Change size of memories from Int to BigInt

[jackkoenig]

Relies on chipsalliance/firrtl#1075

Related issue: Fixes #856

Type of change: other enhancement

Impact: API addition (no impact on existing code)

Development Phase: implementation

Release Notes
Support memories larger than 2^(31)-1 (not supported by most simulators)

[aswaterman]

It looks like this can break some code, both because it relies on an implicit conversion from BigInt to Int, and because length is a public field whose type has changed.

I'd suggest fixing the first set of problems by adding new apply methods that accept Int (both for the companion-object factories and for the class methods used for indexing the structure).

The dependence on length is fundamentally backwards incompatible (it breaks code like for (i <- 0 until mem.length)), but I guess we have to suck it up.

[ducky64]

For reference, looking through Bits.scala indicates that many (if not all) of the methods that take BigInt as an argument also have Int counterparts, so having an Int version of apply here would be consistent with the rest of the codebase.

[jackkoenig]

Yeah y’all are right of course, will do

[jackkoenig]

I added back Int versions of the apply methods. It appears unnecessary to have them for the do_applys as well, although if y'all think I should add those too to be safe I will.

[jackkoenig]

retest this please

[jackkoenig]

retest this please