Chapter 1.1 : The main.cpp file

First, we have to include the appropriate files :
1
2
3
#include <iostream>

using namespace std;
Then, we define our hadamard kernel :
1
2
3
4
5
6
7
8
9
10
11
///Do the Hadamard product
/**	@param[out] tabResult : table of results of tabX*tabY
 * 	@param tabX : input table
 * 	@param tabY : input table
 * 	@param nbElement : number of elements in the tables
*/
void hadamard_product(float* tabResult, const float* tabX, const float* tabY, long unsigned int nbElement){
	for(long unsigned int i(0lu); i < nbElement; ++i){
		tabResult[i] = tabX[i]*tabY[i];
	}
}
We add the function to evaluate our kernel :
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
///Get the number of cycles per elements of the Hadamard product
/**	@param nbElement : number of elements of the tables
*/
void evaluateHadamardProduct(long unsigned int nbElement){
	//Allocation of the tables
	float * tabResult = new float[nbElement];
	float * tabX = new float[nbElement];
	float * tabY = new float[nbElement];
	//Initialisation of the tables
	for(long unsigned int i(0lu); i < nbElement; ++i){
		tabX[i] = (float)(i*32lu%17lu);
		tabY[i] = (float)(i*57lu%31lu);
	}
	//Do the hadamard product
	hadamard_product(tabResult, tabX, tabY, 4000lu);
	
	cout << "tabResult[0] = " << tabResult[0] << endl;
	
	//Deallocate the tables
	delete[] tabResult;
	delete[] tabX;
	delete[] tabY;
}
Finally, we call the function to evaluate several points in order to make plots :
1
2
3
4
5
6
7
8
9
int main(int argc, char** argv){
	cout << "Hadamard product" << endl;
	evaluateHadamardProduct(1000lu);
	evaluateHadamardProduct(2000lu);
	evaluateHadamardProduct(3000lu);
	evaluateHadamardProduct(5000lu);
	evaluateHadamardProduct(10000lu);
	return 0;
}
The full main.cpp file :
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
/***************************************
	Auteur : Pierre Aubert
	Mail : aubertp7@gmail.com
	Licence : CeCILL-C
****************************************/

#include <iostream>

using namespace std;

///Do the Hadamard product
/**	@param[out] tabResult : table of results of tabX*tabY
 * 	@param tabX : input table
 * 	@param tabY : input table
 * 	@param nbElement : number of elements in the tables
*/
void hadamard_product(float* tabResult, const float* tabX, const float* tabY, long unsigned int nbElement){
	for(long unsigned int i(0lu); i < nbElement; ++i){
		tabResult[i] = tabX[i]*tabY[i];
	}
}

///Get the number of cycles per elements of the Hadamard product
/**	@param nbElement : number of elements of the tables
*/
void evaluateHadamardProduct(long unsigned int nbElement){
	//Allocation of the tables
	float * tabResult = new float[nbElement];
	float * tabX = new float[nbElement];
	float * tabY = new float[nbElement];
	//Initialisation of the tables
	for(long unsigned int i(0lu); i < nbElement; ++i){
		tabX[i] = (float)(i*32lu%17lu);
		tabY[i] = (float)(i*57lu%31lu);
	}
	//Do the hadamard product
	hadamard_product(tabResult, tabX, tabY, 4000lu);
	
	cout << "tabResult[0] = " << tabResult[0] << endl;
	
	//Deallocate the tables
	delete[] tabResult;
	delete[] tabX;
	delete[] tabY;
}

int main(int argc, char** argv){
	cout << "Hadamard product" << endl;
	evaluateHadamardProduct(1000lu);
	evaluateHadamardProduct(2000lu);
	evaluateHadamardProduct(3000lu);
	evaluateHadamardProduct(5000lu);
	evaluateHadamardProduct(10000lu);
	return 0;
}
You can get the file here.