Hi, Please take a look into https://gist.github.com/dstogov/43eaa3f3b68583877322
This is variation on Bob's idea about variable liveness. The patch is incomplete. Liveness construction is still naive. However, all tests are passed. Ranges are represented by start/end/variable cartages. (I suppose this representation is more compact, than in the original proposal). In general, it's possible to use few ranges for the same variable, if its whole live range is not linear. (this is not implemented yet). Related ideas and tests are welcome. Thanks. Dmitry.
