/sys$common/syshlp/helplib.hlb MACRO, VAX MACRO Assembler, Vector Instructions, IOTA  *Conan The Librarian (sorry for the slow response - running on an old VAX)

      Generate Compressed Iota Vector

    Format:

      IOTA    [/0|1]    stride, Vc

    Architecture

    Format
    opcode   cntrl.rw, stride.rl
    opcodes

    EDFD    IOTA      Generate Compressed Iota Vector

    vector_control_word

             1 1 1 1 1
             5 4 3 2 1     8 7     4 3     0
            +-+-+-+-+-------+-------+-------+
            | |M| | |       |       |       |
            |0|T|0|0|   0   |   0   |  Vc   |
            | |F| | |       |       |       |
            +-+-+-+-+-------+-------+-------+
    exceptions

       None.

    operation
      j   <- 0
      tmp <- 0
      FOR i <- 0 TO VLR-1
        BEGIN
          IF {VMR<i> EQL MTF} THEN
            BEGIN

              Vc[j]<31:0> <- tmp<31:0>

              j <- j + 1
            END
          tmp <- tmp + stride
        END
      VCR <- j                        !return vector count