Add C version of testcase from issue 602

cpp_thread_test/test_dgemm_omp.c

@@ -1 +1,56 @@
+#include <stdlib.h>
+#include <stdio.h>
 
+
+#ifdef _OPENMP
+    int omp_get_num_procs();
+    int omp_get_max_threads();
+    void omp_set_num_threads(int);
+#endif
+
+
+#define bint int
+
+void dgemm_(char *transa, char *transb, bint *m, bint *n, bint *k, double *alpha,
+    const double *a, bint *lda, const double *b, bint *ldb,
+    double *beta, double *c, bint *ldc);
+
+void test(int id)
+{
+    bint i = 0, m = 1000, n = 800, k = 600, N = m*k + k*n + m*n;
+    double alpha = 1.0, beta = 0.0;
+    double *A, *B, *C;
+
+    printf("%d\n", id);
+
+    A = (double*)malloc(N*sizeof(double));
+    B = A + m*k;
+    C = B + k*n;
+
+    for (i = 0; i < N; ++i)
+        A[i] = (double) rand() / RAND_MAX;
+
+    dgemm_("N", "N", &m, &n, &k, &alpha, A, &m, B, &k, &beta, C, &m);
+    dgemm_("T", "N", &m, &n, &k, &alpha, A, &k, B, &k, &beta, C, &m);
+    dgemm_("N", "T", &m, &n, &k, &alpha, A, &m, B, &n, &beta, C, &m);
+    dgemm_("T", "T", &m, &n, &k, &alpha, A, &k, B, &n, &beta, C, &m);
+
+    free(A);
+}
+
+int main()
+{
+    int i = 0;
+
+#ifdef _OPENMP
+    int num_procs = omp_get_num_procs();
+    if (num_procs < omp_get_max_threads() * 2)
+        omp_set_num_threads(num_procs < 4 ? 1 : num_procs/2);
+#endif
+
+    #pragma omp parallel for
+    for (i = 0; i < 100; ++i)
+        test(i);
+
+    return 0;
+}