68 Commits

Author SHA1 Message Date
Eugene Zhulenev
621ad468d9 [mlir] Async: lowering async.value to LLVM
1. Add new methods to Async runtime API to support yielding async values
2. Add lowering from `async.yield` with value payload to the new runtime API calls

`async.value` lowering requires that payload type is convertible to LLVM and supported by `llvm.mlir.cast` (DialectCast) operation.

Reviewed By: csigg

Differential Revision: https://reviews.llvm.org/D93592
2020-12-25 02:23:48 -08:00
Alex Zinenko
7ed9cfc7b1 [mlir] Remove static constructors from LLVMType
LLVMType contains numerous static constructors that were initially introduced
for API compatibility with LLVM. Most of these merely forward to arguments to
`SpecificType::get` (MLIR defines classes for all types, unlike LLVM IR), while
some introduce subtle semantics differences due to different modeling of MLIR
types (e.g., structs are not auto-renamed in case of conflicts). Furthermore,
these constructors don't match MLIR idioms and actively prevent us from making
the LLVM dialect type system more open. Remove them and use `SpecificType::get`
instead.

Depends On D93680

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D93681
2020-12-23 13:12:47 +01:00
Chris Lattner
75a3f326c3 [IR] Add an ImplicitLocOpBuilder helper class for building IR with the same loc.
One common situation is to create a lot of IR at a well known location,
e.g. when doing a big rewrite from one dialect to another where you're expanding
ops out into lots of other ops.

For these sorts of situations, it is annoying to pass the location into
every create call.  As we discused in a few threads on the forum, a way to help
with this is to produce a new sort of builder that holds a location and provides
it to each of the create<> calls automatically.

This patch implements an ImplicitLocOpBuilder class that does this.  We've had
good experience with this in the CIRCT project, and it makes sense to upstream to
MLIR.

I picked a random pass to adopt it to show the impact, but I don't think there is
any particular need to force adopt it in the codebase.

Differential Revision: https://reviews.llvm.org/D93717
2020-12-22 14:47:33 -08:00
Alex Zinenko
8de43b926f [mlir] Remove instance methods from LLVMType
LLVMType contains multiple instance methods that were introduced initially for
compatibility with LLVM API. These methods boil down to `cast` followed by
type-specific call. Arguably, they are mostly used in an LLVM cast-follows-isa
anti-pattern. This doesn't connect nicely to the rest of the MLIR
infrastructure and actively prevents it from making the LLVM dialect type
system more open, e.g., reusing built-in types when appropriate. Remove such
instance methods and replaces their uses with apporpriate casts and methods on
derived classes. In some cases, the result may look slightly more verbose, but
most cases should actually use a stricter subtype of LLVMType anyway and avoid
the isa/cast.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D93680
2020-12-22 23:34:54 +01:00
River Riddle
1b97cdf885 [mlir][IR][NFC] Move context/location parameters of builtin Type::get methods to the start of the parameter list
This better matches the rest of the infrastructure, is much simpler, and makes it easier to move these types to being declaratively specified.

Differential Revision: https://reviews.llvm.org/D93432
2020-12-17 13:01:36 -08:00
Christian Sigg
0bf4a82a5a [mlir] Use mlir::OpState::operator->() to get to methods of mlir::Operation. This is a preparation step to remove the corresponding methods from OpState.
Reviewed By: silvas, rriddle

Differential Revision: https://reviews.llvm.org/D92878
2020-12-09 12:11:32 +01:00
Tres Popp
111ae220a3 [mlir] Use rewriting infrastructure in AsyncToLLVM
This is needed so a listener hears all changes during the dialect
conversion to allow correct rollbacks upon failure.

Differential Revision: https://reviews.llvm.org/D92685
2020-12-08 17:30:01 +01:00
Eugene Zhulenev
13ab072b25 [mlir] AsynToLLVM: do no use op->getOperands() in conversion patterns
Differential Revision: https://reviews.llvm.org/D91910
2020-11-21 04:57:26 -08:00
Eugene Zhulenev
a86a9b5ef7 [mlir] Automatic reference counting for Async values + runtime support for ref counted objects
Depends On D89963

**Automatic reference counting algorithm outline:**

1. `ReturnLike` operations forward the reference counted values without
    modifying the reference count.
2. Use liveness analysis to find blocks in the CFG where the lifetime of
   reference counted values ends, and insert `drop_ref` operations after
   the last use of the value.
3. Insert `add_ref` before the `async.execute` operation capturing the
   value, and pairing `drop_ref` before the async body region terminator,
   to release the captured reference counted value when execution
   completes.
4. If the reference counted value is passed only to some of the block
   successors, insert `drop_ref` operations in the beginning of the blocks
   that do not have reference coutned value uses.

Reviewed By: silvas

Differential Revision: https://reviews.llvm.org/D90716
2020-11-20 03:08:44 -08:00
Alex Zinenko
9bb5bff570 [mlir] Add an assertion on creating an Operation with null result types
Null types are commonly used as an error marker. Catch them in the constructor
of Operation if they are present in the result type list, as otherwise this
could lead to further surprising behavior when querying op result types.

Fix AsyncToLLVM and StandardToLLVM that were using null types when constructing
operations.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D91770
2020-11-19 22:28:38 +01:00
Rahul Joshi
b7382ed3fe [MLIR] Extend Symbol verification to reject public symbol declarations.
- Extend the Symbol interface with `isDeclaration` to identify operations that declare
  a symbol as opposed to define it.
- Extend verification to disallow public declarations as per the discussion in
   https://llvm.discourse.group/t/rfc-symbol-definition-declaration-x-visibility-checks/2140
- Adopt the new interface for `FuncOp` and fix test and code to not have/create public
  function declarations.

Differential Revision: https://reviews.llvm.org/D91456
2020-11-16 16:05:32 -08:00
Rahul Joshi
d843755220 [NFC] Refactor function declaration addition in AsyncToLLVM
- Extract repeated code into helper function/lambdas.

Differential Revision: https://reviews.llvm.org/D91453
2020-11-13 12:53:19 -08:00
Eugene Zhulenev
c30ab6c2a3 [mlir] Transform scf.parallel to scf.for + async.execute
Depends On D89958

1. Adds `async.group`/`async.awaitall` to group together multiple async tokens/values
2. Rewrite scf.parallel operation into multiple concurrent async.execute operations over non overlapping subranges of the original loop.

Example:

```
   scf.for (%i, %j) = (%lbi, %lbj) to (%ubi, %ubj) step (%si, %sj) {
     "do_some_compute"(%i, %j): () -> ()
   }
```

Converted to:

```
   %c0 = constant 0 : index
   %c1 = constant 1 : index

   // Compute blocks sizes for each induction variable.
   %num_blocks_i = ... : index
   %num_blocks_j = ... : index
   %block_size_i = ... : index
   %block_size_j = ... : index

   // Create an async group to track async execute ops.
   %group = async.create_group

   scf.for %bi = %c0 to %num_blocks_i step %c1 {
     %block_start_i = ... : index
     %block_end_i   = ... : index

     scf.for %bj = %c0 t0 %num_blocks_j step %c1 {
       %block_start_j = ... : index
       %block_end_j   = ... : index

       // Execute the body of original parallel operation for the current
       // block.
       %token = async.execute {
         scf.for %i = %block_start_i to %block_end_i step %si {
           scf.for %j = %block_start_j to %block_end_j step %sj {
             "do_some_compute"(%i, %j): () -> ()
           }
         }
       }

       // Add produced async token to the group.
       async.add_to_group %token, %group
     }
   }

   // Await completion of all async.execute operations.
   async.await_all %group
```
In this example outer loop launches inner block level loops as separate async
execute operations which will be executed concurrently.

At the end it waits for the completiom of all async execute operations.

Reviewed By: ftynse, mehdi_amini

Differential Revision: https://reviews.llvm.org/D89963
2020-11-13 04:02:56 -08:00
Eugene Zhulenev
f507aa17b7 [mlir] Implement lowering to LLVM of async.execute ops with token dependencies
Add support for lowering `async.execute` operations with token dependencies

Example:

```
%dep = ... : !async.token
%token = async.execute[%dep] {
...
}
```

Token dependencies lowered to `async.await` operations inside the outline coroutine body.

Reviewed By: herhut, mehdi_amini, ftynse

Differential Revision: https://reviews.llvm.org/D89958
2020-10-30 05:59:03 -07:00
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
Lei Zhang
36ce915ac5 Revert "Revert "[mlir] Convert from Async dialect to LLVM coroutines""
This reverts commit 4986d5eaff359081a867def1c6a2e1147dbb2ad6 with
proper patches to CMakeLists.txt:

- Add MLIRAsync as a dependency to MLIRAsyncToLLVM
- Add Coroutines as a dependency to MLIRExecutionEngine
2020-10-22 15:23:11 -04:00
Mehdi Amini
4986d5eaff Revert "[mlir] Convert from Async dialect to LLVM coroutines"
This reverts commit a8b0ae3bddee311cbc97801089a95702f32773f8
and commit f8fcff5a9d7ee948add3f28382d4ced5710edaaf.

The build with SHARED_LIBRARY=ON is broken.
2020-10-22 19:12:19 +00:00
Eugene Zhulenev
f8fcff5a9d [mlir] Convert from Async dialect to LLVM coroutines
Lower from Async dialect to LLVM by converting async regions attached to `async.execute` operations into LLVM coroutines (https://llvm.org/docs/Coroutines.html):
1. Outline all async regions to functions
2. Add LLVM coro intrinsics to mark coroutine begin/end
3. Use MLIR conversion framework to convert all remaining async types and ops to LLVM + Async runtime function calls

All `async.await` operations inside async regions converted to coroutine suspension points. Await operation outside of a coroutine converted to the blocking wait operations.

Implement simple runtime to support concurrent execution of coroutines.

Reviewed By: herhut

Differential Revision: https://reviews.llvm.org/D89292
2020-10-22 06:30:46 -07:00