Manual Reference Pages - bit_size (3fortran)

NAME

BIT_SIZE(3) - [BIT:INQUIRY] Bit size inquiry function

SYNOPSIS

result = bit_size(i)

         integer(kind=KIND) function bit_size(i)

          integer(kind=KIND),intent(in) :: i(..)

CHARACTERISTICS

o I shall be of type integer. It may be a scalar or an array.

o the value of KIND is any valid value for an integer kind parameter on the processor.

o the return value is a scalar of the same kind as the input value.

DESCRIPTION

BIT_SIZE(3) returns the number of bits (integer precision plus sign bit) represented by the type of the integer I.

OPTIONS

o I : An integer value of any kind whose size in bits is to be determined. Because only the type of the argument is examined, the argument need not be defined; I can be a scalar or an array, but a scalar representing just a single element is always returned.

RESULT

The number of bits used to represent a value of the type and kind of i. The result is a integer scalar of the same kind as i.

EXAMPLES

Sample program:

    program demo_bit_size
    use,intrinsic :: iso_fortran_env, only : int8, int16, int32, int64
    use,intrinsic :: iso_fortran_env, only : integer_kinds
    implicit none
    character(len=*),parameter   :: fmt=&
    & ’(a,": bit size is ",i3," which is kind=",i3," on this platform")’

        ! default integer bit size on this platform
        write(*,fmt) "default", bit_size(0), kind(0)

        write(*,fmt) "int8   ", bit_size(0_int8),   kind(0_int8)
        write(*,fmt) "int16  ", bit_size(0_int16),  kind(0_int16)
        write(*,fmt) "int32  ", bit_size(0_int32),  kind(0_int32)
        write(*,fmt) "int64  ", bit_size(0_int64),  kind(0_int64)

        write(*,’(a,*(i0:,", "))’) "The available kinds are ",integer_kinds

    end program demo_bit_size

Typical Results:

default: bit size is 32 which is kind= 4 on this platform int8 : bit size is 8 which is kind= 1 on this platform int16 : bit size is 16 which is kind= 2 on this platform int32 : bit size is 32 which is kind= 4 on this platform int64 : bit size is 64 which is kind= 8 on this platform The available kinds are 1, 2, 4, 8, 16

STANDARD

Fortran 95

o	I shall be of type integer. It may be a scalar or an array.
o	the value of KIND is any valid value for an integer kind parameter on the processor.
o	the return value is a scalar of the same kind as the input value.