Georg Wiese cb8969368b BlockMachine: Don't look into other fixed columns for period detection (#1383) ...

Fixes an issue that @leonardoalt had on his `binary-mux2` branch.

There are two ways to have a block machine that is connected via a
permutation:
1. Use permutations `<sel> { ... } is (sub.sel * sub.LATCH) { ... }`.
This makes sure only rows where `sub.LATCH` is `1` can be selected. This
is what we do when we compile from ASM to PIL.
2. Use permutations `<sel> { ... } is sub.sel { ... }`, but also a
constraint `(1 - sub.LATCH) * sub.sel = 0`. This achieves something
similar.

The problem is that in the second case, detecting the block size is
harder, because the latch doesn't appear anywhere in the selector. So we
used to look into *all* fixed columns to detect the period. But this
includes fixed columns that might have a larger period (as is the case
for the multiplexer machine).

This PR simply removes support for the second approach. I think this is
fine in practice, as I don't see a disadvantage of the first approach
and when you come from ASM everything works as expected. I did need to
adjust `test_data/pil/block_lookup_or_permutation.pil`, which used the
second approach.

2024-05-17 16:24:08 +00:00

..

src

BlockMachine: Don't look into other fixed columns for period detection (#1383)

2024-05-17 16:24:08 +00:00

Cargo.toml

move internal dependencies to shared version (#1379)

2024-05-15 10:46:34 +00:00