Confusing doc on arm_nn_requantize

[ghost]

The documentation of arm_nn_requantize is

/**
 * @brief           Requantize a given value.
 * @param[in]       val         Value to be requantized
 * @param[in]       multiplier  multiplier. Range {NN_Q31_MIN + 1, Q32_MAX}
 * @param[in]       shift       left or right shift for 'val * multiplier'
 *
 * @return          Returns (val * multiplier)/(2 ^ shift)
 *
 */

But the CMSIS_USE_SINGLE_ROUNDING path does not compute that, but some rounding of (val * multipler) / (2^(shift+31))

Besides, the left or right shift part of the doc is not very clear: how to specify the direction of the shift?
It seems that it is based on the sign of shift, with positive shifts being left shift and negative shifts being right shifts.