Use 2*63 for the genesis slot

[JustinDrake]

No description provided.

[djrtwo]

Rationale here -- #534

set initial slot to 2**63 such that you can always do state.slot << 1 to get the number of slots since genesis. Seems nice.

[Nashatyrev]

Slot #‭576460752303423590‬6 doesn't look too user friendly.
From engineering point of view: the only reference point when understanding/debugging Eth1 blockchain issues was always the block number. This change will complicate the things.

BTW state.slot << 1 wouldn't be [slots since genesis] * 2 then ?

[JustinDrake]

Slot #‭576460752303423590‬6 doesn't look too user friendly.

Right, this number should not be exposed to users. Abstracting the most significant bit at a very low level would make sense.

state.slot << 1 wouldn't be [slots since genesis] * 2 then ?

(state.slot << 1) >> 1 is what you want :)

[djrtwo]

@Nashatyrev Given the (slot << 1) >>1 or slot - 2**63 does this satisfy the debugging requirement?

Starting at slot/epoch 0 requires adding a bunch of conditional underflow logic that will only be needed in the first few epochs.

[vbuterin]

Seems reasonable to me. As said above, we can have a UI convention that we subtract 2**63.

[vbuterin]

👍