GCC plugin : add a simple "vector scal" example.

gcc-plugin/examples/Makefile.am

@@ -14,7 +14,7 @@
 # See the GNU Lesser General Public License in COPYING.LGPL for more details.
 
 noinst_PROGRAMS =				\
-  matrix-mult stencil5
+  matrix-mult stencil5 vector_scal/vector_scal
 
 if !NO_BLAS_LIB
 noinst_PROGRAMS +=				\

gcc-plugin/examples/vector_scal/vector_scal.c

@@ -0,0 +1,126 @@
+/* StarPU --- Runtime system for heterogeneous multicore architectures.
+ *
+ * Copyright (C) 2012 INRIA
+ *
+ * StarPU is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * StarPU is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU Lesser General Public License in COPYING.LGPL for more details.
+ */
+#ifndef STARPU_GCC_PLUGIN
+# error must be compiled with the StarPU GCC plug-in
+#endif
+
+/*
+ * This is a very simple example that is primarily meant to test the
+ * features offered by the StarPU GCC plug-in.
+ *
+ * Currently tested features :
+ * 	- multi-implementations
+ *	- CPU codelet
+ *
+ * Features to test in a near future :
+ *	- CUDA
+ *	- OpenCL
+ *	- Filters
+ */
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef __SSE__
+#include <xmmintrin.h>
+#endif
+
+#define NX     16
+#define FACTOR 3.14
+
+static float vector[NX];
+
+static void vector_scal(float *v, size_t n, float factor)
+__attribute__ ((task));
+
+static void vector_scal_cpu(float *v, size_t n, float factor)
+__attribute__ ((task_implementation ("cpu", vector_scal)));
+
+#ifdef __SSE__
+static void vector_scal_sse(float *v, size_t n, float factor)
+__attribute__ ((task_implementation ("cpu", vector_scal)));
+#endif /* !__SSE__ */
+
+static void
+vector_scal_cpu(float *v, size_t n, float factor)
+{
+	int i;
+	for (i = 0; i < n; i++)
+		v[i] *= factor;
+}
+
+#ifdef __SSE__
+static void
+vector_scal_sse(float *vector, size_t n, float factor)
+{
+	unsigned int n_iterations = n/4;
+
+	__m128 *VECTOR = (__m128*) vector;
+	__m128 _FACTOR __attribute__((aligned(16)));
+	_FACTOR = _mm_set1_ps(factor);
+
+	unsigned int i;	
+	for (i = 0; i < n_iterations; i++)
+		VECTOR[i] = _mm_mul_ps(_FACTOR, VECTOR[i]);
+
+	unsigned int remainder = n%4;
+	if (remainder != 0)
+	{
+		unsigned int start = 4 * n_iterations;
+		for (i = start; i < start+remainder; ++i)
+		{
+			vector[i] = factor * vector[i];
+		}
+	}
+}
+#endif /* !__SSE__ */
+
+static void
+init_data(void)
+{
+	int i;
+	for (i = 0; i < NX; i++)
+		vector[i] = (float) i;
+}
+
+#define EPSILON 1e-3
+static int
+check(void)
+{
+	int i;
+	for (i = 0; i < NX; i++)
+		if (vector[i] - i*FACTOR > EPSILON)
+			return 1;
+
+	return 0;
+}
+
+int
+main(void)
+{
+#pragma  starpu initialize
+
+	init_data();
+
+#pragma starpu register &vector NX
+
+	vector_scal(vector, NX, FACTOR);
+
+#pragma starpu wait
+#pragma starpu unregister &vector
+#pragma starpu shutdown
+
+	return check()?EXIT_FAILURE:EXIT_SUCCESS;
+}