VMS Help MACRO, VAX MACRO Assembler, Instructions, CVTxx  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        Convert a signed quantity to a different signed
                    data type
    Format:         opcode src.rx,dst.wy
    Operation:      dst = conversion or src
    C. Codes:       N = dst LSS 0, Z = dst EQL 0, C = 0
                    V = {src cannot be represented in dst}
    Exceptions:     Integer/floating overflow, reserved operand
    Opcodes:        See table below:

      from/to |Byte  |Word  |Long  |F_float|D_float|G_float|H_float|
      --------|------|------|------|------|------|-------|-------|
      Byte    |      |99   x|98   x|4C   e|6C   e|4CFD  e|6CFD  e|
      Word    |33   t|      |32   x|4D   e|6D   e|4DFD  e|6DFD  e|
      Long    |F6   t|F7   t|      |4E   r|6E   e|4EFD  e|6EFD  e|
      F_float |48   t|49   t|4A   t|      |56   e|99FD  e|98FD  e|
      D_float |68   t|69   t|6A   t|76   r|      |       |32FD  e|
      G_float |48FD t|49FD t|4AFD t|33FD r|      |       |56FD  e|
      H_float |68FD t|69FD t|6AFD t|F6FD r|F7FD r|76FD  r|       |
      --------|------|------|------|------|------|-------|-------|
     legend: t - truncate, x - sign extend, e - exact, r - rounded,

                4B    CVTRFL   Convert and round F_floating to long
                6B    CVTRDL   Convert and round D_floating to long
                4BFD  CVTRGL   Convert and round G_floating to long
                6BFD  CVTRHL   Convert and round H_floating to long