Determining an optimal path to search a branch target buffer

A computer system comprising:

• a processor set;
• a set of one or more computer-readable storage media;
• and
• program instructions, collectively stored in the set of one or more computer-readable storage media, for causing the processor set to perform the following computer operations:
• generate initial branch target buffer (BTB) search index results in a first stream of BTB search index results for the program instructions by searching a first accelerator optimized to minimize prediction latency, wherein the first accelerator is a first memory device coupled to the processor set;
• add the initial BTB search index results as tentative items in a search index list;
• generate other BTB search index results in a second stream of BTB search index results for the program instructions by searching a second accelerator optimized to maximize capacity, the second accelerator running concurrently with the first accelerator, wherein the second accelerator is a second memory device coupled to the processor set, the second memory device having a capacity greater than the first memory device;
• determine one or more differences between one or more results of the other BTB search index results and one or more results of the initial BTB search index results based on a comparison between respective results in the other BTB search index results and the initial BTB search index results;
• and
• in response to determining the one or more differences, replace the one or more results of the initial BTB search index results in the search index list with the one or more results of the other BTB search index results in order to execute the one or more results of the other BTB, thereby improving a speed of the execution of the program instructions.

A computer program product comprising:

• a set of one or more computer-readable storage media;
• and
• program instructions, collectively stored in the set of one or more computer-readable storage media, for causing a processor set to perform the following computer operations:
• generate initial branch target buffer (BTB) search index results in a first stream of BTB search index results for the program instructions by searching a first accelerator optimized to minimize prediction latency, wherein the first accelerator is a first memory device coupled to the processor set;
• add the initial BTB search index results as tentative items in a search index list;
• generate other BTB search index results in a second stream of BTB search index results for the program instructions by searching a second accelerator optimized to maximize capacity, the second accelerator running concurrently with the first accelerator, wherein the second accelerator is a second memory device coupled to the processor set, the second memory device having a capacity greater than the first memory device;
• determine one or more differences between one or more results of the other BTB search index results and one or more results of the initial BTB search index results based on a comparison between respective results in the other BTB search index results and the initial BTB search index results;
• and
• in response to determining the one or more differences, replace the one or more results of the initial BTB search index results in the search index list with the one or more results of the other BTB search index results in order to execute the one or more results of the other BTB, thereby improving a speed of the execution of the program instructions.