mirror of
https://github.com/Steffo99/unimore-hpc-assignments.git
synced 2024-11-30 03:54:20 +00:00
81 lines
2.4 KiB
C
81 lines
2.4 KiB
C
|
/*
|
||
|
|
* BSD 2-Clause License
|
||
|
|
*
|
||
|
|
* Copyright (c) 2020, Alessandro Capotondi
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions are met:
|
||
|
|
*
|
||
|
|
* * Redistributions of source code must retain the above copyright notice, this
|
||
|
|
* list of conditions and the following disclaimer.
|
||
|
|
*
|
||
|
|
* * Redistributions in binary form must reproduce the above copyright notice,
|
||
|
|
* this list of conditions and the following disclaimer in the documentation
|
||
|
|
* and/or other materials provided with the distribution.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
||
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
||
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @file exercise7.c
|
||
|
|
* @author Alessandro Capotondi
|
||
|
|
* @date 27 Mar 2020
|
||
|
|
* @brief Exercise 8
|
||
|
|
*
|
||
|
|
* Pi calculation
|
||
|
|
* @see https://dolly.fim.unimore.it/2019/course/view.php?id=152
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <omp.h>
|
||
|
|
|
||
|
|
#include "utils.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @brief EX 8- Pi Calculation
|
||
|
|
*
|
||
|
|
* This program computes pi as
|
||
|
|
* \pi = 4 arctan(1)
|
||
|
|
* = 4 \int _0 ^1 \frac{1} {1 + x^2} dx
|
||
|
|
*
|
||
|
|
* @return void
|
||
|
|
*/
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <math.h>
|
||
|
|
#include <omp.h>
|
||
|
|
|
||
|
|
#define NSTEPS 134217728
|
||
|
|
|
||
|
|
void exercise()
|
||
|
|
{
|
||
|
|
long i;
|
||
|
|
double dx = 1.0 / NSTEPS;
|
||
|
|
double pi = 0.0;
|
||
|
|
|
||
|
|
double start_time = omp_get_wtime();
|
||
|
|
|
||
|
|
#pragma omp parallel for reduction(+ \
|
||
|
|
: pi)
|
||
|
|
for (i = 0; i < NSTEPS; i++)
|
||
|
|
{
|
||
|
|
double x = (i + 0.5) * dx;
|
||
|
|
pi += 1.0 / (1.0 + x * x);
|
||
|
|
}
|
||
|
|
pi *= 4.0 * dx;
|
||
|
|
|
||
|
|
double run_time = omp_get_wtime() - start_time;
|
||
|
|
double ref_pi = 4.0 * atan(1.0);
|
||
|
|
printf("pi with %ld steps is %.10f in %.6f seconds (error=%e)\n",
|
||
|
|
NSTEPS, pi, run_time, fabs(ref_pi - pi));
|
||
|
|
}
|