Function MLUOP_WIN_API calParallelNumLowBound

kernels/fft/fft.cpp:1176–1370

low bound

// low bound
mluOpStatus_t MLUOP_WIN_API calParallelNumLowBound(mluOpHandle_t handle,
                                                   mluOpFFTPlan_t fft_plan,
                                                   int *facbuf, const int stage,
                                                   int &parallel_num_lb,
                                                   const int is_row_major) {
  const size_t nram_space_size =
      (handle->nram_size + REM_FOR_STACK - 32 * 1024 - FFT_MAXFACTORS * 4);
  size_t workspace_size = 0;
  size_t reservespace_size = 0;
  const int max_radix = 64;
  size_t TYPE_SIZE = 0;
  parallel_num_lb = 0;
  size_t nram_space_need = 0;
  size_t nram_space_need_tw = 0;
  size_t nram_space_need_dftmtx =
      (stage == 1) ? max_radix * max_radix * 2 * 2 * 4
                   : max_radix * max_radix * 2 * 4;  // complex
  // int nram_space_need_dftmtx_align = 0;
  size_t space_need_matmul = 0;
  size_t space_need_matmul_tmp = 0;
  int small_stage_num = facbuf[0];
  int _n = facbuf[1];
  int radix = 0;
  int section_num = 0;
  int butterfly_num = 0;
  int para_num = 0;
  int K_num = 0;
  int align_M = 0;
  int align_K = 0;
  int align_N = 0;

  mluOpStatus_t status;

  switch (fft_plan->fft_type) {
    // r2c
    case CNFFT_COMPLEX_HALF2HALF:
    case CNFFT_COMPLEX_FLOAT2FLOAT:
    case CNFFT_HALF2COMPLEX_HALF:
    case CNFFT_FLOAT2COMPLEX_FLOAT: {
      TYPE_SIZE = 4;
      K_num = 64 / TYPE_SIZE;

      if (stage == 1) {
        nram_space_need = 0;
        // nram_para_load_ping
        nram_space_need += _n * 2 * TYPE_SIZE;  // complex
        // nram_para_load_pong
        nram_space_need += _n * 2 * TYPE_SIZE;  // complex
        // nram_para_store_ping
        nram_space_need += _n * 2 * TYPE_SIZE;  // complex
        // nram_para_store_pong
        nram_space_need += _n * 2 * TYPE_SIZE;  // complex

        nram_space_need += _n * 5 * TYPE_SIZE;  // complex
      } else {
        nram_space_need = 0;
        // nram_para_load_ping
        nram_space_need += _n * 2 * TYPE_SIZE;  // complex