/* { dg-do run } */ #define N 128 #define BS 16 #define EPS 0.000001 #include void matmul_depend (float A[N][N], float B[N][N], float C[N][N]) { int i, j, k, ii, jj, kk; for (i = 0; i < N; i+=BS) for (j = 0; j < N; j+=BS) for (k = 0; k < N; k+=BS) // Note 1: i, j, k, A, B, C are firstprivate by default // Note 2: A, B and C are just pointers #pragma omp task private(ii, jj, kk) \ depend ( in: A[i:BS][k:BS], B[k:BS][j:BS] ) \ depend ( inout: C[i:BS][j:BS] ) for (ii = i; ii < i+BS; ii++ ) for (jj = j; jj < j+BS; jj++ ) for (kk = k; kk < k+BS; kk++ ) C[ii][jj] = C[ii][jj] + A[ii][kk] * B[kk][jj]; } void matmul_ref (float A[N][N], float B[N][N], float C[N][N]) { int i, j, k; for (i = 0; i < N; i++) for (j = 0; j < N; j++) for (k = 0; k < N; k++) C[i][j] += A[i][k] * B[k][j]; } void init (float A[N][N], float B[N][N]) { int i, j, s = -1; for (i = 0; i < N; i++) for (j = 0; j < N; j++) { A[i][j] = i * j * s; B[i][j] = i + j; s = -s; } } void init_zero (float A[N][N], float B[N][N]) { int i, j, s = -1; for (i = 0; i < N; i++) for (j = 0; j < N; j++) { A[i][j] = 0; B[i][j] = 0; } } void check (float A[N][N], float B[N][N]) { int i, j; for (i = 0; i < N; i++) for (j = 0; j < N; j++) if (A[i][j] - B[i][j] > EPS || B[i][j] - A[i][j] > EPS) abort (); } int main () { float A[N][N], B[N][N], C[N][N], C_ref[N][N]; init (A, B); init_zero (C, C_ref); matmul_depend (A, B, C); matmul_ref (A, B, C_ref); check (C, C_ref); return 0; }