`psyclone.psyir.nodes.reference`#

This module contains the implementation of the Reference node.

Classes #

Reference: Node representing a Reference Expression.

class psyclone.psyir.nodes.reference.Reference(symbol, **kwargs)[source]#

Node representing a Reference Expression.

Parameters:

symbol (psyclone.psyir.symbols.Symbol) – the symbol being referenced.
kwargs (unwrapped dict.) – additional keyword arguments provided to the super class.

Inheritance

property datatype#

Returns:: the datatype of this reference.
Return type:: psyclone.psyir.symbols.DataType

enters_scope(scope, visited_nodes=None)[source]#

Whether the symbol lifetime starts before the given scope. For example, given the following fortran code:

do i=1,10
  a = 1
  if (b>3) c = 1
end do

‘a’ does not enter the scope. Even if it had a value before in the loop scope this is reassigned to a new value. However, ‘b’ and ‘c’ values enter the scope, because there is a path in which they take the value the symbol had before the scope.

Parameters:

scope (Node) – the given scope that we evaluate.
visited_nodes (Optional[set]) – a set of nodes already visited, this is necessary because the dependency chains may contain cycles. Defaults to an empty set.

Return type:

bool

Returns:

whether the symbol lifetime starts before the given scope.

escapes_scope(scope, visited_nodes=None)[source]#

Whether the symbol lifetime continues after the given scope. For example, given the following fortran code:

    do i=1,10
      a = 1
      b = 2
      c = 3
    end do
    b = 4
    call mysub(a, b)
end subroutine

‘b’ and ‘c’ if it is local, finish their value lifetime at the end of the loop scope (it is not re-used afterwards). While for ‘a’ and ‘c’ if it is global, their value may be used later and they “escape the scope”.

Parameters:

scope (Node) – the given scope that we evaluate.
visited_nodes (Optional[set]) – a set of nodes already visited, this is necessary because the dependency chains may contain cycles. Defaults to an empty set.

Return type:

bool

Returns:

whether the symbol lifetime continues after the given scope.

get_all_accessed_symbols()[source]#

Return type:: set[Symbol]
Returns:: a set of all the symbols accessed inside this Reference.

get_signature_and_indices()[source]#

Returns:: the Signature of this reference, and an empty list of lists as ‘indices’ since this reference does not represent an array access.
Return type:: tuple(psyclone.core.Signature, list of list of indices)

property is_read#

Returns:: whether this reference is reading from its symbol.
Return type:: bool

property is_write#

Returns:: whether this reference is writing to its symbol.
Return type:: bool

property name#

Return the name of the referenced symbol.

Returns:: Name of the referenced symbol.
Return type:: str

next_accesses()[source]#

Returns:: the nodes accessing the same symbol directly after this reference. It can be multiple nodes if the control flow diverges and there are multiple possible accesses.
Return type:: List[psyclone.psyir.nodes.Node]

node_str(colour=True)[source]#

Create a text description of this node in the schedule, optionally including control codes for colour.

Parameters:: colour (bool) – whether or not to include colour control codes.
Returns:: text description of this node.
Return type:: str

previous_accesses()[source]#

Returns:: the nodes accessing the same symbol directly before this reference. It can be multiple nodes if the control flow diverges and there are multiple possible accesses.
Return type:: List[psyclone.psyir.nodes.Node]

reference_accesses()[source]#

Return type:: VariablesAccessMap
Returns:: a map of all the symbol accessed inside this node, the keys are Signatures (unique identifiers to a symbol and its structure acccessors) and the values are AccessSequence (a sequence of AccessTypes).

replace_symbols_using(table_or_symbol)[source]#

Update any Symbols referenced by this Node with those in the supplied table (or just the supplied Symbol instance) if they have matching names. If there is no match for a given Symbol then it is left unchanged.

Parameters:: table_or_symbol (psyclone.psyir.symbols.SymbolTable | psyclone.psyir.symbols.Symbol) – the symbol table from which to get replacement symbols or a single, replacement Symbol.

property symbol#

Return the referenced symbol.

Returns:: the referenced symbol.
Return type:: psyclone.psyir.symbols.Symbol

psyclone.psyir.nodes.reference#

Classes#

`psyclone.psyir.nodes.reference`#

Classes #