tbb/examples/parallel_reduce/primes/main.cpp

/*
    Copyright (c) 2005-2016 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the 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;
}