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Cleanup and format a lot of the atax.cu file

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Steffo 2022-11-28 15:43:05 +01:00
parent 2f476affee
commit bf873d846c
Signed by: steffo
GPG key ID: 6965406171929D01
1 changed files with 41 additions and 40 deletions
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81
OpenMP/linear-algebra/kernels/atax/atax.cu
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@ -17,96 +17,97 @@
#define M_PI 3.141 #define M_PI 3.141
#endif #endif
/* Array initialization. */ /**
static void init_array(int nx, int ny, DATA_TYPE POLYBENCH_2D(A, NX, NY, nx, ny), DATA_TYPE POLYBENCH_1D(x, NY, ny)) * 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(int nx, int ny, DATA_TYPE POLYBENCH_2D(A, NX, NY, nx, ny), DATA_TYPE POLYBENCH_1D(x, NY, ny))
{ {
int i, j; for (int i = 0; i < ny; i++) {
/// Initialize the `x` array with PI and its multiples.
for (i = 0; i < ny; i++) {
x[i] = i * M_PI; x[i] = i * M_PI;
} }
/// Initialize the `A` matrix for (int i = 0; i < nx; i++) {
for (i = 0; i < nx; i++) { for (int j = 0; j < ny; j++) {
for (j = 0; j < ny; j++) {
A[i][j] = ((DATA_TYPE)i * (j + 1)) / nx; A[i][j] = ((DATA_TYPE)i * (j + 1)) / nx;
} }
} }
} }
/* DCE code. Must scan the entire live-out data. /**
Can be used also to check the correctness of the output. */ * Print the given array.
static void print_array(int nx, DATA_TYPE POLYBENCH_1D(y, NX, nx)) *
* 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(int nx, DATA_TYPE POLYBENCH_1D(y, NX, nx))
{ {
int i; int i;
/// Print all numbers in the array sequentially.
// Cannot parallelize this: prints have to be sequential to make sense!
for (i = 0; i < nx; i++) { for (i = 0; i < nx; i++) {
fprintf(stderr, DATA_PRINTF_MODIFIER, y[i]); fprintf(stderr, DATA_PRINTF_MODIFIER, y[i]);
} }
fprintf(stderr, "\n"); fprintf(stderr, "\n");
} }
/* Main computational kernel. The whole function will be timed,
including the call and return. */
static void kernel_atax(int nx, int ny, DATA_TYPE POLYBENCH_2D(A, NX, NY, nx, ny), DATA_TYPE POLYBENCH_1D(x, NY, ny), DATA_TYPE POLYBENCH_1D(y, NY, ny))
{
int i, j;
for (i = 0; i < _PB_NY; i++) /**
* 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(int nx, int ny, DATA_TYPE POLYBENCH_2D(A, NX, NY, nx, ny), DATA_TYPE POLYBENCH_1D(x, NY, ny), DATA_TYPE POLYBENCH_1D(y, NY, ny))
{
for (int i = 0; i < _PB_NY; i++) {
y[i] = 0; y[i] = 0;
}
/// This computes... something? I guess whatever ATAX is? for (int i = 0; i < _PB_NX; i++) {
// Now this gives a nice speedup, especially with a lot more threads than the count!
// THREAD_COUNT * 4 seems to be the best on my local computer. What's the best for the Jetson Nano?
for (i = 0; i < _PB_NX; i++)
{
/// Every iteration has its own tmp variable
DATA_TYPE tmp = 0; DATA_TYPE tmp = 0;
for (j = 0; j < _PB_NY; j++) { for (int j = 0; j < _PB_NY; j++) {
/// Which gets increased by a bit on every iteration
tmp += A[i][j] * x[j]; tmp += A[i][j] * x[j];
} }
for (j = 0; j < _PB_NY; j++) { for (int j = 0; j < _PB_NY; j++) {
/// Which is later used for to compute ATAX
y[j] = y[j] + A[i][j] * tmp; y[j] = y[j] + A[i][j] * tmp;
} }
} }
} }
int main(int argc, char **argv) /**
* 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)
{ {
/* Retrieve problem size. */
int nx = NX; int nx = NX;
int ny = NY; int ny = NY;
/* Variable declaration/allocation. */
POLYBENCH_2D_ARRAY_DECL(A, DATA_TYPE, NX, NY, nx, ny); POLYBENCH_2D_ARRAY_DECL(A, DATA_TYPE, NX, NY, nx, ny);
POLYBENCH_1D_ARRAY_DECL(x, DATA_TYPE, NY, ny); POLYBENCH_1D_ARRAY_DECL(x, DATA_TYPE, NY, ny);
POLYBENCH_1D_ARRAY_DECL(y, DATA_TYPE, NY, ny); POLYBENCH_1D_ARRAY_DECL(y, DATA_TYPE, NY, ny);
/* Initialize array(s). */
init_array(nx, ny, POLYBENCH_ARRAY(A), POLYBENCH_ARRAY(x)); init_array(nx, ny, POLYBENCH_ARRAY(A), POLYBENCH_ARRAY(x));
/* Start timer. */
polybench_start_instruments; polybench_start_instruments;
/* Run kernel. */
kernel_atax(nx, ny, POLYBENCH_ARRAY(A), POLYBENCH_ARRAY(x), POLYBENCH_ARRAY(y)); kernel_atax(nx, ny, POLYBENCH_ARRAY(A), POLYBENCH_ARRAY(x), POLYBENCH_ARRAY(y));
/* Stop and print timer. */
polybench_stop_instruments; polybench_stop_instruments;
polybench_print_instruments; polybench_print_instruments;
/* Prevent dead-code elimination. All live-out data must be printed /* Prevent dead-code elimination. All live-out data must be printed by the function call in argument. */
by the function call in argument. */
polybench_prevent_dce(print_array(nx, POLYBENCH_ARRAY(y))); polybench_prevent_dce(print_array(nx, POLYBENCH_ARRAY(y)));
/* Be clean. */
POLYBENCH_FREE_ARRAY(A); POLYBENCH_FREE_ARRAY(A);
POLYBENCH_FREE_ARRAY(x); POLYBENCH_FREE_ARRAY(x);
POLYBENCH_FREE_ARRAY(y); POLYBENCH_FREE_ARRAY(y);