o  If automatic data alignment is enabled, the .BLKx directives
       align the current location counter to one of the alignments
       listed in the following table:

       DirectiAlignment

       .BLKA  Quadword (64-bit) boundary
       .BLKB  None
       .BLKD  Quadword (64-bit) boundary
       .BLKF  Longword (32-bit) boundary
       .BLKG  Quadword (64-bit) boundary
       .BLKL  Longword (32-bit) boundary
       .BLKO  Octaword (128-bit) boundary
       .BLKQ  Quadword (64-bit) boundary
       .BLKS  Longword (32-bit) boundary
       .BLKT  Quadword (64-bit) boundary
       .BLKW  Word (16-bit) boundary

    o  You can only use these directives within psects having either
       the NOEXE or MIX attributes.