Multiple job signals per processing unit in a multiprocessing system

A processing system having multiple processing units for processing parallel job signals, said processing system comprising:

• a selected processing unit having commit priority, said selected processing unit executing a priority job non-speculatively;
• for at least one of the multiple processing units that does not have commit priority,
• means for assigning a first job signal to the processing unit that does not have commit priority for speculative execution of a corresponding first job in parallel with the non-speculative execution of the priority job;
• means for determining that the processing unit that does not have commit priority has completed speculative execution of the first job prior to completion of the non-speculative execution of the priority job by the selected processing unit having commit priority;
• a write queue for temporarily storing results of the speculatively executed first job;
• and
• means for assigning a further job signal to the processing unit that does not have commit priority for speculative execution of a corresponding further job in parallel with the non-speculative execution of the priority job;
• means for determining that the processing unit having commit priority has completed non-speculative execution of the priority job;
• means for determining whether the speculatively executed first job now has commit priority;
• and
• means for retrieving the results of the speculatively executed first job from the write queue upon determining that the speculatively executed first job now has commit priority.

A method of handling job signals in a processing system having multiple processing units for parallel job signal processing, said method comprising the steps of:

• assigning a priority job signal to a selected processing unit having commit priority;
• non-speculatively executing a corresponding priority job by the selected processing unit;
• assigning a first job signal to a processing unit that does not have commit priority;
• speculatively executing by the processing unit that does not have commit priority, a first job corresponding to the first job signal, said first job being executed in parallel with the non-speculative execution of the priority job;
• determining whether the processing unit that does not have commit priority completes speculative execution of the first job prior to completion of the non-speculative execution of the priority job by the selected processing unit having commit priority;
• upon determining that the processing unit that does not have commit priority completes speculative execution of the first job prior to completion of the non-speculative execution of the priority job:
• temporarily storing results of the speculatively executed first job in a write queue;
• assigning a second job signal to the processing unit that does not have commit priority;
• and
• speculatively executing a second job corresponding to the second job signal in parallel with the non-speculative execution of the priority job;
• upon determining that the selected processing unit having commit priority completes non-speculative execution of the priority job prior to completion of the speculative execution of the first job by the processing unit that does not have commit priority:
• writing back results of the priority job to a memory system;
• assigning a further job signal to the selected processing unit having commit priority;
• and
• speculatively or non-speculatively executing a further job corresponding to the further job signal in parallel with the speculative execution of the first job by the processing unit that does not have commit priority.