void peano_hilbert_order(void)
{
int i;
if(ThisTask == 0)
printf("begin Peano-Hilbert order...\n");
if(N_gas)
{
mp = malloc(sizeof(struct peano_hilbert_data) * N_gas);
Id = malloc(sizeof(int) * N_gas);
for(i = 0; i < N_gas; i++)
{
mp[i].index = i;
mp[i].key = Key[i];
}
qsort(mp, N_gas, sizeof(struct peano_hilbert_data), compare_key);
for(i = 0; i < N_gas; i++)
Id[mp[i].index] = i;
reorder_gas();
free(Id);
free(mp);
}
if(NumPart - N_gas > 0)
{
mp = malloc(sizeof(struct peano_hilbert_data) * (NumPart - N_gas));
mp -= (N_gas);
Id = malloc(sizeof(int) * (NumPart - N_gas));
Id -= (N_gas);
for(i = N_gas; i < NumPart; i++)
{
mp[i].index = i;
mp[i].key = Key[i];
}
qsort(mp + N_gas, NumPart - N_gas, sizeof(struct peano_hilbert_data), compare_key);
for(i = N_gas; i < NumPart; i++)
Id[mp[i].index] = i;
reorder_particles();
Id += N_gas;
free(Id);
mp += N_gas;
free(mp);
}
if(ThisTask == 0)
printf("Peano-Hilbert done.\n");
}
/*! This function puts the particles into Peano-Hilbert order by sorting them
* according to their keys. The latter half already been computed in the
* domain decomposition. Since gas particles need to stay at the beginning of
* the particle list, they are sorted as a separate block.
*/
void peano_hilbert_order(void)
{
int i;
#if N_GRAVS > 1
int offset, k;
#endif
if(ThisTask == 0)
printf("begin Peano-Hilbert order...\n");
if(N_gas)
{
mp = malloc(sizeof(struct peano_hilbert_data) * N_gas);
Id = malloc(sizeof(int) * N_gas);
for(i = 0; i < N_gas; i++)
{
mp[i].index = i;
mp[i].key = Key[i];
}
qsort(mp, N_gas, sizeof(struct peano_hilbert_data), compare_key);
for(i = 0; i < N_gas; i++)
Id[mp[i].index] = i;
reorder_gas();
free(Id);
free(mp);
}
#if N_GRAVS > 1 // && defined PMGRID
// KC 10/8/14
// To keep from traversing the entire particle list N_GRAVS^2 times
// while in PMGRID mode
// we Peano-Hilbert sort each type of particle, but keep the types strictly
// ordered on the local processors. Thus, we do what is done for gas particles (they sit
// at the head of the P list) for all the types.
//
// Hopefully this will still reap some of the spatial localization/memory localization
// benefits of Peano-Hilbert ordering!
// First, type order
if(NumPart - N_gas > 0) {
mp = malloc(sizeof(struct peano_hilbert_data) * (NumPart - N_gas));
mp -= N_gas;
Id = malloc(sizeof(int) * (NumPart - N_gas));
memset(Id, -1, NumPart-N_gas);
Id -= N_gas;
for(i = N_gas; i < NumPart; ++i) {
mp[i].index = i;
mp[i].key = TypeToGrav[P[i].Type];
}
// KC 10/20/14
// Sort based on gravitational interaction, not on particle type
// KC 10/12/14
// mp[position in P list] = {position in P list, type of particle in this position}
qsort(mp + N_gas, NumPart - N_gas, sizeof(struct peano_hilbert_data), compare_key);
// KC 10/12/14
// mp[destination position] = {(source) position in P list, type of particle in this position}
// Now sort within type by peano-hilbert key
// The indexes of Key correspond to the original indexes of P before any kind of sort.
// So we care about mp[i].index
// Temporarily ignore the gas particles
NgravLocal[0] -= N_gas;
offset = N_gas;
for(k = 0; k < N_GRAVS; ++k) {
mp2 = malloc(sizeof(struct peano_hilbert_data) * NgravLocal[k]);
mp2 -= offset;
for(i = offset; i < offset + NgravLocal[k]; ++i) {
mp2[i].index = mp[i].index;
mp2[i].key = Key[mp[i].index];
}
qsort(mp2 + offset, NgravLocal[k], sizeof(struct peano_hilbert_data), compare_key);
for(i = offset; i < offset + NgravLocal[k]; ++i)
Id[mp2[i].index] = i;
mp2 += offset;
free(mp2);
offset += NgravLocal[k];
}
// Put the gas particles back on
NgravLocal[0] += N_gas;
mp += N_gas;
free(mp);
reorder_particles();
// Dump particles
// for(i = 0; i < NumPart; ++i)
// printf("PEANO: %d has {type,gravtype}={%d, %d}\n", i, P[i].Type, TypeToGrav[P[i].Type]);
Id += N_gas;
free(Id);
if(ThisTask == 0)
printf("ngravs: Type ordering complete, Peano-Hilbert subordered.\n");
}
#else
if(NumPart - N_gas > 0)
{
mp = malloc(sizeof(struct peano_hilbert_data) * (NumPart - N_gas));
mp -= (N_gas);
Id = malloc(sizeof(int) * (NumPart - N_gas));
Id -= (N_gas);
for(i = N_gas; i < NumPart; i++)
{
mp[i].index = i;
mp[i].key = Key[i];
}
qsort(mp + N_gas, NumPart - N_gas, sizeof(struct peano_hilbert_data), compare_key);
for(i = N_gas; i < NumPart; i++)
Id[mp[i].index] = i;
reorder_particles();
Id += N_gas;
free(Id);
mp += N_gas;
free(mp);
}
#endif
if(ThisTask == 0)
printf("Peano-Hilbert done.\n");
}
