51 Commits

Author SHA1 Message Date
Kazu Hirata
921d162460
[mlir] Remove unused local variables (NFC) (#138642) 2025-05-06 07:55:50 -07:00
Nachi G
2f7e685e3d
[MLIR] Ensure deterministic parallel verification (#134963)
`failableParallelForEach` will non-deterministically early terminate
upon failure, leading to inconsistent and potentially missing
diagnostics.

This PR uses `parallelForEach` to ensure all operations are verified and
all diagnostics are handled, while tracking the failure state
separately.

Other potential fixes include:
- Making `failableParallelForEach` have deterministic early-exit
behavior (or have an option for it)
- I didn't want to change more than what was required (and potentially
incur perf hits for unrelated code), but if this is a better fix I'm
happy to submit a patch.
- I think all diagnostics that can be detected from verification
failures should be reported, so I don't even think this would be correct
behavior anyway

- Adding an option for `failableParallelForEach` to still execute on
every element on the range while still returning `LogicalResult`
2025-04-09 15:43:26 -07:00
AdityaK
fb0cd9899d
NFC: Remove unused includes (#133474) 2025-03-28 17:29:56 -07:00
Kazu Hirata
fcb1591b46
[IR] Migrate away from PointerUnion::{is,get} (NFC) (#119802)
Note that PointerUnion::{is,get} have been soft deprecated in
PointerUnion.h:

  // FIXME: Replace the uses of is(), get() and dyn_cast() with
  //        isa<T>, cast<T> and the llvm::dyn_cast<T>

I'm not touching PointerUnion::dyn_cast for now because it's a bit
complicated; we could blindly migrate it to dyn_cast_if_present, but
we should probably use dyn_cast when the operand is known to be
non-null.
2024-12-13 08:00:45 -08:00
Will Dietz
7a98071da2
[mlir] Verifier: steal bit to track seen instead of set. (#102626)
Tracking a set containing every block and operation visited can become
very expensive and is unnecessary.

Co-authored-by: Will Dietz <w@wdtz.org>
2024-08-09 10:50:25 -05:00
Benjamin Kramer
ae4f2495a4 [IR] Verifier: Use a SmallPtrSet for a small set of pointers. NFC 2024-07-27 13:55:04 +02:00
Hideto Ueno
892abd34d2
[mlir][IR] Make verifyDominanceOfContainedRegions iterative (#74428)
This commit refactors `verifyDominanceOfContainedRegions` to iterative
algorithms similar to https://reviews.llvm.org/D154925 to fix stack
overflow for deeply nested regions (e.g.
https://github.com/llvm/circt/issues/5316). There should be no
functional change except that this could result in slightly different
order of verification.
2023-12-05 18:06:28 +09:00
Alexander Shaposhnikov
7689179ac9 [MLIR][IR] Rewrite OperationVerifier using worklist
This diff switches OperationVerifier to using a worklist
rather than recursion. The exception is our handling of isolated regions,
it can still contain recursive calls, however, the parallel processing
of these regions is preserved. This fixes the crash of the "verifier"
on the input from https://github.com/llvm/circt/issues/5316
(but the IR printer would still crash with stack overflow).

Test plan: ninja check-mlir check-all

Differential revision: https://reviews.llvm.org/D154925
2023-07-12 09:05:31 +00:00
Mehdi Amini
bbe5bf1788 Cleanup uses of getAttrDictionary() in MLIR to use getDiscardableAttrDictionary() when possible
This also speeds up some benchmarks in compiling simple fortan file by 2x!
Fixes #62687

Differential Revision: https://reviews.llvm.org/D150540
2023-05-15 11:35:50 -07:00
Tres Popp
c1fa60b4cd [mlir] Update method cast calls to function calls
The MLIR classes Type/Attribute/Operation/Op/Value support
cast/dyn_cast/isa/dyn_cast_or_null functionality through llvm's doCast
functionality in addition to defining methods with the same name.
This change begins the migration of uses of the method to the
corresponding function call as has been decided as more consistent.

Note that there still exist classes that only define methods directly,
such as AffineExpr, and this does not include work currently to support
a functional cast/isa call.

Context:

* https://mlir.llvm.org/deprecation/ at "Use the free function variants for dyn_cast/cast/isa/…"
* Original discussion at https://discourse.llvm.org/t/preferred-casting-style-going-forward/68443

Implementation:
This follows a previous patch that updated calls
`op.cast<T>()-> cast<T>(op)`. However some cases could not handle an
unprefixed `cast` call due to occurrences of variables named cast, or
occurring inside of class definitions which would resolve to the method.
All C++ files that did not work automatically with `cast<T>()` are
updated here to `llvm::cast` and similar with the intention that they
can be easily updated after the methods are removed through a
find-replace.

See https://github.com/llvm/llvm-project/compare/main...tpopp:llvm-project:tidy-cast-check
for the clang-tidy check that is used and then update printed
occurrences of the function to include `llvm::` before.

One can then run the following:
```
ninja -C $BUILD_DIR clang-tidy

run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
                 -export-fixes /tmp/cast/casts.yaml mlir/*\
                 -header-filter=mlir/ -fix

rm -rf $BUILD_DIR/tools/mlir/**/*.inc
```

Differential Revision: https://reviews.llvm.org/D150348
2023-05-12 11:21:30 +02:00
Kazu Hirata
0a81ace004 [mlir] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 01:25:58 -08:00
Kazu Hirata
a1fe1f5f77 [mlir] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-13 21:05:06 -08:00
Chia-hung Duan
5232c5c5d4 [mlir] Fix verification order of nested ops.
In order to increase parallism, certain ops with regions and have the
IsIsolatedFromAbove trait will have their verification delayed. That
means the region verifier may access the invalid ops and may lead to a
crash.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D122771
2022-04-15 04:41:10 +00:00
River Riddle
50f82e6847 [mlir] Fix missing verification after running an OpToOpAdaptorPass
The current decision of when to run the verifier is running on the
assumption that nested passes can't affect the validity of the parent
operation, which isn't true. Parent operations may attach any number
of constraints on nested operations, which may not necessarily be
captured (or shouldn't be captured) at a smaller granularity.

This commit rectifies this by properly running the verifier after an
OpToOpAdaptor pass. To avoid an explosive increase in compile time,
we only run verification on the parent operation itself. To do this, a
flag to mlir::verify is added to avoid recursive verification if it isn't
desired.

Fixes #54288

Differential Revision: https://reviews.llvm.org/D121836
2022-03-16 14:53:41 -07:00
Chia-hung Duan
9445b39673 [mlir] Support verification order (2/3)
This change gives explicit order of verifier execution and adds
    `hasRegionVerifier` and `verifyWithRegions` to increase the granularity
    of verifier classification. The orders are as below,

    1. InternalOpTrait will be verified first, they can be run independently.
    2. `verifyInvariants` which is constructed by ODS, it verifies the type,
       attributes, .etc.
    3. Other Traits/Interfaces that have marked their verifier as
       `verifyTrait` or `verifyWithRegions=0`.
    4. Custom verifier which is defined in the op and has marked
       `hasVerifier=1`

    If an operation has regions, then it may have the second phase,

    5. Traits/Interfaces that have marked their verifier as
       `verifyRegionTrait` or
       `verifyWithRegions=1`. This implies the verifier needs to access the
       operations in its regions.
    6. Custom verifier which is defined in the op and has marked
       `hasRegionVerifier=1`

    Note that the second phase will be run after the operations in the
    region are verified. Based on the verification order, you will be able to
    avoid verifying duplicate things.

Reviewed By: Mogball

Differential Revision: https://reviews.llvm.org/D116789
2022-02-25 19:04:56 +00:00
Mehdi Amini
e4853be2f1 Apply clang-tidy fixes for performance-for-range-copy to MLIR (NFC) 2022-01-02 22:19:56 +00:00
Mehdi Amini
be0a7e9f27 Adjust "end namespace" comment in MLIR to match new agree'd coding style
See D115115 and this mailing list discussion:
https://lists.llvm.org/pipermail/llvm-dev/2021-December/154199.html

Differential Revision: https://reviews.llvm.org/D115309
2021-12-08 06:05:26 +00:00
River Riddle
0c7890c844 [mlir] Convert NamedAttribute to be a class
NamedAttribute is currently represented as an std::pair, but this
creates an extremely clunky .first/.second API. This commit
converts it to a class, with better accessors (getName/getValue)
and also opens the door for more convenient API in the future.

Differential Revision: https://reviews.llvm.org/D113956
2021-11-18 05:39:29 +00:00
River Riddle
edc6c0ecb9 [mlir] Refactor AbstractOperation and OperationName
The current implementation is quite clunky; OperationName stores either an Identifier
or an AbstractOperation that corresponds to an operation. This has several problems:

* OperationNames created before and after an operation are registered are different
* Accessing the identifier name/dialect/etc. from an OperationName are overly branchy
  - they need to dyn_cast a PointerUnion to check the state

This commit refactors this such that we create a single information struct for every
operation name, even operations that aren't registered yet. When an OperationName is
created for an unregistered operation, we only populate the name field. When the
operation is registered, we populate the remaining fields. With this we now have two
new classes: OperationName and RegisteredOperationName. These both point to the
same underlying operation information struct, but only RegisteredOperationName can
assume that the operation is actually registered. This leads to a much cleaner API, and
we can also move some AbstractOperation functionality directly to OperationName.

Differential Revision: https://reviews.llvm.org/D114049
2021-11-17 22:29:57 +00:00
River Riddle
120591e126 [mlir] Replace usages of Identifier with StringAttr
Identifier and StringAttr essentially serve the same purpose, i.e. to hold a string value. Keeping these seemingly identical pieces of functionality separate has caused problems in certain situations:

* Identifier has nice accessors that StringAttr doesn't
* Identifier can't be used as an Attribute, meaning strings are often duplicated between Identifier/StringAttr (e.g. in PDL)

The only thing that Identifier has that StringAttr doesn't is support for caching a dialect that is referenced by the string (e.g. dialect.foo). This functionality is added to StringAttr, as this is useful for StringAttr in generally the same ways it was useful for Identifier.

Differential Revision: https://reviews.llvm.org/D113536
2021-11-11 02:02:24 +00:00
Mehdi Amini
1a406cd5f2 Remove unused llvm/Support/Parallel.h from MLIR (NFC)
This header aren't needed anymore: MLIR is using a thread pool
injected in the context instead of a global one.
2021-09-14 23:30:42 +00:00
Mehdi Amini
0f9e6451a8 Defend early against operation created without a registered dialect
Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D105961
2021-07-15 03:52:32 +00:00
Mehdi Amini
3e25ea709c Revert "Defend early against operation created without a registered dialect"
This reverts commit 58018858e887320e2432e2e00ace13273b8a1f29.

The Python bindings test are broken.
2021-07-15 03:31:44 +00:00
Mehdi Amini
58018858e8 Defend early against operation created without a registered dialect
Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D105961
2021-07-15 03:02:52 +00:00
River Riddle
6569cf2a44 [mlir] Add a ThreadPool to MLIRContext and refactor MLIR threading usage
This revision refactors the usage of multithreaded utilities in MLIR to use a common
thread pool within the MLIR context, in addition to a new utility that makes writing
multi-threaded code in MLIR less error prone. Using a unified thread pool brings about
several advantages:

* Better thread usage and more control
We currently use the static llvm threading utilities, which do not allow multiple
levels of asynchronous scheduling (even if there are open threads). This is due to
how the current TaskGroup structure works, which only allows one truly multithreaded
instance at a time. By having our own ThreadPool we gain more control and flexibility
over our job/thread scheduling, and in a followup can enable threading more parts of
the compiler.

* The static nature of TaskGroup causes issues in certain configurations
Due to the static nature of TaskGroup, there have been quite a few problems related to
destruction that have caused several downstream projects to disable threading. See
D104207 for discussion on some related fallout. By having a ThreadPool scoped to
the context, we don't have to worry about destruction and can ensure that any
additional MLIR thread usage ends when the context is destroyed.

Differential Revision: https://reviews.llvm.org/D104516
2021-06-23 01:29:24 +00:00
Stella Laurenzo
4b9d28bd53 Partial rollback: Disable MLIR verifier parallelism.
Deadlocks have been found in several downstream projects as noted on the original patch: https://reviews.llvm.org/D104207

Disabling pending full root cause analysis.

Differential Revision: https://reviews.llvm.org/D104570
2021-06-18 21:58:03 +00:00
Chris Lattner
ce77039596 [Verifier] Parallelize verification and dom checking. NFC.
This changes the outer verification loop to not recurse into
IsolatedFromAbove operations - instead return them up to a place
where a parallel for loop can process them all in parallel.  This
also changes Dominance checking to happen on IsolatedFromAbove
chunks of the region tree, which makes it easy to fold operation
and dominance verification into a single simple parallel regime.

This speeds up firtool in CIRCT from ~40s to 31s on a large
testcase in -verify-each mode (the default).  The .fir parser and
module passes in particular benefit from this - FModule passes
(roughly analogous to function passes) were already running the
verifier in parallel as part of the pass manager.  This allows
the whole-module passes to verify their enclosed functions /
FModules in parallel.

-verify-each mode is still faster (26.3s on the same testcase),
but we do expect the verifier to take *some* time.

Differential Revision: https://reviews.llvm.org/D104207
2021-06-14 10:03:07 -07:00
Chris Lattner
4fa8677860 [DominanceInfo] Make the ctor take a defaulted value for the operand. NFC.
This allows it to be default constructible, which makes sense given it
ignores the operand.
2021-06-13 18:25:47 -07:00
Alexander Kornienko
ad6a84f82c Revert "[Verifier] Speed up and parallelize dominance checking. NFC"
This reverts commit 08664d005c02003180371049b19c7e5d01541c58, which according to
https://reviews.llvm.org/D103373 was pushed accidentally, and I believe it
causes timeouts in some internal mlir tests.
2021-06-10 09:58:05 +02:00
Mehdi Amini
30bb5dcb0a Add missing header <atomic> in lib/IR/Verifier.cpp (NFC)
Fix the build on some platform.
2021-06-08 17:08:55 +00:00
Chris Lattner
08664d005c [Verifier] Speed up and parallelize dominance checking. NFC
One of the key algorithms used in the "mlir::verify(op)" method is the
dominance checker, which ensures that operand values properly dominate
the operations that use them.

The MLIR dominance implementation has a number of algorithmic problems,
and is not really set up in general to answer dense queries: it's constant
factors are really slow with multiple map lookups and scans, even in the
easy cases.  Furthermore, when calling mlir::verify(module) or some other
high level operation, it makes sense to parallelize the dominator
verification of all the functions within the module.

This patch has a few changes to enact this:
 1) It splits dominance checking into "IsolatedFromAbove" units.  Instead
    of building a monolithic DominanceInfo for everything in a module,
    for example, it checks dominance for the module to all the functions
    within it (noop, since there are no operands at this level) then each
    function gets their own DominanceInfo for each of their scope.
 2) It adds the ability for mlir::DominanceInfo (and post dom) to be
    constrained to an IsolatedFromAbove region.  There is no reason to
    recurse into IsolatedFromAbove regions since use/def relationships
    can't span this region anyway.  This is already checked by the time
    the verifier gets here.
 3) It avoids querying DominanceInfo for trivial checks (e.g. intra Block
    references) to eliminate constant factor issues).
 4) It switches to lazily constructing DominanceInfo because the trivial
    check case handles the vast majority of the cases and avoids
    constructing DominanceInfo entirely in some cases (e.g. at the module
    level or for many Regions's that contain a single Block).
 5) It parallelizes analysis of collections IsolatedFromAbove operations,
    e.g. each of the functions within a Module.

All together this is more than a 10% speedup on `firtool` in circt on a
large design when run in -verify-each mode (our default) since the verifier
is invoked after each pass.

Still todo is to parallelize the main verifier pass.  I decided to split
this out to its own thing since this patch is already large-ish.

Differential Revision: https://reviews.llvm.org/D103373
2021-06-08 09:47:07 -07:00
Chris Lattner
d11abdfd5a [Verifier] Inline a method to simplify the code in preparation for bigger changes, NFC.
Differential Revision: https://reviews.llvm.org/D103365
2021-05-29 10:33:27 -07:00
Chris Lattner
be8ad4e98e [Verifier] Slightly refactor code to reduce duplication, NFC. 2021-05-01 11:43:15 -07:00
Chris Lattner
f0c22c3d58 [Verifier] Tidy up the code a bit, NFC.
This tidies up the code a bit:
 * Eliminate the ctx member, which doesn't need to be stored.
 * Rename verify(Operation) to make it more clear that it is
   doing more than verifyOperation and that the dominance check
   isn't being done multiple times.
 * Rename mayNotHaveTerminator which was confusing about whether
   it wasn't known whether it had a terminator, when it is really
   about whether it is legal to have a terminator.
 * Some minor optimizations: don't check for RegionKindInterface
   if there are no regions.  Don't do two passes over the
   operations in a block in OperationVerifier::verifyDominance when
   one will do.

The optimizations are actually a measurable (but minor) win in some
CIRCT cases.

Differential Revision: https://reviews.llvm.org/D101267
2021-04-26 11:54:02 -07:00
Mehdi Amini
973ddb7d6e Define a NoTerminator traits that allows operations with a single block region to not provide a terminator
In particular for Graph Regions, the terminator needs is just a
historical artifact of the generalization of MLIR from CFG region.
Operations like Module don't need a terminator, and before Module
migrated to be an operation with region there wasn't any needed.

To validate the feature, the ModuleOp is migrated to use this trait and
the ModuleTerminator operation is deleted.

This patch is likely to break clients, if you're in this case:

- you may iterate on a ModuleOp with `getBody()->without_terminator()`,
  the solution is simple: just remove the ->without_terminator!
- you created a builder with `Builder::atBlockTerminator(module_body)`,
  just use `Builder::atBlockEnd(module_body)` instead.
- you were handling ModuleTerminator: it isn't needed anymore.
- for generic code, a `Block::mayNotHaveTerminator()` may be used.

Differential Revision: https://reviews.llvm.org/D98468
2021-03-25 03:59:03 +00:00
River Riddle
e6260ad043 [mlir] Simplify various pieces of code now that Identifier has access to the Context/Dialect
This also exposed a bug in Dialect loading where it was not correctly identifying identifiers that had the dialect namespace as a prefix.

Differential Revision: https://reviews.llvm.org/D97431
2021-02-26 18:00:05 -08:00
River Riddle
fe7c0d90b2 [mlir][IR] Remove the concept of OperationProperties
These properties were useful for a few things before traits had a better integration story, but don't really carry their weight well these days. Most of these properties are already checked via traits in most of the code. It is better to align the system around traits, and improve the performance/cost of traits in general.

Differential Revision: https://reviews.llvm.org/D96088
2021-02-09 12:00:15 -08:00
Mehdi Amini
c21ee1a942 Improve the verifier diagnostic on dominance error
Address PR47937

Differential Revision: https://reviews.llvm.org/D93361
2020-12-16 22:05:17 +00:00
Rahul Joshi
c96168975b [MLIR] Flag no-terminator error on the last operation of non-empty blocks
- When a block is not empty and does not end with a terminator, flag the error on the
  last operation of the block instead of the start of the block.

Differential Revision: https://reviews.llvm.org/D90988
2020-11-09 09:42:11 -08:00
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 d14cf45735b0d09d7d3caf0824779520dd20ef10.
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 e1de2b75501e5eaf8777bd5248382a7c55a44fd6.
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 20563933875a9396c8ace9c9770ecf6a988c4ea6.

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
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
Stephen Neuendorffer
9de4ee3815 [MLIR] Allow unreachable blocks to violate dominance property.
It is possible for optimizations to create SSA code which violates
the dominance property in unreachable blocks.  Equivalently, dominance
computed using normal mechanisms is undefined in unreachable blocks.

See discussion here: https://llvm.discourse.group/t/rfc-allowing-dialects-to-relax-the-ssa-dominance-condition/833/51

This patch only checks the dominance condition inside blocks which are
reachable from the the entry block of their region.  Note that the
dominance conditions of regions contained in an unreachable block are
still checked.

Differential Revision: https://reviews.llvm.org/D79922
2020-05-15 10:31:57 -07:00