Processor, multiprocessor system and method for data dependence speculative execution

A multiprocessor system including two or more processors for executing parallel processing in units of threads, comprising:

• thread assignment means for assigning the threads to the processors so that the threads will be executed by the processors in parallel;
• address conversion means for converting a target address of a memory operation instruction included in the threads into a corresponding entry number allowing the existence of aliases;
• speculative execution result history storage means for storing history information concerning success/failure results of speculative execution of the memory operation instructions of the past, with regard to each of the entry numbers;
• speculative execution success/failure prediction means for predicting whether the speculative execution of a memory operation instruction that is going to be carried out by a processor will succeed or fail by referring to an entry of the speculative execution result history storage means corresponding to the entry number that is obtained by the address conversion means for the target address of the memory operation instruction;
• speculation control means for letting the processor execute the memory operation instruction in out-of-order execution by means of the speculative execution if the prediction by the speculative execution success/failure prediction means is success while letting the processor execute the memory operation instruction in in-order execution by means of non-speculative execution if the prediction by the speculative execution success/failure prediction means is failure;
• speculative execution success/failure judgment means for judging whether the speculative execution of the memory operation instructions has succeeded or failed by detecting the dependence relationship between the memory operation instructions;
• and
• speculative execution result history update means for updating the history information stored in the speculative execution result history storage means taking the judgment by the speculative execution success/failure judgment means into account.

A data dependence speculative execution method for executing memory operation instructions in out-of-order execution by means of speculative execution with regard to dependence relationship between the instructions, comprising the steps of

• an address conversion step for converting a target address of the memory operation instruction into a corresponding entry number allowing the existence of aliases;
• a speculative execution result history storage step for storing history information concerning success/failure results of the speculative execution of the memory operation instructions of the past in history storage means, with regard to each of the entry numbers;
• a speculative execution success/failure prediction step for predicting whether the speculative execution of a memory operation instruction that is going to be carried out will succeed or fail by referring to an entry of the history storage means corresponding to the entry number that is obtained by the address conversion step for the target address of the memory operation instruction;
• a speculative execution step for executing the memory operation instruction in the out-of-order execution by means of the speculative execution if the prediction by the speculative execution success/failure prediction step is success;
• a non-speculative execution step for executing the memory operation instruction in in-order execution by means of non-speculative execution if the prediction by the speculative execution success/failure prediction step is failure;
• a speculative execution success/failure judgment step for judging whether the speculative execution of the memory operation instructions has succeeded or failed by detecting the dependence relationship between the memory operation instructions;
• and
• a speculative execution result history update step for updating the history information stored in the history storage means taking the judgment by the speculative execution success/failure judgment step into account.

A data dependence speculative execution method for executing parallel processing in units of threads by executing memory operation instructions in out-of-order execution by means of speculative execution with regard to dependence relationship between the instructions, comprising the steps of

• a thread assignment step for assigning the threads to two or more processors so that the threads will be executed by the processors in parallel;
• an address conversion step for converting a target address of the memory operation instruction included in the threads into a corresponding entry number allowing the existence of aliases;
• a speculative execution result history storage step for storing history information concerning success/failure results of the speculative execution of the memory operation instructions of the past in history storage means, with regard to each of the entry numbers;
• a speculative execution success/failure prediction step for predicting whether the speculative execution of a memory operation instruction that is going to be carried out by a processor will succeed or fail by referring to an entry of the history storage means corresponding to the entry number that is obtained by the address conversion step for the target address of the memory operation instruction;
• a speculative execution step for letting the processor execute the memory operation instruction in the out-of-order execution by means of the speculative execution if the prediction by the speculative execution success/failure prediction step is success;
• a non-speculative execution step for letting the processor execute the memory operation instruction in in-order execution by means of non-speculative execution if the prediction by the speculative execution success/failure prediction step is failure;
• a speculative execution success/failure judgment step for judging whether the speculative execution of the memory operation instructions has succeeded or failed by detecting the dependence relationship between the memory operation instructions;
• and
• a speculative execution result history update step for updating the history information stored in the history storage means taking the judgment by the speculative execution success/failure judgment step into account.