Ensure we explicitly document the modulus for fixed-width arithmetic
@@ -167,6 +167,8 @@ int mbedtls_mpi_core_write_be( const mbedtls_mpi_uint *A,
* return carry;
* ```
*
+ * This function operates modulo `2^(biL*limbs)`.
+ *
* \param[in,out] X The pointer to the (little-endian) array
* representing the bignum to accumulate onto.
* \param[in] A The pointer to the (little-endian) array
@@ -217,6 +219,8 @@ mbedtls_mpi_uint mbedtls_mpi_core_sub( mbedtls_mpi_uint *X,
* \p X may be aliased to \p A (when \p X_limbs == \p A_limbs), but may not
* otherwise overlap.
*
+ * This function operates modulo `2^(biL*X_limbs)`.
+ *
* \param[in,out] X The pointer to the (little-endian) array
* representing the bignum to accumulate onto.
* \param X_limbs The number of limbs of \p X. This must be
