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lammps/lib/gpu/lal_base_charge.cpp
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lal_base_charge.cpp
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/***************************************************************************
base_charge.cpp
-------------------
W. Michael Brown (ORNL)
Base class for pair styles needing per-particle data for position,
charge, and type.
__________________________________________________________________________
This file is part of the LAMMPS Accelerator Library (LAMMPS_AL)
__________________________________________________________________________
begin :
email : brownw@ornl.gov
***************************************************************************/
#include "lal_base_charge.h"
using namespace LAMMPS_AL;
#define BaseChargeT BaseCharge<numtyp, acctyp>
extern Device<PRECISION,ACC_PRECISION> global_device;
template <class numtyp, class acctyp>
BaseChargeT::BaseCharge() : _compiled(false), _max_bytes(0) {
device=&global_device;
ans=new Answer<numtyp,acctyp>();
nbor=new Neighbor();
}
template <class numtyp, class acctyp>
BaseChargeT::~BaseCharge() {
delete ans;
delete nbor;
}
template <class numtyp, class acctyp>
int BaseChargeT::bytes_per_atom_atomic(const int max_nbors) const {
return device->atom.bytes_per_atom()+ans->bytes_per_atom()+
nbor->bytes_per_atom(max_nbors);
}
template <class numtyp, class acctyp>
int BaseChargeT::init_atomic(const int nlocal, const int nall,
const int max_nbors, const int maxspecial,
const double cell_size, const double gpu_split,
FILE *_screen, const void *pair_program,
const char *k_name) {
screen=_screen;
int gpu_nbor=0;
if (device->gpu_mode()==Device<numtyp,acctyp>::GPU_NEIGH)
gpu_nbor=1;
else if (device->gpu_mode()==Device<numtyp,acctyp>::GPU_HYB_NEIGH)
gpu_nbor=2;
int _gpu_host=0;
int host_nlocal=hd_balancer.first_host_count(nlocal,gpu_split,gpu_nbor);
if (host_nlocal>0)
_gpu_host=1;
_threads_per_atom=device->threads_per_charge();
if (_threads_per_atom>1 && gpu_nbor==0) {
nbor->packing(true);
_nbor_data=&(nbor->dev_packed);
} else
_nbor_data=&(nbor->dev_nbor);
int success=device->init(*ans,true,false,nlocal,host_nlocal,nall,nbor,
maxspecial,_gpu_host,max_nbors,cell_size,false,
_threads_per_atom);
if (success!=0)
return success;
ucl_device=device->gpu;
atom=&device->atom;
_block_size=device->pair_block_size();
_block_bio_size=device->block_bio_pair();
compile_kernels(*ucl_device,pair_program,k_name);
// Initialize host-device load balancer
hd_balancer.init(device,gpu_nbor,gpu_split);
// Initialize timers for the selected GPU
time_pair.init(*ucl_device);
time_pair.zero();
pos_tex.bind_float(atom->x,4);
q_tex.bind_float(atom->q,1);
_max_an_bytes=ans->gpu_bytes()+nbor->gpu_bytes();
return success;
}
template <class numtyp, class acctyp>
void BaseChargeT::estimate_gpu_overhead() {
device->estimate_gpu_overhead(1,_gpu_overhead,_driver_overhead);
}
template <class numtyp, class acctyp>
void BaseChargeT::clear_atomic() {
// Output any timing information
acc_timers();
double avg_split=hd_balancer.all_avg_split();
_gpu_overhead*=hd_balancer.timestep();
_driver_overhead*=hd_balancer.timestep();
device->output_times(time_pair,*ans,*nbor,avg_split,_max_bytes+_max_an_bytes,
_gpu_overhead,_driver_overhead,_threads_per_atom,screen);
if (_compiled) {
k_pair_fast.clear();
k_pair.clear();
delete pair_program;
_compiled=false;
}
time_pair.clear();
hd_balancer.clear();
nbor->clear();
ans->clear();
device->clear();
}
// ---------------------------------------------------------------------------
// Copy neighbor list from host
// ---------------------------------------------------------------------------
template <class numtyp, class acctyp>
int * BaseChargeT::reset_nbors(const int nall, const int inum, int *ilist,
int *numj, int **firstneigh, bool &success) {
success=true;
int mn=nbor->max_nbor_loop(inum,numj,ilist);
resize_atom(inum,nall,success);
resize_local(inum,mn,success);
if (!success)
return NULL;
nbor->get_host(inum,ilist,numj,firstneigh,block_size());
double bytes=ans->gpu_bytes()+nbor->gpu_bytes();
if (bytes>_max_an_bytes)
_max_an_bytes=bytes;
return ilist;
}
// ---------------------------------------------------------------------------
// Build neighbor list on device
// ---------------------------------------------------------------------------
template <class numtyp, class acctyp>
inline void BaseChargeT::build_nbor_list(const int inum, const int host_inum,
const int nall, double **host_x,
int *host_type, double *sublo,
double *subhi, tagint *tag,
int **nspecial, tagint **special,
bool &success) {
success=true;
resize_atom(inum,nall,success);
resize_local(inum,host_inum,nbor->max_nbors(),success);
if (!success)
return;
atom->cast_copy_x(host_x,host_type);
int mn;
nbor->build_nbor_list(host_x, inum, host_inum, nall, *atom, sublo, subhi, tag,
nspecial, special, success, mn);
double bytes=ans->gpu_bytes()+nbor->gpu_bytes();
if (bytes>_max_an_bytes)
_max_an_bytes=bytes;
}
// ---------------------------------------------------------------------------
// Copy nbor list from host if necessary and then calculate forces, virials,..
// ---------------------------------------------------------------------------
template <class numtyp, class acctyp>
void BaseChargeT::compute(const int f_ago, const int inum_full,
const int nall, double **host_x, int *host_type,
int *ilist, int *numj, int **firstneigh,
const bool eflag, const bool vflag,
const bool eatom, const bool vatom,
int &host_start, const double cpu_time,
bool &success, double *host_q,
const int nlocal, double *boxlo, double *prd) {
acc_timers();
if (inum_full==0) {
host_start=0;
// Make sure textures are correct if realloc by a different hybrid style
resize_atom(0,nall,success);
zero_timers();
return;
}
int ago=hd_balancer.ago_first(f_ago);
int inum=hd_balancer.balance(ago,inum_full,cpu_time);
ans->inum(inum);
host_start=inum;
if (ago==0) {
reset_nbors(nall, inum, ilist, numj, firstneigh, success);
if (!success)
return;
}
atom->cast_x_data(host_x,host_type);
atom->cast_q_data(host_q);
hd_balancer.start_timer();
atom->add_x_data(host_x,host_type);
atom->add_q_data();
device->precompute(f_ago,nlocal,nall,host_x,host_type,success,host_q,
boxlo, prd);
loop(eflag,vflag);
ans->copy_answers(eflag,vflag,eatom,vatom,ilist);
device->add_ans_object(ans);
hd_balancer.stop_timer();
}
// ---------------------------------------------------------------------------
// Reneighbor on GPU if necessary and then compute forces, virials, energies
// ---------------------------------------------------------------------------
template <class numtyp, class acctyp>
int** BaseChargeT::compute(const int ago, const int inum_full,
const int nall, double **host_x, int *host_type,
double *sublo, double *subhi, tagint *tag,
int **nspecial, tagint **special, const bool eflag,
const bool vflag, const bool eatom,
const bool vatom, int &host_start,
int **ilist, int **jnum,
const double cpu_time, bool &success,
double *host_q, double *boxlo, double *prd) {
acc_timers();
if (inum_full==0) {
host_start=0;
// Make sure textures are correct if realloc by a different hybrid style
resize_atom(0,nall,success);
zero_timers();
return NULL;
}
hd_balancer.balance(cpu_time);
int inum=hd_balancer.get_gpu_count(ago,inum_full);
ans->inum(inum);
host_start=inum;
// Build neighbor list on GPU if necessary
if (ago==0) {
build_nbor_list(inum, inum_full-inum, nall, host_x, host_type,
sublo, subhi, tag, nspecial, special, success);
if (!success)
return NULL;
atom->cast_q_data(host_q);
hd_balancer.start_timer();
} else {
atom->cast_x_data(host_x,host_type);
atom->cast_q_data(host_q);
hd_balancer.start_timer();
atom->add_x_data(host_x,host_type);
}
atom->add_q_data();
*ilist=nbor->host_ilist.begin();
*jnum=nbor->host_acc.begin();
device->precompute(ago,inum_full,nall,host_x,host_type,success,host_q,
boxlo, prd);
loop(eflag,vflag);
ans->copy_answers(eflag,vflag,eatom,vatom);
device->add_ans_object(ans);
hd_balancer.stop_timer();
return nbor->host_jlist.begin()-host_start;
}
template <class numtyp, class acctyp>
double BaseChargeT::host_memory_usage_atomic() const {
return device->atom.host_memory_usage()+nbor->host_memory_usage()+
4*sizeof(numtyp)+sizeof(BaseCharge<numtyp,acctyp>);
}
template <class numtyp, class acctyp>
void BaseChargeT::compile_kernels(UCL_Device &dev, const void *pair_str,
const char *kname) {
if (_compiled)
return;
std::string s_fast=std::string(kname)+"_fast";
pair_program=new UCL_Program(dev);
pair_program->load_string(pair_str,device->compile_string().c_str());
k_pair_fast.set_function(*pair_program,s_fast.c_str());
k_pair.set_function(*pair_program,kname);
pos_tex.get_texture(*pair_program,"pos_tex");
q_tex.get_texture(*pair_program,"q_tex");
_compiled=true;
}
template class BaseCharge<PRECISION,ACC_PRECISION>;
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