摘要:
An apparatus for storing predicted return addresses of instructions being executed by a pipelined processor, the apparatus includes a two part return address buffer that includes a speculative return address buffer and a committed return address buffer, both of which having multiple entries that may include predicted return addresses that have been pushed onto the return buffer.
摘要:
Toggling between accessing an entry in a global history with a stew created from branch predictions implied by the ordering of instructions within a trace of a trace cache when a trace is read out of a trace cache, and accessing an entry in a global history with repeatable variations of a stew when there is more than branch instruction within a trace within the trace cache and at least a second branch instruction is read out.
摘要:
In a processing core, a newly received load instruction may be dependent upon a previously received store instruction. The core may include a predictor to predict such dependencies and provide an identification of a colliding store instruction. The load instruction may be stored in a scheduler with a dependency marker. Thereafter, the load instruction may be prevented from executing until after execution of the colliding store. Upon execution of the load, the accuracy of the prediction is confirmed. Upon retirement of the load instruction, new prediction results may be provided to the predictor.
摘要:
A method and system to enable power measurements of a system-on-chip in various modes. In one embodiment of the invention, the system-on-chip has full controllability of its logic and circuitry to facilitate configuration of the system-on-chip into a desired mode of operation. This allows hooks or interfaces to access the system-on-chip externally for measurements. For example, in one embodiment of the invention, the hooks in the system-on-chip allow a backend tester to configure the system-on-chip into various modes easily to perform power consumption measurements of one or more individual components of the system-on-chip. The power consumption measurement of the individual components in the system-on-chip can be performed faster and can be more accurate. In addition, the overall yield of the SOC can be increased as it is easier to detect failure parts.
摘要:
Systems and methods of managing threads provide for supporting a plurality of logical threads with a plurality of simultaneous physical threads in which the number of logical threads may be greater than or less than the number of physical threads. In one approach, each of the plurality of logical threads is maintained in one of a wait state, an active state, a drain state, and a stall state. A state machine and hardware sequencer can be used to transition the logical threads between states based on triggering events and whether or not an interruptible point has been encountered in the logical threads. The logical threads are scheduled on the physical threads to meet, for example, priority, performance or fairness goals. It is also possible to specify the resources that are available to each logical thread in order to meet these and other, goals. In one example, a single logical thread can speculatively use more than one physical thread, pending a selection of which physical thread should be committed.
摘要:
A memory cache bank prediction unit is provided for use in a processor having a plurality of memory cache banks. The memory cache bank prediction unit has an input port that receives an instruction. The memory cache bank prediction unit also has an evaluation unit, coupled to the input port, that predicts which of the plurality of memory cache banks is associated with the instruction.
摘要:
A method and apparatus for rescheduling operations in a processor. More particularly, the present invention relates to optimally using a scheduler resource in a processor by analyzing, predicting, and sorting the write order of instructions into the scheduler so that the duration the instructions sit idle in the scheduler is minimized. The analyses, prediction, and sorting may be done between an instruction queue and a scheduler by using delay units. The prediction can be based on history (latency, dependency, and resource) or on a general prediction scheme.
摘要:
Systems and methods of processing addresses provide for receiving a full linear address of an instruction and reducing a size of the full linear address to obtain a reduced linear address. A data block can be retrieved from a data array if the reduced linear address corresponds to a tag in a tag array, where the tag array is associated with the data array. The reduced linear address enables the tag array to either be smaller in size or achieve enhanced performance. The data array may be a prediction array of a branch predictor or a cache array of a cache.
摘要:
A multi-mode predictor for a processor having a plurality of prediction modes is disclosed. The prediction modes are used to predict non-binary values. The predictor is a multi-mode predictor comprising a per-IP (“PIP”) table and a next value table. The PIP table includes a plurality of PIP information fields and the next value table includes a plurality of fields. The multi-mode predictor also includes a plurality of prediction modes. The processor includes a set of instructions that index the PIP table to provide a valid signal. The processor also includes a set of predicted values for the set of instructions. The set of predicted values is stored in the PIP table and the next value table. According to the valid signal a hit/miss condition in the next value table, a predicted value is selected from the PIP table or the next value table.
摘要:
A hybrid branch predictor is disclosed. The predictor includes prediction aiding information, a plurality of branch predictors to provide a plurality of branch predictions, a plurality of storage elements to hold less than full extent of the branch predictions, but sharing information among said plurality of storage elements enables extraction of said full extent of the prediction. The predictor also includes a selection mechanism to select a prediction from the plurality of branch predictions.