In a deeply pipelined superscalar processor, what is the purpose of a "reorder buffer" (ROB)?
Correct! Well done.
Incorrect.
The correct answer is A) It temporarily holds the results of instructions executed out of order, allowing them to be committed (written to architectural state) in the original program order to maintain correct program semantics and support precise exception handling
Correct Answer
It temporarily holds the results of instructions executed out of order, allowing them to be committed (written to architectural state) in the original program order to maintain correct program semantics and support precise exception handling
Out-of-order execution can complete instructions in any order, but the architectural state must appear as if instructions executed in program order; the ROB tracks completed instructions and commits results in order, also enabling precise exceptions and speculative execution rollback.