Netlist Traversal Decorator

class hal_py.NetlistTraversalDecorator

A netlist decorator that provides functionality to traverse the associated netlist without making any modifications.

__init__(self: hal_py.NetlistTraversalDecorator, netlist: hal_py.Netlist) → None

Construct new NetlistTraversalDecorator object.

Parameters

netlist (hal_py.Netlist) – The netlist to operate on.

get_next_combinational_gates(*args, **kwargs)

Overloaded function.

  1. get_next_combinational_gates(self: hal_py.NetlistTraversalDecorator, net: hal_py.Net, successors: bool, forbidden_pins: Set[hal_py.PinType]) -> Optional[Set[hal_py.Gate]]

    Starting from the given net, traverse the netlist and return all combinational successor/predecessor gates. Continue traversal as long as further combinational gates are found and stop at gates that are not combinational. All combinational gates found during traversal are added to the result. Forbidden pins can be provided to, e.g., avoid the inclusion of logic in front of flip-flop control inputs.

    param hal_py.Net net

    Start net.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param set[hal_py.PinType] forbidden_pins

    Netlist traversal stops at these pins.

    returns

    The next combinational gates on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

  2. get_next_combinational_gates(self: hal_py.NetlistTraversalDecorator, gate: hal_py.Gate, successors: bool, forbidden_pins: Set[hal_py.PinType]) -> Optional[Set[hal_py.Gate]]

    Starting from the given gate, traverse the netlist and return all combinational successor/predecessor gates. Continue traversal as long as further combinational gates are found and stop at gates that are not combinational. All combinational gates found during traversal are added to the result. Forbidden pins can be provided to, e.g., avoid the inclusion of logic in front of flip-flop control inputs.

    param hal_py.Gate gate

    Start gate.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param set[hal_py.PinType] forbidden_pins

    Netlist traversal stops at these pins.

    returns

    The next combinational gates on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

get_next_matching_gates(*args, **kwargs)

Overloaded function.

  1. get_next_matching_gates(self: hal_py.NetlistTraversalDecorator, net: hal_py.Net, successors: bool, target_gate_filter: Callable[[hal_py.Gate], bool], continue_on_match: bool = False, exit_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None, entry_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None) -> Optional[Set[hal_py.Gate]]

    Starting from the given net, traverse the netlist and return only the successor/predecessor gates for which the target_gate_filter evaluates to True. Traverse over gates that do not meet the target_gate_filter condition. Stop traversal if (1) continue_on_match is False the target_gate_filter evaluates to True, (2) the exit_endpoint_filter evaluates to False on a fan-in/out endpoint (i.e., when exiting the current gate during traversal), or (3) the entry_endpoint_filter evaluates to False on a successor/predecessor endpoint (i.e., when entering the next gate during traversal). Both the entry_endpoint_filter and the exit_endpoint_filter may be omitted.

    param hal_py.Net net

    Start net.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param lambda target_gate_filter

    Filter condition that must be met for the target gates.

    param bool continue_on_match

    Set True to continue even if target_gate_filter evaluated to True, False otherwise. Defaults to False.

    param lambda exit_endpoint_filter

    Filter condition that determines whether to stop traversal on a fan-in/out endpoint.

    param lambda entry_endpoint_filter

    Filter condition that determines whether to stop traversal on a successor/predecessor endpoint.

    returns

    The next gates fulfilling the target gate filter condition on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

  2. get_next_matching_gates(self: hal_py.NetlistTraversalDecorator, gate: hal_py.Gate, successors: bool, target_gate_filter: Callable[[hal_py.Gate], bool], continue_on_match: bool = False, exit_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None, entry_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None) -> Optional[Set[hal_py.Gate]]

    Starting from the given gate, traverse the netlist and return only the successor/predecessor gates for which the target_gate_filter evaluates to True. Traverse over gates that do not meet the target_gate_filter condition. Stop traversal if (1) continue_on_match is False the target_gate_filter evaluates to True, (2) the exit_endpoint_filter evaluates to False on a fan-in/out endpoint (i.e., when exiting the current gate during traversal), or (3) the entry_endpoint_filter evaluates to False on a successor/predecessor endpoint (i.e., when entering the next gate during traversal). Both the entry_endpoint_filter and the exit_endpoint_filter may be omitted.

    param hal_py.Gate gate

    Start gate.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param lambda target_gate_filter

    Filter condition that must be met for the target gates.

    param bool continue_on_match

    Set True to continue even if target_gate_filter evaluated to True, False otherwise. Defaults to False.

    param lambda exit_endpoint_filter

    Filter condition that determines whether to stop traversal on a fan-in/out endpoint.

    param lambda entry_endpoint_filter

    Filter condition that determines whether to stop traversal on a successor/predecessor endpoint.

    returns

    The next gates fulfilling the target gate filter condition on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

get_next_matching_gates_until(*args, **kwargs)

Overloaded function.

  1. get_next_matching_gates_until(self: hal_py.NetlistTraversalDecorator, net: hal_py.Net, successors: bool, target_gate_filter: Callable[[hal_py.Gate], bool], continue_on_mismatch: bool = False, exit_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None, entry_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None) -> Optional[Set[hal_py.Gate]]

    Starting from the given net, traverse the netlist and return only the successor/predecessor gates for which the target_gate_filter evaluates to True. Continue traversal independent of whatever target_gate_filter evaluates to. Stop traversal if (1) continue_on_mismatch is False the target_gate_filter evaluates to False, (2) the exit_endpoint_filter evaluates to False on a fan-in/out endpoint (i.e., when exiting the current gate during traversal), or (3) the entry_endpoint_filter evaluates to False on a successor/predecessor endpoint (i.e., when entering the next gate during traversal). Both entry_endpoint_filter and the exit_endpoint_filter may be omitted.

    param hal_py.Net net

    Start net.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param lambda target_gate_filter

    Filter condition that must be met for the target gates.

    param bool continue_on_mismatch

    Set True to continue even if target_gate_filter evaluated to False, False otherwise. Defaults to False.

    param lambda exit_endpoint_filter

    Filter condition that determines whether to stop traversal on a fan-in/out endpoint.

    param lambda entry_endpoint_filter

    Filter condition that determines whether to stop traversal on a successor/predecessor endpoint.

    returns

    The next gates fulfilling the target gate filter condition on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

  2. get_next_matching_gates_until(self: hal_py.NetlistTraversalDecorator, gate: hal_py.Gate, successors: bool, target_gate_filter: Callable[[hal_py.Gate], bool], continue_on_mismatch: bool = False, exit_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None, entry_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None) -> Optional[Set[hal_py.Gate]]

    Starting from the given gate, traverse the netlist and return only the successor/predecessor gates for which the target_gate_filter evaluates to True. Continue traversal independent of whatever target_gate_filter evaluates to. Stop traversal if (1) continue_on_mismatch is False the target_gate_filter evaluates to False, (2) the exit_endpoint_filter evaluates to False on a fan-in/out endpoint (i.e., when exiting the current gate during traversal), or (3) the entry_endpoint_filter evaluates to False on a successor/predecessor endpoint (i.e., when entering the next gate during traversal). Both entry_endpoint_filter and the exit_endpoint_filter may be omitted.

    param hal_py.Gate gate

    Start gate.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param lambda target_gate_filter

    Filter condition that must be met for the target gates.

    param bool continue_on_mismatch

    Set True to continue even if target_gate_filter evaluated to False, False otherwise. Defaults to False.

    param lambda exit_endpoint_filter

    Filter condition that determines whether to stop traversal on a fan-in/out endpoint.

    param lambda entry_endpoint_filter

    Filter condition that determines whether to stop traversal on a successor/predecessor endpoint.

    returns

    The next gates fulfilling the target gate filter condition on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

get_next_matching_gates_until_depth(*args, **kwargs)

Overloaded function.

  1. get_next_matching_gates_until_depth(self: hal_py.NetlistTraversalDecorator, net: hal_py.Net, successors: bool, max_depth: int, target_gate_filter: Callable[[hal_py.Gate], bool] = None) -> Optional[Set[hal_py.Gate]]

    Starting from the given net, traverse the netlist and return only the successor/predecessor gates for which the target_gate_filter evaluates to True. Continue traversal independent of whatever target_gate_filter evaluates to. Stop traversal if the specified depth is reached. The current depth is counted starting at 1 for the destinations of the provided net. For a max_depth of 0, all gates between the start net and the global netlist outputs will be traversed. The target_gate_filter may be omitted in which case all traversed gates will be returned.

    param hal_py.Net net

    Start net.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param int max_depth

    The maximum depth for netlist traversal starting from the start net.

    param lambda target_gate_filter

    Filter condition that must be met for the target gates.

    returns

    The next gates fulfilling the target gate filter condition on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

  2. get_next_matching_gates_until_depth(self: hal_py.NetlistTraversalDecorator, gate: hal_py.Gate, successors: bool, max_depth: int, target_gate_filter: Callable[[hal_py.Gate], bool] = None) -> Optional[Set[hal_py.Gate]]

    Starting from the given gate, traverse the netlist and return only the successor/predecessor gates for which the target_gate_filter evaluates to True. Continue traversal independent of whatever target_gate_filter evaluates to. Stop traversal if the specified depth is reached. The current depth is counted starting at 1 for the direct successors/predecessors of the provided gate. For a max_depth of 0, all gates between the start gate and the global netlist outputs will be traversed. The target_gate_filter may be omitted in which case all traversed gates will be returned.

    param hal_py.Gate gate

    Start gate.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param int max_depth

    The maximum depth for netlist traversal starting from the start gate.

    param lambda target_gate_filter

    Filter condition that must be met for the target gates.

    returns

    The next gates fulfilling the target gate filter condition on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

get_next_sequential_gates(*args, **kwargs)

Overloaded function.

  1. get_next_sequential_gates(self: hal_py.NetlistTraversalDecorator, net: hal_py.Net, successors: bool, forbidden_pins: Set[hal_py.PinType]) -> Optional[Set[hal_py.Gate]]

    Starting from the given net, traverse the netlist and return only the next layer of sequential successor/predecessor gates. Traverse over gates that are not sequential until a sequential gate is found. Stop traversal at all sequential gates, but only adds those to the result that have not been reached through a pin of one of the forbidden types.

    param hal_py.Net net

    Start net.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param set[hal_py.PinType] forbidden_pins

    Sequential gates reached through these pins will not be part of the result. Defaults to an empty set.

    returns

    The next sequential gates on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

  2. get_next_sequential_gates(self: hal_py.NetlistTraversalDecorator, gate: hal_py.Gate, successors: bool, forbidden_pins: Set[hal_py.PinType]) -> Optional[Set[hal_py.Gate]]

    Starting from the given gate, traverse the netlist and return only the next layer of sequential successor/predecessor gates. Traverse over gates that are not sequential until a sequential gate is found. Stop traversal at all sequential gates, but only adds those to the result that have not been reached through a pin of one of the forbidden types.

    param hal_py.Gate gate

    Start gate.

    param bool successors

    Set True to get successors, set False to get predecessors.

    param set[hal_py.PinType] forbidden_pins

    Sequential gates reached through these pins will not be part of the result.

    returns

    The next sequential gates on success, None otherwise.

    rtype

    set[hal_py.Gate] or None

get_next_sequential_gates_map(self: hal_py.NetlistTraversalDecorator, successors: bool, forbidden_pins: Set[hal_py.PinType]) → Optional[Dict[hal_py.Gate, Set[hal_py.Gate]]]

Get the next sequential gates for all sequential gates in the netlist by traversing through remaining logic (e.g., combinational logic). Compute a dict from a sequential gate to all its successors. Stop traversal at all sequential gates, but only adds those to the result that have not been reached through a pin of one of the forbidden types.

Parameters

  • successors (bool) – Set True to get successors, set False to get predecessors.

  • forbidden_pins (set[hal_py.PinType]) – Sequential gates reached through these pins will not be part of the result.

Returns

A dict from each sequential gate to all its sequential successors on success, None otherwise.

Return type

dict[hal_py.Gate,set[hal_py.Gate]] or None

get_shortest_path(self: hal_py.NetlistTraversalDecorator, start_gate: hal_py.Gate, end_gate: hal_py.Gate, direction: hal_py.PinDirection, exit_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None, entry_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None) → Optional[List[hal_py.Gate]]

Find the shortest path (i.e., the smallest number of gates) that connects the start gate with the end gate. The gate where the search started from will be the first in the result list, the end gate will be the last. If there is no such path, None is returned. If there is more than one path with the same length, only the first one is returned.

Parameters

  • start_gate (hal_py.Gate) – The gate to start from.

  • end_gate (hal_py.Gate) – The gate to connect to.

  • direction (hal_py.PinDirection) – The direction to search in. Can be hal_py.PinDirection.input, hal_py.PinDirection.output, or hal_py.PinDirection.inout to search both directions and return the shorter one.

  • exit_endpoint_filter (lambda) – Filter condition that determines whether to stop traversal on a fan-in/out endpoint.

  • entry_endpoint_filter (lambda) – Filter condition that determines whether to stop traversal on a successor/predecessor endpoint.

Returns

A list of gates that connect the start with end gate on success, None otherwise.

Return type

list[hal_py.Gate] or None

get_shortest_path_distance(self: hal_py.NetlistTraversalDecorator, start_gate: hal_py.Gate, end_gate: hal_py.Gate, direction: hal_py.PinDirection, exit_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None, entry_endpoint_filter: Callable[[hal_py.Endpoint, int], bool] = None) → Optional[int]

Find the length of the shortest path (i.e., the smallest number of gates) that connects the start gate with the end gate. If there is no such path, None is returned. Computing only the shortest distance to a gate is faster than computing the shortest path, since it does not have to keep track of the path to reach each gate.

Parameters

  • start_gate (hal_py.Gate) – The gate to start from.

  • end_gate (hal_py.Gate) – The gate to connect to.

  • direction (hal_py.PinDirection) – The direction to search in. Can be hal_py.PinDirection.input, hal_py.PinDirection.output, or hal_py.PinDirection.inout to search both directions and return the shorter one.

  • exit_endpoint_filter (lambda) – Filter condition that determines whether to stop traversal on a fan-in/out endpoint.

  • entry_endpoint_filter (lambda) – Filter condition that determines whether to stop traversal on a successor/predecessor endpoint.

Returns

The shortest distance between the start and end gate on success, None otherwise.

Return type

int or None