10.3.2. Member-by-Member Guide - 5.2 English - 57404

1. Buffers (`in`, `out`)

• in: Points to the input data (signal for forward FFT, frequency for backward FFT).

• out: Points to the output data (frequency for forward FFT, signal for backward FFT).

• Constraints:

  • Must not be NULL.

  • For in-place transforms (flags.fft_placement == 0), in and out must be the same pointer.

  • For out-of-place transforms (flags.fft_placement == 1), in and out must be different pointers.

2. Ranks (`vec_rank`, `dim_rank`)

• vec_rank: Number of batch dimensions (length of vecs array). Must be \(\geq 1\).

• dim_rank: Number of signal/frequency dimensions (length of dims array). Must be \(\geq 1\).

3. Dimension Arrays (`dims`, `vecs`)

• dims: Array of aoclfftz_dim_t describing each signal/frequency dimension.

• vecs: Array of aoclfftz_dim_t describing each batch dimension.

• Constraints for each element:

  • n (size): Must be > 0.

  • in_stride, out_stride: Must be > 0.

  • For in-place transforms, in_stride must equal out_stride for each dimension.

  • For real transforms (R2C/C2R), only 1D is supported (dim_rank == 1) in this release, and special stride rules apply (see Stride Setting).

4. Flags (`flags`)

• fft_type: Complex (0) or Real (1).

• fft_direction: Forward (0) or Backward (1).

• storage_order: Must be 0 (in-order only; out-of-order not supported).

• fft_placement: In-place (0) or Out-of-place (1).

• transpose_mode: Must be 0 (standalone transpose not supported).

5. Parallel FFT (`pthr_fft`)

• num_threads: Number of threads (\(\geq 1\)). If greater than available CPUs, defaults to max CPUs. If less than 1, defaults to single-threaded execution.

• dynamic_load_model: 0 (fixed threads) or 1 (dynamic threads - not supported in this release). Invalid values default to 0.

6. Control Parameters (`cntrl_params`)

• opt_level: 0-3 (optimization level). Out-of-range values default to maximum opt level - 3.

• opt_off: 0 (optimizations enabled) or 1 (disabled).

• logger_mode: 0-3. Out-of-range values default to 0. Error logs are always enabled despite logger_mode setting.

• measure_stats: Must be 0 (not supported).