This is a refactoring patch that moves the callback registration for
getting notified about new instructions from the scheduler to the DAG.
This makes sense from a design and testing point of view:
- the DAG should not rely on the scheduler for getting notified
- the notifiers don't need to be public
- it's easier to test the notifiers directly from within the DAG unit
tests
This patch adds support for re-scheduling already scheduled
instructions. For now this will clear and rebuild the DAG, and will
reschedule the code using the new DAG.
This patch registers the "createInstr" callback that notifies the
scheduler about newly created instructions. This guarantees that all
newly created instructions have a corresponding DAG node associated with
them. Without this the pass crashes when the scheduler encounters the
newly created vector instructions.
This patch also changes the lifetime of the sandboxir Ctx variable in
the SandboxVectorizer pass. It needs to be destroyed after the passes
get destroyed. Without this change when components like the Scheduler
get destroyed Ctx will have already been freed, which is not legal.
This patch implements a ready-list-based scheduler that operates on
DependencyGraph.
It is used by the sandbox vectorizer to test the legality of vectorizing
a group of instrs.
SchedBundle is a helper container, containing all DGNodes that
correspond to the instructions that we are attempting to schedule with
trySchedule(Instrs).
