fhelium.compile.passes.lowering._select_execution

Select registered lowerings independently at each execution operation.

SelectExecutionLoweringsPass

class View source

SelectExecutionLoweringsPass(implementations: OperationImplementationRegistry, fusion_implementations: Sequence[FusionImplementation] = (), lowerings: CkksLoweringRegistry = DEFAULT_CKKS_LOWERINGS, allow_partial_fusion: bool = True, name: str = 'select-execution-lowerings', execution_cost: Callable[[Operation, Sequence[Operation]], tuple[float, float] | None] | None = None)

Keep applicable whole operations or expose a supported fusion expression.

A supplied implementation assignment is local to its operation. Unassigned operations without whole-operation coverage require lowering. Where both routes exist, an isolated lowering probe is accepted only when a fusion implementation supports the complete expression. With partial fusion enabled, supported subregions may instead be combined with independent implementations for the remaining operations.

execution_cost may compare the whole operation with the isolated lowered candidate after this pass's fusion scheduling. It returns (whole, lowered) costs in one caller-selected unit, or None when the comparison is unknown. Lowering is selected only for a strictly smaller supplied cost; ties retain the whole operation. Missing estimates retain the fusion-coverage decision. Implementation assignments always take precedence over this callback.

Attributes

Name	Type	Default/value
implementations	OperationImplementationRegistry
fusion_implementations	Sequence[FusionImplementation]	()
lowerings	CkksLoweringRegistry	DEFAULT_CKKS_LOWERINGS
allow_partial_fusion	bool	True
name	str	'select-execution-lowerings'
execution_cost	Callable[[Operation, Sequence[Operation]], tuple[float, float] | None] | None	None

run

method

def run(compilation: 'Compilation') -> PassResult: ...