Abstract: Embodiments of the invention are generally related to image processing, and more specifically to vector units for supporting image processing. A combined vector/scalar unit is provided wherein one or more processing lanes of the vector unit are used for performing scalar operations. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated and a significant amount of chip area is saved.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: A processor includes primary threads of execution that may simultaneously issue instructions, and one or more backup threads. When a primary thread stalls, the contents of its instruction buffer may be switched with the instruction buffer for a backup thread, thereby allowing the backup thread to begin execution. This design allows two primary threads to issue simultaneously, which allows for overlap of instruction pipeline latencies. This design further allows a fast switch to a backup thread when a primary thread stalls, thereby providing significantly improved throughput in executing instructions by the processor.

Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for improved techniques for executing instructions in a pipelined manner is provided. Such techniques may reduce stalls that occur when executing dependent instructions. Stalls may be reduced by utilizing a cascaded arrangement of pipelines with execution units that are delayed with respect to each other. This cascaded delayed arrangement allows dependent instructions to be issued within a common issue group by scheduling them for execution in different pipelines to execute at different times.

Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for forwarding data in a processor is provided. The design structure includes a processor. The processor includes at least one cascaded delayed execution pipeline unit having a first and second pipeline, wherein the second pipeline is configured to execute instructions in a common issue group in a delayed manner relative to the first pipeline, and circuitry. The circuitry is configured to determine if a first instruction being executed in the first pipeline modifies data in a data register which is accessed by a second instruction being executed in the second pipeline, and if the first instruction being executed in the first pipeline modifies data in the data register which is accessed by the second instruction being executed in the second pipeline, forward the modified data from the first pipeline to the second pipeline.

Abstract: A method and apparatus for accessing a processor cache. The method includes executing an access instruction in a processor core of the processor. The access instruction provides an untranslated effective address of data to be accessed by the access instruction. The method also includes determining whether a level one cache for the processor core includes the data corresponding to the effective address of the access instruction. The effective address of the access instruction is used without address translation to determine whether the level one cache for the processor core includes the data corresponding to the effective address. If the level one cache includes the data corresponding to the effective address, the data for the access instruction is provided from the level one cache.

Abstract: Embodiments of the invention relate to methods and systems for error detection and recovery from errors during pipelined execution of data. A cascaded, delayed execution pipeline may be implemented to maintain a precise machine state. In some embodiments, a delay of one or more clock cycles may be inserted prior to a write back stage of each pipeline to facilitate error detection and recovery. Because a precise machine state is maintained error detection and recovery mechanisms may be built directly into register files of the system. If an error is detected execution of the instruction associated with the error and all subsequent instructions may be restarted.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: A method and apparatus for forwarding data in a processor. The method includes providing at least one cascaded delayed execution pipeline unit having a first pipeline and a second pipeline, wherein the second pipeline executes instructions in a common issue group in a delayed manner relative to the first pipeline. The method further includes determining if a first instruction being executed in the first pipeline modifies data in a data register which is accessed by a second instruction being executed in the second pipeline. If the first instruction being executed in the first pipeline modifies data in the data register which is accessed by the second instruction being executed in the second pipeline, the modified data is forwarded from the first pipeline to the second pipeline.

Abstract: A register file bit includes a primary latch and a secondary latch with a feedback path and a context switch mechanism that allows a fast context switch when execution changes from one thread to the next. A bit value for a second thread of execution is stored in the primary latch, then transferred to the secondary latch. The bit value for a first thread of execution is then written to the primary latch. When a context switch is needed (when the first thread stalls and the second thread needs to begin execution), the register file bit can perform a context switch from the first thread to the second thread in a single clock cycle. The register file bit contains a backup latch inside the register file itself so that minimal extra wire paths are needed to or from the existing register file.

Abstract: A method and apparatus for executing instructions. The method includes receiving a first load instruction and a second load instruction. The method also includes issuing the first load instruction and the second load instruction to a cascaded delayed execution pipeline unit having at least a first execution pipeline and a second execution pipeline, wherein the second execution pipeline executes an instruction in a common issue group in a delayed manner relative to another instruction in the common issue group executed in the first execution pipeline. The method also includes accessing a cache by executing the first load instruction and the second load instruction. A delay between execution of the first load instruction and the second load instruction allows the cache to complete the access with the first load instruction before beginning the access with the second load instruction.

Abstract: A method and apparatus for accessing a cache. The method includes receiving a request to access the cache. The request includes an address of requested data to be accessed. The method also includes using a first portion of the address to perform an access to a first directory for the cache and using a second portion of the address to perform an access to a second directory for the cache. Results from the access to the first directory for the cache and results from the access to the second directory for the cache are used to determine whether the cache includes the requested data to be accessed.

Abstract: Embodiments of the invention are generally related to image processing, and more specifically to register files for supporting image processing. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated.

Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for image processing, and more specifically to vector units for supporting image processing is provided. A combined vector/scalar unit is provided wherein one or more processing lanes of the vector unit are used for performing scalar operations. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated and a significant amount of chip area is saved.

Abstract: Embodiments of the invention are generally related to image processing, and more specifically to vector units for supporting image processing. A combined vector/scalar unit is provided wherein one or more processing lanes of the vector unit are used for performing scalar operations. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated and a significant amount of chip area is saved.

Abstract: A multiple parallel pipeline digital processing apparatus has the capability to substitute a second pipeline for a first in the event that a failure is detected in the first pipeline. Preferably, a redundant pipeline is shared by multiple primary pipelines. Preferably, the pipelines are located physically adjacent one another in an array. Preferably, a pipeline failure causes data to be shifted one position within the array of pipelines, to by-pass the failing pipeline, so that each pipeline has only two sources of data, a primary and an alternate. Preferably, selection logic controlling the selection between a primary and alternate source of pipeline data is integrated with other pipeline operand selection logic.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: In a dynamically compiling computer system, a system and method for efficiently transferring control from execution of an instruction in a first representation to a second representation of the instruction is disclosed. The system and method include the setting of a tag for entry points of each instruction in a first representation that has been translated to a second representation. The tag is stored in memory in association with each such instruction. When a given instruction in a first representation is to be executed, the tag is examined, and if it indicates that a translated version of the instruction has previously been generated, control is passed to execution of the instruction in the second representation. The second representation can be a different instruction set representation, or an optimized representation in the same instruction set as the original instruction.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: The present invention related to computer architecture, and more specifically to evaluating performance of processors. A performance monitor may be placed in an L2 cache nest of a processor. The performance monitor may monitor L2 cache accesses and receive performance data from one or more processor cores over a bus coupling the processor cores with the L2 cache nest. In one embodiment the bus may include additional lines for transferring performance data from the processor cores to the performance monitor.