Commit Graph

1063 Commits

Author SHA1 Message Date
Mehdi Amini bf523186fb Change the PrintOpStatsPass to operate on any operation instead of just ModuleOp
This allows to use it on other operation, like a GPUModule for example.
2020-11-03 11:15:32 +00:00
Sean Silva 52b0fe6404 [mlir] Add func-bufferize pass.
This is the most basic possible finalizing bufferization pass, which I
also think is sufficient for most new use cases. The more concentrated
nature of this pass also greatly clarifies the invariants that it
requires on its input to safely transform the program (see the
pass description in Passes.td).

With this pass, I have now upstreamed practically all of the
bufferizations from npcomp (the exception being std.constant, which can
be upstreamed when std.global_memref lands:
https://llvm.discourse.group/t/rfc-global-variables-in-mlir/2076/16 )

Differential Revision: https://reviews.llvm.org/D90205
2020-11-02 12:42:32 -08:00
Sean Silva b866574246 [mlir] Add BufferResultsToOutParams pass.
This pass allows removing getResultConversionKind from
BufferizeTypeConverter. This pass replaces the AppendToArgumentsList
functionality. As far as I could tell, the only use of this functionlity
is to perform the transformation that is implemented in this pass.

Future patches will remove the getResultConversionKind machinery from
BufferizeTypeConverter, but sending this patch for individual review for
clarity.

Differential Revision: https://reviews.llvm.org/D90071
2020-10-30 14:06:14 -07:00
River Riddle fa4174792a [mlir][Inliner] Add a `wouldBeCloned` flag to each of the `isLegalToInline` hooks.
Often times the legality of inlining can change depending on if the callable is going to be inlined in-place, or cloned. For example, some operations are not allowed to be duplicated and can only be inlined if the original callable will cease to exist afterwards. The new `wouldBeCloned` flag allows for dialects to hook into this when determining legality.

Differential Revision: https://reviews.llvm.org/D90360
2020-10-28 21:49:28 -07:00
River Riddle 501fda0167 [mlir][Inliner] Add a new hook for checking if it is legal to inline a callable into a call
In certain situations it isn't legal to inline a call operation, but this isn't something that is possible(at least not easily) to prevent with the current hooks. This revision adds a new hook so that dialects with call operations that shouldn't be inlined can prevent it.

Differential Revision: https://reviews.llvm.org/D90359
2020-10-28 21:49:28 -07:00
Kazuaki Ishizaki 41b09f4eff [mlir] NFC: fix trivial typos
fix typos in comments and documents

Reviewed By: jpienaar

Differential Revision: https://reviews.llvm.org/D90089
2020-10-29 04:05:22 +09:00
River Riddle 3fffffa882 [mlir][Pattern] Add a new FrozenRewritePatternList class
This class represents a rewrite pattern list that has been frozen, and thus immutable. This replaces the uses of OwningRewritePatternList in pattern driver related API, such as dialect conversion. When PDL becomes more prevalent, this API will allow for optimizing a set of patterns once without the need to do this per run of a pass.

Differential Revision: https://reviews.llvm.org/D89104
2020-10-26 18:01:06 -07:00
River Riddle b6eb26fd0e [mlir][NFC] Move around the code related to PatternRewriting to improve layering
There are several pieces of pattern rewriting infra in IR/ that really shouldn't be there. This revision moves those pieces to a better location such that they are easier to evolve in the future(e.g. with PDL). More concretely this revision does the following:

* Create a Transforms/GreedyPatternRewriteDriver.h and move the apply*andFold methods there.
The definitions for these methods are already in Transforms/ so it doesn't make sense for the declarations to be in IR.

* Create a new lib/Rewrite library and move PatternApplicator there.
This new library will be focused on applying rewrites, and will also include compiling rewrites with PDL.

Differential Revision: https://reviews.llvm.org/D89103
2020-10-26 18:01:06 -07:00
River Riddle b99bd77162 [mlir][Pattern] Refactor the Pattern class into a "metadata only" class
The Pattern class was originally intended to be used for solely matching operations, but that use never materialized. All of the pattern infrastructure uses RewritePattern, and the infrastructure for pure matching(Matchers.h) is implemented inline. This means that this class isn't a useful abstraction at the moment, so this revision refactors it to solely encapsulate the "metadata" of a pattern. The metadata includes the various state describing a pattern; benefit, root operation, etc. The API on PatternApplicator is updated to now operate on `Pattern`s as nothing special from `RewritePattern` is necessary.

This refactoring is also necessary for the upcoming use of PDL patterns alongside C++ rewrite patterns.

Differential Revision: https://reviews.llvm.org/D86258
2020-10-26 18:01:06 -07:00
Mehdi Amini 035a6b95c3 Fix a few warnings from GCC (NFC) 2020-10-24 00:35:55 +00:00
Frederik Gossen 8039b3f966 [MLIR] Fix bad merge with buffer alias analysis. 2020-10-23 14:11:27 +00:00
Frederik Gossen 6d83e3b443 [MLIR] Extract buffer alias analysis for reuse
Extract buffer alias analysis from buffer placement.

Differential Revision: https://reviews.llvm.org/D89902
2020-10-23 13:23:32 +00:00
Julian Gross 0d1d363c51 [MLIR] Added PromoteBuffersToStackPass to convert heap- to stack-based allocations.
Added optimization pass to convert heap-based allocs to stack-based allocas in
buffer placement. Added the corresponding test file.

Differential Revision: https://reviews.llvm.org/D89688
2020-10-23 12:02:25 +02:00
Christian Sigg ff87c4d3e7 [mlir] Fix exiting OpPatternRewriteDriver::simplifyLocally after first iteration that didn't change the op.
Before this change, we would run `maxIterations` if the first iteration changed the op.
After this change, we exit the loop as soon as an iteration hasn't changed the op.
Assuming that we have reached a fixed point when an iteration doesn't change the op, this doesn't affect correctness.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D89981
2020-10-23 11:10:31 +02:00
Sean Silva f0292ede9b [mlir] Add structural type conversions for SCF dialect.
A "structural" type conversion is one where the underlying ops are
completely agnostic to the actual types involved and simply need to update
their types. An example of this is scf.if -- the scf.if op and the
corresponding scf.yield ops need to update their types accordingly to the
TypeConverter, but otherwise don't care what type conversions are happening.

To test the structural type conversions, it is convenient to define a
bufferize pass for a dialect, which exercises them nicely.

Differential Revision: https://reviews.llvm.org/D89757
2020-10-21 11:58:27 -07:00
Marcel Koester 1b1c61ff47 [mlir] Refactored BufferPlacement transformation.
The current BufferPlacement transformation contains several concepts for
hoisting allocations. However, more advanced hoisting techniques should not be
integrated into the BufferPlacement transformation. Hence, this CL refactors the
current BufferPlacement pass into three separate pieces: BufferDeallocation and
BufferAllocation(Loop)Hoisting. Moreover, it extends the hoisting functionality
by allowing to move allocations out of loops.

Differential Revision: https://reviews.llvm.org/D87756
2020-10-19 12:52:16 +02:00
River Riddle a5ea60456c [mlir] Update SCCP and the Inliner to use SymbolTableCollection for symbol lookups
This transforms the symbol lookups to O(1) from O(NM), greatly speeding up both passes. For a large MLIR module this shaved seconds off of the compilation time.

Differential Revision: https://reviews.llvm.org/D89522
2020-10-16 12:08:48 -07:00
River Riddle 7bc7d0ac7a [mlir] Optimize symbol related checks in SymbolDCE
This revision contains two optimizations related to symbol checking:
* Optimize SymbolOpInterface to only check for a name attribute if the operation is an optional symbol.
This removes an otherwise unnecessary attribute lookup from a majority of symbols.
* Add a new SymbolTableCollection class to represent a collection of SymbolTables.
This allows for perfoming non-flat symbol lookups in O(1) time by caching SymbolTables for symbol table operations. This class is very useful for algorithms that operate on multiple symbol tables, either recursively or not.

Differential Revision: https://reviews.llvm.org/D89505
2020-10-16 12:08:48 -07:00
Sean Silva ee491ac91e [mlir] Add std.tensor_to_memref op and teach the infra about it
The opposite of tensor_to_memref is tensor_load.

- Add some basic tensor_load/tensor_to_memref folding.
- Add source/target materializations to BufferizeTypeConverter.
- Add an example std bufferization pattern/pass that shows how the
  materialiations work together (more std bufferization patterns to come
  in subsequent commits).
  - In coming commits, I'll document how to write composable
  bufferization passes/patterns and update the other in-tree
  bufferization passes to match this convention. The populate* functions
  will of course continue to be exposed for power users.

The naming on tensor_load/tensor_to_memref and their pretty forms are
not very intuitive. I'm open to any suggestions here. One key
observation is that the memref type must always be the one specified in
the pretty form, since the tensor type can be inferred from the memref
type but not vice-versa.

With this, I've been able to replace all my custom bufferization type
converters in npcomp with BufferizeTypeConverter!

Part of the plan discussed in:
https://llvm.discourse.group/t/what-is-the-strategy-for-tensor-memref-conversion-bufferization/1938/17

Differential Revision: https://reviews.llvm.org/D89437
2020-10-15 12:19:20 -07:00
Sean Silva dd378739d7 [mlir] Fix some style comments from D89268
That change was a pure move, so split out the stylistic changes into
this patch.

Differential Revision: https://reviews.llvm.org/D89272
2020-10-14 12:39:16 -07:00
Sean Silva 9a14cb53cb [mlir][bufferize] Rename BufferAssignment* to Bufferize*
Part of the refactor discussed in:
https://llvm.discourse.group/t/what-is-the-strategy-for-tensor-memref-conversion-bufferization/1938/17

Differential Revision: https://reviews.llvm.org/D89271
2020-10-14 12:39:16 -07:00
Sean Silva 1cca0f323e [mlir] Refactor code out of BufferPlacement.cpp
Now BufferPlacement.cpp doesn't depend on Bufferize.h.

Part of the refactor discussed in:
https://llvm.discourse.group/t/what-is-the-strategy-for-tensor-memref-conversion-bufferization/1938/17

Differential Revision: https://reviews.llvm.org/D89268
2020-10-14 12:39:16 -07:00
Nicolas Vasilache 422aaf31da [mlir][Linalg] Add named Linalg ops on tensor to buffer support.
This revision introduces support for buffer allocation for any named linalg op.
To avoid template instantiating many ops, a new ConversionPattern is created to capture the LinalgOp interface.

Some APIs are updated to remain consistent with MLIR style:
`OwningRewritePatternList * -> OwningRewritePatternList &`
`BufferAssignmentTypeConverter * -> BufferAssignmentTypeConverter &`

Differential revision: https://reviews.llvm.org/D89226
2020-10-12 11:20:23 +00:00
Tatiana Shpeisman 9909ef292d [mlir][scf] Fix a bug in scf::ForOp loop unroll with an epilogue
Fixes a bug in formation and simplification of an epilogue loop generated
during loop unroll of scf::ForOp (https://bugs.llvm.org/show_bug.cgi?id=46689)

Differential Revision: https://reviews.llvm.org/D87583
2020-10-10 14:18:25 +05:30
Sean Silva a2b6c75ac0 [mlir] Rename BufferPlacement.h to Bufferize.h
Context: https://llvm.discourse.group/t/what-is-the-strategy-for-tensor-memref-conversion-bufferization/1938/14

Differential Revision: https://reviews.llvm.org/D89174
2020-10-09 17:48:20 -07:00
Nicolas Vasilache 30e6033b45 [mlir][Linalg] Add TensorsToBuffers support for Constant ops.
This revision also inserts an end-to-end test that lowers tensors to buffers all the way to executable code on CPU.

Differential revision: https://reviews.llvm.org/D88998
2020-10-08 13:15:45 +00:00
Stephen Neuendorffer 47df8c57e4 [MLIR] Updates around MemRef Normalization
The documentation for the NormalizeMemRefs pass and the associated MemRefsNormalizable
traits was confusing and not on the website.  This update clarifies the language
around the difference between a MemRef Type, an operation that accesses the value of
MemRef Type, and better documents the limitations of the current implementation.
This patch also includes some basic debugging information for the pass so people
might have a chance of figuring out why it doesn't work on their code.

Differential Revision: https://reviews.llvm.org/D88532
2020-10-01 21:11:41 -07:00
Geoffrey Martin-Noble d4e889f1f5 Remove `Ops` suffix from dialect library names
Dialects include more than just ops, so this suffix is outdated. Follows
discussion in
https://llvm.discourse.group/t/rfc-canonical-file-paths-to-dialects/621

Reviewed By: stellaraccident

Differential Revision: https://reviews.llvm.org/D88530
2020-09-30 18:00:44 -07:00
Haruki Imai c1f8568031 [MLIR] Fix for updating function signature in normalizing memrefs
Normalizing memrefs failed when a caller of symbolic use in a function
can not be casted to `CallOp`. This patch avoids the failure by checking
the result of the casting. If the caller can not be casted to `CallOp`,
it is skipped.

Differential Revision: https://reviews.llvm.org/D87746
2020-09-25 22:56:56 +05:30
Navdeep Kumar 0602e8f77f [MLIR][Affine] Add parametric tile size support for affine.for tiling
Add support to tile affine.for ops with parametric sizes (i.e., SSA
values). Currently supports hyper-rectangular loop nests with constant
lower bounds only. Move methods

  - moveLoopBody(*)
  - getTileableBands(*)
  - checkTilingLegality(*)
  - tilePerfectlyNested(*)
  - constructTiledIndexSetHyperRect(*)

to allow reuse with constant tile size API. Add a test pass -test-affine
-parametric-tile to test parametric tiling.

Differential Revision: https://reviews.llvm.org/D87353
2020-09-17 23:39:14 +05:30
Marcel Koester feb0b9c3bb [mlir] Added support for loops to BufferPlacement transformation.
The current BufferPlacement transformation cannot handle loops properly. Buffers
passed via backedges will not be freed automatically introducing memory leaks.
This CL adds support for loops to overcome these limitations.

Differential Revision: https://reviews.llvm.org/D85513
2020-09-09 10:53:35 +02:00
Lubomir Litchev e2394245eb Add an option for unrolling loops up to a factor.
Currently, there is no option to allow for unrolling a loop up to a specific factor (specified by the user).
The code for doing that is there and there are benefits when unrolling is done  to smaller loops (smaller than the factor specified).

Reviewed By: bondhugula

Differential Revision: https://reviews.llvm.org/D87111
2020-09-08 09:23:38 -07:00
Ehsan Toosi 4e9f4d0b9d [mlir] Fix bug in copy removal
A crash could happen due to copy removal. The bug is fixed and two more
test cases are added.

Differential Revision: https://reviews.llvm.org/D87128
2020-09-08 14:17:13 +02:00
Ehsan Toosi 847299d3f0 [mlir] remove BufferAssignmentPlacer from BufferAssignmentOpConversionPattern
BufferPlacement has been removed, as allocations are no longer placed during the conversion.

Differential Revision: https://reviews.llvm.org/D87079
2020-09-08 13:04:22 +02:00
Ehsan Toosi 39cf83cc78 [mlir] Extend BufferAssignmentTypeConverter with result conversion callbacks
In this PR, the users of BufferPlacement can configure
BufferAssginmentTypeConverter. These new configurations would give the user more
freedom in the process of converting function signature, and return and call
operation conversions.

These are the new features:
    - Accepting callback functions for decomposing types (i.e. 1 to N type
    conversion such as unpacking tuple types).
    - Defining ResultConversionKind for specifying whether a function result
    with a certain type should be appended to the function arguments list or
    should be kept as function result. (Usage:
    converter.setResultConversionKind<MemRefType>(AppendToArgumentList))
    - Accepting callback functions for composing or decomposing values (i.e. N
    to 1 and 1 to N value conversion).

Differential Revision: https://reviews.llvm.org/D85133
2020-09-02 17:53:42 +02:00
Lei Zhang 1b88bbf5eb Revert "[mlir] Extend BufferAssignmentTypeConverter with result conversion callbacks"
This reverts commit 94f5d24877 because
of failing the following tests:

MLIR :: Dialect/Linalg/tensors-to-buffers.mlir
MLIR :: Transforms/buffer-placement-preparation-allowed-memref-results.mlir
MLIR :: Transforms/buffer-placement-preparation.mlir
2020-09-02 09:24:36 -04:00
Ehsan Toosi 94f5d24877 [mlir] Extend BufferAssignmentTypeConverter with result conversion callbacks
In this PR, the users of BufferPlacement can configure
BufferAssginmentTypeConverter. These new configurations would give the user more
freedom in the process of converting function signature, and return and call
operation conversions.

These are the new features:
    - Accepting callback functions for decomposing types (i.e. 1 to N type
    conversion such as unpacking tuple types).
    - Defining ResultConversionKind for specifying whether a function result
    with a certain type should be appended to the function arguments list or
    should be kept as function result. (Usage:
    converter.setResultConversionKind<MemRefType>(AppendToArgumentList))
    - Accepting callback functions for composing or decomposing values (i.e. N
    to 1 and 1 to N value conversion).

Differential Revision: https://reviews.llvm.org/D85133
2020-09-02 13:26:55 +02:00
Kamlesh Kumar deb99610ab Improve doc comments for several methods returning bools
Differential Revision: https://reviews.llvm.org/D86848
2020-08-30 13:33:05 +05:30
Alexandre E. Eichenberger a14a2805b0 [MLIR] MemRef Normalization for Dialects
When dealing with dialects that will results in function calls to
external libraries, it is important to be able to handle maps as some
dialects may require mapped data.  Before this patch, the detection of
whether normalization can apply or not, operations are compared to an
explicit list of operations (`alloc`, `dealloc`, `return`) or to the
presence of specific operation interfaces (`AffineReadOpInterface`,
`AffineWriteOpInterface`, `AffineDMAStartOp`, or `AffineDMAWaitOp`).

This patch add a trait, `MemRefsNormalizable` to determine if an
operation can have its `memrefs` normalized.

This trait can be used in turn by dialects to assert that such
operations are compatible with normalization of `memrefs` with
nontrivial memory layout specification. An example is given in the
literal tests.

Differential Revision: https://reviews.llvm.org/D86236
2020-08-27 20:26:59 +05:30
River Riddle 474f7639e3 [mlir] Fix bug in block merging when the types of the operands differ
The merging algorithm was previously not checking for type equivalence.

Fixes PR47314

Differential Revision: https://reviews.llvm.org/D86594
2020-08-26 01:17:20 -07:00
Mehdi Amini f9dc2b7079 Separate the Registration from Loading dialects in the Context
This changes the behavior of constructing MLIRContext to no longer load globally
registered dialects on construction. Instead Dialects are only loaded explicitly
on demand:
- the Parser is lazily loading Dialects in the context as it encounters them
during parsing. This is the only purpose for registering dialects and not load
them in the context.
- Passes are expected to declare the dialects they will create entity from
(Operations, Attributes, or Types), and the PassManager is loading Dialects into
the Context when starting a pipeline.

This changes simplifies the configuration of the registration: a compiler only
need to load the dialect for the IR it will emit, and the optimizer is
self-contained and load the required Dialects. For example in the Toy tutorial,
the compiler only needs to load the Toy dialect in the Context, all the others
(linalg, affine, std, LLVM, ...) are automatically loaded depending on the
optimization pipeline enabled.

To adjust to this change, stop using the existing dialect registration: the
global registry will be removed soon.

1) For passes, you need to override the method:

virtual void getDependentDialects(DialectRegistry &registry) const {}

and registery on the provided registry any dialect that this pass can produce.
Passes defined in TableGen can provide this list in the dependentDialects list
field.

2) For dialects, on construction you can register dependent dialects using the
provided MLIRContext: `context.getOrLoadDialect<DialectName>()`
This is useful if a dialect may canonicalize or have interfaces involving
another dialect.

3) For loading IR, dialect that can be in the input file must be explicitly
registered with the context. `MlirOptMain()` is taking an explicit registry for
this purpose. See how the standalone-opt.cpp example is setup:

  mlir::DialectRegistry registry;
  registry.insert<mlir::standalone::StandaloneDialect>();
  registry.insert<mlir::StandardOpsDialect>();

Only operations from these two dialects can be in the input file. To include all
of the dialects in MLIR Core, you can populate the registry this way:

  mlir::registerAllDialects(registry);

4) For `mlir-translate` callback, as well as frontend, Dialects can be loaded in
the context before emitting the IR: context.getOrLoadDialect<ToyDialect>()

Differential Revision: https://reviews.llvm.org/D85622
2020-08-19 01:19:03 +00:00
Mehdi Amini e75bc5c791 Revert "Separate the Registration from Loading dialects in the Context"
This reverts commit d14cf45735.
The build is broken with GCC-5.
2020-08-19 01:19:03 +00:00
Mehdi Amini d14cf45735 Separate the Registration from Loading dialects in the Context
This changes the behavior of constructing MLIRContext to no longer load globally
registered dialects on construction. Instead Dialects are only loaded explicitly
on demand:
- the Parser is lazily loading Dialects in the context as it encounters them
during parsing. This is the only purpose for registering dialects and not load
them in the context.
- Passes are expected to declare the dialects they will create entity from
(Operations, Attributes, or Types), and the PassManager is loading Dialects into
the Context when starting a pipeline.

This changes simplifies the configuration of the registration: a compiler only
need to load the dialect for the IR it will emit, and the optimizer is
self-contained and load the required Dialects. For example in the Toy tutorial,
the compiler only needs to load the Toy dialect in the Context, all the others
(linalg, affine, std, LLVM, ...) are automatically loaded depending on the
optimization pipeline enabled.

To adjust to this change, stop using the existing dialect registration: the
global registry will be removed soon.

1) For passes, you need to override the method:

virtual void getDependentDialects(DialectRegistry &registry) const {}

and registery on the provided registry any dialect that this pass can produce.
Passes defined in TableGen can provide this list in the dependentDialects list
field.

2) For dialects, on construction you can register dependent dialects using the
provided MLIRContext: `context.getOrLoadDialect<DialectName>()`
This is useful if a dialect may canonicalize or have interfaces involving
another dialect.

3) For loading IR, dialect that can be in the input file must be explicitly
registered with the context. `MlirOptMain()` is taking an explicit registry for
this purpose. See how the standalone-opt.cpp example is setup:

  mlir::DialectRegistry registry;
  registry.insert<mlir::standalone::StandaloneDialect>();
  registry.insert<mlir::StandardOpsDialect>();

Only operations from these two dialects can be in the input file. To include all
of the dialects in MLIR Core, you can populate the registry this way:

  mlir::registerAllDialects(registry);

4) For `mlir-translate` callback, as well as frontend, Dialects can be loaded in
the context before emitting the IR: context.getOrLoadDialect<ToyDialect>()

Differential Revision: https://reviews.llvm.org/D85622
2020-08-18 23:23:56 +00:00
Mehdi Amini d84fe55e0d Revert "Separate the Registration from Loading dialects in the Context"
This reverts commit e1de2b7550.
Broke a build bot.
2020-08-18 22:16:34 +00:00
Mehdi Amini e1de2b7550 Separate the Registration from Loading dialects in the Context
This changes the behavior of constructing MLIRContext to no longer load globally
registered dialects on construction. Instead Dialects are only loaded explicitly
on demand:
- the Parser is lazily loading Dialects in the context as it encounters them
during parsing. This is the only purpose for registering dialects and not load
them in the context.
- Passes are expected to declare the dialects they will create entity from
(Operations, Attributes, or Types), and the PassManager is loading Dialects into
the Context when starting a pipeline.

This changes simplifies the configuration of the registration: a compiler only
need to load the dialect for the IR it will emit, and the optimizer is
self-contained and load the required Dialects. For example in the Toy tutorial,
the compiler only needs to load the Toy dialect in the Context, all the others
(linalg, affine, std, LLVM, ...) are automatically loaded depending on the
optimization pipeline enabled.

To adjust to this change, stop using the existing dialect registration: the
global registry will be removed soon.

1) For passes, you need to override the method:

virtual void getDependentDialects(DialectRegistry &registry) const {}

and registery on the provided registry any dialect that this pass can produce.
Passes defined in TableGen can provide this list in the dependentDialects list
field.

2) For dialects, on construction you can register dependent dialects using the
provided MLIRContext: `context.getOrLoadDialect<DialectName>()`
This is useful if a dialect may canonicalize or have interfaces involving
another dialect.

3) For loading IR, dialect that can be in the input file must be explicitly
registered with the context. `MlirOptMain()` is taking an explicit registry for
this purpose. See how the standalone-opt.cpp example is setup:

  mlir::DialectRegistry registry;
  mlir::registerDialect<mlir::standalone::StandaloneDialect>();
  mlir::registerDialect<mlir::StandardOpsDialect>();

Only operations from these two dialects can be in the input file. To include all
of the dialects in MLIR Core, you can populate the registry this way:

  mlir::registerAllDialects(registry);

4) For `mlir-translate` callback, as well as frontend, Dialects can be loaded in
the context before emitting the IR: context.getOrLoadDialect<ToyDialect>()
2020-08-18 21:14:39 +00:00
Mehdi Amini 25ee851746 Revert "Separate the Registration from Loading dialects in the Context"
This reverts commit 2056393387.

Build is broken on a few bots
2020-08-15 09:21:47 +00:00
Mehdi Amini 2056393387 Separate the Registration from Loading dialects in the Context
This changes the behavior of constructing MLIRContext to no longer load globally registered dialects on construction. Instead Dialects are only loaded explicitly on demand:
- the Parser is lazily loading Dialects in the context as it encounters them during parsing. This is the only purpose for registering dialects and not load them in the context.
- Passes are expected to declare the dialects they will create entity from (Operations, Attributes, or Types), and the PassManager is loading Dialects into the Context when starting a pipeline.

This changes simplifies the configuration of the registration: a compiler only need to load the dialect for the IR it will emit, and the optimizer is self-contained and load the required Dialects. For example in the Toy tutorial, the compiler only needs to load the Toy dialect in the Context, all the others (linalg, affine, std, LLVM, ...) are automatically loaded depending on the optimization pipeline enabled.

Differential Revision: https://reviews.llvm.org/D85622
2020-08-15 08:07:31 +00:00
Mehdi Amini ba92dadf05 Revert "Separate the Registration from Loading dialects in the Context"
This was landed by accident, will reland with the right comments
addressed from the reviews.
Also revert dependent build fixes.
2020-08-15 07:35:10 +00:00
Mehdi Amini ebf521e784 Separate the Registration from Loading dialects in the Context
This changes the behavior of constructing MLIRContext to no longer load globally registered dialects on construction. Instead Dialects are only loaded explicitly on demand:
- the Parser is lazily loading Dialects in the context as it encounters them during parsing. This is the only purpose for registering dialects and not load them in the context.
- Passes are expected to declare the dialects they will create entity from (Operations, Attributes, or Types), and the PassManager is loading Dialects into the Context when starting a pipeline.

This changes simplifies the configuration of the registration: a compiler only need to load the dialect for the IR it will emit, and the optimizer is self-contained and load the required Dialects. For example in the Toy tutorial, the compiler only needs to load the Toy dialect in the Context, all the others (linalg, affine, std, LLVM, ...) are automatically loaded depending on the optimization pipeline enabled.
2020-08-14 09:40:27 +00:00
Mehdi Amini 1e484b8a24 Remove spurious empty line at the beginning of source file (NFC) 2020-08-14 08:02:59 +00:00
Mehdi Amini 5035d192fa Fix BufferPlacement Pass to derive from the TableGen generated parent class (NFC) 2020-08-14 08:01:47 +00:00
avarmapml 6d4f7801b1 [MLIR] Support for ReturnOps in memref map layout normalization
-- This commit handles the returnOp in memref map layout normalization.
-- An initial filter is applied on FuncOps which helps us know which functions can be
   a suitable candidate for memref normalization which doesn't lead to invalid IR.
-- Handles memref map normalization for external function assuming the external function
   is normalizable.

Differential Revision: https://reviews.llvm.org/D85226
2020-08-13 19:10:47 +05:30
Mehdi Amini b28e3db88d Merge OpFolderDialectInterface with DialectFoldInterface (NFC)
Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D85823
2020-08-13 00:39:22 +00:00
Vincent Zhao 654e8aadfd [MLIR] Consider AffineIfOp when getting the index set of an Op wrapped in nested loops
This diff attempts to resolve the TODO in `getOpIndexSet` (formerly
known as `getInstIndexSet`), which states "Add support to handle IfInsts
surronding `op`".

Major changes in this diff:

1. Overload `getIndexSet`. The overloaded version considers both
`AffineForOp` and `AffineIfOp`.
2. The `getInstIndexSet` is updated accordingly: its name is changed to
`getOpIndexSet` and its implementation is based on a new API `getIVs`
instead of `getLoopIVs`.
3. Add `addAffineIfOpDomain` to `FlatAffineConstraints`, which extracts
new constraints from the integer set of `AffineIfOp` and merges it to
the current constraint system.
4. Update how a `Value` is determined as dim or symbol for
`ValuePositionMap` in `buildDimAndSymbolPositionMaps`.

Differential Revision: https://reviews.llvm.org/D84698
2020-08-09 03:16:03 +05:30
Diego Caballero 3bfbc5df87 [MLIR][Affine] Fix createPrivateMemRef in affine fusion
Always define a remapping for the memref replacement (`indexRemap`)
with the proper number of inputs, including all the `outerIVs`, so that
the number of inputs and the operands provided for the map don't mismatch.

Reviewed By: bondhugula, andydavis1

Differential Revision: https://reviews.llvm.org/D85177
2020-08-04 12:17:48 -07:00
MaheshRavishankar 32f3a9a9d6 [mlir][DialectConversion] Remove usage of std::distance to track position.
Remove use of iterator::difference_type to know where to insert a
moved or erased block during undo actions.

Differential Revision: https://reviews.llvm.org/D85066
2020-08-03 10:06:05 -07:00
MaheshRavishankar e888886cc3 [mlir][DialectConversion] Add support for mergeBlocks in ConversionPatternRewriter.
Differential Revision: https://reviews.llvm.org/D84795
2020-08-03 10:06:04 -07:00
Julian Gross 6d47431d7e [mlir] Extended Buffer Assignment to support AllocaOps.
Added support for AllocaOps in Buffer Assignment.

Differential Revision: https://reviews.llvm.org/D85017
2020-08-03 11:20:30 +02:00
Abhishek Varma 76d07503f0 [MLIR] Introduce inter-procedural memref layout normalization
-- Introduces a pass that normalizes the affine layout maps to the identity layout map both within and across functions by rewriting function arguments and call operands where necessary.
-- Memref normalization is now implemented entirely in the module pass '-normalize-memrefs' and the limited intra-procedural version has been removed from '-simplify-affine-structures'.
-- Run using -normalize-memrefs.
-- Return ops are not handled and would be handled in the subsequent revisions.

Signed-off-by: Abhishek Varma <abhishek.varma@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D84490
2020-07-30 18:12:56 +05:30
Rahul Joshi 706d992ced [NFC] Add getArgumentTypes() to Region
- Add getArgumentTypes() to Region (missed from before)
- Adopt Region argument API in `hasMultiplyAddBody`
- Fix 2 typos in comments

Differential Revision: https://reviews.llvm.org/D84807
2020-07-28 18:27:42 -07:00
Anand Kodnani 834133c950 [MLIR] Vector store to load forwarding
The MemRefDataFlow pass does store to load forwarding
only for affine store/loads. This patch updates the pass
to use affine read/write interface which enables vector
forwarding.

Reviewed By: dcaballe, bondhugula, ftynse

Differential Revision: https://reviews.llvm.org/D84302
2020-07-28 11:30:54 -07:00
Ehsan Toosi 486d2750c7 [mlir][NFC] Polish copy removal transform
Address a few remaining comments in copy removal transform.

Differential Revision: https://reviews.llvm.org/D84529
2020-07-28 08:34:44 +02:00
River Riddle 4589dd924d [mlir][DialectConversion] Enable deeper integration of type conversions
This revision adds support for much deeper type conversion integration into the conversion process, and enables auto-generating cast operations when necessary. Type conversions are now largely automatically managed by the conversion infra when using a ConversionPattern with a provided TypeConverter. This removes the need for patterns to do type cast wrapping themselves and moves the burden to the infra. This makes it much easier to perform partial lowerings when type conversions are involved, as any lingering type conversions will be automatically resolved/legalized by the conversion infra.

To support this new integration, a few changes have been made to the type materialization API on TypeConverter. Materialization has been split into three separate categories:
* Argument Materialization: This type of materialization is used when converting the type of block arguments when calling `convertRegionTypes`. This is useful for contextually inserting additional conversion operations when converting a block argument type, such as when converting the types of a function signature.
* Source Materialization: This type of materialization is used to convert a legal type of the converter into a non-legal type, generally a source type. This may be called when uses of a non-legal type persist after the conversion process has finished.
* Target Materialization: This type of materialization is used to convert a non-legal, or source, type into a legal, or target, type. This type of materialization is used when applying a pattern on an operation, but the types of the operands have not yet been converted.

Differential Revision: https://reviews.llvm.org/D82831
2020-07-23 19:40:31 -07:00
Haruki Imai 7f44a7130b [MLIR] Set alignment in AllocOp of normalizeMemref()
AllocOp is updated in normalizeMemref(AllocOp allocOp), but, when the
AllocOp has `alignment` attribute, it was ignored and updated AllocOp
does not have `alignment` attribute. This patch fixes it.

Differential Revision: https://reviews.llvm.org/D83656
2020-07-22 12:34:35 +05:30
Stephen Neuendorffer 628288658c [MLIR] Add RegionKindInterface
Some dialects have semantics which is not well represented by common
SSA structures with dominance constraints.  This patch allows
operations to declare the 'kind' of their contained regions.
Currently, two kinds are allowed: "SSACFG" and "Graph".  The only
difference between them at the moment is that SSACFG regions are
required to have dominance, while Graph regions are not required to
have dominance.  The intention is that this Interface would be
generated by ODS for existing operations, although this has not yet
been implemented. Presumably, if someone were interested in code
generation, we might also have a "CFG" dialect, which defines control
flow, but does not require SSA.

The new behavior is mostly identical to the previous behavior, since
registered operations without a RegionKindInterface are assumed to
contain SSACFG regions.  However, the behavior has changed for
unregistered operations.  Previously, these were checked for
dominance, however the new behavior allows dominance violations, in
order to allow the processing of unregistered dialects with Graph
regions.  One implication of this is that regions in unregistered
operations with more than one op are no longer CSE'd (since it
requires dominance info).

I've also reorganized the LangRef documentation to remove assertions
about "sequential execution", "SSA Values", and "Dominance".  Instead,
the core IR is simply "ordered" (i.e. totally ordered) and consists of
"Values".  I've also clarified some things about how control flow
passes between blocks in an SSACFG region. Control Flow must enter a
region at the entry block and follow terminator operation successors
or be returned to the containing op.  Graph regions do not define a
notion of control flow.

see discussion here:
https://llvm.discourse.group/t/rfc-allowing-dialects-to-relax-the-ssa-dominance-condition/833/53

Differential Revision: https://reviews.llvm.org/D80358
2020-07-15 14:27:05 -07:00
Uday Bondhugula ec85d7c8f3 [MLIR][NFC] Fix clang tidy warnings in misc utilities
Fix clang tidy warnings in misc utilities - missing const or a star in
declaration.

Differential Revision: https://reviews.llvm.org/D83861
2020-07-16 00:27:30 +05:30
River Riddle b98f414a04 [mlir][DialectConversion] Emit an error if an operation marked as erased has live users after conversion
Up until now, there has been an implicit agreement that when an operation is marked as
"erased" all uses of that operation's results are guaranteed to be removed during conversion. How this works in practice is that there is either an assert/crash/asan failure/etc. This revision adds support for properly detecting when an erased operation has dangling users, emits and error and fails the conversion.

Differential Revision: https://reviews.llvm.org/D82830
2020-07-14 13:06:08 -07:00
Uday Bondhugula 9b974dfa72 [MLIR] [NFC] Buffer placement pass - clang tidy warnings
Add missing const - addresses clang tidy warnings.

Differential Revision: https://reviews.llvm.org/D83794
2020-07-14 23:49:24 +05:30
Rahul Joshi e2b716105b [MLIR] Add argument related API to Region
- Arguments of the first block of a region are considered region arguments.
- Add API on Region class to deal with these arguments directly instead of
  using the front() block.
- Changed several instances of existing code that can use this API
- Fixes https://bugs.llvm.org/show_bug.cgi?id=46535

Differential Revision: https://reviews.llvm.org/D83599
2020-07-14 09:28:29 -07:00
Nicolai Hähnle 3fa989d4fd DomTree: remove explicit use of DomTreeNodeBase::iterator
Summary:
Almost all uses of these iterators, including implicit ones, really
only need the const variant (as it should be). The only exception is
in NewGVN, which changes the order of dominator tree child nodes.

Change-Id: I4b5bd71e32d71b0c67b03d4927d93fe9413726d4

Reviewers: arsenm, RKSimon, mehdi_amini, courbet, rriddle, aartbik

Subscribers: wdng, Prazek, hiraditya, kuhar, rogfer01, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, stephenneuendorffer, Joonsoo, grosul1, vkmr, Kayjukh, jurahul, msifontes, cfe-commits, llvm-commits

Tags: #clang, #mlir, #llvm

Differential Revision: https://reviews.llvm.org/D83087
2020-07-08 18:18:49 +02:00
Alexander Belyaev 1a2ed71a8a [mlir] Support unranked types in func signature conversion in BufferPlacement.
Currently, only ranked tensor args and results can be converted to memref types.

Differential Revision: https://reviews.llvm.org/D83324
2020-07-07 19:43:48 +02:00
River Riddle 9db53a1827 [mlir][NFC] Remove usernames and google bug numbers from TODO comments.
These were largely leftover from when MLIR was a google project, and don't really follow LLVM guidelines.
2020-07-07 01:40:52 -07:00
Julian Gross 91c320e9d8 [mlir] Add check for ViewLikeOpInterface that creates additional aliases.
ViewLikeOpInterfaces introduce new aliases that need to be added to the alias
list. This is necessary to place deallocs in the right positions.

Differential Revision: https://reviews.llvm.org/D83044
2020-07-03 16:38:21 +02:00
Ehsan Toosi 0f03b2bfda [mlir] Add redundant copy removal transform
This pass removes redundant dialect-independent Copy operations in different
situations like the following:

%from = ...
%to = ...
... (no user/alias for %to)
copy(%from, %to)
... (no user/alias for %from)
dealloc %from
use(%to)

Differential Revision: https://reviews.llvm.org/D82757
2020-07-03 15:36:25 +02:00
Marcel Koester 6f5da84f7b [mlir] Extended BufferPlacement to support nested region control flow.
Summary: The current BufferPlacement implementation does not support
nested region control flow. This CL adds support for nested regions via
the RegionBranchOpInterface and the detection of branch-like
(ReturnLike) terminators inside nested regions.

Differential Revision: https://reviews.llvm.org/D81926
2020-06-30 12:10:01 +02:00
Rahul Joshi ee394e6842 [MLIR] Add variadic isa<> for Type, Value, and Attribute
- Also adopt variadic llvm::isa<> in more places.
- Fixes https://bugs.llvm.org/show_bug.cgi?id=46445

Differential Revision: https://reviews.llvm.org/D82769
2020-06-29 15:04:48 -07:00
Tobias Gysi 652a79659a [mlir] fix off-by-one error in collapseParallelLoops
Summary: The patch fixes an off by one error in the method collapseParallelLoops. It ensures the same normalized bound is used for the computation of the division and the remainder.

Reviewers: herhut

Reviewed By: herhut

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, stephenneuendorffer, Joonsoo, grosul1, Kayjukh, jurahul, msifontes

Tags: #mlir

Differential Revision: https://reviews.llvm.org/D82634
2020-06-26 15:39:46 +02:00
Tung D. Le 2b5d1776ff [MLIR][Affine-loop-fusion] Fix a bug in affine-loop-fusion pass when there are non-affine operations
When there is a mix of affine load/store and non-affine operations (e.g. std.load, std.store),
affine-loop-fusion ignores the present of non-affine ops, thus changing the program semantics.

E.g. we have a program of three affine loops operating on the same memref in which one of them uses std.load and std.store, as follows.
```
affine.for
  affine.store %1
affine.for
  std.load %1
  std.store %1
affine.for
  affine.load %1
  affine.store %1
```
affine-loop-fusion will produce the following result which changed the program semantics:
```
affine.for
  std.load %1
  std.store %1
affine.for
  affine.store %1
  affine.load %1
  affine.store %1
```

This patch is to fix the above problem by checking non-affine users of the memref that are between the source and destination nodes of interest.

Differential Revision: https://reviews.llvm.org/D82158
2020-06-26 18:26:42 +05:30
River Riddle e6a343e491 [mlir][DialectConversion][NFC] Add comment blocks and organize a bit of the code
This helps improve the readability when scrolling through the many functions of ConversionPatternRewriterImpl.
2020-06-24 17:42:10 -07:00
Rahul Joshi d891d738d9 [MLIR][NFC] Adopt variadic isa<>
Differential Revision: https://reviews.llvm.org/D82489
2020-06-24 17:02:44 -07:00
Uday Bondhugula aec5344f48 [MLIR] Fix affine loop fusion private memref alloc
Drop stale code that provided the wrong operands to alloc.

Reported-by: rjnw on discourse

Differential Revision: https://reviews.llvm.org/D82409
2020-06-24 22:19:29 +05:30
Rahul Joshi 60f914e5b1 [NFC][MLIR] Undo anonymous namespace change from https://reviews.llvm.org/D82417
Undo as it does not conform to LLVM coding style
(https://llvm.org/docs/CodingStandards.html#anonymous-namespaces)
2020-06-23 20:21:42 -07:00
Rahul Joshi e7f7137cd7 [MLIR] [NFC] Add new line and empty line before printing modified loop
to make the debug output readable.

Differential Revision: https://reviews.llvm.org/D82417
2020-06-23 17:27:43 -07:00
Rahul Joshi d150662024 [MLIR][NFC] Eliminate .getBlocks() when not needed
Differential Revision: https://reviews.llvm.org/D82229
2020-06-19 14:16:21 -07:00
River Riddle 8d67d187ba [mlir][DialectConversion] Refactor how block argument types get converted
This revision removes the TypeConverter parameter passed to the apply* methods, and instead moves the responsibility of region type conversion to patterns. The types of a region can be converted using the 'convertRegionTypes' method, which acts similarly to the existing 'applySignatureConversion'. This method ensures that all blocks within, and including those moved into, a region will have the block argument types converted using the provided converter.

This has the benefit of making more of the legalization logic controlled by patterns, instead of being handled explicitly by the driver. It also opens up the possibility to support multiple type conversions at some point in the future.

This revision also adds a new utility class `FailureOr<T>` that provides a LogicalResult friendly facility for returning a failure or a valid result value.

Differential Revision: https://reviews.llvm.org/D81681
2020-06-18 15:59:22 -07:00
River Riddle 80d7ac3bc7 [mlir] Allow for patterns to match any root kind.
Traditionally patterns have always had the root operation kind hardcoded to a specific operation name. This has worked well for quite some time, but it has certain limitations that make it undesirable. For example, some lowering have the same implementation for many different operations types with a few lowering entire dialects using the same pattern implementation. This problem has led to several "solutions":
a) Provide a template implementation to the user so that they can instantiate it for each operation combination, generally requiring the inclusion of the auto-generated operation definition file.
b) Use a non-templated pattern that allows for providing the name of the operation to match
  - No one ever does this, because enumerating operation names can be cumbersome and so this quickly devolves into solution a.

This revision removes the restriction that patterns have a hardcoded root type, and allows for a class patterns that could match "any" operation type. The major downside of root-agnostic patterns is that they make certain pattern analyses more difficult, so it is still very highly encouraged that an operation specific pattern be used whenever possible.

Differential Revision: https://reviews.llvm.org/D82066
2020-06-18 13:58:47 -07:00
River Riddle 3e98fbf4f5 [mlir] Refactor RewritePatternMatcher into a new PatternApplicator class.
This class enables for abstracting more of the details for the rewrite process, and will allow for clients to apply specific cost models to the pattern list. This allows for DialectConversion and the GreedyPatternRewriter to share the same underlying matcher implementation. This also simplifies the plumbing necessary to support dynamic patterns.

Differential Revision: https://reviews.llvm.org/D81985
2020-06-18 13:58:47 -07:00
River Riddle f4ef77cbb4 [mlir][Inliner] Properly handle callgraph node deletion
We previously weren't properly updating the SCC iterator when nodes were removed, leading to asan failures in certain situations. This commit adds a CallGraphSCC class and defers operation deletion until inlining has finished.

Differential Revision: https://reviews.llvm.org/D81984
2020-06-17 15:45:56 -07:00
Rahul Joshi 2eaadfc4fe [NFC] Use llvm::hasSingleElement() in place of .size() == 1
- Also use functions in Region instead of Region::getBlocks() where possible.

Differential Revision: https://reviews.llvm.org/D82032
2020-06-17 13:26:10 -07:00
Alex Zinenko 3adced3494 [mlir] Introduce callback-based builders to SCF Parallel and Reduce ops
Similarly to `scf::ForOp`, introduce additional `function_ref` arguments to
`::build` functions of SCF `ParallelOp` and `ReduceOp`. The provided functions
will be called to construct the body of the respective operations while
constructing the operation itself. Exercise them in LoopUtils.

Differential Revision: https://reviews.llvm.org/D81872
2020-06-16 20:51:32 +02:00
River Riddle 0e360744f3 [mlir][DialectConversion] Cache type conversions and add a few useful helpers
It is quite common for the same type to be converted many types throughout the conversion process, and there isn't any good reason why we aren't caching that result. Especially given that we currently use identity conversion to signify legality. This revision also adds a few additional helpers to TypeConverter.

Differential Revision: https://reviews.llvm.org/D81679
2020-06-15 15:57:43 -07:00
Marcel Koester 33879aa0bf [mlir] Fixed GCC compile issues and linking problems using SHARED_LIBS.
Differential Revision: https://reviews.llvm.org/D81839
2020-06-15 15:46:21 +02:00
Marcel Koester ff4c510337 [mlir] Extended BufferPlacement to support more sophisticated scenarios in which
allocations cannot be moved freely and can remain in divergent control flow.

The current BufferPlacement pass does not support allocation nodes that carry
additional dependencies (like in the case of dynamic shaped types). These
allocations can often not be moved freely and in turn might remain in divergent
control-flow branches. This requires a different strategy with respect to block
arguments and aliases. This CL adds additinal functionality to support
allocation nodes in divergent control flow while avoiding memory leaks.

Differential Revision: https://reviews.llvm.org/D79850
2020-06-15 12:19:23 +02:00
Diego Caballero 2e7a084591 [mlir][Affine] Revisit fusion candidates after successful fusion
This patch changes the fusion algorithm so that after fusing two loop nests
we revisit previously visited nodes so that they are considered again for
fusion in the context of the new fused loop nest.

Reviewed By: bondhugula

Differential Revision: https://reviews.llvm.org/D81609
2020-06-11 14:53:08 -07:00
Rahul Joshi 475935113c [MLIR] Emit debug message if inlining fails
Summary: Emit a debug message if inlining fails.

Differential Revision: https://reviews.llvm.org/D81320
2020-06-10 17:38:41 -07:00
Ehsan Toosi 4214031d43 [mlir] Introduce allowMemrefFunctionResults for the helper operation converters of buffer placement
This parameter gives the developers the freedom to choose their desired function
signature conversion for preparing their functions for buffer placement. It is
introduced for BufferAssignmentFuncOpConverter, and also for
BufferAssignmentReturnOpConverter, and BufferAssignmentCallOpConverter to adapt
the return and call operations with the selected function signature conversion.
If the parameter is set, buffer placement won't also deallocate the returned
buffers.

Differential Revision: https://reviews.llvm.org/D81137
2020-06-08 09:25:41 +02:00
Nicolas Vasilache 38c407bf00 [mlir][SCF] Add single iteration scf.for promotion to the FuncOp level helper.
Previously only the Affine version would be folded.

Differential Revision: https://reviews.llvm.org/D81261
2020-06-05 11:28:21 -04:00
Nicolas Vasilache 6953cf6502 [mlir][Linalg] Add a hoistRedundantVectorTransfers helper function
This revision adds a helper function to hoist vector.transfer_read /
vector.transfer_write pairs out of immediately enclosing scf::ForOp
iteratively, if the following conditions are true:
   1. The 2 ops access the same memref with the same indices.
   2. All operands are invariant under the enclosing scf::ForOp.
   3. No uses of the memref either dominate the transfer_read or are
   dominated by the transfer_write (i.e. no aliasing between the write and
   the read across the loop)

To improve hoisting opportunities, call the `moveLoopInvariantCode` helper
function on the candidate loop above which to hoist. Hoisting the transfers
results in scf::ForOp yielding the value that originally transited through
memory.

This revision additionally exposes `moveLoopInvariantCode` as a helper in
LoopUtils.h and updates SliceAnalysis to support return scf::For values and
allow hoisting across multiple scf::ForOps.

Differential Revision: https://reviews.llvm.org/D81199
2020-06-05 06:50:24 -04:00
Diego Caballero 8a418e5f8e [mlir][Affine] Enable fusion of loops with vector loads/stores
This patch enables affine loop fusion for loops with affine vector loads
and stores. For that, we only had to use affine memory op interfaces in
LoopFusionUtils.cpp and Utils.cpp so that vector loads and stores are
also taken into account.

Reviewed By: andydavis1, ftynse

Differential Revision: https://reviews.llvm.org/D80971
2020-06-03 01:26:22 +03:00
Alex Zinenko 5c5dafc534 [mlir] support materialization for 1-1 type conversions
Dialect conversion infrastructure supports 1->N type conversions by requiring
individual conversions to provide facilities to generate operations
retrofitting N values into 1 of the original type when N > 1. This
functionality can also be used to materialize explicit "cast"-like operations,
but it did not support 1->1 type conversions until now. Modify TypeConverter to
support materialization of cast operations for 1-1 conversions.

This also makes materialization specification more extensible following the
same pattern as type conversions. Instead of overloading a virtual function,
users or subclasses of TypeConversion can now register type-specific
materialization callbacks that will be called in order for the given type.

Differential Revision: https://reviews.llvm.org/D79729
2020-06-02 13:48:33 +02:00
Alex Zinenko 195d8571b9 [mlir] post-commit review fixes
This fixes several post-commit nits from D79688 and D80135, namely
typos, debug output and control flow inversion.
2020-06-02 12:08:17 +02:00
Ehsan Toosi 3f6a35e3ff [mlir] Introduce CallOp converter for buffer placement
Add BufferAssignmentCallOpConverter as a pattern rewriter for Buffer
Placement. It matches the signature of the caller operation with the callee
after rewriting the callee with FunctionAndBlockSignatureConverter.

Differential Revision: https://reviews.llvm.org/D80785
2020-06-02 11:35:24 +02:00
Chris Lattner 0cf5ef176b Change some extraneous /// comments to // comments inside methods. NFC. 2020-05-31 11:43:54 -07:00
Mehdi Amini 21fee0921d Use .empty() instead of .size() == 0 (NFC)
Cleanup / Fix a clang-tidy warning
2020-05-30 03:36:22 +00:00
Ehsan Toosi 7a3a253585 [MLIR][BufferPlacement] Support functions that return Memref typed results
Buffer placement can now operates on functions that return buffers. These
buffers escape from the deallocation phase of buffer placement.

Differential Revision: https://reviews.llvm.org/D80696
2020-05-29 11:03:22 +02:00
Alex Zinenko df48026b4c [mlir] DialectConversion: support erasing blocks
PatternRewriter has support for erasing a Block from its parent region, but
this feature has not been implemented for ConversionPatternRewriter that needs
to keep track of and be able to undo block actions. Introduce support for
undoing block erasure in the ConversionPatternRewriter by marking all the ops
it contains for erasure and by detaching the block from its parent region. The
detached block is stored in the action description and is not actually deleted
until the rewrites are applied.

Differential Revision: https://reviews.llvm.org/D80135
2020-05-20 16:12:05 +02:00
Alex Zinenko 5d5df06aac [mlir] DialectConversion: avoid double-free when rolling back op creation
Dialect conversion infrastructure may roll back op creation by erasing the
operations in the reverse order of their creation. While this guarantees uses
of values will be deleted before their definitions, this does not guarantee
that a parent operation will not be deleted before its child. (This may happen
in case of block inlining or if child operations, such as terminators, are
created in the parent's `build` function before the parent itself.) Handle the
parent/child relationship between ops by removing all child ops from the blocks
before erasing the parent. The child ops remain live, detached from a block,
and will be safely destroyed in their turn, which may come later than that of
the parent.

Differential Revision: https://reviews.llvm.org/D80134
2020-05-20 16:12:05 +02:00
Diego Caballero a45fb1942f [mlir][Affine] Introduce affine memory interfaces
This patch introduces interfaces for read and write ops with affine
restrictions. I used `read`/`write` intead of `load`/`store` for the
interfaces so that they can also be implemented by dma ops.
For now, they are only implemented by affine.load, affine.store,
affine.vector_load and affine.vector_store.

For testing purposes, this patch also migrates affine loop fusion and
required analysis to use the new interfaces. No other changes are made
beyond that.

Co-authored-by: Alex Zinenko <zinenko@google.com>

Reviewed By: bondhugula, ftynse

Differential Revision: https://reviews.llvm.org/D79829
2020-05-19 17:32:50 -07:00
Ehsan Toosi 3468300511 [MLIR] Update the FunctionAndBlockSignatureConverter and NonVoidToVoidReturnOpConverter of Buffer Assignment
Making these two converters more generic. FunctionAndBlockSignatureConverter now
moves only memref results (after type conversion) to the function argument and
keeps other legal function results unchanged. NonVoidToVoidReturnOpConverter is
renamed to NoBufferOperandsReturnOpConverter. It removes only the buffer
operands from the operands of the converted ReturnOp and inserts CopyOps to copy
each buffer to the target function argument.

Differential Revision: https://reviews.llvm.org/D79329
2020-05-19 17:04:59 +02:00
Stephen Neuendorffer eb623ae832 [MLIR] Continue renaming of "SideEffects"
MLIRSideEffects -> MLIRSideEffectInterfaces
SideEffects.h -> SideEffectInterfaces.h
SideEffects.cpp -> SideEffectInterface.cpp

Note that I haven't renamed TableGen/SideEffects.h or TableGen/SideEffects.cpp

find -name "*.h" -exec sed -i "s/SideEffects.h/SideEffectInterfaces.h/" "{}" \;
find -name "CMakeLists.txt" -exec sed -i "s/MLIRSideEffects/MLIRSideEffectInterfaces/" "{}" \;

Differential Revision: https://reviews.llvm.org/D79890
2020-05-15 14:37:09 -07:00
Sean Silva 98eead8186 [mlir][Value] Add v.getDefiningOp<OpTy>()
Summary:
This makes a common pattern of
`dyn_cast_or_null<OpTy>(v.getDefiningOp())` more concise.

Differential Revision: https://reviews.llvm.org/D79681
2020-05-11 12:55:27 -07:00
Alex Zinenko c25b20c0f6 [mlir] NFC: Rename LoopOps dialect to SCF (Structured Control Flow)
This dialect contains various structured control flow operaitons, not only
loops, reflect this in the name. Drop the Ops suffix for consistency with other
dialects.

Note that this only moves the files and changes the C++ namespace from 'loop'
to 'scf'. The visible IR prefix remains the same and will be updated
separately. The conversions will also be updated separately.

Differential Revision: https://reviews.llvm.org/D79578
2020-05-11 15:04:27 +02:00
Uday Bondhugula 2affcd664e [MLIR] Fix affine fusion bug/efficiency issue / enable more fusion
The list of destination load ops while evaluating producer-consumer
fusion wasn't being maintained as a set, and as such, duplicate load ops
were being added to it. Although this is harmless correctness-wise, it's
a killer efficiency-wise and it prevents interesting/useful fusions
(including for eg. reshapes into a matmul). The reason the latter
fusions would be missed is that a slice union would be unnecessarily
needed due to the duplicate load ops on a memref added to the 'dst
loads' list. Since slice union is unimplemented for the local var case,
a single destination load op that leads to local vars (like a floordiv /
mod producing fusion), a common case, would not get fused due to an
unnecessary union being tried with itself.  (The union would actually be
the same thing but we would bail out.)

Besides the above, this would also significantly speed up fusion as all
the unnecessary slice computations / unions, checks, etc. due to the
duplicates go away.

Differential Revision: https://reviews.llvm.org/D79547
2020-05-07 10:51:34 +05:30
Uday Bondhugula ca09dab303 [MLIR][NFC] Fix/update debug messages for analysis utils and affine fusion
Drop trailing period in debug messages. Add an extra line for fusion
debug info.

Differential Revision: https://reviews.llvm.org/D79471
2020-05-06 12:27:59 +05:30
Reid Kleckner 932f0276ea [Support] Move LLD's parallel algorithm wrappers to support
Essentially takes the lld/Common/Threads.h wrappers and moves them to
the llvm/Support/Paralle.h algorithm header.

The changes are:
- Remove policy parameter, since all clients use `par`.
- Rename the methods to `parallelSort` etc to match LLVM style, since
  they are no longer C++17 pstl compatible.
- Move algorithms from llvm::parallel:: to llvm::, since they have
  "parallel" in the name and are no longer overloads of the regular
  algorithms.
- Add range overloads
- Use the sequential algorithm directly when 1 thread is requested
  (skips task grouping)
- Fix the index type of parallelForEachN to size_t. Nobody in LLVM was
  using any other parameter, and it made overload resolution hard for
  for_each_n(par, 0, foo.size(), ...) because 0 is int, not size_t.

Remove Threads.h and update LLD for that.

This is a prerequisite for parallel public symbol processing in the PDB
library, which is in LLVM.

Reviewed By: MaskRay, aganea

Differential Revision: https://reviews.llvm.org/D79390
2020-05-05 15:21:05 -07:00
Andy Davis 93d1108801 [MLIR][LoopOps] Adds the loop unroll transformation for loop::ForOp.
Summary:
Adds the loop unroll transformation for loop::ForOp.
Adds support for promoting the body of single-iteration loop::ForOps into its containing block.
Adds check tests for loop::ForOps with dynamic and static lower/upper bounds and step.
Care was taken to share code (where possible) with the AffineForOp unroll transformation to ease maintenance and potential future transition to a LoopLike construct on which loop transformations for different loop types can implemented.

Reviewers: ftynse, nicolasvasilache

Reviewed By: ftynse

Subscribers: bondhugula, mgorny, zzheng, mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, Joonsoo, grosul1, frgossen, Kayjukh, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79184
2020-05-05 10:42:36 -07:00
Stephen Neuendorffer 5469f434bb [MLIR] Reapply: Adjust libMLIR building to more closely follow libClang
This reverts commit ab1ca6e60f.
2020-05-04 20:47:57 -07:00
River Riddle 469c02d058 [mlir] Add support for merging identical blocks during canonicalization
This revision adds support for merging identical blocks, or those with the same operations that branch to the same successors. Operands that mismatch between the different blocks are replaced with new block arguments added to the merged block.

Differential Revision: https://reviews.llvm.org/D79134
2020-05-04 19:56:46 -07:00
River Riddle 1e4faf23ff [mlir][IR] Add a Region::getOps method that returns a range of immediately nested operations
This allows for walking the operations nested directly within a region, without traversing nested regions.

Differential Revision: https://reviews.llvm.org/D79056
2020-05-04 17:46:25 -07:00
Stephen Neuendorffer ab1ca6e60f Revert "[MLIR] Adjust libMLIR building to more closely follow libClang"
This reverts commit 4f0f436749.

This seems to show some compile dependence problems, and also breaks flang.
2020-05-04 12:40:12 -07:00
Valentin Churavy 4f0f436749 [MLIR] Adjust libMLIR building to more closely follow libClang
- Exports MLIR targets to be used out-of-tree.
- mimicks `add_clang_library` and `add_flang_library`.
- Fixes libMLIR.so

After https://reviews.llvm.org/D77515 libMLIR.so was no longer containing
any object files. We originally had a cludge there that made it work with
the static initalizers and when switchting away from that to the way the
clang shlib does it, I noticed that MLIR doesn't create a `obj.{name}` target,
and doesn't export it's targets to `lib/cmake/mlir`.

This is due to MLIR using `add_llvm_library` under the hood, which adds
the target to `llvmexports`.

Differential Revision: https://reviews.llvm.org/D78773

[MLIR] Fix libMLIR.so and LLVM_LINK_LLVM_DYLIB

Primarily, this patch moves all mlir references to LLVM libraries into
either LLVM_LINK_COMPONENTS or LINK_COMPONENTS.  This enables magic in
the llvm cmake files to automatically replace reference to LLVM components
with references to libLLVM.so when necessary.  Among other things, this
completes fixing libMLIR.so, which has been broken for some configurations
since D77515.

Unlike previously, the pattern is now that mlir libraries should almost
always use add_mlir_library.  Previously, some libraries still used
add_llvm_library.  However, this confuses the export of targets for use
out of tree because libraries specified with add_llvm_library are exported
by LLVM.  Instead users which don't need/can't be linked into libMLIR.so
can specify EXCLUDE_FROM_LIBMLIR

A common error mode is linking with LLVM libraries outside of LINK_COMPONENTS.
This almost always results in symbol confusion or multiply defined options
in LLVM when the same object file is included as a static library and
as part of libLLVM.so.  To catch these errors more directly, there's now
mlir_check_all_link_libraries.

To simplify usage of add_mlir_library, we assume that all mlir
libraries depend on LLVMSupport, so it's not necessary to separately specify
it.

tested with:
BUILD_SHARED_LIBS=on,
BUILD_SHARED_LIBS=off + LLVM_BUILD_LLVM_DYLIB,
BUILD_SHARED_LIBS=off + LLVM_BUILD_LLVM_DYLIB + LLVM_LINK_LLVM_DYLIB.

By: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Differential Revision: https://reviews.llvm.org/D79067

[MLIR] Move from using target_link_libraries to LINK_LIBS

This allows us to correctly generate dependencies for derived targets,
such as targets which are created for object libraries.

By: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Differential Revision: https://reviews.llvm.org/D79243

Three commits have been squashed to avoid intermediate build breakage.
2020-05-04 11:40:46 -07:00
Marcel Koester 67b466deda [mlir] Removed tight coupling of BufferPlacement pass to Alloc and Dealloc.
The current BufferPlacement implementation tries to find Alloc and Dealloc
operations in order to move them. However, this is a tight coupling to
standard-dialect ops which has been removed in this CL.

Differential Revision: https://reviews.llvm.org/D78993
2020-05-04 14:23:15 +02:00
River Riddle cb9ae0025c [mlir] Add a new context flag for disabling/enabling multi-threading
This is useful for several reasons:
* In some situations the user can guarantee that thread-safety isn't necessary and don't want to pay the cost of synchronization, e.g., when parsing a very large module.

* For things like logging threading is not desirable as the output is not guaranteed to be in stable order.

This flag also subsumes the pass manager flag for multi-threading.

Differential Revision: https://reviews.llvm.org/D79266
2020-05-02 12:32:25 -07:00
Stephen Neuendorffer 57818885be [MLIR] Move Verifier and Dominance Analysis from /Analysis to /IR
These libraries are distinct from other things in Analysis in that they
operate only on core IR concepts.  This also simplifies dependencies
so that Dialect -> Analysis -> Parser -> IR.  Previously, the parser depended
on portions of the the Analysis directory as well, which sometimes
caused issues with the way the cmake makefile generator discovers
dependencies on generated files during compilation.

Differential Revision: https://reviews.llvm.org/D79240
2020-05-01 20:01:46 -07:00
River Riddle 359164f810 [mlir][OpBuilder] Remove the vtable from OpBuilder in favor of using the listener pattern
The current OpBuilder has a set of virtual functions required by the fact that the PatternRewriter inherits from it for convenience. The PatternRewriter is required to know about IR mutations for correctness. This revision changes the relationship to be explicit by having users register a listener with the builder instead of using inheritance/vtables. This still requires that users properly transfer the listener when creating new builders, but has several benefits:

* More than one builder can be created during pattern rewrites(assuming that the listener is properly forwarded)
* OpBuilder no longer requires a vtable, and thus does not incur the cost when a listener isn't present.

Differential Revision: https://reviews.llvm.org/D79206
2020-04-30 21:29:25 -07:00
Lucy Fox 8de482ea9a [MLIR] Modify Partial op conversion mode to optionally track all non-legalizable operations.
There are three op conversion modes: Partial, Full, and Analysis. This change modifies the Partial mode to optionally take a set of non-legalizable ops. If this parameter is specified, all ops that are not legalizable (i.e. would cause full conversion to fail) are tracked throughout the partial legalization.

Differential Revision: https://reviews.llvm.org/D78788
2020-04-30 09:52:37 -07:00
River Riddle 0752d98ccf [mlir] Simplify BranchOpInterface by using MutableOperandRange
This range allows for performing many different operations on successor operands, including erasing/adding/setting. This removes the need for the explicit canEraseSuccessorOperand and eraseSuccessorOperand methods.

Differential Revision: https://reviews.llvm.org/D79077
2020-04-29 16:48:15 -07:00
River Riddle df00e466da [mlir] Move the operation equivalence out of CSE and into OperationSupport
This provides a general hash and comparison for checking if two operations are equivalent. This revision also optimizes the handling of result types to take advantage of how result types are stored on the operation.

Differential Revision: https://reviews.llvm.org/D79029
2020-04-29 16:48:15 -07:00
Jacques Pienaar 5439582781 Rename NamedAttributeList to MutableDictionaryAttr
Makes the relationship and function clearer. Accordingly rename getAttrList to getMutableAttrDict.

Differential Revision: https://reviews.llvm.org/D79125
2020-04-29 14:58:02 -07:00
Ehsan Toosi 5c352e69e7 Providing buffer assignment for MLIR
We have provided a generic buffer assignment transformation ported from
TensorFlow. This generic transformation pass automatically analyzes the values
and their aliases (also in other blocks) and returns the valid positions for
Alloc and Dealloc operations. To find these positions, the algorithm uses the
block Dominator and Post-Dominator analyses. In our proposed algorithm, we have
considered aliasing, liveness, nested regions, branches, conditional branches,
critical edges, and independency to custom block terminators. This
implementation doesn't support block loops. However, we have considered this in
our design. For this purpose, it is only required to have a loop analysis to
insert Alloc and Dealloc operations outside of these loops in some special
cases.

Differential Revision: https://reviews.llvm.org/D78484
2020-04-28 10:17:59 +02:00
River Riddle a90151d67e [mlir][SCCP] Add support for propagating across symbol based calls
This revision adds support for propagating constants across symbol-based callgraph edges. It uses the existing Call/CallableOpInterfaces to detect the dataflow edges, and propagates constants through arguments and out of returns.

Differential Revision: https://reviews.llvm.org/D78592
2020-04-27 13:04:49 -07:00
River Riddle 7c221a7d4f [mlir][Symbol] Change Symbol from a Trait into an OpInterface.
This provides a much cleaner interface into Symbols, and allows for users to start injecting op-specific information. For example, derived op can now inject when a symbol can be discarded if use_empty. This would let us drop unused external functions, which generally have public visibility.

This revision also adds a new `extraTraitClassDeclaration` field to ODS OpInterface to allow for injecting declarations into the trait class that gets attached to the operations.

Differential Revision: https://reviews.llvm.org/D78522
2020-04-27 13:04:49 -07:00
Alexander Belyaev ed5363a674 [MLIR] Add getBody() method to SingleImplicitBlockTerminator op trait.
Many ops with this trait have `getBody()` and `getBodyBuilder()` methods defined in `extraClassDeclaration` in tablegen. `getBody()` implementation is the same accross all these ops, but `getBodyBuilder()` can return builders with varying insertion points set. In this PR, `getBody()` is moved into `SingleImplicitBlockTerminator` struct and `getBodyBuilder()` is replaced with `OpBuilder::atBlock(End|Terminator)(op.getBody);`.

Differential Revision: https://reviews.llvm.org/D78864
2020-04-27 21:48:52 +02:00
River Riddle 4dfd1b5fcb [mlir] Optimize operand storage such that all operations can have resizable operand lists
This revision refactors the structure of the operand storage such that there is no additional memory cost for resizable operand lists until it is required. This is done by using two different internal representations for the operand storage:
* One using trailing operands
* One using a dynamically allocated std::vector<OpOperand>

This allows for removing the resizable operand list bit, and will free up APIs from needing to workaround non-resizable operand lists.

Differential Revision: https://reviews.llvm.org/D78875
2020-04-26 21:34:01 -07:00
River Riddle 0816de167a [mlir][DialectConversion] Add support for properly tracking replaceUsesOfBlockArgument
The current implementation of this method performs the replacement directly, and thus doesn't support proper back tracking.

Differential Revision: https://reviews.llvm.org/D78790
2020-04-24 12:37:32 -07:00
River Riddle 2eda87dfbe [mlir][SCCP] Add support for propagating constants across inter-region control flow.
This is possible by adding two new ControlFlowInterface additions:

- A new interface, RegionBranchOpInterface
This interface allows for region holding operations to describe how control flows between regions. This interface initially contains two methods:

* getSuccessorEntryOperands
Returns the operands of this operation used as the entry arguments when entering the region at `index`, which was specified as a successor by `getSuccessorRegions`. when entering. These operands should correspond 1-1 with the successor inputs specified in `getSuccessorRegions`, and may be a subset of the entry arguments for that region.

*  getSuccessorRegions
Returns the viable successors of a region, or the possible successor when branching from the parent op. This allows for describing which regions may be executed when entering an operation, and which regions are executed after having executed another region of the parent op. For example, a structured loop operation may always enter into the loop body region. The loop body region may branch back to itself, or exit to the operation.

- A trait, ReturnLike
This trait signals that a terminator exits a region and forwards all of its operands as "exiting" values.

These additions allow for performing more general dataflow analysis in the presence of region holding operations.

Differential Revision: https://reviews.llvm.org/D78447
2020-04-21 02:59:25 -07:00
River Riddle 152d29cc74 [mlir][Transforms] Add pass to perform sparse conditional constant propagation
This revision adds the initial pass for performing SCCP generically in MLIR. SCCP is an algorithm for propagating constants across control flow, and optimistically assumes all values to be constant unless proven otherwise. It currently supports branching control, with support for regions and inter-procedural propagation being added in followups.

Differential Revision: https://reviews.llvm.org/D78397
2020-04-21 02:59:25 -07:00
Sean Silva 22219cfc6a Fix inlining multi-block callees with type conversion.
The previous code result a mismatch between block argument types and
predecessor successor args when a type conversion was needed in a
multiblock case. It was assuming the replaced result types matched the
region result types.

Also, slighly improve the debug output from the inliner.

Differential Revision: https://reviews.llvm.org/D78415
2020-04-20 16:54:01 -07:00
Alexander Belyaev def3e10eac [MLIR] Add #include "llvm/ADT/SmallPtrSet.h" back to LoopUtils.h. 2020-04-20 10:21:18 +02:00
Alexander Belyaev ad9988f4da [MLIR] Move `replaceAllUsesExcept` from LoopUtil.h to Value.h.
Differential Revision: https://reviews.llvm.org/D78426
2020-04-20 09:21:06 +02:00
Uday Bondhugula ecddafd84a [MLIR] NFC affine for op tiling cleanup / utility rename
Rename mlir::tileCodeGen -> mlir::tilePerfectlyNested to be consistent.
NFC clean up tiling utility code, drop dead code, better comments.
Expose isPerfectlyNested and reuse.

Differential Revision: https://reviews.llvm.org/D78423
2020-04-19 00:53:34 +05:30
Uday Bondhugula f043677f6d [MLIR] Make isPerfectlyNested check more efficient
Make mlir::isPerfectlyNested more efficient; use O(1) check instead of
O(N) size() method.

Differential Revision: https://reviews.llvm.org/D78428
2020-04-18 23:34:49 +05:30
Stephen Neuendorffer f061295732 [MLIR] Complete refactoring of Affine dialect into sub-libraries.
There were some unused CMakeFiles for Affine/IR and Affine/EDSC.
This change builds separate MLIRAffineOps and MLIRAffineEDSC libraries
using those CMakeFiles.  This combination replaces the old MLIRAffine
library.

Differential Revision: https://reviews.llvm.org/D78317
2020-04-16 13:41:17 -07:00
Alexander Belyaev be9c3bdc44 [MLIR] Fix fusion of linalg.indexed_generic producer into tiled (Indexed)GenericOp.
Differential Revision: https://reviews.llvm.org/D78209
2020-04-16 10:45:17 +02:00
Lorenzo Chelini a60fdd2ba4 [MLIR] NFC after commit D77478.
Remove leftovers 'applyPatternsGreedily' from the codebase.

Differential Revision: https://reviews.llvm.org/D78274
2020-04-16 10:32:01 +02:00
River Riddle 4f37450b2c [mlir][Inliner] Store the resolved call by-value instead of by-reference
This avoids asan failures as more calls may be added during inlining, invalidating the reference.

Differential Revision: https://reviews.llvm.org/D78258
2020-04-15 17:42:27 -07:00
Jeremy Bruestle 9f3ab92ec8 [MLIR] Improve support for 0-dimensional Affine Maps.
Summary:
Modified AffineMap::get to remove support for the overload which allowed
an ArrayRef of AffineExpr but no context (and gathered the context from a
presumed first entry, resulting in bugs when there were 0 results).

Instead, we support only a ArrayRef and a context, and a version which
takes a single AffineExpr.

Additionally, removed some now needless case logic which previously
special cased which call to AffineMap::get to use.

Reviewers: flaub, bondhugula, rriddle!, nicolasvasilache, ftynse, ulysseB, mravishankar, antiagainst, aartbik

Subscribers: mehdi_amini, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, bader, grosul1, frgossen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78226
2020-04-15 14:15:02 -07:00
Uday Bondhugula 04b5274ede [MLIR] Introduce applyOpPatternsAndFold for op local rewrites
Introduce mlir::applyOpPatternsAndFold which applies patterns as well as
any folding only on a specified op (in contrast to
applyPatternsAndFoldGreedily which applies patterns only on the regions
of an op isolated from above).  The caller is made aware of the op being
folded away or erased.

Depends on D77485.

Differential Revision: https://reviews.llvm.org/D77487
2020-04-15 14:10:01 +05:30
River Riddle 92f1562f3d [mlir][NFC] Remove the STLExtras.h header file now that it has been merged into LLVM.
Now that no more utilities exist within, this file can be deleted.

Differential Revision: https://reviews.llvm.org/D78079
2020-04-14 15:14:41 -07:00
River Riddle ebf190fcda [llvm][ADT] Move TypeSwitch class from MLIR to LLVM
This class implements a switch-like dispatch statement for a value of 'T' using dyn_cast functionality. Each `Case<T>` takes a callable to be invoked if the root value isa<T>, the callable is invoked with the result of dyn_cast<T>() as a parameter.

Differential Revision: https://reviews.llvm.org/D78070
2020-04-14 15:14:41 -07:00
River Riddle 2f21a57966 [llvm][STLExtras] Move the algorithm `interleave*` methods from MLIR to LLVM
These have proved incredibly useful for interleaving values between a range w.r.t to streams. After this revision, the mlir/Support/STLExtras.h is empty. A followup revision will remove it from the tree.

Differential Revision: https://reviews.llvm.org/D78067
2020-04-14 15:14:40 -07:00
River Riddle 204c3b5516 [llvm][STLExtras] Move various iterator/range utilities from MLIR to LLVM
This revision moves the various range utilities present in MLIR to LLVM to enable greater reuse. This revision moves the following utilities:

* indexed_accessor_*
This is set of utility iterator/range base classes that allow for building a range class where the iterators are represented by an object+index pair.

* make_second_range
Given a range of pairs, returns a range iterating over the `second` elements.

* hasSingleElement
Returns if the given range has 1 element. size() == 1 checks end up being very common, but size() is not always O(1) (e.g., ilist). This method provides O(1) checks for those cases.

Differential Revision: https://reviews.llvm.org/D78064
2020-04-14 15:14:40 -07:00
Uday Bondhugula ac047d9fce [MLIR] Remove dead affine.applys while generating pointwise copies
This makes no impact on the test cases because affine-data-copy-generate
runs whole function canonicalization at its end; however, the latter
will be removed in a pending revision. It is thus useful to clean up
these affine.applys right here, and eventually, not even generate
these (when the right API to compose by construction is in place).

Differential Revision: https://reviews.llvm.org/D78055
2020-04-14 09:47:14 +05:30
Uday Bondhugula 42ada5fee9 [MLIR] NFC cleanup/modernize memref-dataflow-opt / getNestingDepth
Bring code to date with recent changes to the core infrastructure /
coding style.

Differential Revision: https://reviews.llvm.org/D77998
2020-04-14 00:03:06 +05:30
Uday Bondhugula cbcb12fd44 [MLIR] Handle in-place folding properly in greedy pattern rewrite driver
OperatioFolder::tryToFold performs both true folding and in a few
instances in-place updates through op rewrites. In the latter case, we
should still be applying the supplied pattern rewrites in the same
iteration; however this wasn't the case since tryToFold returned
success() for both true folding and in-place updates, and the patterns
for the in-place updated ops were being applied only in the next
iteration of the driver's outer loop. This fix would make it converge
faster.

Differential Revision: https://reviews.llvm.org/D77485
2020-04-11 19:57:29 +05:30
Uday Bondhugula a5b9316b24 [MLIR][NFC] applyPatternsGreedily -> applyPatternsAndFoldGreedily
Rename mlir::applyPatternsGreedily -> applyPatternsAndFoldGreedily. The
new name is a more accurate description of the method - it performs
both, application of the specified patterns and folding of all ops in
the op's region irrespective of whether any patterns have been supplied.

Differential Revision: https://reviews.llvm.org/D77478
2020-04-10 12:55:21 +05:30
River Riddle bd1ccfe6df [mlir] Add a new RewritePattern::hasBoundedRewriteRecursion hook.
Summary: Some pattern rewriters, like dialect conversion, prohibit the unbounded recursion(or reapplication) of patterns on generated IR. Most patterns are not written with recursive application in mind, so will generally explode the stack if uncaught. This revision adds a hook to RewritePattern, `hasBoundedRewriteRecursion`, to signal that the pattern can safely be applied to the generated IR of a previous application of the same pattern. This allows for establishing a contract between the pattern and rewriter that the pattern knows and can handle the potential recursive application.

Differential Revision: https://reviews.llvm.org/D77782
2020-04-09 12:42:28 -07:00
River Riddle 400ad6f95d [mlir] Eliminate the remaining usages of cl::opt instead of PassOption.
Summary: Pass options are a better choice for various reasons and avoid the need for static constructors.

Differential Revision: https://reviews.llvm.org/D77707
2020-04-08 13:05:08 -07:00
River Riddle 1834ad4a69 [mlir][Pass] Update the PassGen to generate base classes instead of utilities
Summary:
This is much cleaner, and fits the same structure as many other tablegen backends. This was not done originally as the CRTP in the pass classes made it overly verbose/complex.

Differential Revision: https://reviews.llvm.org/D77367
2020-04-07 14:08:52 -07:00
River Riddle 80aca1eaf7 [mlir][Pass] Remove the use of CRTP from the Pass classes
This revision removes all of the CRTP from the pass hierarchy in preparation for using the tablegen backend instead. This creates a much cleaner interface in the C++ code, and naturally fits with the rest of the infrastructure. A new utility class, PassWrapper, is added to replicate the existing behavior for passes not suitable for using the tablegen backend.

Differential Revision: https://reviews.llvm.org/D77350
2020-04-07 14:08:52 -07:00
River Riddle 722f909f7a [mlir][Pass][NFC] Replace usages of ModulePass with OperationPass<ModuleOp>
ModulePass doesn't provide any special utilities and thus doesn't give enough benefit to warrant a special pass class. This revision replaces all usages with the more general OperationPass.

Differential Revision: https://reviews.llvm.org/D77339
2020-04-07 14:08:52 -07:00
Uday Bondhugula 70da33bf30 [MLIR] fix/update affine data copy utility for max/min bounds
Fix point-wise copy generation to work with bounds that have max/min.
Change structure of copy loop nest to use absolute loop indices and
subtracting base from the indexes of the fast buffers. Update supporting
utilities: Fix FlatAffineConstraints::getLowerAndUpperBound to look at
equalities as well and for a missing division. Update unionBoundingBox
to not discard common constraints (leads to a tighter system). Update
MemRefRegion::getConstantBoundingSizeAndShape to add memref dimension
constraints. Run removeTrivialRedundancy at the end of
MemRefRegion::compute.  Run single iteration loop promotion and
load/store canonicalization after affine data copy (in its test pass as
well).

Differential Revision: https://reviews.llvm.org/D77320
2020-04-07 13:55:42 +05:30
Uday Bondhugula 3f9cdd44d7 [MLIR] Add pattern rewriter util to erase block; remove dead else
Add a pattern rewriter utility to erase blocks (while notifying the
pattern rewriting driver of the erased ops). Use this to remove trivial
else blocks in affine.if ops.

Differential Revision: https://reviews.llvm.org/D77083
2020-04-05 19:24:43 +05:30
Uday Bondhugula cc6738949d [MLIR][NFC] fix name operand -> userOp
The wrong name was confusing to read. value.getUsers() yields
Operation *s.

Differential Revision: https://reviews.llvm.org/D77486
2020-04-05 19:17:15 +05:30
Uday Bondhugula f875e55ba9 [MLIR] fix greedy pattern rewrite driver iteration on change
Removing dead ops should make the outer loop of the pattern rewriting
driver run again. Although its operands are added to the worklist, if no
changes happenned to them or remaining ops in the worklist, the driver
wouldn't run once again - but it should be.

Differential Revision: https://reviews.llvm.org/D77483
2020-04-05 19:15:46 +05:30
Kazuaki Ishizaki 5aacce3db2 [mlir] NFC: Fix trivial typo
Differential Revision: https://reviews.llvm.org/D77473
2020-04-05 11:30:30 +09:00
Alex Zinenko f27f1e8c27 [mlir] DialectConversion: support block creation in ConversionPatternRewriter
PatternRewriter and derived classes provide a set of virtual methods to
manipulate blocks, which ConversionPatternRewriter overrides to keep track of
the manipulations and undo them in case the conversion fails. However, one can
currently create a block only by splitting another block into two. This not
only makes the API inconsistent (`splitBlock` is allowed in conversion
patterns, but `createBlock` is not), but it also make it impossible for one to
create blocks with argument lists different from those of already existing
blocks since in-place block updates are not supported either. Such
functionality precludes dialect conversion infrastructure from being used more
extensively on region-containing ops, for example, for value-returning "if"
operations. At the same time, ConversionPatternRewriter already allows one to
undo block creation as block creation is one of the primitive operations in
already supported region inlining.

Support block creation in conversion patterns by hooking `createBlock` on the
block action undo mechanism. This requires to make `Builder::createBlock`
virtual, similarly to Op insertion. This is a minimal change to the Builder
infrastructure that will later help support additional use cases such as block
signature changes. `createBlock` now additionally takes the types of the block
arguments that are added immediately so as to avoid in-place argument list
manipulation that would be illegal in conversion patterns.
2020-04-03 20:30:03 +02:00
Uday Bondhugula 5e8093134a [MLIR] Add method to drop duplicate result exprs from AffineMap
Add a method that given an affine map returns another with just its unique
results. Use this to drop redundant bounds in max/min for affine.for. Update
affine.for's canonicalization pattern and createCanonicalizedForOp to use
this.

Differential Revision: https://reviews.llvm.org/D77237
2020-04-02 03:00:19 +05:30
Mehdi Amini 0dd21130ef Add LLVM_ATTRIBUTE_UNUSED to function used only in assert (NFC) 2020-04-01 17:21:07 +00:00
Uday Bondhugula 68316afb29 [MLIR][NFC] loop transforms/analyis utils cleanup / modernize
Modernize/cleanup code in loop transforms utils - a lot of this code was
written prior to the currently available IR support / code style. This
patch also does some variable renames including inst -> op, comment
updates, turns getCleanupLoopLowerBound into a local function.

Differential Revision: https://reviews.llvm.org/D77175
2020-04-01 22:36:25 +05:30
River Riddle 9a277af2d4 [mlir][Pass] Add support for generating pass utilities via tablegen
This revision adds support for generating utilities for passes such as options/statistics/etc. that can be inferred from the tablegen definition. This removes additional boilerplate from the pass, and also makes it easier to remove the reliance on the pass registry to provide certain things(e.g. the pass argument).

Differential Revision: https://reviews.llvm.org/D76659
2020-04-01 02:10:46 -07:00
River Riddle 8155e41ac6 [mlir][Pass] Add a tablegen backend for defining Pass information
This will greatly simplify a number of things related to passes:
* Enables generation of pass registration
* Enables generation of boiler plate pass utilities
* Enables generation of pass documentation

This revision focuses on adding the basic structure and adds support for generating the registration for passes in the Transforms/ directory. Future revisions will add more support and move more passes over.

Differential Revision: https://reviews.llvm.org/D76656
2020-04-01 02:10:46 -07:00
Tres Popp 90b7bbffdd [MLIR] Rename collapsePLoops -> collapseParallelLoops
Summary:
Additionally, NFC code cleanups were done.

This is to address additional comments on
https://reviews.llvm.org/D76363

Differential Revision: https://reviews.llvm.org/D77052
2020-04-01 10:15:13 +02:00
Uday Bondhugula f273e5c507 [MLIR] Fix permuteLoops utility
Rewrite mlir::permuteLoops (affine loop permutation utility) to fix
incorrect approach. Avoiding using sinkLoops entirely - use single move
approach. Add test pass.

This fixes https://bugs.llvm.org/show_bug.cgi?id=45328

Depends on D77003.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D77004
2020-03-30 23:38:23 +05:30
scentini 3b20970de8 Fix unused-variable error when assertions are disabled 2020-03-30 13:55:43 +02:00
Uday Bondhugula 4e4ea2cde4 [MLIR] Add missing asserts in interchangeLoops util, doc comment update
Add missing assert checks for input to mlir::interchangeLoops utility.
Rename interchangeLoops -> permuteLoops; update doc comments to clarify
inputs / return val. Other than the assert checks, this is NFC.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D77003
2020-03-30 00:03:12 +05:30
Uday Bondhugula 43a95a543f [MLIR] Introduce full/partial tile separation using if/else
This patch introduces a utility to separate full tiles from partial
tiles when tiling affine loop nests where trip counts are unknown or
where tile sizes don't divide trip counts. A conditional guard is
generated to separate out the full tile (with constant trip count loops)
into the then block of an 'affine.if' and the partial tile to the else
block. The separation allows the 'then' block (which has constant trip
count loops) to be optimized better subsequently: for eg. for
unroll-and-jam, register tiling, vectorization without leading to
cleanup code, or to offload to accelerators. Among techniques from the
literature, the if/else based separation leads to the most compact
cleanup code for multi-dimensional cases (because a single version is
used to model all partial tiles).

INPUT

  affine.for %i0 = 0 to %M {
    affine.for %i1 = 0 to %N {
      "foo"() : () -> ()
    }
  }

OUTPUT AFTER TILING W/O SEPARATION

  map0 = affine_map<(d0) -> (d0)>
  map1 = affine_map<(d0)[s0] -> (d0 + 32, s0)>

  affine.for %arg2 = 0 to %M step 32 {
    affine.for %arg3 = 0 to %N step 32 {
      affine.for %arg4 = #map0(%arg2) to min #map1(%arg2)[%M] {
        affine.for %arg5 = #map0(%arg3) to min #map1(%arg3)[%N] {
          "foo"() : () -> ()
        }
      }
    }
  }

  OUTPUT AFTER TILING WITH SEPARATION

  map0 = affine_map<(d0) -> (d0)>
  map1 = affine_map<(d0) -> (d0 + 32)>
  map2 = affine_map<(d0)[s0] -> (d0 + 32, s0)>

  #set0 = affine_set<(d0, d1)[s0, s1] : (-d0 + s0 - 32 >= 0, -d1 + s1 - 32 >= 0)>

  affine.for %arg2 = 0 to %M step 32 {
    affine.for %arg3 = 0 to %N step 32 {
      affine.if #set0(%arg2, %arg3)[%M, %N] {
        // Full tile.
        affine.for %arg4 = #map0(%arg2) to #map1(%arg2) {
          affine.for %arg5 = #map0(%arg3) to #map1(%arg3) {
            "foo"() : () -> ()
          }
        }
      } else {
        // Partial tile.
        affine.for %arg4 = #map0(%arg2) to min #map2(%arg2)[%M] {
          affine.for %arg5 = #map0(%arg3) to min #map2(%arg3)[%N] {
            "foo"() : () -> ()
          }
        }
      }
    }
  }

The separation is tested via a cmd line flag on the loop tiling pass.
The utility itself allows one to pass in any band of contiguously nested
loops, and can be used by other transforms/utilities. The current
implementation works for hyperrectangular loop nests.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D76700
2020-03-28 06:58:35 +05:30
Uday Bondhugula ad4b4acbb0 [MLIR][NFC] drop some unnecessary includes
Drop unnecessary includes

Differential Revision: https://reviews.llvm.org/D76898
2020-03-27 09:17:27 +05:30
Tres Popp 27c201aa1d [MLIR] Add parallel loop collapsing.
This allows conversion of a ParallelLoop from N induction variables to
some nuber of induction variables less than N.

The first intended use of this is for the GPUDialect to convert
ParallelLoops to iterate over 3 dimensions so they can be launched as
GPU Kernels.

To implement this:
- Normalize each iteration space of the ParallelLoop
- Use the same induction variable in a new ParallelLoop for multiple
  original iterations.
- Split the new induction variable back into the original set of values
  inside the body of the ParallelLoop.

Subscribers: mgorny, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76363
2020-03-26 09:32:52 +01:00
Uday Bondhugula 98fa615002 [MLIR] move loopUnrollJamBy*Factor to loop transforms utils
The declarations for these were already part of transforms utils, but
the definitions were left in affine transforms. Move definitions to loop
transforms utils.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D76633
2020-03-24 08:08:57 +05:30
MaheshRavishankar 04f2b717d2 [mlir] Fix unsafe create operation in GreedyPatternRewriter
When trying to fold an operation during operation creation check that
the operation folding succeeds before inserting the op.

Differential Revision: https://reviews.llvm.org/D76415
2020-03-23 11:50:40 -07:00
Uday Bondhugula b873761496 [MLIR][NFC] Move some of the affine transforms / tests to dialect dirs
Move some of the affine transforms and their test cases to their
respective dialect directory. This patch does not complete the move, but
takes care of a good part.

Renames: prefix 'affine' to affine loop tiling cl options,
vectorize -> super-vectorize

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D76565
2020-03-23 08:25:07 +05:30
River Riddle e9482ed194 [mlir] Move several static cl::opts to be pass options instead.
This removes the reliance on global options, and also simplifies the pass registration.

Differential Revision: https://reviews.llvm.org/D76552
2020-03-22 03:16:21 -07:00
Rob Suderman e708471395 [mlir][NFC] Cleanup AffineOps directory structure
Summary:
Change AffineOps Dialect structure to better group both IR and Tranforms. This included extracting transforms directly related to AffineOps. Also move AffineOps to Affine.

Differential Revision: https://reviews.llvm.org/D76161
2020-03-20 14:23:43 -07:00
Uday Bondhugula 0ddd04391d [MLIR] Fix op folding to not run pre-replace when not constant folding
OperationFolder::tryToFold was running the pre-replacement
action even when there was no constant folding, i.e., when the operation
was just being updated in place but was not going to be replaced. This
led to nested ops being unnecessarily removed from the worklist and only
being processed in the next outer iteration of the greedy pattern
rewriter, which is also why this didn't affect the final output IR but
only the convergence rate. It also led to an op's results' users to be
unnecessarily added to the worklist.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D76268
2020-03-20 07:49:49 +05:30
Yaxun (Sam) Liu f528df8e26 Revert "Add a test for UsedDeclVisitor"
This reverts commit b58f6bb120.
2020-03-19 00:15:47 -04:00
Yaxun (Sam) Liu b58f6bb120 Add a test for UsedDeclVisitor
This test is reduced from mlir/lib/Transforms/AffineDataCopyGeneration.cpp
to make sure there is no assertion due to UsedDeclVisitor.
2020-03-19 00:05:10 -04:00
River Riddle 4be504a97f [mlir] Add support for detecting single use callables in the Inliner.
Summary: This is somewhat complex(annoying) as it involves directly tracking the uses within each of the callgraph nodes, and updating them as needed during inlining. The benefit of this is that we can have a more exact cost model, enable inlining some otherwise non-inlinable cases, and also ensure that newly dead callables are properly disposed of.

Differential Revision: https://reviews.llvm.org/D75476
2020-03-18 13:10:41 -07:00
River Riddle 34d0d6ba74 [mlir][DialectConversion] Print the operation being legalized if it has no regions
This helps when looking at the debug log and understanding what properties the invalid operation has when legalization fails.
2020-03-17 21:05:58 -07:00
River Riddle 3145427dd7 [mlir][NFC] Replace all usages of PatternMatchResult with LogicalResult
This also replaces usages of matchSuccess/matchFailure with success/failure respectively.

Differential Revision: https://reviews.llvm.org/D76313
2020-03-17 20:21:32 -07:00
Rob Suderman 4d60f47b08 [mlir][NFC] Renamed VectorOps to Vector
Summary: Renamed VectorOps to Vector to avoid the redundant Ops suffix.

Differential Revision: https://reviews.llvm.org/D76317
2020-03-17 15:28:08 -07:00
River Riddle 5267f5e6b4 [mlir] Add a hook to PatternRewriter to allow for patterns to notify why a match failed.
Summary:
This revision adds a new hook, `notifyMatchFailure`, that allows for notifying the rewriter that a match failure is coming with the provided reason. This hook takes as a parameter a callback that fills a `Diagnostic` instance with the reason why the match failed. This allows for the rewriter to decide how this information can be displayed to the end-user, and may completely ignore it if desired(opt mode). For now, DialectConversion is updated to include this information in the debug output.

Differential Revision: https://reviews.llvm.org/D76203
2020-03-17 12:12:21 -07:00
River Riddle bd5941b9ce [mlir] Remove the PatternState class and simplify PatternMatchResult.
Summary: PatternState was a mechanism to pass state between the match and rewrite calls of a RewritePattern. With the rise of matchAndRewrite, this class is unused and unnecessary. This revision removes PatternState and simplifies PatternMatchResult to just be a LogicalResult. A future revision will replace all usages of PatternMatchResult/matchSuccess/matchFailure with LogicalResult equivalents.

Differential Revision: https://reviews.llvm.org/D76202
2020-03-16 17:55:54 -07:00
Uday Bondhugula d811aee5d9 [MLIR][NFC] update/clean up affine PDT, related utils, its test case
- rename vars that had inst suffixes (due to ops earlier being
  known as insts); other renames for better readability
- drop unnecessary matches in test cases
- iterate without block terminator
- comment/doc updates
- instBodySkew -> affineForOpBodySkew

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D76214
2020-03-17 06:12:16 +05:30
River Riddle 43959a2592 [mlir][NFC] Move the LoopLike interface out of Transforms/ and into Interfaces/
Differential Revision: https://reviews.llvm.org/D76155
2020-03-14 13:37:56 -07:00
Uday Bondhugula bf0cc6b328 [mlir][NFC] modernize / clean up some loop transform utils, affine analysis utils
Summary:
- remove stale declarations on flat affine constraints
- avoid allocating small vectors where possible
- clean up code comments, rename some variables

Differential Revision: https://reviews.llvm.org/D76117
2020-03-13 21:16:05 -07:00
Rob Suderman 40f4a9fdaa [mlir][NFC] Removed unnecessary StandardOp includes
Summary: A number of transform import StandardOps despite not being dependent on it. Cleaned it up to better understand what dialects each of these transforms depend on.

Differential Revision: https://reviews.llvm.org/D76112
2020-03-12 18:31:09 -07:00
River Riddle 0ddba0bd59 [mlir][SideEffects] Replace HasNoSideEffect with the memory effect interfaces.
HasNoSideEffect can now be implemented using the MemoryEffectInterface, removing the need to check multiple things for the same information. This also removes an easy foot-gun for users as 'Operation::hasNoSideEffect' would ignore operations that dynamically, or recursively, have no side effects. This also leads to an immediate improvement in some of the existing users, such as DCE, now that they have access to more information.

Differential Revision: https://reviews.llvm.org/D76036
2020-03-12 14:26:15 -07:00
River Riddle 907403f342 [mlir] Add a new `ConstantLike` trait to better identify operations that represent a "constant".
The current mechanism for identifying is a bit hacky and extremely adhoc, i.e. we explicit check 1-result, 0-operand, no side-effect, and always foldable and then assume that this is a constant. Adding a trait adds structure to this, and makes checking for a constant much more efficient as we can guarantee that all of these things have already been verified.

Differential Revision: https://reviews.llvm.org/D76020
2020-03-12 14:26:15 -07:00
River Riddle d5f53253a0 [mlir][SideEffects] Mark the CFG only terminator operations as NoSideEffect
These terminator operations don't really have any side effects, and this allows for more accurate side-effect analysis for region operations. For example, currently we can't detect like a loop.for or affine.for are dead because the affine.terminator is "side effecting".

Note: Marking as NoSideEffect doesn't mean that these operations can be opaquely erased.

Differential Revision: https://reviews.llvm.org/D75888
2020-03-12 14:26:14 -07:00