The way Intel IPP for small matrices operates on matrix arrays is similar to its operation on single matrices. Thus, different matrices cannot be combined into one array, unless the following conditions are met:
matrices have equal width and height
matrices have identical structure, i.e. if superposed by memory shift, they will coincide.
See Figure “Combining Matrices into an Array”, cases A, B, C for proper matrix sets. If one or both of these conditions is not met, matrices cannot be combined into an array (see Figure “Combining Matrices into an Array”, cases D, E).
However, not all proper matrices can be combined into an array. Another important condition is matrix layout.
The matrix layout is called regular, if the matrices are equally spaced in memory; otherwise, the layout is called irregular. In these terms, matrices can be combined in the following way (see Figure “Permissible Matrix Arrays”, cases A, B, C):
regular matrices with regular layout
regular matrices with irregular layout
irregular matrices with regular layout
Irregular matrices with irregular layout cannot be combined into an array (see Figure “Permissible Matrix Arrays”, case D).
