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.
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.
[Retry 110696 with a proper rebase.]
Seed collection will assemble instructions to be vectorized into
SeedBundles. This data structure is not intended to be used directly,
but will be the basis for load bundles, store bundles, and so on.
This patch moves:
- Utils::isStackSaveOrRestoreIntrinsic()
- Utils::isMemIntrinsic()
- Utils::isMemDepCandidate()
to DGNode because they no longer require LLVM IR access and are used
only by the DAG.
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 implements a few set operations for the intervals. These
include:
- operator==() and operator!=() for comparing two intervals.
- disjoint()
- intersection()
- difference, which uses operator-()
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.
I'm planning to add RegionPass and RegionPassManager next to the
equivalent FunctionPass and FunctionPassManager in SandboxIR, which
means that SandboxIR has to know about Regions.
There's nothing vectorizer-specific about the Region class, and the only
thing using Regions at this moment is the unit test, so this is a
straightforward file move.
For each region, we create a metadata node. Then when an instruction is
added to the Region, it gets tagged with the metadata node for that
region. In the following example, we have a Region that contains only
the `%t0` instruction.
```
define i8 @foo(i8 %v0, i8 %v1) {
%t0 = add i8 %v0, 1, !sbvec !0
%t1 = add i8 %t0, %v1
ret i8 %t1
}
!0 = distinct !{!"region"}
```
This commit also adds a function to create regions from metadata already
present in a Function.
This metadata can be used for debugging: if we dump IR before a Region
pass, the IR will contain enough info to re-create the Region and run
the pass by itself in a later invocation.
---------
Co-authored-by: Alina Sbirlea <alina.g.simion@gmail.com>
This patch adds the basic API for the Legality component of the
vectorizer. It also adds some very basic code in the bottom-up
vectorizer that uses the API.
A region identifies a set of vector instructions generated by
vectorization passes. The vectorizer can then run a series of
RegionPasses on the region, evaluate the cost, and commit/reject the
transforms on a region-by-region basis, instead of an entire basic
block.
This is heavily based ov @vporpo's prototype. In particular, the doc
comment for the Region class is all his. The rest of this commit is
mostly boilerplate around a SetVector: getters, iterators, and some
debug helpers.
