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 converting memory instructions to prefetch operations during a thread switch window is disclosed. In one embodiment, memory access instructions that are already inside an instruction pipeline when the current thread is switched out may be decoded and then converted to the complementary prefetch operations. The prefetch operation may place the data into the cache during the execution of the alternate thread.

Abstract: In a multi-threaded processor, a long latency data dependent thread is flushed from the execution pipelines. Once the stalled thread is flushed, the non-stalling threads in the pipeline can continue their execution. Several resources are used to reduce this unwanted impact of stalls on the non-stalling threads. Also, these resources ensure that the earlier stalled thread, now flushed, is re-executed when the data dependency is resolved.

Abstract: A method and apparatus for improving dispersal performance of instruction threads is described. In one embodiment, the dispersal logic determines whether the instructions supplied to it include any NOP instructions. When a NOP instruction is detected, the dispersal logic places the NOP into a no-op port for execution. All other instructions are distributed to the proper execution pipes in a normal manner. Because the NOP instructions do not use the execution resources of other instructions, all instruction threads can be executed in one cycle.

Abstract: An multi-threading processor is provided. The multi-threading processor includes a front end module, an execution module coupled to the front end module, and a state module coupled to both the front end module and the execution module. The processor also includes a switch logic module, which is coupled to the state module. The switch logic module detects switching events and mispredicted branches and conceals switch latency by attempting to schedule switches to other software threads during the latencies of the mispredicted branches.

Abstract: A pipelined look-up in a content addressable memory disclosed. In one embodiment, a content addressable memory includes a first cell and a second cell. The first cell is to compare a first bit of look-up data to a first bit of stored data. The second cell is to compare a second bit of look-up data to a second bit of stored data, and to generate a signal to disable the first cell if the second bit of look-up data does not match the second bit of stored data.

Abstract: A resource management system and method is disclosed. The resource management system and method enable first and second instructions, each of which requires access to a memory resource, to be processed in an instruction pipeline at the same time. The resource management system and method manage the memory resource to prevent a data hazard based on an order of receipt of a first instruction response and a second instruction response.

Abstract: A method and apparatus for improving dispersal performance of instruction threads is described. In one embodiment, the dispersal logic determines whether the instructions supplied to it include any NOP instructions. When a NOP instruction is detected, the dispersal logic places the NOP into a no-op port for execution. All other instructions are distributed to the proper execution pipes in a normal manner. Because the NOP instructions do not use the execution resources of other instructions, all instruction threads can be executed in one cycle.

Abstract: A method and apparatus for improving dispersal performance of instruction threads is described. In one embodiment, the dispersal logic determines whether the instructions supplied to it include any NOP instructions. When a NOP instruction is detected, the dispersal logic places the NOP into a no-op port for execution. All other instructions are distributed to the proper execution pipes in a normal manner. Because the NOP instructions do not use the execution resources of other instructions, all instruction threads can be executed in one cycle.

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 converting memory instructions to prefetch operations during a thread switch window is disclosed. In one embodiment, memory access instructions that are already inside an instruction pipeline when the current thread is switched out may be decoded and then converted to the complementary prefetch operations. The prefetch operation may place the data into the cache during the execution of the alternate thread.

Abstract: A method and apparatus for a processor is described. In one embodiment, in a processor capable of executing multiple instructions simultaneously, simplified execution units are utilized that execute those instructions which are predicated-off. Dispersal logic is described that maps predicated-off instructions to these simplified execution units at appropriate times in order to enhance system performance.

Abstract: A resource management system and method is disclosed. The resource management system and method enables multiple instructions that access the same memory resource to be processed at the same time without write after write data hazards.

Abstract: In a multi-threaded processor, a long latency data dependent thread is flushed from the execution pipelines. Once the stalled thread is flushed, the non-stalling threads in the pipeline can continue their execution. Several resources are used to reduce this unwanted impact of stalls on the non-stalling threads. Also, these resources ensure that the earlier stalled thread, now flushed, is re-executed when the data dependency is resolved.

Abstract: A method and apparatus for improving dispersal performance of instruction threads is described. In one embodiment, the dispersal logic determines whether the instructions supplied to it include any NOP instructions. When a NOP instruction is detected, the dispersal logic places the NOP into a no-op port for execution. All other instructions are distributed to the proper execution pipes in a normal manner. Because the NOP instructions do not use the execution resources of other instructions, all instruction threads can be executed in one cycle.

Abstract: An multi-threading processor is provided. The multi-threading processor includes a front end module, an execution module coupled to the front end module, and a state module coupled to both the front end module and the execution module. The processor also includes a switch logic module, which is coupled to the state module. The switch logic module detects switching events and mispredicted branches and conceals switch latency by attempting to schedule switches to other software threads during the latencies of the mispredicted branches.