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/* StarPU --- Runtime system for heterogeneous multicore architectures.
*
* Copyright (C) 2010, 2011, 2012 Centre National de la Recherche Scientifique
*
* 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.
*/
/*
* This example complements vector_scale.c: here we implement a CPU version.
*/
#include <starpu.h>
#ifdef __SSE__
#include <xmmintrin.h>
#endif
/* This kernel takes a buffer and scales it by a constant factor */
void scal_cpu_func(void *buffers[], void *cl_arg)
{
unsigned i;
float *factor = (float *) cl_arg;
/*
* 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 = (struct starpu_vector_interface *) 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 */
for (i = 0; i < n; i++)
val[i] *= *factor;
}
#ifdef __SSE__
void scal_sse_func(void *buffers[], void *cl_arg)
{
float *vector = (float *) STARPU_VECTOR_GET_PTR(buffers[0]);
unsigned int n = STARPU_VECTOR_GET_NX(buffers[0]);
unsigned int n_iterations = n/4;
__m128 *VECTOR = (__m128*) vector;
__m128 FACTOR __attribute__((aligned(16)));
float factor = *(float *) cl_arg;
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
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