Patent application number | Description | Published |
20080250275 | Program Counter (PC) Trace - In one embodiment, an integrated circuit comprises a first processor configured to output program counter (PC) trace records, wherein PC trace records provide data indicating the PCs of instructions retired by the first processor. The integrated circuit further comprises a second source of trace records, and a trace unit coupled to receive the PC trace records from the first processor and the trace records from the second source. The trace unit comprises a trace memory into which the trace unit is configured to store the PC trace records and trace records from the second source. The trace unit is configured to interleave the PC trace records and the trace records from the second source in the trace memory according to the order of receipt of the records. | 10-09-2008 |
20100162262 | Split Scheduler - In an embodiment, a scheduler implements a first dependency array that tracks dependencies on instruction operations (ops) within a distance N of a given op and which are short execution latency ops. Other dependencies are tracked in a second dependency array. The first dependency array may evaluate quickly, to support back-to-back issuance of short execution latency ops and their dependent ops. The second array may evaluate more slowly than the first dependency array. | 06-24-2010 |
20100205384 | Store Hit Load Predictor - In one embodiment, a processor implements a store hit load predictor. The store hit load predictor is configured to monitor fetched ops in the processor, and is configured to detect stores that may have previously caused store hit load events. The store hit load predictor is configured to predict that the store will cause a store hit load event again, and is further configured to monitor subsequent fetched ops for the load. The store hit load predictor may locate the load using, e.g., an offset from the store to the load in the code sequence. In response to locating the load, the store hit load predictor may create a dependency of the load on the store, preventing the load from executing out of order with respect to the store. A store hit load event may be avoided in this fashion, at least in some cases. | 08-12-2010 |
20100218051 | Program Counter (PC) Trace - In one embodiment, an integrated circuit comprises a first processor configured to output program counter (PC) trace records, wherein PC trace records provide data indicating the PCs of instructions retired by the first processor. The integrated circuit further comprises a second source of trace records, and a trace unit coupled to receive the PC trace records from the first processor and the trace records from the second source. The trace unit comprises a trace memory into which the trace unit is configured to store the PC trace records and trace records from the second source. The trace unit is configured to interleave the PC trace records and the trace records from the second source in the trace memory according to the order of receipt of the records. | 08-26-2010 |
20110246836 | Program Counter (PC) Trace - In one embodiment, an integrated circuit comprises a first processor configured to output program counter (PC) trace records, wherein PC trace records provide data indicating the PCs of instructions retired by the first processor. The integrated circuit further comprises a second source of trace records, and a trace unit coupled to receive the PC trace records from the first processor and the trace records from the second source. The trace unit comprises a trace memory into which the trace unit is configured to store the PC trace records and trace records from the second source. The trace unit is configured to interleave the PC trace records and the trace records from the second source in the trace memory according to the order of receipt of the records. | 10-06-2011 |
20120290818 | Split Scheduler - In an embodiment, a scheduler implements a first dependency array that tracks dependencies on instruction operations (ops) within a distance N of a given op and which are short execution latency ops. Other dependencies are tracked in a second dependency array. The first dependency array may evaluate quickly, to support back-to-back issuance of short execution latency ops and their dependent ops. The second array may evaluate more slowly than the first dependency array. | 11-15-2012 |
Patent application number | Description | Published |
20130111191 | PROCESSOR INSTRUCTION ISSUE THROTTLING | 05-02-2013 |
20130132781 | Program Counter (PC) Trace - In one embodiment, an integrated circuit comprises a first processor configured to output program counter (PC) trace records, wherein PC trace records provide data indicating the PCs of instructions retired by the first processor. The integrated circuit further comprises a second source of trace records, and a trace unit coupled to receive the PC trace records from the first processor and the trace records from the second source. The trace unit comprises a trace memory into which the trace unit is configured to store the PC trace records and trace records from the second source. The trace unit is configured to interleave the PC trace records and the trace records from the second source in the trace memory according to the order of receipt of the records. | 05-23-2013 |
20130191677 | Regional Clock Gating and Dithering - A system and method for dithering a clock signal during idle times is disclosed. An integrated circuit (IC) includes a number of functional units and a clock tree. The clock tree includes a root level clock-gating circuit, a number of regional clock-gating circuits, and a number of leaf level clock-gating circuits. The root level clock-gating circuit is coupled to distribute an operating clock signal to the regional clock-gating circuits, while the regional clock-gating circuits are each configured to distribute the operating clock signal to correspondingly coupled ones of the leaf level clock-gating circuits. The IC may further include a control unit configured to monitor activity levels and indications from each of the functional units. The control unit may cause the root clock-gating circuit to dither the clock signal if the IC is idle, wherein dithering includes reducing the duty cycle and the effective frequency of the operating clock signal. | 07-25-2013 |
20130275720 | ZERO CYCLE MOVE - A system and method for reducing the latency of data move operations. A register rename unit within a processor determines whether a decoded move instruction is eligible for a zero cycle move operation. If so, control logic assigns a physical register identifier associated with a source operand of the move instruction to the destination operand of the move instruction. Additionally, the register rename unit marks the given move instruction to prevent it from proceeding in the processor pipeline. Further maintenance of the particular physical register identifier may be done by the register rename unit during commit of the given move instruction. | 10-17-2013 |
20130290680 | OPTIMIZING REGISTER INITIALIZATION OPERATIONS - A system and method for efficiently reducing the latency of initializing registers. A register rename unit within a processor determines whether prior to an execution pipeline stage it is known a decoded given instruction writes a particular numerical value in a destination operand. An example is a move immediate instruction that writes a value of 0 in its destination operand. Other examples may also qualify. If the determination is made, a given physical register identifier is assigned to the destination operand, wherein the given physical register identifier is associated with the particular numerical value, but it is not associated with an actual physical register in a physical register file. The given instruction is marked to prevent it from proceeding to an execution pipeline stage. When the given physical register identifier is used to read the physical register file, no actual physical register is accessed. | 10-31-2013 |
20130290681 | REGISTER FILE POWER SAVINGS - A system and method for efficiently reducing the power consumption of register file accesses. A processor is operable to execute instructions with two or more data types, each with an associated size and alignment. Data operands for a first data type use operand sizes equal to an entire width of a physical register within a physical register file. Data operands for a second data type use operand sizes less than an entire width of a physical register. Accesses of the physical register file for operands associated with a non-full-width data type do not access a full width of the physical registers. A given numerical value may be bypassed for the portion of the physical register that is not accessed. | 10-31-2013 |
20130298127 | LOAD-STORE DEPENDENCY PREDICTOR CONTENT MANAGEMENT - Methods and apparatuses for managing load-store dependencies in an out-of-order processor. A load store dependency predictor may include a table for storing entries for load-store pairs that have been found to be dependent and execute out of order. Each entry in the table includes a counter to indicate a strength of the dependency prediction. If the counter is above a threshold, a dependency is enforced for the load-store pair. If the counter is below the threshold, the dependency is not enforced for the load-store pair. When a store is dispatched, the table is searched, and any matching entries in the table are armed. If a load is dispatched, matches on an armed entry, and the counter is above the threshold, then the load will wait to issue until the corresponding store issues. | 11-07-2013 |
20130326198 | LOAD-STORE DEPENDENCY PREDICTOR PC HASHING - Methods and processors for managing load-store dependencies in an out-of-order instruction pipeline. A load store dependency predictor includes a table for storing entries for load-store pairs that have been found to be dependent and execute out of order. Each entry in the table includes hashed values to identify load and store operations. When a load or store operation is detected, the PC and an architectural register number are used to create a hashed value that can be used to uniquely identify the operation. Then, the load store dependency predictor table is searched for any matching entries with the same hashed value. | 12-05-2013 |
20130339671 | ZERO CYCLE LOAD - A system and method for reducing the latency of load operations. A register rename unit within a processor determines whether a decoded load instruction is eligible for conversion to a zero-cycle load operation. If so, control logic assigns a physical register identifier associated with a source operand of an older dependent store instruction to the destination operand of the load instruction. Additionally, the register rename unit marks the load instruction to prevent it from reading data associated with the source operand of the store instruction from memory. Due to the duplicate renaming, this data may be forwarded from a physical register file to instructions that are younger and dependent on the load instruction. | 12-19-2013 |
20140013085 | LOW POWER AND HIGH PERFORMANCE PHYSICAL REGISTER FREE LIST IMPLEMENTATION FOR MICROPROCESSORS - A system and method for reducing latency and power of register renaming. A free list in processor includes multiple banks for indicating availability of register identifiers used for register renaming. A register rename unit receives one or more destination architectural registers to rename with physical register identifiers. Responsive to determining the multiple banks within the free list are unbalanced with available physical register identifiers, one or more returning physical register identifiers are assigned to the destination architectural registers before assigning any physical register identifiers from any bank of the multiple banks with a lowest number of available physical register identifiers. A returning physical register identifier is a physical register identifier that is available again for assignment to a destination architectural register but not yet indicated in the free list as available. Each of the banks includes a single bit width decoded vector for indicating availability of given physical register identifiers. | 01-09-2014 |
20140089638 | Multi-Destination Instruction Handling - Various techniques for processing instructions that specify multiple destinations. A first portion of a processor pipeline is configured to split a multi-destination instruction into a plurality of single-destination operations. A second portion of the pipeline is configured to process the plurality of single-destination operations. A third portion of the pipeline is configured to merge the plurality of single-destination operations into one or more multi-destination operations. The one or more multi-destination operations may be performed. The first portion of the pipeline may include a decode unit. The second portion of the pipeline may include a map unit, which may in turn include circuitry configured to maintain a list of free architectural registers and a mapping table that maps physical registers to architectural registers. The third portion of the pipeline may comprise a dispatch unit. In some embodiments, this may provide certain advantages such as reduced area and/or power consumption. | 03-27-2014 |
20140215188 | Multi-Level Dispatch for a Superscalar Processor - In an embodiment, a processor includes a multi-level dispatch circuit configured to supply operations for execution by multiple parallel execution pipelines. The multi-level dispatch circuit may include multiple dispatch buffers, each of which is coupled to multiple reservation stations. Each reservation station may be coupled to a respective execution pipeline and may be configured to schedule instruction operations (ops) for execution in the respective execution pipeline. The sets of reservation stations coupled to each dispatch buffer may be non-overlapping. Thus, if a given op is to be executed in a given execution pipeline, the op may be sent to the dispatch buffer which is coupled to the reservation station that provides ops to the given execution pipeline. | 07-31-2014 |
20140215190 | COMPLETING LOAD AND STORE INSTRUCTIONS IN A WEAKLY-ORDERED MEMORY MODEL - Techniques are disclosed relating to completion of load and store instructions in a weakly-ordered memory model. In one embodiment, a processor includes a load queue and a store queue and is configured to associate queue information with a load instruction in an instruction stream. In this embodiment, the queue information indicates a location of the load instruction in the load queue and one or more locations in the store queue that are associated with one or more store instructions that are older than the load instruction. The processor may determine, using the queue information, that the load instruction does not conflict with a store instruction in the store queue that is older than the load instruction. The processor may remove the load instruction from the load queue while the store instruction remains in the store queue. The queue information may include a wrap value for the load queue. | 07-31-2014 |