| 摘要 |
One embodiment of the present invention provides a system that marks memory elements based upon how information retrieved from the memory elements affects speculative program execution. This system operates by allowing a programmer to examine source code that is to be compiled into executable code for a head thread that executes program instructions, and for a speculative thread that executes program instructions in advance of the head thread. During read operations to memory elements by the speculative thread, this executable code generally causes the speculative thread to update status information associated with the memory elements to indicate that the memory elements have been read by the speculative thread. Next, the system allows the programmer to identify a given read operation directed to a given memory element, wherein a given value retrieved from the given memory element during the given read operation does not affect subsequent execution of the speculative thread. The programmer is then allowed to insert a hint into the source code specifying that the speculative thread is not to update status information during the given read operation directed to the given memory element. Next, the system compiles the source code, including the hint, into the executable code, so that during the given read operation, the executable code does not cause the speculative thread to update status information associated with the given memory element to indicate that the given memory element has been read by the speculative thread. |
