Abstract: A system and method for determine which threads to execute at a given time in a multi-threaded computer system. A thread prioritizer determines execution fairness between pairs of potentially executing threads. A switch enabler determines forward progress of each executing thread. The resulting indicators from the thread prioritizer and switch enabler may aid in the determination of whether or not to switch a particular potentially executing thread into execution resources.

Abstract: A method and apparatus for enabling the speculative forking of a speculative thread is disclosed. In one embodiment, a speculative fork instruction is conditioned by the results of a fork predictor. The fork predictor may issue predictions as to whether or not a speculative thread would execute desirably. The fork predictor may be implemented as a modified branch predictor circuit, and may have execution history updates entered by a determination of whether or not the execution of a speculative thread was or would have been desirable.

Abstract: A processor comprising a feature indicator associated with at least one of a first sequence of one or more instructions, a first register, a second register, and an execution core is provided. The execution core is configured to execute a second instruction to cause the first register to be set to a first value using the feature indicator and to cause the second register to be set to a second value using the feature indicator. The execution core is configured to execute the first sequence of one or more instructions to cause a function to be performed in response to the first value in the first register indicating a true condition, and the execution core is configured to execute a second sequence of one or more instructions to cause the function to be performed in response to the second value in the second register indicating the true condition.

Abstract: A system and method for determine which threads to execute at a given time in a multi-threaded computer system. A thread prioritizer determines execution fairness between pairs of potentially executing threads. A switch enabler determines forward progress of each executing thread. The resulting indicators from the thread prioritizer and switch enabler may aid in the determination of whether or not to switch a particular potentially executing thread into execution resources.