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hpc-2022-g3/atax/atax.cu

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#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
/* Include polybench common header. */
#include "polybench.hu"
/* Include benchmark-specific header. */
/* Default data type is double, default size is 4000. */
#include "atax.hu"
// Workaround for the editor not finding M_PI
// It is exclusive to the GNU C compiler
// https://www.gnu.org/software/libc/manual/html_node/Mathematical-Constants.html
#ifndef M_PI
#define M_PI 3.141
#endif
/**
* Initialize the arrays to be used in the computation:
*
* - `x` is filled with multiples of `M_PI`;
* - `A` is filled with sample data.
*
* To be called on the CPU (uses the `__host__` qualifier).
*/
__host__ static void init_array(DATA_TYPE** A, DATA_TYPE* X)
{
/* X = [ 3.14, 6.28, 9.42, ... ] */
for (unsigned int y = 0; y < NY; y++)
{
X[y] = y * M_PI;
}
/*
* A = [
* [ 0, 0, 0, 0, ... ],
* [ 1 / NX, 2 / NX, 3 / NX, 4 / NX, ... ],
* [ 2 / NX, 4 / NX, 6 / NX, 8 / NX, ... ],
* [ 3 / NX, 6 / NX, 9 / NX, 12 / NX, ... ],
* ...
* ]
*/
for (unsigned int x = 0; x < NX; x++)
{
for (unsigned int y = 0; y < NY; y++)
{
A[x][y] = (DATA_TYPE)(x * (y + 1)) / NX;
}
}
}
/**
* Print the given array.
*
* Cannot be parallelized, as the elements of the array should be
*
* To be called on the CPU (uses the `__host__` qualifier).
*/
__host__ static void print_array(DATA_TYPE* Y)
{
for (unsigned int x = 0; x < NX; x++)
{
fprintf(stderr, DATA_PRINTF_MODIFIER, Y[x]);
}
fprintf(stderr, "\n");
}
/**
* Compute ATAX.
*
* Parallelizing this is the goal of the assignment.
*
* Currently to be called on the CPU (uses the `__host__` qualifier), but we may probably want to change that soon.
*/
__host__ static void kernel_atax(DATA_TYPE** A, DATA_TYPE* X, DATA_TYPE* Y)
{
for (unsigned int x = 0; x < NY; x++)
{
Y[i] = 0;
}
for (unsigned int i = 0; i < NX; i++)
{
DATA_TYPE tmp = 0;
for (unsigned int j = 0; j < NY; j++)
{
tmp += A[i][j] * X[j];
}
for (unsigned int j = 0; j < NY; j++)
{
Y[j] = Y[j] + A[i][j] * tmp;
}
}
}
/**
* The main function of the benchmark, which sets up tooling to measure the time spent computing `kernel_atax`.
*
* We should probably avoid editing this.
*/
__host__ int main(int argc, char **argv)
{
// A[NY][NX]
DATA_TYPE** A = new DATA_TYPE*[NX] {};
for(int i = 0; i < NX; i++)
{
A[i] = new DATA_TYPE[NY];
}
DATA_TYPE* x = new DATA_TYPE[NY] {};
DATA_TYPE* y = new DATA_TYPE[NX] {};
#ifdef POLYBENCH_INCLUDE_INIT
polybench_start_instruments;
#endif
init_array(A, x);
#ifndef POLYBENCH_INCLUDE_INIT
polybench_start_instruments;
#endif
kernel_atax(A, x, y);
polybench_stop_instruments;
polybench_print_instruments;
/* Prevent dead-code elimination. All live-out data must be printed by the function call in argument. */
polybench_prevent_dce(print_array(y));
return 0;
}