How does top_left work?

[narutozxp]

The top_left is a shortcut to define the organization for all the tiles. Fig. 74 shows an example of tiles in the top-left style, where the programmable block locates in the top-left corner of all the tiles, surrounded by two connection blocks and one switch blocks.
However, in my opinion, the organization of a tile is the work of the backend(such as P&R), so I am confused about what impact "top_left" has.
Thanks!

[tangxifan]

It is mainly for the physical design, opening up more opportunities in optimization. It does not change the bitstream values (only bitstream paths will be impacted).