Abstract: A higher level shared cache of a hierarchical cache of a multi-processor system utilizes transaction identifiers to manage memory conflicts in corresponding transactions. The higher level cache is shared with two or more processors. A processor may have a corresponding accelerator that performs operations on behalf of the processor. Transaction indicators are set in the higher level cache corresponding to the cache lines being accessed. The transaction aborts if a memory conflict with the transaction's cache lines from another transaction is detected, and the corresponding cache lines are invalidated. For a successfully completing transaction, the corresponding cache lines are committed and the data from store operations is stored.

Abstract: Embodiments relate to multithreaded transactions. An aspect includes assigning a same transaction identifier (ID) corresponding to the multithreaded transaction to a plurality of threads of the multithreaded transaction, wherein the plurality of threads execute the multithreaded transaction in parallel. Another aspect includes determining one or more memory areas that are owned by the multithreaded transaction. Another aspect includes receiving a memory access request from a requester that is directed to a memory area that is owned by the transaction. Yet another aspect includes based on determining that the requester has a transaction ID that matches the transaction ID of the multithreaded transaction, performing the memory access request without aborting the multithreaded transaction.

Abstract: Embodiments relate to implementing a coherence protocol. An aspect includes sending a request for data to a remote processor and receiving by a processor a response from the remote processor. The response has a transaction status of a remote transaction on the remote processor. The processor adds the transaction status of the remote transaction on the remote processor in a local transaction interference tracking table.

Abstract: Dynamic resource allocation is provided in which additional resources, such as additional architected registers, are provided to an instruction, if it is determined that resources in addition to those configured to be provided to the instruction are to be used for the particular instruction. An instruction to be executed is dispatched on a pipe of a pipeline and that pipe is configured to have a set number of architected registers for use by the instruction. However, if one or more other architected registers are needed, those additional architected registers are dynamically allocated to the instruction by assigning one or more source ports of an additional pipe to the instruction.

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: Execution of a set of instructions within a transaction is prevented. A processor identifies a first set of instructions in an instruction stream of a transaction. The first set of instructions incurs a first memory access that is not visible to the transaction and will cause the transaction to abort. The processor generates a second set of instructions that incurs a second memory access that is visible to the transaction. The second set of instructions is generated based on the first memory access and first set of instructions. The processor executes, within the transaction, the second set of instructions instead of the first set of instructions.

Abstract: Embodiments of the invention relate to dynamically routing instructions to execution units based on detected errors in the execution units. An aspect of the invention includes a computer system including a processor having an instruction issue unit and a plurality of execution units. The processor is configured to detect an error in a first execution unit among the plurality of execution units and adjust instruction dispatch rules of the instruction issue unit based on detecting the error in the first execution unit to restrict access to the first execution unit while leaving un-restricted access to the remaining execution units of the plurality of execution units.

Abstract: Execution of a set of instructions within a transaction is prevented. A processor identifies a first set of instructions in an instruction stream of a transaction. The first set of instructions incurs a first memory access that is not visible to the transaction and will cause the transaction to abort. The processor generates a second set of instructions that incurs a second memory access that is visible to the transaction. The second set of instructions is generated based on the first memory access and first set of instructions. The processor executes, within the transaction, the second set of instructions instead of the first set of instructions.

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: Embodiments relate to address expansion and contraction in a multithreading computer system. According to one aspect, a computer system includes a configuration with a core configurable between a single thread (ST) mode and a multithreading (MT) mode. The ST mode addresses a primary thread and the MT mode addresses the primary thread and one or more secondary threads on shared resources of the core. A multithreading facility is configured to control utilization of the configuration to perform a method that includes accessing the primary thread in the ST mode using a core address value and switching from the ST mode to the MT mode. The primary thread or one of the one or more secondary threads is accessed in the MT mode using an expanded address value, where the expanded address value includes the core address value concatenated with a thread address value.

Abstract: Embodiments relate to address expansion and contraction in a multithreading computer system. According to one aspect, a computer implemented method for address adjustment in a configuration is provided. The configuration includes a core configurable between an ST mode and an MT mode, where the ST mode addresses a primary thread and the MT mode addresses the primary thread and one or more secondary threads on shared resources of the core. The primary thread is accessed in the ST mode using a core address value. Switching from the ST mode to the MT mode is performed. The primary thread or one of the one or more secondary threads is accessed in the MT mode using an expanded address value. The expanded address value includes the core address value concatenated with a thread address value.

Abstract: A transactional memory system dynamically predicts the resource requirements of hardware transactions. A processor of the transactional memory system predicts resource requirements of a first hardware transaction to be executed based on a resource hint, a type of hardware transaction that is associated with a given hardware transaction, and a previous execution of a prior hardware transaction that is associated with the type of hardware transaction. The processor allocates resources for the given hardware transaction based on the predicted resource requirements. The processor initiates execution of the first hardware transaction using at least a portion of the allocated resources.

Abstract: Embodiments relate to multithreaded transactions. An aspect includes assigning a same transaction identifier (ID) corresponding to the multithreaded transaction to a plurality of threads of the multithreaded transaction, wherein the plurality of threads execute the multithreaded transaction in parallel. Another aspect includes determining one or more memory areas that are owned by the multithreaded transaction. Another aspect includes receiving a memory access request from a requester that is directed to a memory area that is owned by the transaction. Yet another aspect includes based on determining that the requester has a transaction ID that matches the transaction ID of the multithreaded transaction, performing the memory access request without aborting the multithreaded transaction.

Abstract: As disclosed herein a method, executed by a processor, for accelerated instruction execution includes retrieving an execute instruction including a register reference and a reference to a target instruction, retrieving the target instruction, decoding the execute instruction using an instruction pipeline, decoding the target instruction using the instruction pipeline, associating the register reference to the target instruction, and executing the target instruction using the register reference as a source operand modifier. The instruction pipeline is configured such that it allows the target instruction to continue processing without waiting for the register reference to be resolved. The contents of the referenced register may be retrieved in a later stage of the instruction pipeline, and the target instruction may be modified and executed. An apparatus corresponding to the described method is also disclosed herein.

Abstract: A transactional memory system dynamically predicts the resource requirements of hardware transactions. A processor of the transactional memory system predicts resource requirements of a first hardware transaction to be executed based on a resource hint, a type of hardware transaction that is associated with a given hardware transaction, and a previous execution of a prior hardware transaction that is associated with the type of hardware transaction. The processor allocates resources for the given hardware transaction based on the predicted resource requirements. The processor initiates execution of the first hardware transaction using at least a portion of the allocated resources.

Abstract: A transactional memory system dynamically predicts the resource requirements of hardware transactions. A processor of the transactional memory system predicts resource requirements of a first hardware transaction to be executed based on any one of a resource hint and a previous execution of a prior hardware transaction. The processor allocates resources for the first hardware transaction based on the predicted resource requirements. The processor executes the first hardware transaction. The processor saves resource usage information of the first hardware transaction for future prediction.

Abstract: A system and method of executing a plurality of threads, including a first thread and a set of remaining threads, on a computer processor core. The system and method includes determining that a start interpretive execution exit condition exists; determining that the computer processor core is within a grace period; and entering by the first thread a start interpretive execution exit sync loop without signaling to any of the set of remaining threads. In turn, the first thread remains in the start interpretive execution exit sync loop until the grace period expires or each of the remaining threads enters a corresponding start interpretive execution exit sync loop.

Abstract: A system and method of executing a plurality of threads, including a first thread and a set of remaining threads, on a computer processor core. The system and method includes determining that a start interpretive execution exit condition exists; determining that the computer processor core is within a grace period; and entering by the first thread a start interpretive execution exit sync loop without signaling to any of the set of remaining threads. In turn, the first thread remains in the start interpretive execution exit sync loop until the grace period expires or each of the remaining threads enters a corresponding start interpretive execution exit sync loop.

Abstract: As disclosed herein a method, executed by a processor, for accelerated instruction execution includes retrieving an execute instruction including a register reference and a reference to a target instruction, retrieving the target instruction, decoding the execute instruction using an instruction pipeline, decoding the target instruction using the instruction pipeline, associating the register reference to the target instruction, and executing the target instruction using the register reference as a source operand modifier. The instruction pipeline is configured such that it allows the target instruction to continue processing without waiting for the register reference to be resolved. The contents of the referenced register may be retrieved in a later stage of the instruction pipeline, and the target instruction may be modified and executed. An apparatus corresponding to the described method is also disclosed herein.

Abstract: A system and method of executing a plurality of threads, including a first thread and a set of remaining threads, on a computer processor core. The system and method includes determining that a start interpretive execution exit condition exists; determining that the computer processor core is within a grace period; and entering by the first thread a start interpretive execution exit sync loop without signaling to any of the set of remaining threads. In turn, the first thread remains in the start interpretive execution exit sync loop until the grace period expires or each of the remaining threads enters a corresponding start interpretive execution exit sync loop.