/* ---------------------------------------------------------------------- LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator Original Version: http://lammps.sandia.gov, Sandia National Laboratories Steve Plimpton, sjplimp@sandia.gov See the README file in the top-level LAMMPS directory. ----------------------------------------------------------------------- USER-CUDA Package and associated modifications: https://sourceforge.net/projects/lammpscuda/ Christian Trott, christian.trott@tu-ilmenau.de Lars Winterfeld, lars.winterfeld@tu-ilmenau.de Theoretical Physics II, University of Technology Ilmenau, Germany See the README file in the USER-CUDA directory. This software is distributed under the GNU General Public License. ------------------------------------------------------------------------- */ /* ---------------------------------------------------------------------- LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator http://lammps.sandia.gov, Sandia National Laboratories Steve Plimpton, sjplimp@sandia.gov Copyright (2003) Sandia Corporation. Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain rights in this software. This software is distributed under the GNU General Public License. See the README file in the top-level LAMMPS directory. ------------------------------------------------------------------------- */ /* ---------------------------------------------------------------------- Contributing authors: Jim Shepherd (GA Tech) added SGI SCSL support ------------------------------------------------------------------------- */ #include "mpi.h" #include #include #include #include "fft3d_cuda.h" #include "fft3d_cuda_cu.h" #include "remap.h" #include #include "cuda_wrapper_cu.h" #ifdef FFT_CUFFT #endif #define MIN(A,B) ((A) < (B)) ? (A) : (B) #define MAX(A,B) ((A) > (B)) ? (A) : (B) /* ---------------------------------------------------------------------- Data layout for 3d FFTs: data set of Nfast x Nmid x Nslow elements is owned by P procs on input, each proc owns a subsection of the elements on output, each proc will own a (possibly different) subsection my subsection must not overlap with any other proc's subsection, i.e. the union of all proc's input (or output) subsections must exactly tile the global Nfast x Nmid x Nslow data set when called from C, all subsection indices are C-style from 0 to N-1 where N = Nfast or Nmid or Nslow when called from F77, all subsection indices are F77-style from 1 to N where N = Nfast or Nmid or Nslow a proc can own 0 elements on input or output by specifying hi index < lo index on both input and output, data is stored contiguously on a processor with a fast-varying, mid-varying, and slow-varying index ------------------------------------------------------------------------- */ /* ---------------------------------------------------------------------- Perform 3d FFT Arguments: in starting address of input data on this proc out starting address of where output data for this proc will be placed (can be same as in) flag 1 for forward FFT, -1 for inverse FFT plan plan returned by previous call to fft_3d_create_plan ------------------------------------------------------------------------- */ void fft_3d_cuda(FFT_DATA *in, FFT_DATA *out, int flag, struct fft_plan_3d *plan) { #ifdef FFT_CUFFT plan->iterate++; timespec starttime,starttime2; timespec endtime,endtime2; int i,total,length,offset,num; double norm; FFT_DATA *data,*copy; // system specific constants // pre-remap to prepare for 1st FFTs if needed // copy = loc for remap result int nprocs=plan->nprocs; if(nprocs>1) { if(plan->init) clock_gettime(CLOCK_REALTIME,&starttime); if (plan->pre_plan) { if (plan->pre_target == 0) copy = out; else copy = plan->copy; if(plan->init) remap_3d((double *) in, (double *) out, (double *) plan->scratch,plan->pre_plan); data = out; } else data = in; } cufftResult retvalc; if(plan->init) { if(nprocs>1) { if(sizeof(FFT_FLOAT)==sizeof(double))cudaMemcpy((void*) (plan->cudata2), (void*) data, plan->cudatasize/2,cudaMemcpyHostToDevice); if(sizeof(FFT_FLOAT)==sizeof(float)) cudaMemcpy((void*) (plan->cudata2), (void*) data, plan->cudatasize,cudaMemcpyHostToDevice); initfftdata((double*)plan->cudata2,(FFT_FLOAT*)plan->cudata,plan->nfast,plan->nmid,plan->nslow); } } if (flag == -1) { retvalc=cufft(plan->plan_3d, plan->cudata, plan->cudata2,CUFFT_FORWARD); } else { retvalc=cufft(plan->plan_3d, plan->cudata, plan->cudata2,CUFFT_INVERSE); } if(retvalc!=CUFFT_SUCCESS) {printf("ErrorCUFFT: %i\n",retvalc);exit(EXIT_FAILURE);} FFTsyncthreads(); #endif } /* ---------------------------------------------------------------------- Create plan for performing a 3d FFT Arguments: comm MPI communicator for the P procs which own the data nfast,nmid,nslow size of global 3d matrix in_ilo,in_ihi input bounds of data I own in fast index in_jlo,in_jhi input bounds of data I own in mid index in_klo,in_khi input bounds of data I own in slow index out_ilo,out_ihi output bounds of data I own in fast index out_jlo,out_jhi output bounds of data I own in mid index out_klo,out_khi output bounds of data I own in slow index scaled 0 = no scaling of result, 1 = scaling permute permutation in storage order of indices on output 0 = no permutation 1 = permute once = mid->fast, slow->mid, fast->slow 2 = permute twice = slow->fast, fast->mid, mid->slow nbuf returns size of internal storage buffers used by FFT ------------------------------------------------------------------------- */ struct fft_plan_3d *fft_3d_create_plan_cuda( MPI_Comm comm, int nfast, int nmid, int nslow, int in_ilo, int in_ihi, int in_jlo, int in_jhi, int in_klo, int in_khi, int out_ilo, int out_ihi, int out_jlo, int out_jhi, int out_klo, int out_khi, int scaled, int permute, int *nbuf,bool ainit) { #ifdef FFT_CUFFT struct fft_plan_3d *plan; int me,nprocs; int i,num,flag,remapflag,fftflag; int first_ilo,first_ihi,first_jlo,first_jhi,first_klo,first_khi; int second_ilo,second_ihi,second_jlo,second_jhi,second_klo,second_khi; int third_ilo,third_ihi,third_jlo,third_jhi,third_klo,third_khi; int out_size,first_size,second_size,third_size,copy_size,scratch_size; int np1,np2,ip1,ip2; int list[50]; // system specific variables // query MPI info MPI_Comm_rank(comm,&me); MPI_Comm_size(comm,&nprocs); #ifndef FFT_CUFFT error->all(FLERR,"ERROR: Trying to use cuda fft without FFT_CUFFT set. Recompile with make option 'cufft=1'."); #endif // compute division of procs in 2 dimensions not on-processor bifactor_cuda(nprocs,&np1,&np2); ip1 = me % np1; ip2 = me/np1; // in case of CUDA FFT every proc does the full FFT in order to avoid data transfers (the problem is other wise heavily bandwidth limited) int ip1out = ip1; int ip2out = ip2; int np1out = np1; int np2out = np2; ip1 = 0; ip2 = 0; np1 = 1; np2 = 1; // allocate memory for plan data struct plan = (struct fft_plan_3d *) malloc(sizeof(struct fft_plan_3d)); if (plan == NULL) return NULL; plan->init=ainit; // remap from initial distribution to layout needed for 1st set of 1d FFTs // not needed if all procs own entire fast axis initially // first indices = distribution after 1st set of FFTs if (in_ilo == 0 && in_ihi == nfast-1) flag = 0; else flag = 1; if(nprocs>1)flag=1; MPI_Allreduce(&flag,&remapflag,1,MPI_INT,MPI_MAX,comm); if (remapflag == 0) { first_ilo = in_ilo; first_ihi = in_ihi; first_jlo = in_jlo; first_jhi = in_jhi; first_klo = in_klo; first_khi = in_khi; plan->pre_plan = NULL; } else { first_ilo = 0; first_ihi = nfast - 1; first_jlo = ip1*nmid/np1; first_jhi = (ip1+1)*nmid/np1 - 1; first_klo = ip2*nslow/np2; first_khi = (ip2+1)*nslow/np2 - 1; int members=2; if(plan->init) members=1; plan->pre_plan = remap_3d_create_plan(comm,in_ilo,in_ihi,in_jlo,in_jhi,in_klo,in_khi, first_ilo,first_ihi,first_jlo,first_jhi, first_klo,first_khi, members,0,0,2); if (plan->pre_plan == NULL) return NULL; } // 1d FFTs along fast axis plan->length1 = nfast; plan->total1 = nfast * nmid * nslow; // remap from 1st to 2nd FFT // choose which axis is split over np1 vs np2 to minimize communication // second indices = distribution after 2nd set of FFTs second_ilo = ip1*nfast/np1; second_ihi = (ip1+1)*nfast/np1 - 1; second_jlo = 0; second_jhi = nmid - 1; second_klo = ip2*nslow/np2; second_khi = (ip2+1)*nslow/np2 - 1; plan->mid1_plan = remap_3d_create_plan(comm, first_ilo,first_ihi,first_jlo,first_jhi, first_klo,first_khi, second_ilo,second_ihi,second_jlo,second_jhi, second_klo,second_khi, 2,1,0,2); if (plan->mid1_plan == NULL) return NULL; // 1d FFTs along mid axis plan->length2 = nmid; plan->total2 = nfast * nmid * nslow; // remap from 2nd to 3rd FFT // if final distribution is permute=2 with all procs owning entire slow axis // then this remapping goes directly to final distribution // third indices = distribution after 3rd set of FFTs flag=1; MPI_Allreduce(&flag,&remapflag,1,MPI_INT,MPI_MAX,comm); if (remapflag == 0) { third_ilo = out_ilo; third_ihi = out_ihi; third_jlo = out_jlo; third_jhi = out_jhi; third_klo = out_klo; third_khi = out_khi; } else { third_ilo = ip1*nfast/np1; third_ihi = (ip1+1)*nfast/np1 - 1; third_jlo = ip2*nmid/np2; third_jhi = (ip2+1)*nmid/np2 - 1; third_klo = 0; third_khi = nslow - 1; } plan->mid2_plan = remap_3d_create_plan(comm, second_jlo,second_jhi,second_klo,second_khi, second_ilo,second_ihi, third_jlo,third_jhi,third_klo,third_khi, third_ilo,third_ihi, 2,1,0,2); if (plan->mid2_plan == NULL) return NULL; // 1d FFTs along slow axis plan->length3 = nslow; plan->total3 = nfast * nmid * nslow; // remap from 3rd FFT to final distribution // not needed if permute = 2 and third indices = out indices on all procs flag=1; MPI_Allreduce(&flag,&remapflag,1,MPI_INT,MPI_MAX,comm); if (remapflag == 0) plan->post_plan = NULL; else { plan->post_plan = remap_3d_create_plan(comm, third_klo,third_khi,third_ilo,third_ihi, third_jlo,third_jhi, out_klo,out_khi,out_ilo,out_ihi, out_jlo,out_jhi, 2,(permute+1)%3,0,2); if (plan->post_plan == NULL) return NULL; } // configure plan memory pointers and allocate work space // out_size = amount of memory given to FFT by user // first/second/third_size = amount of memory needed after pre,mid1,mid2 remaps // copy_size = amount needed internally for extra copy of data // scratch_size = amount needed internally for remap scratch space // for each remap: // out space used for result if big enough, else require copy buffer // accumulate largest required remap scratch space out_size = (out_ihi-out_ilo+1) * (out_jhi-out_jlo+1) * (out_khi-out_klo+1); first_size = (first_ihi-first_ilo+1) * (first_jhi-first_jlo+1) * (first_khi-first_klo+1); second_size = (second_ihi-second_ilo+1) * (second_jhi-second_jlo+1) * (second_khi-second_klo+1); third_size = (third_ihi-third_ilo+1) * (third_jhi-third_jlo+1) * (third_khi-third_klo+1); plan->ihi_out=out_ihi; plan->ilo_out=out_ilo; plan->jhi_out=out_jhi; plan->jlo_out=out_jlo; plan->khi_out=out_khi; plan->klo_out=out_klo; copy_size = 0; scratch_size = 0; if (plan->pre_plan) { if (first_size <= out_size) plan->pre_target = 0; else { plan->pre_target = 1; copy_size = MAX(copy_size,first_size); } scratch_size = MAX(scratch_size,first_size); } if (plan->mid1_plan) { if (second_size <= out_size) plan->mid1_target = 0; else { plan->mid1_target = 1; copy_size = MAX(copy_size,second_size); } scratch_size = MAX(scratch_size,second_size); } if (plan->mid2_plan) { if (third_size <= out_size) plan->mid2_target = 0; else { plan->mid2_target = 1; copy_size = MAX(copy_size,third_size); } scratch_size = MAX(scratch_size,third_size); } if (plan->post_plan) scratch_size = MAX(scratch_size,out_size); *nbuf = copy_size + scratch_size; if (copy_size) { plan->copy = (FFT_DATA *) malloc(copy_size*sizeof(FFT_DATA)); if (plan->copy == NULL) return NULL; } else plan->copy = NULL; if (scratch_size) { plan->scratch = (FFT_DATA *) malloc(scratch_size*sizeof(FFT_DATA)); if (plan->scratch == NULL) return NULL; } else plan->scratch = NULL; // system specific pre-computation of 1d FFT coeffs // and scaling normalization cufftResult retvalc; int nfft = (in_ihi-in_ilo+1) * (in_jhi-in_jlo+1) * (in_khi-in_klo+1); int nfft_brick = (out_ihi-out_ilo+1) * (out_jhi-out_jlo+1) * (out_khi-out_klo+1); int nfft_both = MAX(nfft,nfft_brick); nfft_both=nfast*nmid*nslow; plan->cudatasize=nfft_both*sizeof(FFT_DATA); //retvalc=cufftPlan1d(&(plan->plan_fast), nfast, CUFFT_PLAN,plan->total1/nfast); //if(retvalc!=CUFFT_SUCCESS) printf("ErrorCUFFT1: %i\n",retvalc); plan->nfast=nfast; //retvalc=cufftPlan1d(&(plan->plan_mid), nmid, CUFFT_PLAN,plan->total2/nmid); //if(retvalc!=CUFFT_SUCCESS) printf("ErrorCUFFT2: %i\n",retvalc); plan->nmid=nmid; //retvalc=cufftPlan1d(&(plan->plan_slow), nslow, CUFFT_PLAN,plan->total3/nslow); //if(retvalc!=CUFFT_SUCCESS) printf("ErrorCUFFT3: %i\n",retvalc); plan->nslow=nslow; retvalc=cufftPlan3d(&(plan->plan_3d), nslow,nmid,nfast, CUFFT_PLAN); if(retvalc!=CUFFT_SUCCESS) printf("ErrorCUFFT3: %i\n",retvalc); plan->nprocs=nprocs; plan->me=me; if (scaled == 0) plan->scaled = 0; else { plan->scaled = 1; plan->norm = 1.0/(nfast*nmid*nslow); plan->normnum = (out_ihi-out_ilo+1) * (out_jhi-out_jlo+1) * (out_khi-out_klo+1); } plan->coretime=0; plan->iterate=0; plan->ffttime=0; return plan; #endif } /* ---------------------------------------------------------------------- Destroy a 3d fft plan ------------------------------------------------------------------------- */ void fft_3d_destroy_plan_cuda(struct fft_plan_3d *plan) { #ifdef FFT_CUFFT if (plan->pre_plan) remap_3d_destroy_plan(plan->pre_plan); if (plan->mid1_plan) remap_3d_destroy_plan(plan->mid1_plan); if (plan->mid2_plan) remap_3d_destroy_plan(plan->mid2_plan); if (plan->post_plan) remap_3d_destroy_plan(plan->post_plan); if (plan->copy) free(plan->copy); if (plan->scratch) free(plan->scratch); //cufftDestroy(plan->plan_fast); //cufftDestroy(plan->plan_mid); //cufftDestroy(plan->plan_slow); cufftDestroy(plan->plan_3d); free(plan); #endif } /* ---------------------------------------------------------------------- recursively divide n into small factors, return them in list ------------------------------------------------------------------------- */ void factor_cuda(int n, int *num, int *list) { if (n == 1) { return; } else if (n % 2 == 0) { *list = 2; (*num)++; factor_cuda(n/2,num,list+1); } else if (n % 3 == 0) { *list = 3; (*num)++; factor_cuda(n/3,num,list+1); } else if (n % 5 == 0) { *list = 5; (*num)++; factor_cuda(n/5,num,list+1); } else if (n % 7 == 0) { *list = 7; (*num)++; factor_cuda(n/7,num,list+1); } else if (n % 11 == 0) { *list = 11; (*num)++; factor_cuda(n/11,num,list+1); } else if (n % 13 == 0) { *list = 13; (*num)++; factor_cuda(n/13,num,list+1); } else { *list = n; (*num)++; return; } } /* ---------------------------------------------------------------------- divide n into 2 factors of as equal size as possible ------------------------------------------------------------------------- */ void bifactor_cuda(int n, int *factor1, int *factor2) { int n1,n2,facmax; facmax = static_cast (sqrt((double) n)); for (n1 = facmax; n1 > 0; n1--) { n2 = n/n1; if (n1*n2 == n) { *factor1 = n1; *factor2 = n2; return; } } } /* ---------------------------------------------------------------------- perform just the 1d FFTs needed by a 3d FFT, no data movement used for timing purposes Arguments: in starting address of input data on this proc, all set to 0.0 nsize size of in flag 1 for forward FFT, -1 for inverse FFT plan plan returned by previous call to fft_3d_create_plan ------------------------------------------------------------------------- */ void fft_1d_only_cuda(FFT_DATA *data, int nsize, int flag, struct fft_plan_3d *plan) { #ifdef FFT_CUFFT int i,total,length,offset,num; double norm; // system specific constants // total = size of data needed in each dim // length = length of 1d FFT in each dim // total/length = # of 1d FFTs in each dim // if total > nsize, limit # of 1d FFTs to available size of data int total1 = plan->total1; int length1 = plan->length1; int total2 = plan->total2; int length2 = plan->length2; int total3 = plan->total3; int length3 = plan->length3; if (total1 > nsize) total1 = (nsize/length1) * length1; if (total2 > nsize) total2 = (nsize/length2) * length2; if (total3 > nsize) total3 = (nsize/length3) * length3; // perform 1d FFTs in each of 3 dimensions // data is just an array of 0.0 cudaMemcpy((void**) &(plan->cudata), (void*) data, plan->cudatasize,cudaMemcpyHostToDevice); if (flag == -1) { cufft(plan->plan_3d, plan->cudata, plan->cudata,CUFFT_FORWARD); /*cufft(plan->plan_fast, plan->cudata, plan->cudata,CUFFT_FORWARD); cufft(plan->plan_mid, plan->cudata, plan->cudata,CUFFT_FORWARD); cufft(plan->plan_slow, plan->cudata, plan->cudata,CUFFT_FORWARD);*/ } else { cufft(plan->plan_3d, plan->cudata, plan->cudata,CUFFT_FORWARD); /*cufft(plan->plan_fast, plan->cudata, plan->cudata,CUFFT_INVERSE); cufft(plan->plan_mid,plan->cudata, plan->cudata,CUFFT_INVERSE); cufft(plan->plan_slow, plan->cudata, plan->cudata,CUFFT_INVERSE);*/ } cudaMemcpy((void*) data, (void**) &(plan->cudata), plan->cudatasize,cudaMemcpyDeviceToHost); // scaling if required // limit num to size of data #endif }