Iterative process partner pairing scheme for global reduce operation

A computer program product embodied in non-transitory computer readable medium for gathering results of a computing operation distributed among a plurality of processes, the computer program product comprising:

• program code for pairing the plurality of processes such that each process has at least one interaction partner;
• program code for transmitting a result of one or more computing operations from a process to the interaction partner of the process;
• program code for iterating over the pairing and transmitting operations, wherein pairing operations subsequent to the first pairing operation associate a process with an interaction partner with which the process has not previously been paired;
• wherein the result of one or more computing operations comprises results of computing operations received at the process during previous iterations
• program code for assigning a number to each of the plurality of processes, wherein no two processes are assigned the same number;
• program code for calculating the exclusive or of the number of a process and a mask and performing the first pairing operation such that a process is associated with an interaction partner having a number equal to the result of the calculating operation;
• program code for repeatedly performing the exclusive or calculation for each pairing operation subsequent to the first pairing operation, wherein the mask contains a value not used in a preceding pairing operation;
• wherein the iterating program code causes a next pairing operation subsequent to a first pairing operation to associate the process with a subsequent interaction partner with which the process has not previously been paired;
• and
• wherein the result of one or more computing operations comprises results of computing operations received at the process during previous iterations.