9 Commits

Author SHA1 Message Date
Mogball
a54f4eae0e [MLIR] Replace std ops with arith dialect ops
Precursor: https://reviews.llvm.org/D110200

Removed redundant ops from the standard dialect that were moved to the
`arith` or `math` dialects.

Renamed all instances of operations in the codebase and in tests.

Reviewed By: rriddle, jpienaar

Differential Revision: https://reviews.llvm.org/D110797
2021-10-13 03:07:03 +00:00
Eugene Zhulenev
d43b23608a [mlir:Async] Add the size parameter to the async.group
Specify the `!async.group` size (the number of tokens that will be added to it) at construction time. `async.await_all` operation can potentially race with `async.execute` operations that keep updating the group, for this reason it is required to know upfront how many tokens will be added to the group.

Reviewed By: ftynse, herhut

Differential Revision: https://reviews.llvm.org/D104780
2021-06-25 10:26:50 -07:00
Eugene Zhulenev
9c53b8e52e [mlir:Async] Add intermediate async.coro and async.runtime operations to simplify Async to LLVM lowering
[NFC] No new functionality, mostly a cleanup and one more abstraction level between Async and LLVM IR.

Instead of lowering from Async to LLVM coroutines and Async Runtime API in one shot, do it progressively via async.coro and async.runtime operations.

1. Lower from async to async.runtime/coro (e.g. async.execute to function with coro setup and runtime calls)
2. Lower from async.runtime/coro to LLVM intrinsics and runtime API calls

Intermediate coro/runtime operations will allow to run transformations on a higher level IR and do not try to match IR based on the LLVM::CallOp properties.

Although async.coro is very close to LLVM coroutines, it is not exactly the same API, instead it is optimized for usability in async lowering, and misses a lot of details that are present in @llvm.coro intrinsic.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D94923
2021-01-25 14:04:33 -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
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
61dce0f308 [mlir] Add async.await operation to async dialect
Add async.await operation to "unwrap" async.values

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D89137
2020-10-12 21:05:36 -07:00
Eugene Zhulenev
4e69a52952 [MLIR] Add async token/value arguments to async.execute op
Async execute operation can take async arguments as dependencies.

Change `async.execute` custom parser/printer format to use `%value as %unwrapped: !async.value<!type>` sytax.

Reviewed By: mehdi_amini, herhut

Differential Revision: https://reviews.llvm.org/D88601
2020-10-09 08:52:27 -07:00
Eugene Zhulenev
655af658c9 [MLIR] Add async.value type to Async dialect
Return values from async regions as !async.value<...>.

Reviewed By: mehdi_amini, csigg

Differential Revision: https://reviews.llvm.org/D88510
2020-09-30 11:30:06 -07:00
Eugene Zhulenev
05a3b4fe30 [MLIR] Add Async dialect with trivial async.region operation
Start Async dialect for modeling asynchronous execution.

Reviewed By: mehdi_amini, herhut

Differential Revision: https://reviews.llvm.org/D88459
2020-09-29 11:11:08 -07:00