// ************************************************************************** //
//                                                                            //
//    eses                   eses                                             //
//   eses                     eses                                            //
//  eses    eseses  esesese    eses   Embedded Systems Group                  //
//  ese    ese  ese ese         ese                                           //
//  ese    eseseses eseseses    ese   Department of Computer Science          //
//  eses   eses          ese   eses                                           //
//   eses   eseses  eseseses  eses    University of Kaiserslautern            //
//    eses                   eses                                             //
//                                                                            //
// ************************************************************************** //
// PeriodicBalanceSortNet implements the periodic balanced sorting network    //
// [DPRS89]. This sorting network has depth log(N)^2 and requires N*log(N)^2  //
// comparators. It is therefore not very efficient; it simply consists of a   //
// sequence of log(N) blocks of the same kind, where each block consists of   //
// log(N) columns where each has N comparators in form of reversed half       //
// cleaners in the single partitions.                                         //
// ************************************************************************** //

macro aSize = 16;
macro iSize = 64;

module PeriodicBalancedSortNet([aSize]int{iSize} ?a,b, event !ready) {
    
    // gather the inputs
    for(i=0..aSize-1)
        b[i] = a[i];

    for(l=0..log(aSize)-1) {              // for every block
        for(d=0..log(aSize)-1) {          // for every column the block
            let(L = exp(2,log(aSize)-d))  // size of a partition
            let(n = aSize/L)              // number of partitions
            for(p=0..n-1) {                 // for each partition p 
                for(i=0..L/2-1) {
                    let(x = p*L+i)
                    let(y = (p+1)*L-1-i)
                    if(b[x]>b[y]) {
                        next(b[x]) = b[y];
                        next(b[y]) = b[x];
                    }
                }
            }
        w2: pause;
        }
    }
    emit(ready);
}
drivenby Test01 {
    for(i=0..aSize-1) a[i] = i;
    dw: await(ready);
    for(i=0..aSize-1) assert(b[i] == i);
}
drivenby Test02 {
    for(i=0..aSize-1) a[i] = aSize-1-i;
    dw: await(ready);
    for(i=0..aSize-1) assert(b[i] == i);
}
drivenby Test03 {
    for(i=0..aSize-1)
        a[i] = ((i%2==0)?i:((aSize%2==0)?aSize-i:aSize-1-i));
    dw: await(ready);
    for(i=0..aSize-1) assert(b[i] == i);
}