tbb/examples/parallel_reduce/primes/main.cpp

/*
    Copyright 2005-2016 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks. Threading Building Blocks is free software;
    you can redistribute it and/or modify it under the terms of the GNU General Public License
    version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks 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 General Public License for more details.   You should have received a copy of
    the  GNU General Public License along with Threading Building Blocks; if not, write to the
    Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA

    As a special exception,  you may use this file  as part of a free software library without
    restriction.  Specifically,  if other files instantiate templates  or use macros or inline
    functions from this file, or you compile this file and link it with other files to produce
    an executable,  this file does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however invalidate any other
    reasons why the executable file might be covered by the GNU General Public License.
*/

#include "primes.h"
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <utility>
#include <iostream>
#include <sstream>
#include "tbb/tick_count.h"

#include "../../common/utility/utility.h"

struct RunOptions{
    //! NumberType of threads to use.
    utility::thread_number_range threads;
    //whether to suppress additional output
    bool silentFlag;
    //
    NumberType n;
    //! Grain size parameter
    NumberType grainSize;
    // number of time to repeat calculation
    NumberType repeatNumber;

    RunOptions(utility::thread_number_range threads, NumberType grainSize, NumberType n, bool silentFlag, NumberType repeatNumber)
        : threads(threads), grainSize(grainSize), n(n), silentFlag(silentFlag), repeatNumber(repeatNumber)
    {}
};

int do_get_default_num_threads() {
    int threads;
    #if __TBB_MIC_OFFLOAD
    #pragma offload target(mic) out(threads)
    #endif // __TBB_MIC_OFFLOAD
    threads = tbb::task_scheduler_init::default_num_threads();
    return threads;
}

int get_default_num_threads() {
    static int threads = do_get_default_num_threads();
    return threads;
}

//! Parse the command line.
static RunOptions ParseCommandLine( int argc, const char* argv[] ) {
    utility::thread_number_range threads( get_default_num_threads, 0, get_default_num_threads() );
    NumberType grainSize = 1000;
    bool silent = false;
    NumberType number = 100000000;
    NumberType repeatNumber = 1;

    utility::parse_cli_arguments(argc,argv,
        utility::cli_argument_pack()
            //"-h" option for displaying help is present implicitly
            .positional_arg(threads,"n-of-threads",utility::thread_number_range_desc)
            .positional_arg(number,"number","upper bound of range to search primes in, must be a positive integer")
            .positional_arg(grainSize,"grain-size","must be a positive integer")
            .positional_arg(repeatNumber,"n-of-repeats","repeat the calculation this number of times, must be a positive integer")
            .arg(silent,"silent","no output except elapsed time")
    );

    RunOptions options(threads,grainSize, number, silent, repeatNumber);
    return options;
}

int main( int argc, const char* argv[] ) {
    tbb::tick_count mainBeginMark = tbb::tick_count::now();
    RunOptions options =ParseCommandLine(argc,argv);

    // Try different numbers of threads
    for( int p=options.threads.first; p<=options.threads.last; p=options.threads.step(p) ) {
        for (NumberType i=0; i<options.repeatNumber;++i){
            tbb::tick_count iterationBeginMark = tbb::tick_count::now();
            NumberType count = 0;
            NumberType n = options.n;
            if( p==0 ) {
                #if __TBB_MIC_OFFLOAD
                #pragma offload target(mic) in(n) out(count)
                #endif // __TBB_MIC_OFFLOAD
                count = SerialCountPrimes(n);
            } else {
                NumberType grainSize = options.grainSize;
                #if __TBB_MIC_OFFLOAD
                #pragma offload target(mic) in(n, p, grainSize) out(count)
                #endif // __TBB_MIC_OFFLOAD
                count = ParallelCountPrimes(n, p, grainSize);
            }
            tbb::tick_count iterationEndMark = tbb::tick_count::now();
            if (!options.silentFlag){
                std::cout
                        <<"#primes from [2.." <<options.n<<"] = " << count
                        <<" ("<<(iterationEndMark-iterationBeginMark).seconds()<< " sec with "
                ;
                if( 0 != p )
                    std::cout<<p<<"-way parallelism";
                else
                    std::cout<<"serial code";
                std::cout<<")\n" ;
            }
        }
    }
    utility::report_elapsed_time((tbb::tick_count::now()-mainBeginMark).seconds());
    return 0;
}