ArrayIsContiguous

Whether an array occupies contiguous storage.

Declaration

Syntax

ArrayIsContiguous(expr array, ttype type, expr? value)

Arguments

Argument

Description

array

the array to test.

type

the logical type of the result.

value

the compile time value of the expression, when the frontend could fold it; nil otherwise.

Return values

The value of the expression.

Description

is_contiguous(a). A section with a stride, or one that fixes a subscript in the wrong dimension, is not contiguous, and a procedure that requires contiguity has to copy it. The test lets generated code choose between a fast path and a copy.

Examples

(ArrayIsContiguous
  :array (Var
    :v (SymbolRef 1 "a")
  )
  :type (Logical
    :kind 4
  )
  :value nil
)

It comes from this complete ASR text document:

(TranslationUnit
  :symtab (SymbolTable
    :id 0
    :symbols {
      "main" (Program
        :symtab (SymbolTable
          :id 1
          :symbols {
            "a" (Variable
              :parent_symtab 1
              :name "a"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :FixedSizeArray
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "b" (Variable
              :parent_symtab 1
              :name "b"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :FixedSizeArray
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "i" (Variable
              :parent_symtab 1
              :name "i"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "l" (Variable
              :parent_symtab 1
              :name "l"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Logical
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
          }
        )
        :name "main"
        :dependencies []
        :body [
          (Assignment
            :target (Var
              :v (SymbolRef 1 "a")
            )
            :value (ArrayConstant
              :n_data 12
              :data #asr/bytes "010000000200000003000000"
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :FixedSizeArray
              )
              :storage_format :ColMajor
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "i")
            )
            :value (ArrayItem
              :v (Var
                :v (SymbolRef 1 "a")
              )
              :args [
                (array_index
                  :left nil
                  :right (IntegerConstant
                    :n 2
                    :type (Integer
                      :kind 4
                    )
                    :intboz_type :Decimal
                  )
                  :step nil
                )
              ]
              :type (Integer
                :kind 4
              )
              :storage_format :ColMajor
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "b")
            )
            :value (ArraySection
              :v (Var
                :v (SymbolRef 1 "a")
              )
              :args [
                (array_index
                  :left (IntegerConstant
                    :n 1
                    :type (Integer
                      :kind 4
                    )
                    :intboz_type :Decimal
                  )
                  :right (IntegerConstant
                    :n 3
                    :type (Integer
                      :kind 4
                    )
                    :intboz_type :Decimal
                  )
                  :step (IntegerConstant
                    :n 1
                    :type (Integer
                      :kind 4
                    )
                    :intboz_type :Decimal
                  )
                )
              ]
              :type (Array
                :type (Integer
                  :kind 4
                )
                :dims [
                  (dimension
                    :start (IntegerConstant
                      :n 1
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                    :length (IntegerConstant
                      :n 3
                      :type (Integer
                        :kind 4
                      )
                      :intboz_type :Decimal
                    )
                  )
                ]
                :physical_type :DescriptorArray
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "i")
            )
            :value (ArraySize
              :v (Var
                :v (SymbolRef 1 "a")
              )
              :dim (IntegerConstant
                :n 1
                :type (Integer
                  :kind 4
                )
                :intboz_type :Decimal
              )
              :type (Integer
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "i")
            )
            :value (ArrayRank
              :v (Var
                :v (SymbolRef 1 "a")
              )
              :type (Integer
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "i")
            )
            :value (ArrayBound
              :v (Var
                :v (SymbolRef 1 "a")
              )
              :dim (IntegerConstant
                :n 1
                :type (Integer
                  :kind 4
                )
                :intboz_type :Decimal
              )
              :type (Integer
                :kind 4
              )
              :bound :UBound
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "l")
            )
            :value (ArrayIsContiguous
              :array (Var
                :v (SymbolRef 1 "a")
              )
              :type (Logical
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
        ]
      )
    }
  )
  :items []
)

See Also

ArraySection, ArrayPhysicalCast, array_physical_type