsum << endl;
|
||||
}
|
||||
|
||||
void xorsum_jmp(int *data)
|
||||
{
|
||||
int xorsum = 0;
|
||||
timeval start, end;
|
||||
gettimeofday(&start, nullptr);
|
||||
for (int idx = 0; idx < pagesize; idx++)
|
||||
{
|
||||
for (int page = 0; page < pagenum; page++)
|
||||
xorsum ^= data[page * pagesize + idx];
|
||||
}
|
||||
gettimeofday(&end, nullptr);
|
||||
double usec = (end.tv_sec - start.tv_sec) + (double)(end.tv_usec - start.tv_usec) / 1000000;
|
||||
cout << __func__ << " duration: " << usec << ", xorsum: " << xorsum << endl;
|
||||
}
|
||||
|
||||
int main()
|
||||
{
|
||||
int *data = new int[SIZE];
|
||||
int xorsum = 0;
|
||||
srand(time(nullptr));
|
||||
for (int idx = 0; idx < SIZE; idx++)
|
||||
{
|
||||
data[idx] = rand();
|
||||
}
|
||||
xorsum_seq(data);
|
||||
xorsum_jmp(data);
|
||||
}
|
Loading…
Reference in New Issue
Block a user