SLIDING-WINDOW, BLOCK-BASED BRANCH TARGET ADDRESS CACHE

摘要

A sliding-window, block-based branch target address cache (BTAC) comprises a plurality of entries, each entry associated with a block of instructions containing at least one branch instruction having been evaluated taken, and having a tag associated with the address of the first instruction in the block. The blocks each correspond to a group of instructions fetched from memory, such as an I-cache. Where a branch instruction is included in two or more fetch groups, it is also included in two or more instruction blocks associated with BTAC entries. The sliding-window, block-based BTAC allows for storing the branch target address (BTA) of two or more taken branch instructions that fall in the same instruction block, without providing for multiple BTA storage space in each BTAC entry, by storing BTAC entries associated with different instruction blocks, each containing at least one of the taken branch instructions.