Function arm_convolve_s8

Function Documentation

arm_cmsis_nn_status arm_convolve_s8(const cmsis_nn_context *ctx, const cmsis_nn_context *weight_sum_ctx, const cmsis_nn_conv_params *conv_params, const cmsis_nn_per_channel_quant_params *quant_params, const cmsis_nn_dims *input_dims, const int8_t *input_data, const cmsis_nn_dims *filter_dims, const int8_t *filter_data, const cmsis_nn_dims *bias_dims, const int32_t *bias_data, const cmsis_nn_dims *upscale_dims, const cmsis_nn_dims *output_dims, int8_t *output_data)

Basic s8 convolution function.

  1. Supported framework: TensorFlow Lite micro

  2. Additional memory is required for optimization. Refer to argument ‘ctx’ for details.

Parameters:

  • ctx – [inout] Function context that contains the additional buffer if required by the function. arm_convolve_s8_get_buffer_size will return the buffer_size if required. The caller is expected to clear the buffer, if applicable, for security reasons.

  • weight_sum_ctx – [in] Per-output-channel weight sums, supplied by the caller. This function only reads the buffer and never writes it, so it is filled once and may then be reused for as long as filter_data, bias_data and conv_params->input_offset are unchanged - see arm_convolve_weight_sum() for the layout and the full reuse rules. Fill it with arm_convolve_weight_sum(), passing conv_params->input_offset as lhs_offset and the same bias_data given here, so that entry j holds input_offset * sum(weights of output channel j) + bias_data[j]. For grouped convolution the entries run over all output_dims->c channels, groups laid out consecutively. That helper returns ARM_CMSIS_NN_NO_IMPL_ERROR on non-MVE builds, which is not a failure. Pass a valid context on every build. Currently the contents are read only on builds with the MVE extension (ARM_MATH_MVEI); an unfilled buffer there yields wrong output while still returning ARM_CMSIS_NN_SUCCESS, and a NULL buf is currently reported as ARM_CMSIS_NN_ARG_ERROR. On other builds this function currently derives the same quantity itself and does not read the context. None of this is a guarantee about future versions. Sized by arm_convolve_s8_get_weights_sum_size(): output_dims->c * sizeof(int32_t) where the sums are used, 0 otherwise. The caller is expected to clear the buffer, if applicable, for security reasons.

  • conv_params – [in] Convolution parameters (e.g. strides, dilations, pads,…). Range of conv_params->input_offset : [-127, 128] Range of conv_params->output_offset : [-128, 127]

  • quant_params – [in] Per-channel quantization info. It contains the multiplier and shift values to be applied to each output channel

  • input_dims – [in] Input (activation) tensor dimensions. Format: [N, H, W, C_IN]

  • input_data – [in] Input (activation) data pointer. Data type: int8

  • filter_dims – [in] Filter tensor dimensions. Format: [C_OUT, HK, WK, CK] where HK, WK and CK are the spatial filter dimensions. CK != C_IN is used for grouped convolution, in which case the required conditions are C_IN = N * CK and C_OUT = N * M for N groups of size M.

  • filter_data – [in] Filter data pointer. Data type: int8

  • bias_dims – [in] Bias tensor dimensions. Format: [C_OUT]

  • bias_data – [in] Optional bias data pointer. Data type: int32

  • upscale_dims – [in] Upscale tensor dimensions for transpose. Format: [H_UP, W_UP]

  • output_dims – [in] Output tensor dimensions. Format: [N, H, W, C_OUT]

  • output_data – [out] Output data pointer. Data type: int8

Returns:

The function returns ARM_CMSIS_NN_SUCCESS if successful or ARM_CMSIS_NN_ARG_ERROR if incorrect arguments or ARM_CMSIS_NN_NO_IMPL_ERROR