IntegerBitLen

The number of bits in the integer type of a value.

Declaration

Syntax

IntegerBitLen(expr a, ttype type, expr? value)

Arguments

Argument

Description

a

the value whose type is measured.

type

the type of the expression.

value

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

Return values

The value of the expression.

Description

This is bit_size(i). The operand is not read: only its type matters, so the result is a compile time constant.

Examples

(IntegerBitLen
  :a (Var
    :v (SymbolRef 1 "i")
  )
  :type (Integer
    :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 {
            "b" (Variable
              :parent_symtab 1
              :name "b"
              :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 []
            )
            "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 []
            )
            "j" (Variable
              :parent_symtab 1
              :name "j"
              :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 []
            )
          }
        )
        :name "main"
        :dependencies []
        :body [
          (Assignment
            :target (Var
              :v (SymbolRef 1 "i")
            )
            :value (IntegerConstant
              :n 255
              :type (Integer
                :kind 4
              )
              :intboz_type :Hex
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "j")
            )
            :value (IntegerBinOp
              :left (Var
                :v (SymbolRef 1 "i")
              )
              :op :Mul
              :right (IntegerConstant
                :n 2
                :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 "j")
            )
            :value (IntegerUnaryMinus
              :arg (Var
                :v (SymbolRef 1 "i")
              )
              :type (Integer
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "j")
            )
            :value (IntegerBitNot
              :arg (Var
                :v (SymbolRef 1 "i")
              )
              :type (Integer
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "j")
            )
            :value (IntegerBitLen
              :a (Var
                :v (SymbolRef 1 "i")
              )
              :type (Integer
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "b")
            )
            :value (IntegerCompare
              :left (Var
                :v (SymbolRef 1 "i")
              )
              :op :Lt
              :right (Var
                :v (SymbolRef 1 "j")
              )
              :type (Logical
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
        ]
      )
    }
  )
  :items []
)

See Also

IntegerBitNot, SizeOfType, TypeInquiry