First draft of the matrix multiply example.

Author: isazi

examples/directives/matrix_multiply_c_openacc.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+"""This is an example tuning a naive matrix multiplication using the simplified directives interface"""
+
+from kernel_tuner import tune_kernel
+from kernel_tuner.utils.directives import (
+    Code,
+    OpenACC,
+    Cxx,
+    process_directives
+)
+
+code = """
+#include <stdlib.h>
+
+#define N 4096
+
+void matrix_multiply(float *A, float *B, float *C) {
+    #pragma tuner start mm A(float*:NN) B(float*:NN) C(float*:NN)
+    #pragma acc parallel vector_length(nthreads)
+    #pragma acc loop
+    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];
+            }
+        }
+    }
+    #pragma tuner stop
+}
+"""
+
+# Extract tunable directive
+app = Code(OpenACC(), Cxx())
+dims = {"NN": 4096*4096}
+kernel_string, kernel_args = process_directives(app, code, user_dimensions=dims)
+
+tune_params = dict()
+tune_params["nthreads"] = [32 * i for i in range(1, 33)]
+metrics = dict()
+metrics["GB/s"] = lambda x: (4096 * 4096 * 4) / (x["time"] / 10**3) / 10**9
+
+tune_kernel(
+    "mm",
+    kernel_string["mm"],
+    0,
+    kernel_args["mm"],
+    tune_params,
+    metrics=metrics,
+    compiler_options=["-fast", "-acc=gpu"],
+    compiler="nvc++",
+)