Register Rename Maps for Precise Exception Semantics

The gated store buffer is designed to serve multiple functions within the processor architecture. It not only provides precise exception semantics by controlling store commit timing, but also supports out-of-order execution, enables speculative execution, and manages register renaming. By making this single hardware structure multi-functional, the patent reduces overall hardware complexity compared to implementing separate dedicated structures for each function.

The patent changes the operational parameters of the store buffer by introducing a gate control mechanism that dynamically controls when stores are committed to memory. Instead of a simple write-through or write-back buffer, the gated store buffer allows selective delaying of store operations based on exception conditions and commit status. This parameter change enables the buffer to adapt its behavior to different execution scenarios, providing precise exception handling without requiring complex additional hardware.

The patent implements preliminary actions by maintaining a gated store buffer that records store operations before they are committed to memory. When an exception occurs, the system can revert to a previous safe state by flushing the gated store buffer, thereby discarding any speculative or out-of-order store operations that were not yet committed. This preliminary recording of operations allows the system to maintain exception precision even while permitting out-of-order execution to proceed.

The system implements feedback mechanisms by monitoring the commit status of instructions and using this information to control the gating of store operations. When an exception is detected or a commit boundary is reached, the feedback signal triggers a flush of the gated store buffer, ensuring that only committed operations remain. This feedback loop allows the system to dynamically adjust the gating behavior to maintain exception precision while maximizing out-of-order execution benefits.