Date: 2026-05-01T06:11:57+00:00

Actual source code: cufft.cu

      1: /*
      2:     Provides an interface to the CUFFT package.
      3:     Testing examples can be found in ~src/mat/tests
      4: */

      6: #include <petscdevice_cuda.h>
      7: #include <petsc/private/matimpl.h>

      9: typedef struct {
     10:   PetscInt      ndim;
     11:   PetscInt     *dim;
     12:   cufftHandle   p_forward, p_backward;
     13:   cufftComplex *devArray;
     14: } Mat_CUFFT;

     16: static PetscErrorCode MatMult_SeqCUFFT(Mat A, Vec x, Vec y)
     17: {
     18:   Mat_CUFFT    *cufft    = (Mat_CUFFT *)A->data;
     19:   cufftComplex *devArray = cufft->devArray;
     20:   PetscInt      ndim = cufft->ndim, *dim = cufft->dim;
     21:   PetscScalar  *x_array, *y_array;

     23:   PetscFunctionBegin;
     24:   PetscCall(VecGetArray(x, &x_array));
     25:   PetscCall(VecGetArray(y, &y_array));
     26:   if (!cufft->p_forward) {
     27:     /* create a plan, then execute it */
     28:     switch (ndim) {
     29:     case 1:
     30:       PetscCallCUFFT(cufftPlan1d(&cufft->p_forward, dim[0], CUFFT_C2C, 1));
     31:       break;
     32:     case 2:
     33:       PetscCallCUFFT(cufftPlan2d(&cufft->p_forward, dim[0], dim[1], CUFFT_C2C));
     34:       break;
     35:     case 3:
     36:       PetscCallCUFFT(cufftPlan3d(&cufft->p_forward, dim[0], dim[1], dim[2], CUFFT_C2C));
     37:       break;
     38:     default:
     39:       SETERRQ(PETSC_COMM_SELF, PETSC_ERR_USER, "Cannot create plan for %" PetscInt_FMT "-dimensional transform", ndim);
     40:     }
     41:   }
     42:   /* transfer to GPU memory */
     43:   PetscCallCUDA(cudaMemcpy(devArray, x_array, sizeof(cufftComplex) * dim[ndim], cudaMemcpyHostToDevice));
     44:   /* execute transform */
     45:   PetscCallCUFFT(cufftExecC2C(cufft->p_forward, devArray, devArray, CUFFT_FORWARD));
     46:   /* transfer from GPU memory */
     47:   PetscCallCUDA(cudaMemcpy(y_array, devArray, sizeof(cufftComplex) * dim[ndim], cudaMemcpyDeviceToHost));
     48:   PetscCall(VecRestoreArray(y, &y_array));
     49:   PetscCall(VecRestoreArray(x, &x_array));
     50:   PetscFunctionReturn(PETSC_SUCCESS);
     51: }

     53: static PetscErrorCode MatMultTranspose_SeqCUFFT(Mat A, Vec x, Vec y)
     54: {
     55:   Mat_CUFFT    *cufft    = (Mat_CUFFT *)A->data;
     56:   cufftComplex *devArray = cufft->devArray;
     57:   PetscInt      ndim = cufft->ndim, *dim = cufft->dim;
     58:   PetscScalar  *x_array, *y_array;

     60:   PetscFunctionBegin;
     61:   PetscCall(VecGetArray(x, &x_array));
     62:   PetscCall(VecGetArray(y, &y_array));
     63:   if (!cufft->p_backward) {
     64:     /* create a plan, then execute it */
     65:     switch (ndim) {
     66:     case 1:
     67:       PetscCallCUFFT(cufftPlan1d(&cufft->p_backward, dim[0], CUFFT_C2C, 1));
     68:       break;
     69:     case 2:
     70:       PetscCallCUFFT(cufftPlan2d(&cufft->p_backward, dim[0], dim[1], CUFFT_C2C));
     71:       break;
     72:     case 3:
     73:       PetscCallCUFFT(cufftPlan3d(&cufft->p_backward, dim[0], dim[1], dim[2], CUFFT_C2C));
     74:       break;
     75:     default:
     76:       SETERRQ(PETSC_COMM_SELF, PETSC_ERR_USER, "Cannot create plan for %" PetscInt_FMT "-dimensional transform", ndim);
     77:     }
     78:   }
     79:   /* transfer to GPU memory */
     80:   PetscCallCUDA(cudaMemcpy(devArray, x_array, sizeof(cufftComplex) * dim[ndim], cudaMemcpyHostToDevice));
     81:   /* execute transform */
     82:   PetscCallCUFFT(cufftExecC2C(cufft->p_forward, devArray, devArray, CUFFT_INVERSE));
     83:   /* transfer from GPU memory */
     84:   PetscCallCUDA(cudaMemcpy(y_array, devArray, sizeof(cufftComplex) * dim[ndim], cudaMemcpyDeviceToHost));
     85:   PetscCall(VecRestoreArray(y, &y_array));
     86:   PetscCall(VecRestoreArray(x, &x_array));
     87:   PetscFunctionReturn(PETSC_SUCCESS);
     88: }

     90: static PetscErrorCode MatDestroy_SeqCUFFT(Mat A)
     91: {
     92:   Mat_CUFFT *cufft = (Mat_CUFFT *)A->data;

     94:   PetscFunctionBegin;
     95:   PetscCall(PetscFree(cufft->dim));
     96:   if (cufft->p_forward) PetscCallCUFFT(cufftDestroy(cufft->p_forward));
     97:   if (cufft->p_backward) PetscCallCUFFT(cufftDestroy(cufft->p_backward));
     98:   PetscCallCUDA(cudaFree(cufft->devArray));
     99:   PetscCall(PetscFree(A->data));
    100:   PetscCall(PetscObjectChangeTypeName((PetscObject)A, 0));
    101:   PetscFunctionReturn(PETSC_SUCCESS);
    102: }

    104: /*@
    105:   MatCreateSeqCUFFT - Creates a matrix object that provides `MATSEQCUFFT` via the NVIDIA package CuFFT

    107:   Collective

    109:   Input Parameters:
    110: + comm - MPI communicator, set to `PETSC_COMM_SELF`
    111: . ndim - the ndim-dimensional transform
    112: - dim  - array of size `ndim`, dim[i] contains the vector length in the i-dimension

    114:   Output Parameter:
    115: . A - the matrix

    117:   Options Database Key:
    118: . -mat_cufft_plannerflags - set CuFFT planner flags

    120:   Level: intermediate

    122: .seealso: [](ch_matrices), `Mat`, `MATSEQCUFFT`
    123: @*/
    124: PetscErrorCode MatCreateSeqCUFFT(MPI_Comm comm, PetscInt ndim, const PetscInt dim[], Mat *A)
    125: {
    126:   Mat_CUFFT *cufft;
    127:   PetscInt   m = 1;

    129:   PetscFunctionBegin;
    130:   PetscCheck(ndim >= 0, PETSC_COMM_SELF, PETSC_ERR_USER, "ndim %" PetscInt_FMT " must be > 0", ndim);
    131:   if (ndim) PetscAssertPointer(dim, 3);
    132:   PetscAssertPointer(A, 4);
    133:   PetscCall(MatCreate(comm, A));
    134:   for (PetscInt d = 0; d < ndim; ++d) {
    135:     PetscCheck(dim[d] >= 0, PETSC_COMM_SELF, PETSC_ERR_USER, "dim[%" PetscInt_FMT "]=%" PetscInt_FMT " must be > 0", d, dim[d]);
    136:     m *= dim[d];
    137:   }
    138:   PetscCall(MatSetSizes(*A, m, m, m, m));
    139:   PetscCall(PetscObjectChangeTypeName((PetscObject)*A, MATSEQCUFFT));

    141:   PetscCall(PetscNew(&cufft));
    142:   (*A)->data = (void *)cufft;
    143:   PetscCall(PetscMalloc1(ndim + 1, &cufft->dim));
    144:   PetscCall(PetscArraycpy(cufft->dim, dim, ndim));

    146:   cufft->ndim       = ndim;
    147:   cufft->p_forward  = 0;
    148:   cufft->p_backward = 0;
    149:   cufft->dim[ndim]  = m;

    151:   /* GPU memory allocation */
    152:   PetscCallCUDA(cudaMalloc((void **)&cufft->devArray, sizeof(cufftComplex) * m));

    154:   (*A)->ops->mult          = MatMult_SeqCUFFT;
    155:   (*A)->ops->multtranspose = MatMultTranspose_SeqCUFFT;
    156:   (*A)->assembled          = PETSC_TRUE;
    157:   (*A)->ops->destroy       = MatDestroy_SeqCUFFT;

    159:   /* get runtime options ...what options????? */
    160:   PetscOptionsBegin(comm, ((PetscObject)*A)->prefix, "CUFFT Options", "Mat");
    161:   PetscOptionsEnd();
    162:   PetscFunctionReturn(PETSC_SUCCESS);
    163: }