beginning of this area and only upon encountering this breakpoint by all processors the breakpoint in the procedure is activated after all processors are stopped again at the backup breakpoint at the end of this area the breakpoint in the procedure is deactivated again this corresponds to a feature known as conditional breakpointing in sequential debuggers also in accordance with the invention if a breakpoint is set inside a procedure backup breakpoints may be located outside of the procedure as shown in fig5 in this case the debugger evaluates the call chain of the program if the procedure is called from a plurality of code locations backup points are set such that all these procedure calls are covered the implementation of a hpf parallel debugger requires debugger support from the parallelizing compiler which goes beyond a conventional symbol table as already mentioned it is necessary to provide a run time variable to determine the status of a program e g extrinsic routine hpf code once the program is stopped further it is necessary to provide a mapping from any variable of the hpf code at any program status to the local name of the copy of this variable on all processes which own or use such a copy it is also required to provide a mapping from an instruction of the hpf code to an instruction of the process code and back moreover for each instruction of the hpf code it must be determined whether this instruction belongs to a program segment with common control flow or to a program segment where each process may potentially execute different code in the last case the location of the backup.