Confidence threshold-based opposing branch path execution for branch prediction

A computer implemented method for confidence threshold-based opposing path execution for branch prediction, the method comprising:

• determining, by a processor of a computer, a branch prediction for a first branch instruction that is encountered during execution of a first thread, wherein the branch prediction indicates a primary path and an opposing path for the first branch instruction;
• executing the primary path by the first thread;
• determining a confidence of the branch prediction;
• comparing the confidence of the branch prediction to a confidence threshold;
• based on the confidence of the branch prediction being less than the confidence threshold, starting a second thread that executes the opposing path of the first branch instruction, wherein the second thread is executed in parallel with the first thread, wherein the second thread is started as a transaction that executes in a transactional memory of the processor;
• determining a branch resolution of the first branch instruction, wherein the branch resolution indicates whether one of the primary path and the opposing path comprises a correct path of the first branch instruction;
• based on the branch resolution of the first branch instruction indicating that the opposing path is the correct path of the first branch instruction, aborting the first thread;
• based on the branch resolution of the first branch instruction indicating that the primary path is the correct path of the first branch instruction, aborting the second thread;
• based on the branch resolution of the first branch instruction indicating that the opposing path is the correct path of the first branch instruction, ending and committing the transaction corresponding to the second thread;
• and
• based on the branch resolution of the first branch instruction indicating that the primary path is the correct path of the first branch instruction, rolling back the transaction corresponding to the second thread.