This patch fixes a bug in `DependencyGraph::extend()` when the old
interval contains no memory instructions. When this is the case we
should do a full dependency scan of the new interval.
The TransactionAcceptOrRevert pass is the final pass in the Sandbox
Vectorizer's default pass pipeline. It's job is to check the cost
before/after vectorization and accept or revert the IR to its original
state.
Since we are now starting the transaction in BottomUpVec, tests that run
a custom pipeline need to accept the transaction. This is done with the
help of the TransactionAlwaysAccept pass (tr-accept).
This patch fixes a bug in the dependency node iterators that would
incorrectly not skip nodes that are not in the current DAG. This
resulted in iterators returning nullptr when dereferenced.
The fix is to update the existing "skip" function to not only skip
non-instruction values but also to skip instructions not in the DAG.
This patch fixes a bug in the maintenance of the MemDGNode chain of the
DAG. Whenever we move a memory instruction, the DAG gets notified about
the move and maintains the chain of memory nodes. The bug was that if
the destination of the move was not a memory instruction, then the
memory node's next node would end up pointing to itself.
Crossing BBs is not currently supported by the structures of the
vectorizer. This patch fixes instances where this was happening,
including:
- a walk of use-def operands that updates the UnscheduledSuccs counter,
- the dead instruction removal is now done per BB,
- the scheduler, which will reject bundles that cross BBs.
The DAG maintains a chain of MemDGNodes that links together all the
nodes that may touch memroy.
Whenever a new instruction gets created we need to make sure that this
chain gets updated. If the new instruction touches memory then its
corresponding MemDGNode should be inserted into the chain.
This patch adds the callback registration logic in the DAG's constructor
and the corresponding deregistration logic in the destructor. It also
implements the code that makes sure that SchedBundle and DGNodes can be
safely destroyed in any order.
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).
This patch implements the UnscheduledSuccs counter in DGNode. It counts
the number of unscheduled successors and is used by the scheduler to
determine when a node is ready.
When NewInterval is below DAGInterval we used to revisit instructions
already visited. This patch fixes this by separating the scan in two:
1. The full scan of the NewInterval, and
2. The cross-interval scan for DAGInterval.
This is further explained in the new description.
This patch implements `Interval::comesBefore(const Interval &Other)`
which returns true if this interval is strictly before Other in program
order. The function asserts that the intervals are disjoint.
This patch implements the MemDGNode class for DAG nodes that are
candidates
for memory dependencies. These nodes form a chain that is accessible by
`getPrevNode()` and `getNextNode()`.
It also implements a builder class that creates MemDGNode intervals from
Instructions.
This patch converts InstrInterval class to a class template and renames
InstrInterval to Itnerval.
This change will allow us to reuse the Interval for dependency graph
nodes.
