Flowgraphs [Experimental]

Primary APIs

pystencils.flow.operator(func=None, /, preds=None, name=None, ispace=None, config=None, **kwargs)

Overloads:

• preds (Iterable[FlowgraphNode] | None), name (str | None), ispace (PatchSliceSpec | PatchSlice | None), config (CreateKernelConfig | None), kwargs → Callable[[FlowgraphNode | _SingleBlockOperatorFunc | _ComplexGraphOperatorFunc], Operator]

• func (_SingleBlockOperatorFunc | _ComplexGraphOperatorFunc) → Operator

Parameters:

• func (Callable[[EquationsBlockBuilder], None] | Callable[[], FlowgraphNode | tuple[FlowgraphNode, ...]] | None)

• preds (Iterable[FlowgraphNode] | None)

• name (str | None)

• ispace (PatchSliceSpec | PatchSlice | None)

• config (CreateKernelConfig | None)

pystencils.flow.block(func=None, /, preds=None, name=None)

Define a flowgraph block using let syntax.

Overloads:

• preds (Iterable[FlowgraphNode] | None), name (str | None) → Callable[[Callable[[EquationsBlockBuilder], None]], EquationsBlock]

• func (Callable[[EquationsBlockBuilder], None]) → EquationsBlock

Parameters:

• func (Callable[[EquationsBlockBuilder], None] | None)

• preds (Iterable[FlowgraphNode] | None)

• name (str | None)

block is a decorator used to define flowgraph blocks using Python function syntax.

Parameters:

• preds (Optional[Iterable[FlowgraphNode]]) – Predecessor nodes to this block

• name (str | None) – Name of this block. If none is given, the function’s name will be used

• func (Callable[[EquationsBlockBuilder], None] | None)

pystencils.flow.guarded_block(cond, *, preds=None, name=None)

Define a guarded block that is protected by a condition.

Return type:

Callable[[Callable[[EquationsBlockBuilder], None]], EquationsBlock | Cases]

Parameters:

• cond (Basic)

• preds (Iterable[FlowgraphNode] | None)

• name (str | None)

pystencils.flow.cases(func=None, /, preds=None, name=None)

Define a flowgraph cases block.

Overloads:

• preds (Iterable[FlowgraphNode] | None), name (str | None) → Callable[[Callable[[CasesBuilder], None]], Cases]

• func (Callable[[CasesBuilder], None]) → Cases

Parameters:

• func (Callable[[CasesBuilder], None] | None)

• preds (Iterable[FlowgraphNode] | None)

• name (str | None)

cases is a decorator used to define flowgraph case blocks using Python function syntax.

pystencils.flow.tie(*nodes, name=None)

Tie multiple nodes together into a flowgraph

Return type:

Flowgraph

Parameters:

• nodes (FlowgraphNode)

• name (str | None)

pystencils.flow.subgraph(*args, preds=(), name=None)

Overloads:

• graph (Flowgraph), preds (Sequence[FlowgraphNode]) → Subgraph

• nodes (FlowgraphNode), preds (Sequence[FlowgraphNode]), name (str | None) → Subgraph

Parameters:

• args (Flowgraph | FlowgraphNode)

• preds (Sequence[FlowgraphNode])

• name (str | None)

Return type:

Subgraph

pystencils.flow.guarded_subgraph(cond, *, preds=None, name=None)

Create a guarded subgraph.

guarded_subgraph is a function decorator; the decorated function should constuct and return the output nodes of the guarded graph.

Example:

@ps.flow.guarded_subgraph(condition)
def mygraph():
    # ... define subgraph

    #   return output nodes
    return block1, block2

Parameters:

• cond (Basic)

• preds (Iterable[FlowgraphNode] | None)

• name (str | None)

Flowgraph Nodes

Inheritance Diagram

Classes

pystencils.flow.flowgraph.SymbolicMemoryLoc = pystencils.field.Field.Access | pystencils.sympyextensions.pointers.mem_acc | pystencils.grids.protocols.IFieldAccess

Expression types that are valid memory locations and can be used on the LHS of Store.

Flowgraph	A closed flowgraph in canonical form.
FlowgraphAssignment	Base class for assignments.
Let	Let assignments define subexpressions to be used within the same EquationsBlock.
Export	Export assignments define subexpressions that can be used within the same EquationsBlock and its direct successors in the flowgraph.
Store	Store assignments represent writing a value to an abstract memory location.
Reduce	Reduce assignments perform reductions onto a target typed symbol with a given operation.
FlowgraphNode	Base class for data-flow graph nodes in pystencils.flow.
Top	A flowgraph's top node.
Bottom	A flowgraph's bottom node.
EquationsBlock	A block of symbol assignments in static single-assignment form.
Subgraph	Another flowgraph embedded as a subgraph.
Cases	Case distinction.

Operator

Builders

EquationsBlockBuilder	Builder for equation blocks.
CasesBuilder

Canonicalization

CanonicalizeFlowgraph	Check a flowgraph for consistency and transform it into canonical form.
CanonicalizationResult	Result of the flowgraph canonicalizer
CanonicalizationError	Indicates that a flowgraph violates a canonicality condition.