This CL utilizies the more robust fusion feasibility analysis being built out in LoopFusionUtils, which will eventually be used to replace the current affine loop fusion pass.
PiperOrigin-RevId: 281112340
This PR is a stepping stone towards supporting generic multi-store
source loop nests in affine loop fusion. It extends the algorithm to
support fusion of multi-store loop nests that:
1. have only one store that writes to a function-local live out, and
2. the remaining stores are involved in loop nest self dependences
or no dependences within the function.
Closestensorflow/mlir#162
COPYBARA_INTEGRATE_REVIEW=https://github.com/tensorflow/mlir/pull/162 from dcaballe:dcaballe/multi-output-fusion 7fb7dec6fe8b45f5ce176f018bfe37b256420c45
PiperOrigin-RevId: 273773907
- extend canonicalizeMapAndOperands to propagate constant operands into
the map's expressions (and thus drop those operands).
- canonicalizeMapAndOperands previously only dropped duplicate and
unused operands; however, operands that were constants were
retained.
This change makes IR maps/expressions generated by various
utilities/passes even simpler; also makes some of the test checks more
accurate and simpler -- for eg., 0' instead of symbol(%{{.*}}).
Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>
Closestensorflow/mlir#107
COPYBARA_INTEGRATE_REVIEW=https://github.com/tensorflow/mlir/pull/107 from bondhugula:canonicalize-maps c889a51486d14fbf7db489f224f881e7e1ff7d72
PiperOrigin-RevId: 266085289
The loop parallelism detection utility only collects the affine.load and
affine.store operations appearing inside the loop to analyze the access
patterns for the absence of dependences. However, any operation, including
unregistered operations, can appear in a body of an affine loop. If such
operation has side effects, the result of parallelism analysis is incorrect.
Conservatively assume affine loops are not parallel in presence of operations
other than affine.load, affine.store, affine.for, affine.terminator that may
have side effects.
This required to update the loop-fusion unit test that relies on parallelism
analysis and was exercising loop fusion in presence of an unregistered
operation.
PiperOrigin-RevId: 259560935
Change the AsmPrinter to number values breadth-first so that values in adjacent regions can have the same name. This allows for ModuleOp to contain operations that produce results. This also standardizes the special name of region entry arguments to "arg[0-9+]" now that Functions are also operations.
PiperOrigin-RevId: 257225069
In most places, this is just a name change (with the exception of affine.dma_start swapping the operand positions of its tag memref and num_elements operands).
Significant code changes occur here:
*) Vectorization: LoopAnalysis.cpp, Vectorize.cpp
*) Affine Transforms: Transforms/Utils/Utils.cpp
PiperOrigin-RevId: 256395088
The current syntax separates the name and value with ':', but ':' is already overloaded by several other things(e.g. trailing types). This makes the syntax difficult to parse in some situtations:
Old:
"foo: 10 : i32"
New:
"foo = 10 : i32"
PiperOrigin-RevId: 255097928
These were likely added in error because of confusion about the flag when it was just called "-verify". The extra flag doesn't cause much harm, but it does make mlir-opt do more work and clutter the RUN line
PiperOrigin-RevId: 254037016
This name has caused some confusion because it suggests that it's running op verification (and that this verification isn't getting run by default).
PiperOrigin-RevId: 254035268
Trying to activate both LLVM and MLIR passes in mlir-cpu-runner showed name collisions when registering pass names.
One possible way of disambiguating that should also work across dialects is to prepend the dialect name to the passes that specifically operate on that dialect.
With this CL, mlir-cpu-runner tests still run when both LLVM and MLIR passes are registered
--
PiperOrigin-RevId: 246539917
Adds utility to convert slice bounds to a FlatAffineConstraints representation.
Adds utility to FlatAffineConstraints to promote loop IV symbol identifiers to dim identifiers.
PiperOrigin-RevId: 236973261
- fix for the mod detection
- simplify/avoid the mod at construction (if the dividend is already known to be less
than the divisor), since the information is available at hand there
PiperOrigin-RevId: 236882988
- fix out of bounds test case
- -memref-bound-check on the test/Transforms/loop-fusion.mlir no longer reports any
errors, before or after -loop-fusion is run
PiperOrigin-RevId: 236757658
- this was detected when memref-bound-check was run on the output of the
loop-fusion pass
- the addition (to represent ceildiv as a floordiv) had to be performed only
for the constant term of the constraint
- update test cases
- memref-bound-check no longer returns an error on the output of this test case
PiperOrigin-RevId: 236731137
*) Breaks fusion pass into multiple sub passes over nodes in data dependence graph:
- first pass fuses single-use producers into their unique consumer.
- second pass enables fusing for input-reuse by fusing sibling nodes which read from the same memref, but which do not share dependence edges.
- third pass fuses remaining producers into their consumers (Note that the sibling fusion pass may have transformed a producer with multiple uses into a single-use producer).
*) Fusion for input reuse is enabled by computing a sibling node slice using the load/load accesses to the same memref, and fusion safety is guaranteed by checking that the sibling node memref write region (to a different memref) is preserved.
*) Enables output vector and output matrix computations from KFAC patches-second-moment operation to fuse into a single loop nest and reuse input from the image patches operation.
*) Adds a generic loop utilitiy for finding all sequential loops in a loop nest.
*) Adds and updates unit tests.
PiperOrigin-RevId: 236350987
- compute slices precisely where the destination iteration depends on multiple source
iterations (instead of over-approximating to the whole source loop extent)
- update unionBoundingBox to deal with input with non-matching symbols
- reenable disabled backend test case
PiperOrigin-RevId: 234714069
*) Adds utility to LoopUtils to perform loop interchange of two AffineForOps.
*) Adds utility to LoopUtils to sink a loop to a specified depth within a loop nest, using a series of loop interchanges.
*) Computes dependences between all loads and stores in the loop nest, and classifies each loop as parallel or sequential.
*) Computes loop interchange permutation required to sink sequential loops (and raise parallel loop nests) while preserving relative order among them.
*) Checks each dependence against the permutation to make sure that dependences would not be violated by the loop interchange transformation.
*) Calls loop interchange in LoopFusion pass on consumer loop nests before fusing in producers, sinking loops with loop carried dependences deeper into the consumer loop nest.
*) Adds and updates related unit tests.
PiperOrigin-RevId: 234158370
Update FlatAffineConstraints::getLower/UpperBounds to project to the identifier for which bounds are being computed. This change enables computing bounds on an identifier which were previously dependent on the bounds of another identifier.
PiperOrigin-RevId: 234017514
*) After a private memref buffer is created for a fused loop nest, dependences on the old memref are reduced, which can open up fusion opportunities. In these cases, users of the old memref are added back to the worklist to be reconsidered for fusion.
*) Fixed a bug in fusion insertion point dependence check where the memref being privatized was being skipped from the check.
PiperOrigin-RevId: 232477853
index remapping
- generate a sequence of single result affine_apply's for the index remapping
(instead of one multi result affine_apply)
- update dma-generate and loop-fusion test cases; while on this, change test cases
to use single result affine apply ops
- some fusion comment fix/cleanup
PiperOrigin-RevId: 230985830
- update fusion cost model to fuse while tolerating a certain amount of redundant
computation; add cl option -fusion-compute-tolerance
evaluate memory footprint and intermediate memory reduction
- emit debug info from -loop-fusion showing what was fused and why
- introduce function to compute memory footprint for a loop nest
- getMemRefRegion readability update - NFC
PiperOrigin-RevId: 230541857
- the size of the private memref created for the slice should be based on
the memref region accessed at the depth at which the slice is being
materialized, i.e., symbolic in the outer IVs up until that depth, as opposed
to the region accessed based on the entire domain.
- leads to a significant contraction of the temporary / intermediate memref
whenever the memref isn't reduced to a single scalar (through store fwd'ing).
Other changes
- update to promoteIfSingleIteration - avoid introducing unnecessary identity
map affine_apply from IV; makes it much easier to write and read test cases
and pass output for all passes that use promoteIfSingleIteration; loop-fusion
test cases become much simpler
- fix replaceAllMemrefUsesWith bug that was exposed by the above update -
'domInstFilter' could be one of the ops erased due to a memref replacement in
it.
- fix getConstantBoundOnDimSize bug: a division by the coefficient of the identifier was
missing (the latter need not always be 1); add lbFloorDivisors output argument
- rename getBoundingConstantSizeAndShape -> getConstantBoundingSizeAndShape
PiperOrigin-RevId: 230405218
*) Do not remove loop nests which write to memrefs which escape the function.
*) Do not remove memrefs which escape the function (e.g. are used in the return instruction).
PiperOrigin-RevId: 230398630
- detected with memref-bound-check
- fixes b/123072438; while on this, fix another test case which was reported
out of bounds
PiperOrigin-RevId: 229978187
*) Enables reduction of private memref size based on MemRef region accessed by fused slice.
*) Enables maximal fusion by creating a private memref to break a fusion-preventing dependence.
*) Adds maximal fusion flag to enable fusing as much as possible (though it still fuses the minimum cost computation slice).
PiperOrigin-RevId: 229936698
Alexander Belyaev