Up until now we could only support packing of scalar elements. This
patch fixes this by implementing packing of vector elements, by
generating extractelement and insertelement instruction pairs.
This patch implements packing of scalar operands when the vectorizer
decides to stop vectorizing. Packing is implemented with a sequence of
InsertElement instructions.
Packing vectors requires different instructions so it's implemented in a
follow-up patch.
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.
