Abstract: A branch history table cache is a write cache that stores values of branch history counters written to a branch history table. An update to a branch history table counter is reflected in both the branch history table cache and the branch history table. Before a branch history table counter is updated, a check is made to see if the branch history table counter is in the cache. If not, the branch history table counter is updated based on a value of the branch history table counter that was saved during fetch of the branch history table counter. If, however, the branch history table counter value is in the cache, the value in the cache is used to update the branch history table counter. All branches that use the branch history table counter update the correct counter value, improving processor performance by providing more accurate predictions of branches taken.

Abstract: A branch history table cache is a write cache that stores values of branch history counters written to a branch history table. An update to a branch history table counter is reflected in both the branch history table cache and the branch history table. Before a branch history table counter is updated, a check is made to see if the branch history table counter is in the cache. If not, the branch history table counter is updated based on a value of the branch history table counter that was saved during fetch of the branch history table counter. If, however, the branch history table counter value is in the cache, the value in the cache is used to update the branch history table counter. All branches that use the branch history table counter update the correct counter value, improving processor performance by providing more accurate predictions of branches taken.