Actual source code: cufft.cu

      2: /*
      3:     Provides an interface to the CUFFT package.
      4:     Testing examples can be found in ~src/mat/tests
      5: */

      7: #include <petsc/private/matimpl.h>
      8: EXTERN_C_BEGIN
      9: #include <cuda.h>
     10: #include <cuda_runtime.h>
     11: #include <cufft.h>
     12: EXTERN_C_END

     14: typedef struct {
     15:   PetscInt     ndim;
     16:   PetscInt     *dim;
     17:   cufftHandle  p_forward, p_backward;
     18:   cufftComplex *devArray;
     19: } Mat_CUFFT;

     21: PetscErrorCode MatMult_SeqCUFFT(Mat A, Vec x, Vec y)
     22: {
     23:   Mat_CUFFT      *cufft    = (Mat_CUFFT*) A->data;
     24:   cufftComplex   *devArray = cufft->devArray;
     25:   PetscInt       ndim      = cufft->ndim, *dim = cufft->dim;
     26:   PetscScalar    *x_array, *y_array;
     27:   cufftResult    result;

     31:   VecGetArray(x, &x_array);
     32:   VecGetArray(y, &y_array);
     33:   if (!cufft->p_forward) {
     34:     cufftResult result;
     35:     /* create a plan, then execute it */
     36:     switch (ndim) {
     37:     case 1:
     38:       result = cufftPlan1d(&cufft->p_forward, dim[0], CUFFT_C2C, 1);CHKERRQ(result != CUFFT_SUCCESS);
     39:       break;
     40:     case 2:
     41:       result = cufftPlan2d(&cufft->p_forward, dim[0], dim[1], CUFFT_C2C);CHKERRQ(result != CUFFT_SUCCESS);
     42:       break;
     43:     case 3:
     44:       result = cufftPlan3d(&cufft->p_forward, dim[0], dim[1], dim[2], CUFFT_C2C);CHKERRQ(result != CUFFT_SUCCESS);
     45:       break;
     46:     default:
     47:       SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_USER, "Cannot create plan for %d-dimensional transform", ndim);
     48:     }
     49:   }
     50:   /* transfer to GPU memory */
     51:   cudaMemcpy(devArray, x_array, sizeof(cufftComplex)*dim[ndim], cudaMemcpyHostToDevice);
     52:   /* execute transform */
     53:   result = cufftExecC2C(cufft->p_forward, devArray, devArray, CUFFT_FORWARD);CHKERRQ(result != CUFFT_SUCCESS);
     54:   /* transfer from GPU memory */
     55:   cudaMemcpy(y_array, devArray, sizeof(cufftComplex)*dim[ndim], cudaMemcpyDeviceToHost);
     56:   VecRestoreArray(y, &y_array);
     57:   VecRestoreArray(x, &x_array);
     58:   return(0);
     59: }

     61: PetscErrorCode MatMultTranspose_SeqCUFFT(Mat A, Vec x, Vec y)
     62: {
     63:   Mat_CUFFT      *cufft    = (Mat_CUFFT*) A->data;
     64:   cufftComplex   *devArray = cufft->devArray;
     65:   PetscInt       ndim      = cufft->ndim, *dim = cufft->dim;
     66:   PetscScalar    *x_array, *y_array;
     67:   cufftResult    result;

     71:   VecGetArray(x, &x_array);
     72:   VecGetArray(y, &y_array);
     73:   if (!cufft->p_backward) {
     74:     /* create a plan, then execute it */
     75:     switch (ndim) {
     76:     case 1:
     77:       result = cufftPlan1d(&cufft->p_backward, dim[0], CUFFT_C2C, 1);CHKERRQ(result != CUFFT_SUCCESS);
     78:       break;
     79:     case 2:
     80:       result = cufftPlan2d(&cufft->p_backward, dim[0], dim[1], CUFFT_C2C);CHKERRQ(result != CUFFT_SUCCESS);
     81:       break;
     82:     case 3:
     83:       result = cufftPlan3d(&cufft->p_backward, dim[0], dim[1], dim[2], CUFFT_C2C);CHKERRQ(result != CUFFT_SUCCESS);
     84:       break;
     85:     default:
     86:       SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_USER, "Cannot create plan for %d-dimensional transform", ndim);
     87:     }
     88:   }
     89:   /* transfer to GPU memory */
     90:   cudaMemcpy(devArray, x_array, sizeof(cufftComplex)*dim[ndim], cudaMemcpyHostToDevice);
     91:   /* execute transform */
     92:   result = cufftExecC2C(cufft->p_forward, devArray, devArray, CUFFT_INVERSE);CHKERRQ(result != CUFFT_SUCCESS);
     93:   /* transfer from GPU memory */
     94:   cudaMemcpy(y_array, devArray, sizeof(cufftComplex)*dim[ndim], cudaMemcpyDeviceToHost);
     95:   VecRestoreArray(y, &y_array);
     96:   VecRestoreArray(x, &x_array);
     97:   return(0);
     98: }

    100: PetscErrorCode MatDestroy_SeqCUFFT(Mat A)
    101: {
    102:   Mat_CUFFT      *cufft = (Mat_CUFFT*) A->data;
    103:   cufftResult    result;

    107:   PetscFree(cufft->dim);
    108:   if (cufft->p_forward)  {result = cufftDestroy(cufft->p_forward);CHKERRQ(result != CUFFT_SUCCESS);}
    109:   if (cufft->p_backward) {result = cufftDestroy(cufft->p_backward);CHKERRQ(result != CUFFT_SUCCESS);}
    110:   cudaFree(cufft->devArray);
    111:   PetscFree(A->data);
    112:   PetscObjectChangeTypeName((PetscObject)A,0);
    113:   return(0);
    114: }

    116: /*@
    117:   MatCreateSeqCUFFT - Creates a matrix object that provides sequential FFT via the external package CUFFT

    119:   Collective

    121:   Input Parameters:
    122: + comm - MPI communicator, set to PETSC_COMM_SELF
    123: . ndim - the ndim-dimensional transform
    124: - dim  - array of size ndim, dim[i] contains the vector length in the i-dimension

    126:   Output Parameter:
    127: . A - the matrix

    129:   Options Database Keys:
    130: . -mat_cufft_plannerflags - set CUFFT planner flags

    132:   Level: intermediate
    133: @*/
    134: PetscErrorCode  MatCreateSeqCUFFT(MPI_Comm comm, PetscInt ndim, const PetscInt dim[], Mat *A)
    135: {
    136:   Mat_CUFFT      *cufft;
    137:   PetscInt       m, d;

    141:   if (ndim < 0) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_USER, "ndim %d must be > 0", ndim);
    142:   MatCreate(comm, A);
    143:   m    = 1;
    144:   for (d = 0; d < ndim; ++d) {
    145:     if (dim[d] < 0) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_USER, "dim[%d]=%d must be > 0", d, dim[d]);
    146:     m *= dim[d];
    147:   }
    148:   MatSetSizes(*A, m, m, m, m);
    149:   PetscObjectChangeTypeName((PetscObject)*A, MATSEQCUFFT);

    151:   PetscNewLog(*A,&cufft);
    152:   (*A)->data = (void*) cufft;
    153:   PetscMalloc1(ndim+1, &cufft->dim);
    154:   PetscArraycpy(cufft->dim, dim, ndim);

    156:   cufft->ndim       = ndim;
    157:   cufft->p_forward  = 0;
    158:   cufft->p_backward = 0;
    159:   cufft->dim[ndim]  = m;

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

    164:   (*A)->ops->mult          = MatMult_SeqCUFFT;
    165:   (*A)->ops->multtranspose = MatMultTranspose_SeqCUFFT;
    166:   (*A)->assembled          = PETSC_TRUE;
    167:   (*A)->ops->destroy       = MatDestroy_SeqCUFFT;

    169:   /* get runtime options */
    170:   PetscOptionsBegin(comm, ((PetscObject)(*A))->prefix, "CUFFT Options", "Mat");
    171:   PetscOptionsEnd();
    172:   return(0);
    173: }