- 例：C2C变换迁移前：
#include "mkl_cdft.h" #include "mkl_cdft_types.h" DFTI_DESCRIPTOR_HANDLE desc_handle = NULL; MKL_LONG rank = 2; MKL_LONG length[2] = {2, 3}; MKL_LONG istrides[3] = {0, 3, 1}; MKL_LONG ostrides[3] = {0, 3, 1}; MKL_LONG nthreads = 1; MKL_LONG howmany = 2; MKL_LONG idistance = 2 * 3; MKL_LONG odistance = 2 * 3; double init[12][2] = {{120, 0}, {8, 8}, {0, 0}, {0, 16}, {0, 16}, {-8, 8}, {-8, 0}, {-8, 8}, {-16, 0}, {0, -16}, {-40, 8}, {-8, -8}}; double *ri; ri = (double*)malloc(sizeof(double) * 12); double *ii; ii = (double*)malloc(sizeof(double) * 12); for (int i = 0; i < 12; i++) { ri[i] = init[i][0]; ii[i] = init[i][1]; } MKL_LONG s = DftiCreateDescriptor(&desc_handle, DFTI_DOUBLE, DFTI_COMPLEX, rank, length); s = DftiSetValue(desc_handle, DFTI_PLACEMENT, DFTI_NOT_INPLACE); s = DftiSetValue(desc_handle, DFTI_INPUT_STRIDES, istrides); s = DftiSetValue(desc_handle, DFTI_OUTPUT_STRIDES, ostrides); s = DftiSetValue(desc_handle, DFTI_THREAD_LIMIT, nthreads); s = DftiSetValue(desc_handle, DFTI_COMPLEX_STORAGE, DFTI_REAL_REAL); s = DftiSetValue(desc_handle, DFTI_NUMBER_OF_TRANSFORMS, howmany); s = DftiSetValue(desc_handle, DFTI_INPUT_DISTANCE, idistance); s = DftiSetValue(desc_handle, DFTI_OUTPUT_DISTANCE, odistance); s = DftiCommitDescriptor(desc_handle); double *ro; ro = (double*)malloc(sizeof(double) * 12); double *io; io = (double*)malloc(sizeof(double) * 12); DftiComputeForward(desc_handle, ri, ii, ro, io); DftiFreeDescriptor(&desc_handle); free(ri); free(ii); free(ro); free(io);迁移后：#include "kfft.h" int rank = 2; kml_fft_iodim64 *dims; dims = (kml_fft_iodim64*)kml_fft_malloc(sizeof(kml_fft_iodim64) * rank); dims[0].n = 2; dims[0].is = 3; dims[0].os = 3; dims[1].n = 3; dims[1].is = 1; dims[1].os = 1; int howmany_rank = 1; kml_fft_iodim64 *howmany_dims; howmany_dims = (kml_fft_iodim64*)kml_fft_malloc(sizeof(kml_fft_iodim64) * howmany_rank); howmany_dims[0].n = 2; howmany_dims[0].is = 2 * 3; howmany_dims[0].os = 2 * 3; double init[12][2] = {{120, 0}, {8, 8}, {0, 0}, {0, 16}, {0, 16}, {-8, 8}, {-8, 0}, {-8, 8}, {-16, 0}, {0, -16}, {-40, 8}, {-8, -8}}; double *ri; ri = (double*)kml_fft_malloc(sizeof(double) * 12); double *ii; ii = (double*)kml_fft_malloc(sizeof(double) * 12); for (int i = 0; i < 12; i++) { ri[i] = init[i][0]; ii[i] = init[i][1]; } double *ro; ro = (double*)kml_fft_malloc(sizeof(double) * 12); double *io; io = (double*)kml_fft_malloc(sizeof(double) * 12); kml_fft_plan plan; plan = kml_fft_plan_guru64_split_dft(rank, dims, howmany_rank, howmany_dims, ri, ii, ro, io, KML_FFT_ESTIMATE); kml_fft_execute_split_dft(plan, ri, ii, ro, io); kml_fft_destroy_plan(plan); kml_fft_free(howmany_dims); kml_fft_free(dims); kml_fft_free(ri); kml_fft_free(ii); kml_fft_free(ro); kml_fft_free(io); /* * ro = {1.200000e+02, 1.338564e+02, 1.061436e+02, 1.360000e+02, * 1.120000e+02, 1.120000e+02, -8.000000e+01, 4.878461e+01, * 7.215390e+00, 1.600000e+01, -2.692820e+01, -1.307180e+01} */ /* * io = {4.800000e+01, -1.385641e+01, 1.385641e+01, -3.200000e+01, * -8.000000e+00, -8.000000e+00, -8.000000e+00, 7.846097e-01, * -4.078461e+01, 2.400000e+01, -2.264102e+01, 4.664102e+01} */ - 例：R2C变换迁移前：
#include "mkl_cdft.h" #include "mkl_cdft_types.h" DFTI_DESCRIPTOR_HANDLE desc_handle = NULL; MKL_LONG rank = 2; MKL_LONG length[2] = {2, 3}; MKL_LONG istrides[3] = {0, 3, 1}; MKL_LONG ostrides[3] = {0, 2, 1}; MKL_LONG nthreads = 1; MKL_LONG howmany = 2; MKL_LONG idistance = 2 * 3; MKL_LONG odistance = 2 * 2; double init[12] = {120, 8, 0, 0, 0, -8, -8, -8, -16, 0, -40, -8}; double *in; in = (double*)malloc(sizeof(double) * 12); for (int i = 0; i < 12; i++) { in[i] = init[i]; } MKL_LONG s = DftiCreateDescriptor(&desc_handle, DFTI_DOUBLE, DFTI_REAL, rank, length); s = DftiSetValue(desc_handle, DFTI_PLACEMENT, DFTI_NOT_INPLACE); s = DftiSetValue(desc_handle, DFTI_INPUT_STRIDES, istrides); s = DftiSetValue(desc_handle, DFTI_OUTPUT_STRIDES, ostrides); s = DftiSetValue(desc_handle, DFTI_THREAD_LIMIT, nthreads); s = DftiSetValue(desc_handle, DFTI_COMPLEX_STORAGE, DFTI_COMPLEX_COMPLEX); s = DftiSetValue(desc_handle, DFTI_NUMBER_OF_TRANSFORMS, howmany); s = DftiSetValue(desc_handle, DFTI_INPUT_DISTANCE, idistance); s = DftiSetValue(desc_handle, DFTI_OUTPUT_DISTANCE, odistance); s = DftiSetValue(desc_handle, DFTI_CONJUGATE_EVEN_STORAGE, DFTI_COMPLEX_COMPLEX); s = DftiCommitDescriptor(desc_handle); MKL_Complex16 *out; out = (MKL_Complex16*)malloc(sizeof(MKL_Complex16) * 2 * 2 * howmany); DftiComputeForward(desc_handle, in, out); DftiFreeDescriptor(&desc_handle); free(in); free(out);迁移后：#include "kfft.h" int rank = 2; kml_fft_iodim64 *dims; dims = (kml_fft_iodim64*)kml_fft_malloc(sizeof(kml_fft_iodim64) * rank); dims[0].n = 2; dims[0].is = 3; dims[0].os = 2; dims[1].n = 3; dims[1].is = 1; dims[1].os = 1; int howmany_rank = 1; kml_fft_iodim64 *howmany_dims; howmany_dims = (kml_fft_iodim64*)kml_fft_malloc(sizeof(kml_fft_iodim64) * howmany_rank); howmany_dims[0].n = 2; howmany_dims[0].is = 2 * 3; howmany_dims[0].os = 2 * 2; double init[12] = {120, 8, 0, 0, 0, -8, -8, -8, -16, 0, -40, -8}; double *in; in = (double*)kml_fft_malloc(sizeof(double) * 12); for (int i = 0; i < 12; i++) { in[i] = init[i]; } kml_fft_complex *out; out = (kml_fft_complex*)kml_fft_malloc(sizeof(kml_fft_complex) * 8); kml_fft_plan plan; plan = kml_fft_plan_guru64_dft_r2c(rank, dims, howmany_rank, howmany_dims, in, out, KML_FFT_ESTIMATE); kml_fft_execute_dft_r2c(plan, in, out); kml_fft_destroy_plan(plan); kml_fft_free(howmany_dims); kml_fft_free(dims); kml_fft_free(in); kml_fft_free(out); /* * out = {{1.200000e+02, 0.000000e+00}, {1.200000e+02, -1.385641e+01}, * {1.360000e+02, 0.000000e+00}, {1.120000e+02, 0.000000e+00}, * {-8.000000e+01, 0.000000e+00}, {2.800000e+01, 2.078461e+01}, * {1.600000e+01, 0.000000e+00}, {-2.000000e+01, -3.464102e+01}} */ - 例：C2R变换迁移前：
#include "mkl_cdft.h" #include "mkl_cdft_types.h" DFTI_DESCRIPTOR_HANDLE desc_handle = NULL; MKL_LONG rank = 2; MKL_LONG length[2] = {2, 3}; MKL_LONG istrides[3] = {0, 2, 1}; MKL_LONG ostrides[3] = {0, 3, 1}; MKL_LONG nthreads = 1; MKL_LONG howmany = 2; MKL_LONG idistance = 2 * 2; MKL_LONG odistance = 2 * 3; double init[8][2] = {{120, 0}, {8, 8}, {0, 0}, {0, 16}, {0, 16}, {-8, 8}, {-8, 0}, {-8, 8}}; MKL_Complex16 *in; in = (MKL_Complex16*)malloc(sizeof(MKL_Complex16) * 8); for (int i = 0; i < 8; i++) { in[i].real = init[i][0]; in[i].imag = init[i][1]; } MKL_LONG s = DftiCreateDescriptor(&desc_handle, DFTI_DOUBLE, DFTI_REAL, rank, length); s = DftiSetValue(desc_handle, DFTI_PLACEMENT, DFTI_NOT_INPLACE); s = DftiSetValue(desc_handle, DFTI_INPUT_STRIDES, istrides); s = DftiSetValue(desc_handle, DFTI_OUTPUT_STRIDES, ostrides); s = DftiSetValue(desc_handle, DFTI_THREAD_LIMIT, nthreads); s = DftiSetValue(desc_handle, DFTI_COMPLEX_STORAGE, DFTI_COMPLEX_COMPLEX); s = DftiSetValue(desc_handle, DFTI_NUMBER_OF_TRANSFORMS, howmany); s = DftiSetValue(desc_handle, DFTI_INPUT_DISTANCE, idistance); s = DftiSetValue(desc_handle, DFTI_OUTPUT_DISTANCE, odistance); s = DftiSetValue(desc_handle, DFTI_CONJUGATE_EVEN_STORAGE, DFTI_COMPLEX_COMPLEX); s = DftiCommitDescriptor(desc_handle); double *out; out = (double*)malloc(sizeof(double) * 12); DftiComputeBackward(desc_handle, in, out); DftiFreeDescriptor(&desc_handle); free(in); free(out);迁移后：#include "kfft.h" int rank = 2; kml_fft_iodim64 *dims; dims = (kml_fft_iodim64*)kml_fft_malloc(sizeof(kml_fft_iodim64) * rank); dims[0].n = 2; dims[0].is = 2; dims[0].os = 3; dims[1].n = 3; dims[1].is = 1; dims[1].os = 1; int howmany_rank = 1; kml_fft_iodim64 *howmany_dims; howmany_dims = (kml_fft_iodim64*)kml_fft_malloc(sizeof(kml_fft_iodim64) * howmany_rank); howmany_dims[0].n = 2; howmany_dims[0].is = 2 * 2; howmany_dims[0].os = 2 * 3; double init[8][2] = {{120, 0}, {8, 8}, {0, 0}, {0, 16}, {0, 16}, {-8, 8}, {-8, 0}, {-8, 8}}; kml_fft_complex *in; in = (kml_fft_complex*)kml_fft_malloc(sizeof(kml_fft_complex) * 8); for (int i = 0; i < 8; i++) { in[i].r = init[i][0]; in[i].i = init[i][1]; } double *out; out = (double*)kml_fft_malloc(sizeof(double) * 12); kml_fft_plan plan; plan = kml_fft_plan_guru64_dft_c2r(rank, dims, howmany_rank, howmany_dims, in, out, KML_FFT_ESTIMATE); kml_fft_execute_dft_c2r(plan, in, out); kml_fft_destroy_plan(plan); kml_fft_free(howmany_dims); kml_fft_free(dims); kml_fft_free(in); kml_fft_free(out); /* * out = {1.360000e+02, 7.043078e+01, 1.535692e+02, 1.360000e+02, * 1.258564e+02, 9.814359e+01, -4.000000e+01, -1.971281e+01, * 3.571281e+01, 8.000000e+00, 8.000000e+00, 8.000000e+00} */
由于软件架构原因，在业务代码中若有多次计算不同类型的傅里叶变换，则需要构建对应的不同Plan，并且与MKL类似，同类型的变换构建一次Plan可以多次使用。