Abstract: Fast issuance and execution of a multi-width instruction across multiple slices in a parallel slice processor core is supported in part through the use of an early notification signal passed between issue logic associated with multiple slices handling that multi-width instruction coupled with an issuance of a different instruction by the originating issue logic for the early notification signal.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices. Operation of such a multi-slice processor includes: determining, by a hypervisor, that consumption of memory controller resources, by a plurality of processing threads, is above a threshold quantity, wherein respective processing threads of the plurality of processing threads control respective prefetch settings; and responsive to determining that the consumption of the memory controller resources is above the threshold quantity, modifying individual memory controller usage of at least one of the plurality of processing threads such that the consumption of the memory controller resources is reduced below the threshold quantity.

Abstract: A load store unit (LSU) in a processor core detects that new data produced by the processor core is ready to be drained to an L2 cache. In response to the LSU detecting that an earlier version of the new data is not stored in L1 cache, a memory controller sends the new data as L1 cache missed data to a store queue (STQ), where the STQ makes data available for deallocation from the STQ to the L2 cache. In response to determining that there is no newer data waiting to be stored in the STQ, or no cache line invalidate to the line containing the store data in the STQ that misses the cache, the memory controller maintains the new data in the STQ with a zombie stat bit that indicates that the new data is a zombie store entry that can be utilized by the processor core.

Abstract: Embodiments described herein include a computing system that permits partial writes into a memory element—e.g., a register on a processor. For example, the data to be written into the memory element may be spread across multiple sources. The register may receive data from two different sources at different times and perform two separate partial write commands to store the data. Embodiments herein generate an ECC value for each of the partial writes. That is, when storing the data of the first partial write, the computing system generates a first ECC value for the data in the first partial write and stores this value in the memory element. Later, when performing the second partial write, the computing system generates a second ECC value for this data which is also stored in the memory element.

Abstract: Embodiments described herein include a computing system that permits partial writes into a memory element—e.g., a register on a processor. For example, the data to be written into the memory element may be spread across multiple sources. The register may receive data from two different sources at different times and perform two separate partial write commands to store the data. Embodiments herein generate an ECC value for each of the partial writes. That is, when storing the data of the first partial write, the computing system generates a first ECC value for the data in the first partial write and stores this value in the memory element. Later, when performing the second partial write, the computing system generates a second ECC value for this data which is also stored in the memory element.

Abstract: The embodiments relate to a computer system, computer program product and method for managing a garbage collection process. Processing control is obtained based on execution of a load instruction and a determination that an object pointer to be loaded indicates a location within a selected portion of memory undergoing a garbage collection process. The determination includes identifying a base address and size of a first memory block subject to the garbage collection, and assigning a binary value to each first memory block section. An image of the load instruction is obtained and a pointer address is calculated from the image. It is determined whether the object pointer is to be modified. The object pointer is modified and stored in a selected location.

Abstract: An instruction sequencing unit in an out-of-order (OOO) processor includes a Most Favored Instruction (MFI) mechanism that designates an instruction as an MFI. The processing queues in the processor identify when they contain the MFI, and assures processing the MFI. The MFI remains the MFI until it is completed or is flushed, and which time the MFI mechanism selects the next MFI.

Abstract: A system for adjusting a frequency of a processor is disclosed herein. The system includes a processor and a memory, where the memory includes a program configured to adjust a frequency of a multi-core processor. The operations include determining a total current and a temperature of the multi-core processor and estimating a leakage current for the multi-core processor. The operations also include calculating a switching current by subtracting the leakage current from the total current and calculating an effective switching capacitance based at least in part on the switching current. The operations also include calculating a workload activity factor by dividing the effective switching capacitance by a predetermined effective switching capacitance stored in vital product data, and enforcing a turbo frequency limit of the multi-core processor based on the workload activity factor.

Abstract: Operation of a multi-slice processor implementing instruction fusion, where the multi-slice processor includes a plurality of execution slices. Operation of such a multi-slice processor includes: identifying, from a set of instructions, a first instruction that has an operand dependency on a second instruction in the set of instructions; and responsive to the first instruction having an operand dependency on the second instruction: issuing the first instruction and the second instruction to execute in parallel on the particular set of execution slices configured with fusion logic between execution slices that removes the operand dependency between the first instruction and the second instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices and a load/store superslice, where the load/store superslice includes a set predict array, a first load/store slice, and a second load/store slice. Operation of such a multi-slice processor includes: receiving a two-target load instruction directed to the first load/store slice and a store instruction directed to the second load/store slice; determining a first subset of ports of the set predict array as inputs for an effective address for the two-target load instruction; determining a second subset of ports of the set predict array as inputs for an effective address for the store instruction; and generating, in dependence upon logic corresponding to the set predict array that is less than logic implementing an entire load/store slice, output for performing the two-target load instruction in parallel with generating output for performing the store instruction.

Abstract: A method and apparatus for garbage collection is disclosed herein. The method includes performing a garbage collection process without pausing execution of a runtime environment. The method also includes executing a first CPU instruction to load a first pointer that points to a first location in a first region of memory, where the first region of memory is undergoing garbage collection. The method also includes moving a first object pointed to by the first pointer from the first location in memory to a second location in memory.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices and a load/store superslice, where the load/store superslice includes a set predict array, a first load/store slice, and a second load/store slice. Operation of such a multi-slice processor includes: receiving a two-target load instruction directed to the first load/store slice and a store instruction directed to the second load/store slice; determining a first subset of ports of the set predict array as inputs for an effective address for the two-target load instruction; determining a second subset of ports of the set predict array as inputs for an effective address for the store instruction; and generating, in dependence upon logic corresponding to the set predict array that is less than logic implementing an entire load/store slice, output for performing the two-target load instruction in parallel with generating output for performing the store instruction.

Abstract: The embodiments relate to a computer system, computer program product and method for managing a garbage collection process. Processing control is obtained based on execution of a load instruction and a determination that an object pointer to be loaded indicates a location within a selected portion of memory undergoing a garbage collection process. The determination includes identifying a base address and size of a first memory block subject to the garbage collection, subdividing the first memory block into sections, assigning a binary value to each section, and determining if the first memory block corresponds to the enabled section. An image of the load instruction is obtained and a pointer address is calculated from the image. The object pointer is read and it is determined whether the object pointer is to be modified. The object pointer is modified and stored in a selected location.

Abstract: Embodiments of the present invention provide systems and methods for mapping the architected state of one or more threads to a set of distributed physical register files to enable independent execution of one or more threads in a multiple slice processor. In one embodiment, a system is disclosed including a plurality of dispatch queues which receive instructions from one or more threads and an even number of parallel execution slices, each parallel execution slice containing a register file. A routing network directs an output from the dispatch queues to the parallel execution slices and the parallel execution slices independently execute the one or more threads.

Abstract: Embodiments of the present invention provide systems and methods for mapping the architected state of one or more threads to a set of distributed physical register files to enable independent execution of one or more threads in a multiple slice processor. In one embodiment, a system is disclosed including a plurality of dispatch queues which receive instructions from one or more threads and an even number of parallel execution slices, each parallel execution slice containing a register file. A routing network directs an output from the dispatch queues to the parallel execution slices and the parallel execution slices independently execute the one or more threads.

Abstract: Managing a divided load reorder queue including storing load instruction data for a load instruction in an expanded LRQ entry in the LRQ; launching the load instruction from the expanded LRQ entry; determining that the load instruction is in a finished state; moving a subset of the load instruction data from the expanded LRQ entry to a compact LRQ entry in the LRQ, wherein the compact LRQ entry is smaller than the expanded LRQ entry; and removing the load instruction data from the expanded LRQ entry.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices and a load/store superslice, where the load/store superslice includes a set predict array, a first load/store slice, and a second load/store slice. Operation of such a multi-slice processor includes: receiving a two-target load instruction directed to the first load/store slice and a store instruction directed to the second load/store slice; determining a first subset of ports of the set predict array as inputs for an effective address for the two-target load instruction; determining a second subset of ports of the set predict array as inputs for an effective address for the store instruction; and generating, in dependence upon logic corresponding to the set predict array that is less than logic implementing an entire load/store slice, output for performing the two-target load instruction in parallel with generating output for performing the store instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices and a load/store superslice, where the load/store superslice includes a set predict array, a first load/store slice, and a second load/store slice. Operation of such a multi-slice processor includes: receiving a two-target load instruction directed to the first load/store slice and a store instruction directed to the second load/store slice; determining a first subset of ports of the set predict array as inputs for an effective address for the two-target load instruction; determining a second subset of ports of the set predict array as inputs for an effective address for the store instruction; and generating, in dependence upon logic corresponding to the set predict array that is less than logic implementing an entire load/store slice, output for performing the two-target load instruction in parallel with generating output for performing the store instruction.

Abstract: Methods and apparatus for transmitting data between execution slices of a multi-slice processor including receiving, by an execution slice, a broadcast message comprising an instruction tag (ITAG) for a producer instruction, a latency, and a source identifier; determining that an issue queue in the execution slice comprises an ITAG for a consumer instruction, wherein the consumer instruction depends on result data from the producer instruction; calculating a cycle countdown using the latency and the source identifier; determining that the cycle countdown has expired; and in response to determining that the cycle countdown has expired, reading the result data from the producer instruction.

Abstract: Operation of a multi-slice processor implementing datapath steering, where the multi-slice processor includes a plurality of execution slices. Operation of such a multi-slice processor includes: identifying, from a set of instructions, a second instruction that is dependent upon a first instruction in the set of instructions; and responsive to the second instruction being dependent upon the first instruction in the set of instructions, issuing each of the instructions in the set of instructions to a particular set of execution slices configured with bypass logic between execution slices that reduces execution latencies between dependent instructions.