VMS Help MACRO, /MIGRATION, Macros for 64-Bit Addressing, $IS 32BITS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Checks the sign extension of the low 32 bits of a 64-bit value
    and directs the program flow based on the outcome of the check.

    Format

      $IS_32BITS  quad_arg, leq_32bits, gtr_32bits, temp_reg=22

1 - Parameters

 quad_arg

    A 64-bit quantity, either in a register or in an aligned quadword
    memory location.

 leq_32bits

    Label to branch to if quad_arg is a 32-bit sign-extended value.

 gtr_32bits

    Label to branch to if quad_arg is greater than 32 bits.

 temp_reg=22

    Register to use as a temporary register for holding the low
    longword of the source value-R22 is the default.

2 - Description

    $IS_32BITS checks the sign extension of the low 32 bits of a 64-
    bit value and directs the program flow based on the outcome of
    the check.

3 - Examples

    1.$is_32bits  R9, 10$

      In this example, the compiler checks the sign extension of
      the low 32 bits of the 64-bit value at R9 using the default
      temporary register, R22. Depending on the type of branch
      and the outcome of the test, the program either branches or
      continues in line.

    2.$is_32bits  4(R8), 20$, 30$, R28

      In this example, the compiler checks the sign extension of
      the low 32 bits of the 64-bit value at 4(R8) using R28 as a
      temporary register and, based on the check, branches to either
      20$ or 30$.