_SIZE_MISMATCH</a> : Matrix size check failed</li>
</ul>
</dd></dl>
<dl class="section user"><dt>Scaling and Overflow Behavior</dt><dd>The difference between the function <a class="el" href="group__MatrixMult.html#ga2ec612a8c2c4916477fb9bc1ab548a6e">arm_mat_mult_q31()</a> and this fast variant is that the fast variant use a 32-bit rather than a 64-bit accumulator. The result of each 1.31 x 1.31 multiplication is truncated to 2.30 format. These intermediate results are accumulated in a 32-bit register in 2.3