concrete/docs/explanations/RTDialect.md

'RT' Dialect

Runtime dialect A dialect for representation the abstraction needed for the runtime.

Operation definition

RT.await_future (::mlir::concretelang::RT::AwaitFutureOp)

Wait for a future and access its data.

The results of a dataflow task are always futures which could be further used as inputs to subsequent tasks. When the result of a task is needed in the outer execution context, the result future needs to be synchronized and its data accessed using RT.await_future.

Operands:

Operand	Description
input	Future with a parameterized element type

Results:

Result	Description
output	any type

RT.build_return_ptr_placeholder (::mlir::concretelang::RT::BuildReturnPtrPlaceholderOp)

Results:

Result	Description
output	Pointer to a parameterized element type

RT.clone_future (::mlir::concretelang::RT::CloneFutureOp)

Interfaces: AllocationOpInterface, MemoryEffectOpInterface

Operands:

Operand	Description
input	Future with a parameterized element type

Results:

Result	Description
output	Future with a parameterized element type

RT.create_async_task (::mlir::concretelang::RT::CreateAsyncTaskOp)

Create a dataflow task.

Attributes:

Attribute	MLIR Type	Description
workfn	::mlir::SymbolRefAttr	symbol reference attribute

Operands:

Operand	Description
list	any type

RT.dataflow_task (::mlir::concretelang::RT::DataflowTaskOp)

Dataflow task operation

RT.dataflow_task allows to specify a task that will be concurrently executed when their operands are ready. Operands are either the results of computation in other RT.dataflow_task (dataflow dependences) or obtained from the execution context (immediate operands). Operands are synchronized using futures and, in the case of immediate operands, copied when the task is created. Caution is required when the operand is a pointer as no deep copy will occur.

Example:

func @test(%0 : i64): (i64, i64) {
    // Execute right now as %0 is ready.
    %1, %2 = "RT.dataflow_task"(%0) ({
        %a = addi %0, %0 : i64
        %b = muli %0, %0 : i64
        "RT.dataflow_yield"(%a, %b) : (i64, i64) -> i64
    }) : (i64, i64) -> (i64, i64)
    // Concurrently execute both tasks below when the task above is completed.
    %3 = "RT.dataflow_task"(%1) ({
        %c = constant 1 : %i64
        %a = addi %1, %c : i64
        "RT.dataflow_yield"(%a) : (i64, i64) -> i64
    }) : (i64, i64) -> (i64, i64)
    %4 = "RT.dataflow_task"(%2) ({
        %c = constant 2 : %i64
        %a = addi %2, %c : i64
        "RT.dataflow_yield"(%a) : (i64, i64) -> i64
    }) : (i64, i64) -> (i64, i64)
    return %3, %4 : (i64, i64)
}

Traits: AutomaticAllocationScope, SingleBlockImplicitTerminator

Interfaces: AllocationOpInterface, MemoryEffectOpInterface, RegionBranchOpInterface

Operands:

Operand	Description
inputs	any type

Results:

Result	Description
outputs	any type

RT.dataflow_yield (::mlir::concretelang::RT::DataflowYieldOp)

Dataflow yield operation

RT.dataflow_yield is a special terminator operation for blocks inside the region in RT.dataflow_task. It allows to specify the return values of a RT.dataflow_task.

Example:

%0 = constant 1 : i64
%1 = constant 2 : i64
"RT.dataflow_yield" %0, %1 : i64, i64

Traits: ReturnLike, Terminator

Operands:

Operand	Description
values	any type

RT.deallocate_future_data (::mlir::concretelang::RT::DeallocateFutureDataOp)

Operands:

Operand	Description
input	Future with a parameterized element type

RT.deallocate_future (::mlir::concretelang::RT::DeallocateFutureOp)

Operands:

Operand	Description
input	any type

RT.deref_return_ptr_placeholder (::mlir::concretelang::RT::DerefReturnPtrPlaceholderOp)

Operands:

Operand	Description
input	Pointer to a parameterized element type

Results:

Result	Description
output	Future with a parameterized element type

RT.deref_work_function_argument_ptr_placeholder (::mlir::concretelang::RT::DerefWorkFunctionArgumentPtrPlaceholderOp)

Operands:

Operand	Description
input	Pointer to a parameterized element type

Results:

Result	Description
output	any type

RT.make_ready_future (::mlir::concretelang::RT::MakeReadyFutureOp)

Build a ready future.

Data passed to dataflow tasks must be encapsulated in futures, including immediate operands. These must be converted into futures using RT.make_ready_future.

Interfaces: AllocationOpInterface, MemoryEffectOpInterface

Operands:

Operand	Description
input	any type
memrefCloned	any type

Results:

Result	Description
output	Future with a parameterized element type

RT.register_task_work_function (::mlir::concretelang::RT::RegisterTaskWorkFunctionOp)

Register the task work-function with the runtime system.

Operands:

Operand	Description
list	any type

RT.work_function_return (::mlir::concretelang::RT::WorkFunctionReturnOp)

Operands:

Operand	Description
in	any type
out	any type

Type definition

FutureType

Future with a parameterized element type

The value of a !RT.future type represents the result of an asynchronous operation.

Examples:

!RT.future<i64>

Parameters:

Parameter	C++ type	Description
elementType	Type

PointerType

Pointer to a parameterized element type

Parameters:

Parameter	C++ type	Description
elementType	Type