Abstract: Techniques described herein provide for sending and receiving messages. The messages are associated with streams. Indicators associated with the streams determine if the messages are sent.

Abstract: Embodiments involve an embedded processing element that fetches at least two possible next instructions (control words) in parallel in one cycle, and executes one of them during the following cycle based on the result of a conditional branch test. Embodiments reduce or avoid branch penalties (zero penalty branches).

Abstract: A system comprises a processor, a reassembly buffer that receives mini-packets, and at least one data structure that comprises bits. The bits indicate the presence or absence of each of the mini-packets in the reassembly buffer and further indicate whether one of the mini-packets is a final mini-packet in a series of the mini-packets. The processor uses the bits to determine whether all mini-packets forming the series are present in the reassembly buffer. As a result of the determination, the processor causes the series to be read from the reassembly buffer.

Abstract: A credit-based method for controlling data communications in a computer system between a sender and a receiver coupled by an ordered communication link is described herein. A request for a credit check is transmitted from the sender to the receiver via the ordered communication link. An initial number of credits are allocated to the sender in a credit counter. A snapshot counter is set to a value of the credit counter and us updated as returned credits are received. A number of reported credits are determined based on a credit check response message received from the receiver. The returned credits are ordered relative to the credit check response message. The number of credits is checked for consistency based on a number of the snapshot counter and the number of reported credits.

Abstract: The present invention provides for a method and system for ensuring error containment in packet based systems which are capable of large scaleability. In operation, an error bit travels with each data packet and if the bit is set any device which receives the data packet acts to contain that packet. Thus, the error message travels only as far as the error data and does not stop processing at locations not affected by the error. Any system resource, upon receipt of a set error bit, must act to correct the fault.

Abstract: Embodiments involve an embedded processing element that fetches at least two possible next instructions (control words) in parallel in one cycle, and executes one of them during the following cycle based on the result of a conditional branch test. Embodiments reduce or avoid branch penalties (zero penalty branches).

Abstract: Systems, methods, and machine-readable media are disclosed for routing communications to a storage area network (SAN). In one embodiment, the machine-readable media includes first program code to determine a route path through a gateway to a SAN for each of a plurality of addresses of an interface of a server. The first program code determines the route path by applying an algorithm to one or more numerical values associated with the address. The machine-readable media includes second program code to configure the gateway with the route paths.

Abstract: In a multitasking computer system, data is preloaded into cache memory upon the occurrence of a context switch. To this end, processing circuitry stops executing a computer program during a first context switch in response to a first context switch command. Later, the processing circuitry resumes executing the computer program during a second context switch in response to a second context switch command. The memory control circuitry, in response to the second context switch command, identifies an address of computer memory that is storing a data value previously used to execute an instruction of the computer program prior to the first context switch. The memory control circuitry then retrieves the data value from the computer memory and stores the retrieved data value in the cache memory.

Abstract: Method and apparatus for conditioning program control flow on the presence of requested data in a cache memory. In a data processing system that includes a cache memory and a system memory coupled to a processor, in various embodiments program control flow is conditionally changed based on whether the data referenced in an instruction are present in the cache memory. When an instruction that includes a data reference and an alternate control path is executed, the control flow of the program is changed in accordance with the alternate control path if the referenced data are not present in the cache memory. The alternate control path is either explicitly specified or implicit in the instruction.

Abstract: The present invention provides a method (FIG. 6) and an apparatus that enable spare instruction slots within a code module to be utilized opportunistically for insertion of instructions associated with correctness check functions. During the generation of the initial instruction schedule, the compiler examines the initial instruction schedule and determines locations of spare instruction slots that can potentially be utilized for insertion of the correctness check code sequences. If a sufficient number of spare instruction slots exist to accommodate the correctness check code sequences, the sequences are inserted into the instruction schedule. If an insufficient number of spare instruction slots exist to accommodate a code sequence, the compiler adds additional instruction slots if a sufficient number of additional instruction slots can be added for insertion of the check sequences without exceeding a run-time performance cost tolerance level designated by a user.

Abstract: Method and apparatus for resuming execution of a failed computer program. A program is compiled using two compilers to generate first and second sets of object code. Checkpoints are identified in the program, and checkpoint code is generated for execution at the checkpoints. If execution of the first set of object code fails, checkpoint data is recovered and execution of the program is resumed using either the first or second set of object code. In one embodiment, the first set of object code is re-executed before trying the second set of object code.

Abstract: The present invention provides for a method and system for ensuring error containment in packet based systems which are capable of large scaleability. In operation, an error bit travels with each data packet and if the bit is set any device which receives the data packet acts to contain that packet. Thus, the error message travels only as far as the error data and does not stop processing at locations not affected by the error. Any system resource, upon receipt of a set error bit, must act to correct the fault.

Abstract: Compiler-based checkpointing for error recovery. In various embodiments, a compiler is adapted to identify checkpoints in program code. Sets of data objects are associated with the checkpoints, and checkpoint code is generated by the compiler for execution at the checkpoints. The checkpoint code stores state information of the associated data objects for recovery if execution of the program is interrupted.

Abstract: The present invention provides for a method and system for ensuring error containment in packet based systems which are capable of large scaleability. In operation, an error bit travels with each data packet and if the bit is set, any device which receives the data packet acts to contain that packet. Thus, the error message travels only as far as the error data and does not stop processing at locations not affected by the error. Any system resource, upon receipt of a set error bit, must act to correct the fault.

Abstract: Method and apparatus for conditioning program control flow on the presence of requested data in a cache memory. In a data processing system that includes a cache memory and a system memory coupled to a processor, in various embodiments program control flow is conditionally changed based on whether the data referenced in an instruction are present in the cache memory. When an instruction that includes a data reference and an alternate control path is executed, the control flow of the program is changed in accordance with the alternate control path if the referenced data are not present in the cache memory. The alternate control path is either explicitly specified or implicit in the instruction.

Abstract: A method and an apparatus are provided for reducing cache memory misses in a computer that performs context switches between at least a first context and a second context. First logic identifies at least a first prefetch region in a first memory element during compilation of a computer program by the computer. Second logic identifies critical memory references within the first prefetch region during compilation. The critical memory references within the first prefetch region correspond to data that may be needed in cache memory if a context switch occurs from a process or thread associated with the second context to a process or thread associated with the first context during program execution by the computer. Third logic prefetches data associated with the identified critical memory references and stores the prefetched data in cache memory prior to a process or thread associated with the first context being resumed when a switch from the second context to the first context occurs during program execution.

Abstract: In general, a system and method is provided for dynamically reallocating computer memory. A mapper receives requests to access data. The requests include bus addresses, and the mapper maps the bus addresses to memory unit addresses based on a plurality of mappings maintained by the mapper. The memory unit addresses identify a plurality of memory locations including a destination memory location and a source memory location. Data requested by the requests received by the mapper is accessed based on the memory unit addresses mapped from the bus addresses included in the requests. When desired, a data value from the source memory location is dynamically moved to the destination memory location, and the mappings are updated such that a bus address mapped to a memory unit address identifying the source memory location is instead mapped to a memory unit address identifying the destination memory location.

Abstract: A shared bus system having a bus and a set of client modules coupled to the bus. Each client module is capable of sending transactions on the bus to other client modules and receiving transactions on the bus from other client modules for processing. Each module has a queue for storing transactions received by the module for processing. A bus controller limits the types of transactions that can be sent on the bus to prevent any module's queue from overflowing.

Abstract: A computer apparatus incorporating special instructions to force load and store operations to execute in program order. The present invention provides a new and novel store instruction that is suspended until all prior store instructions have been completed by an associated CPU. Also, a new load instruction is provided which blocks any subsequent load instructions from executing until this load instruction has been completed by an associated CPU. These instructions allow for high efficiency computer systems to be implemented which optimize instruction throughput by executing subsequent instructions while waiting for a prior instruction to complete.

Abstract: A method and apparatus for transferring data from a first memory location to a second memory location in a computer system. A load instruction is executed, and, in response, data is transferred from a first memory location to a second memory location during a single bus transaction. During the same bus transaction, a request is made to invalidate a copy of the data that is stored in a third memory location if the load instruction indicates to do so.