TheRock/rocm-libraries/projects/hipfft/clients/samples/hipfft_planmany_2d_r2c.cpp

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#include <complex>
#include <hipfft/hipfft.h>
#include <iostream>
#include <vector>

DISABLE_WARNING_PUSH
DISABLE_WARNING_DEPRECATED_DECLARATIONS
DISABLE_WARNING_RETURN_TYPE
#include <hip/hip_runtime_api.h>
DISABLE_WARNING_POP

int main()
{
    std::cout << "hipfft 2D single-precision real-to-complex transform using "
                 "advanced interface\n";

    int rank    = 2;
    int n[2]    = {4, 5};
    int howmany = 3; // batch size

    int n1_complex_elements      = n[1] / 2 + 1;
    int n1_padding_real_elements = n1_complex_elements * 2;

    int istride    = 1;
    int ostride    = istride;
    int inembed[2] = {n[0], n1_padding_real_elements};
    int onembed[2] = {n[0], n1_complex_elements};
    int idist      = istride * inembed[0] * inembed[1];
    int odist      = ostride * onembed[0] * onembed[1];

    std::cout << "n: " << n[0] << " " << n[1] << "\n"
              << "howmany: " << howmany << "\n"
              << "istride: " << istride << "\tostride: " << ostride << "\n"
              << "inembed: " << inembed[0] << " " << inembed[1] << "\n"
              << "onembed: " << onembed[0] << " " << onembed[1] << "\n"
              << "idist: " << idist << "\todist: " << odist << "\n"
              << std::endl;

    std::vector<float> data(howmany * idist);
    const auto         total_bytes = data.size() * sizeof(decltype(data)::value_type);

    std::cout << "input:\n";
    std::fill(data.begin(), data.end(), 0.0);
    for(int ibatch = 0; ibatch < howmany; ++ibatch)
    {
        for(int i = 0; i < n[0]; i++)
        {
            for(int j = 0; j < n[1]; j++)
            {
                const auto pos = ibatch * idist + istride * (i * inembed[1] + j);
                data[pos]      = i + ibatch + j;
            }
        }
    }
    for(int ibatch = 0; ibatch < howmany; ++ibatch)
    {
        std::cout << "batch: " << ibatch << "\n";
        for(int i = 0; i < n[0]; i++)
        {
            for(int j = 0; j < n[1]; j++)
            {
                const auto pos = ibatch * idist + istride * (i * inembed[1] + j);
                std::cout << data[pos] << " ";
            }
            std::cout << "\n";
        }
        std::cout << "\n";
    }
    std::cout << std::endl;

    hipfftHandle hipForwardPlan;
    hipfftResult hipfft_rt = hipfftPlanMany(&hipForwardPlan,
                                            rank,
                                            n,
                                            inembed,
                                            istride,
                                            idist,
                                            onembed,
                                            ostride,
                                            odist,
                                            HIPFFT_R2C, // Use HIPFFT_D2Z for double-precision.
                                            howmany);
    if(hipfft_rt != HIPFFT_SUCCESS)
        throw std::runtime_error("failed to create plan");

    hipfftReal* gpu_data;

    hipError_t hip_rt = hipMalloc((void**)&gpu_data, total_bytes);
    if(hip_rt != hipSuccess)
        throw std::runtime_error("hipMalloc failed");

    hip_rt = hipMemcpy(gpu_data, (void*)data.data(), total_bytes, hipMemcpyHostToDevice);
    if(hip_rt != hipSuccess)
        throw std::runtime_error("hipMemcpy failed");

    hipfft_rt = hipfftExecR2C(hipForwardPlan, gpu_data, (hipfftComplex*)gpu_data);
    if(hipfft_rt != HIPFFT_SUCCESS)
        throw std::runtime_error("failed to execute plan");

    hip_rt = hipMemcpy((void*)data.data(), gpu_data, total_bytes, hipMemcpyDeviceToHost);
    if(hip_rt != hipSuccess)
        throw std::runtime_error("hipMemcpy failed");

    std::cout << "output:\n";
    const std::complex<float>* output = (std::complex<float>*)data.data();
    for(int ibatch = 0; ibatch < howmany; ++ibatch)
    {
        std::cout << "batch: " << ibatch << "\n";
        for(int i = 0; i < n[0]; i++)
        {
            for(int j = 0; j < n1_complex_elements; j++)
            {
                const auto pos = ibatch * odist + ostride * (i * onembed[1] + j);
                std::cout << output[pos] << " ";
            }
            std::cout << "\n";
        }
        std::cout << "\n";
    }
    std::cout << std::endl;

    if(hipfftDestroy(hipForwardPlan) != HIPFFT_SUCCESS)
        throw std::runtime_error("hipfftDestroy failed");

    hip_rt = hipFree(gpu_data);
    if(hip_rt != hipSuccess)
        throw std::runtime_error("hipFree failed");

    return 0;
}