MVBITS (from, frompos, len, to, topos)

  Class:  Elemental subroutine

  Copies a sequence of bits (a bit field) from one location to
  another.  The following arguments can be of any integer data type:

     from     Represents the location from which a bit
              field is transferred.

     frompos  Identifies the first bit position in the
              field transferred from "from". It must not
              be negative. "frompos" + "len" must be less
              than or equal to BIT_SIZE (from).

     len      Identifies the length of the field transferred
              from "from".  It must not be negative.

     to       Represents the location to which a bit field
              is transferred. It must have the same kind
              parameter as "from".  "to" is set by copying
              the sequence of bits of length "len", starting
              at position "frompos" of "from" to position
              "topos" of "to".  No other bits of "to"
              are altered.

              On return, the "len" bits of "to" (starting
              at "topos") are equal to the value that "len"
              bits of "from" (starting at "frompos") had
              on entry.

     topos    Identifies the starting position (within "to")
              for the bits being transferred.  It must not
              be negative.  "topos" + "len" must be less than
              or equal to BIT_SIZE (to).)

  You can also specify the following specific subroutines:

    IMVBITS   All arguments must be INTEGER*2.
    JMVBITS   Arguments can be INTEGER*2 or INTEGER*4; at least
              one must be INTEGER*4.
    KMVBITS   Arguments can be INTEGER*2, INTEGER*4, or INTEGER*8;
              at least one must be INTEGER*8.