Function arm_convolve_wrapper_s4_get_buffer_size

Function Documentation

int32_t arm_convolve_wrapper_s4_get_buffer_size(const cmsis_nn_conv_params *conv_params, const cmsis_nn_dims *input_dims, const cmsis_nn_dims *filter_dims, const cmsis_nn_dims *output_dims)

Get the required buffer size for arm_convolve_wrapper_s4.

Where a byte count is computed, an out-of-range shape is reported as -1 rather than a wrapped size. Which routes compute a byte count is build-dependent - the 1x1 routes need no buffer on any build, though the 1x1 fast route still rejects a negative input_dims->c with -1, and on a Helium build the 1xN route needs none when its padding lines up with the stride - so a caller that needs its dimensions validated must validate them rather than infer validity from a non-negative return.

Parameters:

  • 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]

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

  • filter_dims – [in] Filter dimensions. Format: [C_OUT, HK, WK, C_IN] where HK and WK are the spatial filter dimensions

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

Returns:

The function returns required buffer size in bytes, or -1 if the shape is out of range - a dimension the selected route reads is negative, or the required size would not fit in an int32_t. A route that needs no scratch buffer returns 0 for an in-range shape, but any route, including one that needs no buffer, may return -1 when a dimension it inspects is negative, so always test for -1 before using the value. Which dimensions a route inspects is build-dependent, so a 0 return is not a statement that the shape is valid.