Speculative execution of correlated memory access instruction methods, apparatuses and systems

Abstract

A processor core, a processor, an apparatus, and an instruction processing method are disclosed. The processor core includes: an instruction fetch unit, where the instruction fetch unit includes a speculative execution predictor and the speculative execution predictor compares a program counter of a memory access instruction with a table entry stored in the speculative execution predictor and marks the memory access instruction; a scheduler unit adapted to adjust a send order of marked memory access instructions and send the marked memory access instructions according to the send order; an execution unit adapted to execute the memory access instructions according to the send order. In the instruction fetch unit, a memory access instruction is marked according to a speculative execution prediction result. In the scheduler unit, a send order of memory access instructions is determined according to the marked memory access instruction and the memory access instructions are sent. In the execution unit, the memory access instructions are executed according to the send order. This helps avoiding re-execution of a memory access instruction due to an address correlation of the memory access instruction. Consequently, this eliminates the need of adding an idle cycle in an instruction pipeline and the need of refreshing the pipeline to clear a memory access instruction that is incorrectly speculated.