摘要:
A system, method, and program product are provided that identifies a cache set using Translation LookAside Buffer (TLB) attributes. When a virtual address is requested, the method, system, and program product identifies a cache set using buffer attributes. When a virtual address is received, an attempt is made to load the received virtual address from a cache. When the attempt results in a cache miss, a page is identified within a Translation LookAside Buffer that includes the virtual address. A class identifier is then retrieved from the identified page, with the class identifier identifying a cache set that is selected from the cache.
摘要:
A method, system and processor for improving the performance of an in-order processor. A processor may include an execution unit with an execution pipeline that includes a backup pipeline and a regular pipeline. The backup pipeline may store a copy of the instructions issued to the regular pipeline. The execution pipeline may include logic for allowing instructions to flow from the backup pipeline to the regular pipeline following the flushing of the instructions younger than the exception detected in the regular pipeline. By maintaining a backup copy of the instructions issued to the regular pipeline, instructions may not need to be flushed from separate execution pipelines and re-fetched. As a result, one may complete the results of the execution units to the architected state out of order thereby allowing the completion point to vary among the different execution pipelines.
摘要:
A write-through cache scheme is created. A store data command is sent to a cache line of a cache array from a processing unit. It is then determined whether the address of the store data is valid, wherein the original data from the store's address has been previously loaded into the cache. A write-through command is sent to a system bus as a function of whether the address of the store data is valid. The bus controller is employed to sense the write-through command. If the write-through command is sensed, a clean command is generated by the bus controller. If the write-through command is sensed, the store data is written into the cache array, and the data is marked as modified. If the write-through command is sensed, the clean command is sent onto the system bus by the bus controller, thereby causing modified data to be written to memory.
摘要:
A system and method for a high frequency stall design is presented. An issue unit includes a first instruction stage, a second instruction stage, and issue control logic. During a first instruction cycle, the issue unit performs two tasks, which are 1) the instructions located in the first instruction stage are moved to a second instruction stage, and 2) the issue control logic determines whether to issue or stall the instructions that are moved to the second instruction stage based upon their particular instruction attributes and the issue control unit's previous state. During a second instruction cycle that immediately follows the first instruction cycle, the second instruction stage's instructions are either issued or stalled based upon the issue control logic's decision from the first instruction cycle.
摘要:
The present invention provides for supporting an on chip-timer facility and, more particularly, to the generation of a constant time incremental increase while changing core mesh-clock frequency. A latch is coupled to the output of a first free-running clock. An inverter is coupled to the output of the first latch. At least one other secondary latch is coupled to the output of the first latch. An edge detector is coupled to the output of the secondary latch. An incrementer or decrementer is coupled to the output of the edge detector. A memory is coupled to the output of the incrementer or decrementer.
摘要:
Tracking the order of issued instructions using a counter is presented. In one embodiment, a saturating, decrementing counter is used. The counter is initialized to a value that corresponds to the processor's commit point. Instructions are issued from a first issue queue to one or more execution units and one or more second issue queues. After being issued by the first issue queue, the counter associated with each instruction is decremented during each instruction cycle until the instruction is executed by one of the execution units. Once the counter reaches zero it will be completed by the execution unit. If a flush condition occurs, instructions with counters equal to zero are maintained (i.e., not flushed or invalidated), while other instructions in the pipeline are invalidated based upon their counter values.
摘要:
A processor includes a general purpose (GP) unit adapted to receive and configured to execute GP instructions; and includes a single instruction multiple data (SIMD) unit adapted to receive and configured to execute SIMD instructions. An instruction unit comprises a first logic unit coupled to the GP unit and a second logic unit coupled to the SIMD unit, wherein SIMD instructions are processed subsequent to GP instructions. In the first logic unit a GP instruction with unresolved dependencies unconditionally causes subsequent SIMD instructions to stall, and an SIMD instruction with unresolved dependencies does not cause subsequent GP instructions to stall. The first logic unit resolves dependencies in GP instructions, provides dependency-free instructions to the GP unit, and provides SIMD instructions to the second logic unit. The second logic unit resolves dependencies in SIMD instructions and provides dependency-free instructions to the SIMD unit.
摘要:
A computer implemented method and system for managing replacement of sets in a locked cache. A cache access by a program is performed, and a side of a binary tree pointed to by a base leaf is identified. A determination is made as to whether a number of accesses to the identified side of the binary tree equals a number of sets associated with the program on the identified side. The base leaf is changed to point to an opposite side of the binary tree if the number of accesses to the identified side equals the number of sets associated with the program on the identified side.
摘要:
A write-through cache scheme is created. A store data command is sent to a cache line of a cache array from a processing unit. It is then determined whether the address of the store data is valid, wherein the original data from the store's address has been previously loaded into the cache. A write-through command is sent to a system bus as a function of whether the address of the store data is valid. The bus controller is employed to sense the write-through command. If the write-through command is sensed, a clean command is generated by the bus controller. If the write-through command is sensed, the store data is written into the cache array, and the data is marked as modified. If the write-through command is sensed, the clean command is sent onto the system bus by the bus controller, thereby causing modified data to be written to memory.
摘要:
Tracking the order of issued instructions using a counter is presented. In one embodiment, a saturating, decrementing counter is used. The counter is initialized to a value that corresponds to the processor's commit point. Instructions are issued from a first issue queue to one or more execution units and one or more second issue queues. After being issued by the first issue queue, the counter associated with each instruction is decremented during each instruction cycle until the instruction is executed by one of the execution units. Once the counter reaches zero it will be completed by the execution unit. If a flush condition occurs, instructions with counters equal to zero are maintained (i.e., not flushed or invalidated), while other instructions in the pipeline are invalidated based upon their counter values.