STRUCTURE   MatrixFloatRow4,0
    FLOAT       r_col0
    FLOAT       r_col1
    FLOAT       r_col2
    FLOAT       r_col3
    LABEL       MatrixFloatRow4_SIZEOF

    STRUCTURE   MatrixFloat44,0
    STRUCT      mat_row0,MatrixFloatRow4_SIZEOF
    STRUCT      mat_row1,MatrixFloatRow4_SIZEOF
    STRUCT      mat_row2,MatrixFloatRow4_SIZEOF
    STRUCT      mat_row3,MatrixFloatRow4_SIZEOF
    LABEL       MatrixFloat44_SIZEOF

_AddMatrix44:
    PRESERVE

    ;a0 = ptr to left  matrix
    ;a1 = ptr to right matrix
    ;results will be stored in MatrixBufferResult

    move.l  mathieeesingbas_base,a6

    ;Move these so they don't get clobbered.
    move.l  a0,a2
    move.l  a1,a3
    lea MatrixBufferResult,a4

    move.l  mat_row0,d4

    move.w  #3,d3 ;loop counter

.addNextRow
    ;Add a row.
    move.l  (r_col0,a2,d4),d0   ; matrix_left[d4/sizeof(row)][0]
    move.l  (r_col0,a3,d4),d1   ;matrix_right[d4/sizeof(row)][0]
    jsr IEEESPAdd(a6)
    move.l  d0,(r_col0,a4,d4)

    move.l  (r_col1,a2,d4),d0   ; matrix_left[d4/sizeof(row)][1]
    move.l  (r_col1,a3,d4),d1   ;matrix_right[d4/sizeof(row)][1]
    jsr IEEESPAdd(a6)
    move.l  d0,(r_col1,a4,d4)

    move.l  (r_col2,a2,d4),d0   ; matrix_left[d4/sizeof(row)][2]
    move.l  (r_col2,a3,d4),d1   ;matrix_right[d4/sizeof(row)][2]
    jsr IEEESPAdd(a6)
    move.l  d0,(r_col2,a4,d4)

    move.l  (r_col3,a2,d4),d0   ; matrix_left[d4/sizeof(row)][3]
    move.l  (r_col3,a3,d4),d1   ;matrix_right[d4/sizeof(row)][3]
    jsr IEEESPAdd(a6)
    move.l  d0,(r_col3,a4,d4)

    add.l   MatrixFloatRow4_SIZEOF,d4 ;advance to next row
    dbra    d3,.addNextRow

    RESTORE
    RTS