Commit Graph

8 Commits

Author SHA1 Message Date
Eugene Zhulenev 25f80e16d1 [mlir] Async: add a separate pass to lower from async to async.coro and async.runtime
Depends On D95000

Move async.execute outlining and async -> async.runtime lowering into the separate Async transformation pass

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D95311
2021-01-26 03:33:20 -08:00
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
Kazuaki Ishizaki f88fab5006 [mlir] NFC: fix trivial typos
fix typo under include and lib directories

Reviewed By: antiagainst

Differential Revision: https://reviews.llvm.org/D94220
2021-01-08 02:10:12 +09:00
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
Eugene Zhulenev 94e645f9cc [mlir] Async: Add numWorkerThreads argument to createAsyncParallelForPass
Add an option to pass the number of worker threads to select the number of async regions for parallel for transformation.
```
std::unique_ptr<OperationPass<FuncOp>> createAsyncParallelForPass(int numWorkerThreads);
```

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D92835
2020-12-08 10:30:14 -08:00
Christian Sigg c4a0405902 Add `Operation* OpState::operator->()` to provide more convenient access to members of Operation.
Given that OpState already implicit converts to Operator*, this seems reasonable.

The alternative would be to add more functions to OpState which forward to Operation.

Reviewed By: rriddle, ftynse

Differential Revision: https://reviews.llvm.org/D92266
2020-12-02 15:46:20 +01:00
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