Abstract: An approach is provided in which a processor includes an adder that concurrently generates one or more intermediate results and a boundary indicator based upon instructions retrieved from a memory area. The boundary indicator indicates whether a collective result generated from the intermediate results is within a boundary precision value.

Abstract: A method and system for tracing in a data processing system. The method includes receiving a plurality of signals associated with an operation during execution of the operation. The method also includes, in response to an indication that the operation is a multiphase operation, during execution of the operation, selection logic, during a first phase of the multiphase operation, selecting and outputting as a trace signal a first signal of the plurality of signals, and during a second phase of the multiphase operation, selecting and outputting as the trace signal a second signal of the plurality of signals.

Abstract: Embodiments relate to thread sparing between cores in a processor. An aspect includes determining that a number of recovery attempts made by a first thread on the first core has exceeded a recovery attempt threshold, and sending a request to transfer the first thread. Another aspect includes, selecting a second core from a plurality of cores to receive the first thread from the first core, wherein the second core is selected based on the second core having an idle thread. Another aspect includes transferring a last good architected state of the first thread from the first core to the second core. Another aspect includes loading the last good architected state of the first thread by the idle thread on the second core. Yet another aspect includes resuming execution of the first thread on the second core from the last good architected state of the first thread by the idle thread.

Abstract: Embodiments relate to thread sparing between cores in a processor. An aspect includes determining that a number of recovery attempts made by a first thread on the first core has exceeded a recovery attempt threshold, and sending a request to transfer the first thread. Another aspect includes, selecting a second core from a plurality of cores to receive the first thread from the first core, wherein the second core is selected based on the second core having an idle thread. Another aspect includes transferring a last good architected state of the first thread from the first core to the second core. Another aspect includes loading the last good architected state of the first thread by the idle thread on the second core. Yet another aspect includes resuming execution of the first thread on the second core from the last good architected state of the first thread by the idle thread.

Abstract: Resources in a computing environment are managed, for example, by a hardware controller controlling dispatching of resources from one or more pools of resources to be used in execution of threads. The controlling includes conditionally dispatching resources from the pool(s) to one or more low-priority threads of the computing environment based on current usage of resources in the pool(s) relative to an associated resource usage threshold. The management further includes monitoring resource dispatching from the pool(s) to one or more high-priority threads of the computing environment, and based on the monitoring, dynamically adjusting the resource usage threshold used in the conditionally dispatching of resources from the pool(s) to the low-priority thread(s).

Abstract: Resources in a computing environment are managed, for example, by a hardware controller controlling dispatching of resources from one or more pools of resources to be used in execution of threads. The controlling includes conditionally dispatching resources from the pool(s) to one or more low-priority threads of the computing environment based on current usage of resources in the pool(s) relative to an associated resource usage threshold. The management further includes monitoring resource dispatching from the pool(s) to one or more high-priority threads of the computing environment, and based on the monitoring, dynamically adjusting the resource usage threshold used in the conditionally dispatching of resources from the pool(s) to the low-priority thread(s).

Abstract: A computer system includes a simultaneous multi-threading processor and memory in operable communication with the processor. The processor is configured to perform a method including running multiple threads simultaneously, detecting a hardware error in one or more hardware structures of the processing circuit, and identifying one or more victim threads of the multiple threads. The processor is further configured to identify a plurality of hardware structures associated with execution of the one or more victim threads, isolate the one or more victim threads from the rest of the multiple threads by preventing access to the plurality of hardware structures by the multiple threads, flush the one or more victim threads by resetting hardware states of the plurality of hardware structures, and restore the one or more victim threads by restoring the plurality of hardware structures to a known safe state.

Abstract: A method and system for tracing in a data processing system. The method includes receiving a plurality of signals associated with an operation during execution of the operation. The method also includes, in response to an indication that the operation is a multiphase operation, during execution of the operation, selection logic, during a first phase of the multiphase operation, selecting and outputting as a trace signal a first signal of the plurality of signals, and during a second phase of the multiphase operation, selecting and outputting as the trace signal a second signal of the plurality of signals.

Abstract: Embodiments of the invention relate to process identifier (PID) based cache information transfer. An aspect of the invention includes sending, by a first core of a processor, a PID associated with a cache miss in a first local cache of the first core to a second cache of the processor. Another aspect of the invention includes determining that the PID associated with the cache miss is listed in a PID table of the second cache. Yet another aspect of the invention includes based on the PID being listed in the PID table of the second cache, determining a plurality of entries in a cache directory of the second cache that are associated with the PID. Yet another aspect of the invention includes pushing cache information associated with each of the determined plurality of entries in the cache directory from the second cache to the first local cache.

Abstract: Embodiments of the invention relate to process identifier (PID) based cache information transfer. An aspect of the invention includes sending, by a first core of a processor, a PID associated with a cache miss in a first local cache of the first core to a second cache of the processor. Another aspect of the invention includes determining that the PID associated with the cache miss is listed in a PID table of the second cache. Yet another aspect of the invention includes based on the PID being listed in the PID table of the second cache, determining a plurality of entries in a cache directory of the second cache that are associated with the PID. Yet another aspect of the invention includes pushing cache information associated with each of the determined plurality of entries in the cache directory from the second cache to the first local cache.

Abstract: A variable write back indicator control is provided to control the amount of data to be re-transmitted when a packet error occurs. A hardware controller obtains an indication that an acknowledge rate or an amount of set write back indicators of a data frame is to be adjusted. The indication is based on an error rate of data transmission over a communication bus. Based on obtaining the indication that the amount of set write back indicators is to be adjusted, one or more write back indicators are adjusted.

Abstract: A decimal floating point (DFP) unit is used to execute fixed point instructions. Two or more operands are accepted, wherein each operand is in a packed binary coded decimal (BCD) format. Any invalid BCD formats are detected by checking the operands for any invalid BCD codes. It is determined if an exception flag exists and, if so, outputting the flag; it is determined if a condition code exists and, if so, outputting the code. An operation is performed on the two or more operands to generate a result; wherein the operation takes place directly on BCD data, thus using the DFP unit to perform a BCD operation; appending a result sign to the result of the operation; and providing the result of the operation and the appended result sign as a result output in a packed BCD format.

Abstract: Several implementations and a design structure for decimal multiplication that uses a BCD 4221 encoding scheme, separate accumulation of partial products, accumulation of the partial products into a final product and conversion from and to a BCD 8421 coding scheme.

Abstract: A computer program product for performing error recovery is configured to perform a method that includes creating, by a processor, a recovery checkpoint. The processor is dynamically switched into a non-recoverable processing mode of operation based on creating the software recovery checkpoint. The non-recoverable processing mode of operation is a mode in which a subset of hardware error recovery resources are powered-down or re-purposed for instruction processing. It is determined, during the non-recoverable processing mode of operation, that a new software recovery checkpoint is required. Based on the determining that a new software recovery checkpoint is required, the processor is dynamically switched into a recoverable processing mode of operation. The recoverable processing mode of operation is a mode in which hardware error recovery resources, including at least one of the hardware error recovery resources in the subset, are purposed for hardware error recovery operations.

Abstract: A method for performing error recovery that includes creating, by a processor, a recovery checkpoint. The processor is dynamically switched into a non-recoverable processing mode of operation based on creating the software recovery checkpoint. The non-recoverable processing mode of operation is a mode in which a subset of hardware error recovery resources are powered-down or re-purposed for instruction processing. It is determined, during the non-recoverable processing mode of operation, that a new software recovery checkpoint is required. Based on the determining that a new software recovery checkpoint is required, the processor is dynamically switched into a recoverable processing mode of operation. The recoverable processing mode of operation is a mode in which hardware error recovery resources, including at least one of the hardware error recovery resources in the subset, are purposed for hardware error recovery operations.

Abstract: Binary code decimal (BCD) arithmetic add/subtract operations on two BCD numbers independent of which BCD number is of a greater magnitude include, responsive to the BCD arithmetic add/subtract operation being a subtract operation, performing a BCD arithmetic subtraction operation on a first BCD number and a second BCD number, the first BCD number having a first magnitude and the second BCD number having a second magnitude. The first magnitude is greater than, equal to, or less than the second magnitude. The performing includes: in parallel to a carry generation, partial sums or partial differences of the first and second BCD numbers are computer such that a final result in signed magnitude form is selectable from the partial sums or differences based on carry information without any post processing steps.

Abstract: Major branch instructions are provided that enable execution of a computer program to branch from one segment of code to another segment of code. These instructions also create a new stream of processing at the other segment of code enabling execution of the other segment of code to be performed in parallel with the segment of code from which the branch was taken. In one example, the other stream of processing starts a transaction for processing instructions of the other stream of processing.

Abstract: Major branch instructions are provided that enable execution of a computer program to branch from one segment of code to another segment of code. These instructions also create a new stream of processing at the other segment of code enabling execution of the other segment of code to be performed in parallel with the segment of code from which the branch was taken. In one example, the other stream of processing starts a transaction for processing instructions of the other stream of processing.

Abstract: A re-characterization process is provided that adjusts one or more operating parameters of a processor to improve the health (e.g., reduce errors) of the processor. The parameters include voltage and/or clock frequency, as examples. The processor can be an inactive or active processor for which the re-characterization process is performed. It is performed, in one instance, by a hardware controller in real-time.

Abstract: A technique is provided for cache management of a cache. The processing circuit determines a miss count and a hit position field during a previous execution of an instruction requesting that a data element be stored in a cache. The miss count and the hit position field are stored for a data element corresponding to an instruction that requests storage of the data element. The processing circuit places the data element in a hierarchical order based on the miss count and/or the hit position field. The hit position field includes a hierarchical position related to the data element in the cache.