Added an optimized popcount TDM generator to bsg_misc #653
Conversation
|
Hi can you commit the .v as well? |
There was a problem hiding this comment.
Let's rename the script bsg_popcount_tdm.py and make the generated module name also bsg_popcount_tdm.
The round robin arb does something similar, we can take some inspiration from:
https://github.com/bespoke-silicon-group/basejump_stl/blob/master/bsg_misc/bsg_round_robin_arb.py
https://github.com/bespoke-silicon-group/basejump_stl/blob/master/bsg_misc/bsg_round_robin_arb.v
The arb script takes the max size as an argument and then from 1 to the max size it generates a single module that uses generate-if statements to select the generated module. Rather than sweeping all widths from 1 to max size, maybe we just take all of the widths on the command line and generate those -- so the usage would be something like python3 ./bsg_popcount_tdm.py 32 64 1000 > bsg_popcount_tdm.v and it would generate a single modules with 3 generate-if statements.
bsg_misc/bsg_generate_popcount.py
Outdated
| print_end_module( 'popcount_tdm', s_o, c_o) # calculate sum in verilog file | ||
|
|
||
| if __name__ == '__main__': | ||
| popcount_gen(8) # generates a "popcount_tdm.v" file for width of 8 |
There was a problem hiding this comment.
Let's expose the width as a command line argument
bsg_misc/bsg_generate_popcount.py
Outdated
| @@ -0,0 +1,259 @@ | |||
| #!/usr/bin/env python3 | |||
There was a problem hiding this comment.
Add a header comment with what the script does and how to use it.
|
Let's try to get to the bottom of why we are not winning on frequency, especially for popcount <= 32. |
|
You can compare the two netlists and also the STA reports. |
…ed .v file from running python .\bsg_popcount_tdm.py 1 2 4 8 bsg_popcount_tdm.v
This is a python script that generates a popcount .v file. It attempts to do a more optimized adder tree using the Three Dimensional Method (TDM). The following PPA analysis compares the original bsg_popcount.v to the generated popcount_tdm.v for widths 8, 32, 64, 128, and 1024.
The full PPA spreadsheet can be found here: https://docs.google.com/spreadsheets/d/1FjDbuVNZ45XHxjTXhP-kz8AH1CuP96d7sxJkHXT-KGA/edit?usp=sharing