Intel Corporation
Instruction set architecture based and automatic load tracking for opportunistic re-steer of data-dependent flaky branches

Abstract:

Methods and apparatuses relating to instruction set architecture (ISA) based and automatic load tracking hardware for opportunistic re-steer of data-dependent flaky branches are described. In one embodiment, a processor includes a pipeline circuit comprising a decoder to decode instructions into decoded instructions and an execution circuit to execute the decoded instructions, a branch predictor circuit to generate a predicted path for a branch instruction, and a branch re-steer circuit to, for the branch instruction dependent on a result from a load instruction, check if an instruction received by the pipeline circuit is the load instruction, and when the instruction received by the pipeline circuit is the load instruction, check for a write back of the result from the load instruction between a decode of the branch instruction with the decoder and an execution of the branch instruction with the execution circuit, and when the predicted path differs from a path based on the result from the load instruction, re-steer the branch instruction in the pipeline circuit to the path and cause execution of the branch instruction for the path based on the result from the load instruction.