Library /sys$common/syshlp/dbg$help.hlb DEBUG, SYNCHRONIZE, VECTOR_MODE, Examples  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    1.DBG> SYNCHRONIZE VECTOR_MODE
      %DEBUG-I-SYNCREPCOM, Synchronize reporting complete

      This command forces immediate synchronization between the
      scalar and vector processors. In this example, the diagnostic
      message indicates that the synchronization operation has
      completed and that all pending vector exceptions have been
      delivered and reported.

    2.DBG> STEP   1
      stepped to .MAIN.\SUB\%LINE 99
          99:         VVDIVD  V1,V0,V2
      DBG> STEP   2
      stepped to .MAIN.\SUB\%LINE 100
         100:         CLRL    R0
      DBG> EXAMINE/FLOAT %V2   3
      0\%V2
          [0]:  13.53400
          [1]:  Reserved operand, encoded as floating divide by zero
          [2]:  247.2450
           . . .
      DBG> SYNCHRONIZE VECTOR_MODE   4
      %SYSTEM-F-VARITH, vector arithmetic fault, summary=00000002,
                        mask=00000004, PC=000002E1, PSL=03C00010
      break on unhandled exception preceding .MAIN.\SUB\%LINE 100
         100:         CLRL    R0)
      DBG>

      The comments that follow refer to the callouts in the previous
      example:

      1  This STEP command suspends program execution on line 99,
         just before a VVDIVD instruction is executed. Assume that,
         in this example, the instruction will trigger a floating-
         point divide-by-zero exception.

      2  This STEP command executes the VVDIVD instruction. Note,
         however, that the exception is not delivered at this point
         in the execution of the program.

      3  The EXAMINE/FLOAT command displays a decoded exception
         message in element 1 of the destination register, V2. This
         confirms that a floating-point divide-by-zero exception was
         triggered and is pending delivery.

      4  The SYNCHRONIZE VECTOR_MODE command forces the immediate
         delivery of the pending vector exception.