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/* StarPU --- Runtime system for heterogeneous multicore architectures.
*
* Copyright (C) 2010-2024 Université de Bordeaux, CNRS (LaBRI UMR 5800), 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.
*/
#include <starpu.h>
/* This kernel takes a buffer and scales it by a constant factor */
void vector_scal_cpu(void *buffers[], void *cl_arg)
{
unsigned i;
float factor;
/*
* The "buffers" array matches the task->handles array: for instance
* task->handles[0] is a handle that corresponds to a data with
* vector "interface", so that the first entry of the array in the
* codelet is a pointer to a structure describing such a vector (ie.
* struct starpu_vector_interface *). Here, we therefore manipulate
* the buffers[0] element as a vector: nx gives the number of elements
* in the array, ptr gives the location of the array (that was possibly
* migrated/replicated), and elemsize gives the size of each elements.
*/
struct starpu_vector_interface *vector = buffers[0];
/* length of the vector */
unsigned n = STARPU_VECTOR_GET_NX(vector);
/* get a pointer to the local copy of the vector : note that we have to
* cast it in (float *) since a vector could contain any type of
* elements so that the .ptr field is actually a uintptr_t */
float *val = (float *)STARPU_VECTOR_GET_PTR(vector);
/* scale the vector */
starpu_codelet_unpack_args(cl_arg, &factor);
for (i = 0; i < n; i++)
val[i] *= factor;
}
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