Abstract: Processing prefetch memory operations and transactions. A local processor receives a prefetch request from a remote processor. Prior to execution of the prefetch request, determining whether a priority of the remote processor is greater than a priority of a local processor. The write prefetch request is executed in response to a to a determination that the priority of the remote processor is greater than the priority of the local processor. Prefetch data produced by execution of the prefetch request is provided to the remote processor.

Abstract: A computer-implemented method includes, in a transactional memory environment, identifying a transaction and identifying one or more cache lines. The cache lines are allocated to the transaction. A cache line record is stored. The cache line record includes a reference to the one or more cache lines. An indication is received. The indication denotes a request to demote the one or more cache lines. The cache line record is retrieved, and the one or more cache lines are released. A corresponding computer program product and computer system are also disclosed.

Abstract: A conditional instruction end facility is provided that allows completion of an instruction to be delayed. In executing the machine instruction, an operand is obtained, and a determination is made as to whether the operand has a predetermined relationship with respect to a value. Based on determining that the operand does not have the predetermined relationship with respect to the value, the obtaining and the determining are repeated. Based on determining that the operand has the predetermined relationship with respect to the value, execution of the instruction is completed.

Abstract: An instruction configured to perform a plurality of functions is executed. Based on a function code associated with the instruction having a selected value, one or more inputs of the instruction are checked to determine which one or more functions of the plurality of functions are to be performed. Based on a first input of the one or more inputs having a first value, a function of providing raw entropy is performed, in which the providing of raw entropy includes storing a number of raw random numbers. Further, based on a second input of the one or more inputs having a second value, a function of providing conditioned entropy is provided, in which the providing of conditioned entropy includes storing a number of conditioned random numbers.

Abstract: Processing prefetch memory operations and transactions. A local processor receives a write prefetch request from a remote processor. Prior to execution of a write prefetch request received from a remote processor, determining whether a priority of the write prefetch request is greater than a priority of a pending transaction of a local processor. The write prefetch request is executed in response to a determination that the priority of the write prefetch request is greater than the priority of a pending transaction. Prefetch data produced by execution of the write prefetch request is provided to the remote processor.

Abstract: Discontiguous storage locations are prefetched by a prefetch instruction. Addresses of the discontiguous storage locations are provided by a list directly or indirectly specified by a parameter of the prefetch instruction, along with metadata and information about the list entries. Fetching of corresponding data blocks to cache lines is initiated. A processor may enter transactional execution mode and memory instructions of a program may be executed using the prefetched data blocks.

Abstract: When executed, a transaction-hint instruction specifies a transaction-count-to-completion (CTC) value for a transaction. The CTC value indicates how far a transaction is from completion. The CTC may be a number of instructions to completion or an amount of time to completion. The CTC value is adjusted as the transaction progresses. When a disruptive event associated with inducing transactional aborts, such as an interrupt or a conflicting memory access, is identified while processing the transaction, processing of the disruptive event is deferred if the adjusted CTC value satisfies deferral criteria. If the adjusted CTC value does not satisfy deferral criteria, the transaction is aborted and the disruptive event is processed.

Abstract: Task specific diagnostic controls are provided to facilitate the debugging of certain types of abort conditions. The diagnostic controls may be set to cause transactions to be selectively aborted, allowing a transaction to drive its abort handler routine for testing purposes. The controls include, for instance, a transaction diagnostic scope and a transaction diagnostic control. The transaction diagnostic scope indicates when the transaction diagnostic control is to be applied, and the transaction diagnostic control indicates whether transactions are to selectively aborted.

Abstract: An aspect includes fetching a computer instruction, the fetching by an instruction fetch unit. It is determined that the instruction is a decimal divide instruction that specifies a decimal divisor and a decimal dividend. The decimal divisor is converted into a floating-point divisor and the decimal dividend is converted into a floating-point dividend. A floating-point division of the floating-point dividend by the floating-point divisor is performed by an instruction execution unit. It is determined that the floating-point division resulted in a quotient overflow. A reduced size floating-point dividend is generated based on the quotient overflow, the floating-point divisor, and the floating-point dividend. The floating point division of the reduced size floating-point dividend by the floating-point divisor is performed by the instruction execution unit, and a specified number of rightmost bits of the result is output as the quotient.

Abstract: When executed, a transaction-hint instruction specifies a transaction-count-to-completion (CTC) value for a transaction. The CTC value indicates how far a transaction is from completion. The CTC may be a number of instructions to completion or an amount of time to completion. The CTC value is adjusted as the transaction progresses. When a disruptive event associated with inducing transactional aborts, such as an interrupt or a conflicting memory access, is identified while processing the transaction, processing of the disruptive event is deferred if the adjusted CTC value satisfies deferral criteria. If the adjusted CTC value does not satisfy deferral criteria, the transaction is aborted and the disruptive event is processed.

Abstract: A delay facility is provided in which program execution may be delayed until a predefined event occurs, such as a comparison of memory locations results in a true condition, a timeout is reached, an interruption is made pending or another condition exists. The delay facility includes one or more compare and delay machine instructions used to delay execution. The one or more compare and delay instructions may include a 32-bit compare and delay (CAD) instruction and a 64-bit compare and delay (CADG) instruction.

Abstract: A TRANSACTION BEGIN instruction and a TRANSACTION END instruction are provided. The TRANSACTION BEGIN instruction causes either a constrained or nonconstrained transaction to be initiated, depending on a field of the instruction. The TRANSACTION END instruction ends the transaction started by the TRANSACTION BEGIN instruction.

Abstract: In a multi-core computer system, a method for dealing with a fault with a core includes detecting a fault in one of the cores. Information is transferred from a recovery buffer to a mapper. The information includes logical register mapping information. A recovery is performed using the information in the mapper. If a recovery cannot proceed, a sparing can be initiated using the information in the mapper.

Abstract: An instruction to perform a sign operation of a plurality of sign operations configured for the instruction. The instruction is executed, and the executing includes selecting at least a portion of an input operand as a result to be placed in a select location. The selecting is based on a control of the instruction, in which the control indicates a user-defined size of the input operand to be selected as the result. A sign of the result is determined based on a plurality of criteria, including a value of the result, obtained based on the control of the instruction, having a first particular relationship or a second particular relationship with respect to a selected value. The result and the sign are stored in the select location to provide a signed output to be used in processing within the computing environment.

Abstract: In an approach for resolving terminated transactions in a transactional memory environment, a processor initiates a hardware transaction in a computing environment, wherein the hardware transaction accesses a memory location, and wherein the hardware transaction includes a transaction begin indicator and a transaction end indicator. A processor detects a conflicting access of the memory location while executing the hardware transaction. A processor aborts the hardware transaction based on the conflicting access of the memory location. Hardware determines that the conflicting access of the memory location is a transient condition. A processor reinitiates the hardware transaction.

Abstract: A prefetch request having a priority assigned thereto is obtained, based on executing a prefetch instruction included within a program. Based on obtaining the prefetch request, a determination is made as to whether the prefetch request may be placed on a prefetch queue. This determination includes determining whether the prefetch queue is full; checking, based on determining the prefetch queue is full, whether the priority of the prefetch request is considered a high priority; determining, based on the checking indicating the priority of the prefetch request is considered a high priority, whether another prefetch request on the prefetch queue may be removed; removing the other prefetch request from the prefetch queue, based on determining the other prefetch request may be removed; and adding the prefetch request to the prefetch queue, based on removing the other prefetch request.

Abstract: A delay facility is provided in which program execution may be delayed until a predefined event occurs, such as a comparison of memory locations results in a true condition, a timeout is reached, an interruption is made pending or another condition exists. The delay facility includes one or more compare and delay machine instructions used to delay execution. The one or more compare and delay instructions may include a 32-bit compare and delay (CAD) instruction and a 64-bit compare and delay (CADG) instruction.

Abstract: Prevention of a prefetch memory operation from causing a transaction to abort. A local processor receives a prefetch request from a remote processor. Prior to execution of the prefetch request, a processor determines whether the prefetch request conflicts with a transaction of the local processor. A processor responds to a determination that the priority of the remote processor is greater than priority of the local processor by (i) aborting the transaction (ii) executing the prefetch request, and (iii) providing requested prefetch data to the remote processor.

Abstract: Prevention of a prefetch memory operation from causing a transaction to abort. A local processor receives a prefetch request from a remote processor. Prior to execution of the prefetch request, a processor determines whether the prefetch request conflicts with a transaction of the local processor. A processor responds to a determination that the priority of the prefetch request is greater than priority of the transaction, by (i) aborting the transaction (ii) executing the prefetch request, and (iii) providing requested prefetch data to the remote processor.

Abstract: Throttling instruction execution in a transaction operating in a processor configured to execute memory instructions out-of-order in a pipelined processor, wherein memory instructions are instructions for accessing operands in memory is provided. Included is executing, by the processor, instructions of a transaction comprising determining whether the transaction is in throttling mode and based on the transaction being in throttling mode, executing memory instructions in-program-order. Also included is based on the transaction not-being in throttling mode, executing memory instructions out-of-program order.