Abstract: Embodiments of the invention are directed to a DEFLATE compression accelerator and to a method for verifying the correctness of the DEFLATE compression accelerator. The accelerator includes an input buffer and a Lempel-Ziv 77 (LZ77) compressor communicatively coupled to an output of the input buffer. A switch is communicatively coupled to the output of the input buffer and to the output of the LZ77 compressor. The switch is configured to bypass the LZ77 compressor during a compression test. The accelerator further includes a deflate Huffman encoder communicatively coupled to an output of the switch and an output buffer communicatively coupled to the deflate Huffman encoder. When the switch is not bypassed, the compressor can be modified to produce repeatable results.

Abstract: Embodiments of the invention are directed to a DEFLATE compression accelerator and to a method for verifying the correctness of the DEFLATE compression accelerator. The accelerator includes an input buffer and a Lempel-Ziv 77 (LZ77) compressor communicatively coupled to an output of the input buffer. A switch is communicatively coupled to the output of the input buffer and to the output of the LZ77 compressor. The switch is configured to bypass the LZ77 compressor during a compression test. The accelerator further includes a deflate Huffman encoder communicatively coupled to an output of the switch and an output buffer communicatively coupled to the deflate Huffman encoder. When the switch is not bypassed, the compressor can be modified to produce repeatable results.

Abstract: Embodiments of the present invention are directed to a computer-implemented method for cache eviction. The method includes detecting a first data in a shared cache and a first cache in response to a request by a first processor. The first data is determined to have a mid-level cache eviction priority. A request is detected from a second processor for a same first data as requested by the first processor. However, in this instance, the second processor has indicated that the same first data has a low-level cache eviction priority. The first data is duplicated and loaded to a second cache, however, the data has a low-level cache eviction priority at the second cache.

Abstract: A method is provided that is executable by a processor of a computer. Note that the processor is communicatively coupled to a memory of the computer, and the memory stores a response block of a call command. In implementing the method, the processor defines a sub-functions field in the response block of the call command. Further the processor indicates that a set of functions of a set of instructions are installed and available at an interface based on a corresponding sub-functions flag within the sub-functions field being set. Note that the interface is also being executed on the computer and that the set of functions being represented by the corresponding sub-functions flag. The processor further indicates that the set of functions of the set of instructions are not installed based on the corresponding sub-functions flag not being set.

Abstract: Methods, systems, and computer program products for queue management are provided. Aspects include receiving a first queue entry and storing the first queue entry in a queue at a first location, wherein the first queue entry includes a first target destination, receiving a second queue entry and storing the second queue entry in the queue at a second location, wherein the second queue entry includes a second target destination, tracking a relative age for each of the first queue entry and the second queue entry, transmitting the first queue entry to the first target destination based at least in part on the relative age for the first queue entry being greater than the relative age for the second queue entry, and receiving a third queue entry and storing the third queue entry in the queue at the first location.

Abstract: A method is provided that includes receiving, by a firmware from an originating software, an asynchronous request for an instruction of an algorithm for compression of data. The firmware operates on a first processor and the originating software operates on a second processor. The firmware issues a synchronous request to the first processor to cause the processor to execute the instruction synchronously. It is determined, by the firmware, whether an interrupt is received from the first processor with respect to the first processor executing the instruction. The firmware retries the issuance of the synchronous request each time the interrupt is received until a retry threshold is reached.

Abstract: A system architecture is provided and includes an on-chip coherency unit, a processing unit, an accelerator and dedicated wiring. The processing unit is communicative with the on-chip coherency unit via a first interface. The accelerator is communicative with the on-chip coherency unit via a second interface. The accelerator is configured to be receptive of a request to execute lossless data compression or decompression from the processing unit and to responsively execute the lossless data compression or decompression faster than the processing unit. The processing unit and the accelerator are directly communicative by way of the dedicated wiring.

Abstract: A system is provided and includes a plurality of machines. The plurality of machines includes a first generation machine and a second generation machine. Each of the plurality of machines includes a machine version. The first generation machine executes a first virtual machine and a virtual architecture level. The second generation machine executes a second virtual machine and the virtual architecture level. The virtual architecture level provides a compatibility level for a complex interruptible instruction to the first and second virtual machines. The compatibility level is architected for a lowest common denominator machine version across the plurality of machines. The compatibility level includes a lowest common denominator indicator identifying the lowest common denominator machine version.

Abstract: Various embodiments are provided for length-limited Huffman encoding in a data compression accelerator in a computing environment by a processor. Symbol counts of a plurality of symbols in compressed data may be normalized and manipulated according to a maximum code length limiting operation such that those of the plurality of symbols having a least frequent symbol count have a symbol count equal to a maximum code length of a Huffman tree.

Abstract: An interrupt signal is provided to a guest operating system. A bus connected module is operationally connected with a plurality of processors via a bus attachment device. The bus attachment device receives an interrupt signal from the bus connected module with an interrupt target ID identifying one of the processors assigned for use by the guest operating system as a target processor for handling the interrupt signal. The bus attachment device checks whether the target processor is running using a running indicator provided by an interrupt table entry stored in a memory operationally connected with the bus attachment device. If the target processor is running, the bus attachment device forwards the interrupt signal to the target processor for handling. A translation of the interrupt target ID to a logical processor ID of the target processor is used to address the target processor directly.

Abstract: An input/output store instruction is handled. A data processing system includes a system nest communicatively coupled to at least one input/output bus by an input/output bus controller. The data processing system further includes at least a data processing unit including a core, system firmware and an asynchronous core-nest interface. The data processing unit is communicatively coupled to the system nest via an aggregation buffer. The system nest is configured to asynchronously load from and/or store data to an external device which is communicatively coupled to the input/output bus. The data processing unit is configured to complete the input/output store instruction before an execution of the input/output store instruction in the system nest is completed.

Abstract: An input/output store instruction is handled. A data processing system includes a system nest coupled to at least one input/output bus by an input/output bus controller. The data processing system further includes at least a data processing unit including a core, system firmware and an asynchronous core-nest interface. The data processing unit is coupled to the system nest via an aggregation buffer. The system nest is configured to asynchronously load from and/or store data to at least one external device which is coupled to the at least one input/output bus. The data processing unit is configured to complete the input/output store instruction before an execution of the input/output store instruction in the system nest is completed. The asynchronous core-nest interface includes an input/output status array with multiple input/output status buffers. The system firmware includes a retry buffer and the core includes an analysis and retry logic.

Abstract: An input/output store instruction is handled. A data processing system includes a system nest coupled to at least one input/output bus by an input/output bus controller. The data processing system further includes at least a data processing unit including a core, system firmware and an asynchronous core-nest interface. The data processing unit is coupled to the system nest via an aggregation buffer. The system nest is configured to asynchronously load from and/or store data to at least one external device which is coupled to the at least one input/output bus. The data processing unit is configured to complete the input/output store instruction before an execution of the input/output store instruction in the system nest is completed. The asynchronous core-nest interface includes an input/output status array with multiple input/output status buffers.

Abstract: An instruction to perform a function of a plurality of functions is obtained. The instruction is a single architected instruction of an instruction set architecture that complies to an industry standard for compression. The instruction is executed, and the executing includes performing the function specified by the instruction. The performing includes, based on the function being a compression function or a decompression function, transforming state of input data between an uncompressed form of the input data and a compressed form of the input data to provide a transformed state of data accessing. During performing the function, history relating to the function is accessed. The history is to be used in transforming the state of input data between the uncompressed form and the compressed form.

Abstract: An input/output store instruction is handled. A data processing system includes a system nest coupled to at least one input/output bus by an input/output bus controller. The data processing system further includes at least a data processing unit including a core, system firmware and an asynchronous core-nest interface. The data processing unit is coupled to the system nest via an aggregation buffer. The system nest is configured to asynchronously load from and/or store data to at least one external device which is coupled to the at least one input/output bus. The data processing unit is configured to complete the input/output store instruction before an execution of the input/output store instruction in the system nest is completed. The asynchronous core-nest interface includes an input/output status array with multiple input/output status buffers.

Abstract: A computer system includes a hardware controller and a host system. The hardware controller includes an accelerator to encode a data stream requested by an application based on a version of the accelerator. The host system executes a compression library linked to the application. The compression library operates according to one or more behavior characteristics to execute a compression algorithm that compresses the encoded data provided by the hardware controller. The behavior characteristics of the compression library is actively changed based on the version of the accelerator.

Abstract: A system architecture is provided and includes first and second processing units respectively communicative with an on-chip coherency unit and an accelerator communicative with the on-chip coherency unit. The accelerator is configured to execute an operation responsive to a call issued by one of the first and second processing units. The first processing unit is configured to set an asynchronous operation flag (AOF) to indicate that the second processing unit is to conduct an operation for the first processing unit. The second processing unit is configured to respond to the AOF by building scatter gather lists and subsequently issuing the call and feeding the scatter gather lists to the accelerator to facilitate execution of the operation by the accelerator.

Abstract: Various embodiments are disclosed that relate to electronic display of serially presented text using techniques for placement of an optimal recognition position of words at a fixed display location. In some embodiments, the optimal recognition position is based on empirically determined optimal recognition positions. In some embodiments, an optimal recognition position character is displayed at the fixed display location. In other embodiments, an optimal recognition proportionate position is displayed at the fixed display location. Various related techniques for processing and displaying text are further disclosed herein.

Abstract: An aspect includes a system architecture that includes a processing unit, an accelerator, a main source buffer, a main target buffer, and a memory block. The main source buffer stores a first part of a source symbol received from an external source. The main target buffer stores an output symbol received from the accelerator. The memory block includes an overflow source buffer that stores the first part of the source symbol received from the main source buffer. The accelerator fetches the first part of the source symbol stored in the overflow source buffer and a second part of the source symbol stored in the main source buffer, and converts the first and second parts of the source symbol together into the output symbol. The second part of the source symbol includes a part of the source symbol not included in the first part of the source symbol.

Abstract: Embodiments of the present invention are directed to a computer-implemented method for data compression. The method includes monitoring data, from a data stream, stored in an input buffer and system memory of a data compression system. The method further includes choosing an encoding scheme based in part upon the amount of data in the input buffer. The method further includes encoding data using the encoding scheme to compress the data from the data stream. The method further includes reevaluating, during the data stream, an encoding scheme choice based in part upon the amount of data in the input buffer.