Matrix multiplication in VHDL

Here is a function for doing matrix multiplication in VHDL.
For storing matrix elements I have declared the following data types:

type t11 is array (0 to numcols1-1) of unsigned(15 downto 0);
type t1 is array (0 to numrows1-1) of t11;     
type t22 is array (0 to numcols2-1) of unsigned(15 downto 0);  
type t2 is array (0 to numrows2-1) of t22;
type t33 is array (0 to numcols3-1) of unsigned(31 downto 0);  
type t3 is array (0 to numrows3-1) of t33;  

Depending upon the size of your matrix you have to set the values numcols1,numcols2,numcols3,numrows1,numrows2,numrows3 etc.Here for valid matrix multiplication, numcols1 = numrows2.
For the resultant matrix, numrows3 = numrows1 and numcols3 = numcols2.

The function is given below:

function  matmul  ( a : t1; b:t2 ) return t3 is
variable i,j,k : integer:=0;
variable prod : t3:=(others => (others => (others => '0')));
begin
for i in 0 to numrows1-1 loop
for j in 0 to numcols2-1 loop
for k in 0 to numcols1-1 loop
   prod(i)(j) := prod(i)(j) + (a(i)(k) * b(k)(j));
end loop;
end loop;
end loop;
return prod;
end matmul;

In the above function replace the names numrows1,numcols1,numcols2 etc with appropriate values.
For example if I want to multiply a 4*3 matrix with 3*5 matrix then :
numcols1=3, numcols2 =5 ,numcols3 = 5,numrows1=4 ,numrows2 =3 and numrows3=4.
So the type declarations will look like this:

type t11 is array (0 to 2) of unsigned(15 downto 0);
type t1 is array (0 to 3) of t11;      
type t22 is array (0 to 4) of unsigned(15 downto 0);
type t2 is array (0 to 2) of t22;
type t33 is array (0 to 4) of unsigned(31 downto 0);
type t3 is array (0 to 3) of t33;

Note :- I have declared the elements of the matrix as unsigned 16 bit and for the product matrix as unsigned 32 bit.If you want to change the size of the operands you can easily do that  in the type declaration.This will not alter the function logic.