Abstract: Operation of a multi-slice processor that includes a plurality of execution slices and a plurality of load/store slices, where each load/store slice includes a load miss queue and a load reorder queue, includes: receiving, at a load reorder queue, a load instruction requesting data; responsive to the data not being stored in a data cache, determining whether a previous load instruction is pending a fetch of a cache line comprising the data; if the cache line does not comprise the data, allocating an entry for the load instruction in the load miss queue; and if the cache line does comprise the data: merging, in the load reorder queue, the load instruction with an entry for the previous load instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices, a plurality of load/store slices, and one or more instruction sequencing units, where operation includes: receiving, at a load/store slice from an instruction sequencing unit, a instruction to be issued; determining, at the load/store slice, a rejection condition for the instruction; and responsive to determining the rejection condition for the instruction, maintaining state information for the instruction in the load/store slice instead of notifying the instruction sequencing unit of a rejection of the instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices, a plurality of load/store slices, and an instruction sequencing unit, where operation includes: receiving, at a load/store slice, a load instruction to be issued; determining, at the load/store slice, that the load instruction has not completed and is to be reissued; and responsive to determining that the load instruction is to be reissued, delaying a signal, from the load/store slice to the instruction sequencing unit, that allows the instruction sequencing unit to issue one or more instructions dependent upon the load instruction.

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: 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: Accessing partial cachelines in a data cache including storing a first portion of a cacheline in a cache entry of the data cache; relaunching a load instruction targeting a second portion of the cacheline, wherein the second portion of the cacheline is not stored in the data cache; determining that the load instruction targets a portion of the cacheline not stored in the cache entry; storing the second portion of the cacheline in the data cache; and reading the second portion of the cacheline from the data cache according to the load instruction.

Abstract: Flush avoidance in a load store unit including launching a load instruction targeting an effective address; encountering a set predict hit and an effective-to-real address translator (ERAT) miss for the effective address, wherein the set predict hit comprises a cache address of a cache entry; sending a data valid message for the load instruction to an instruction sequencing unit; and verifying the data valid message, wherein verifying the data valid message comprises: tracking the cache entry during an ERAT update; and upon completion of the ERAT update, encountering an ERAT hit for the effective address in response to relaunching the load instruction.

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: A technique for operating a processor includes receiving, at an issue queue, a store instruction that has an associated address generation (AGN) operation and an associated data operation. The AGN operation is issued to AGN logic associated with a pipeline slice in response to all source operands for the AGN operation being ready. The AGN logic is configured to generate an address for the store instruction. Confirmation, for the AGN operation is received. The confirmation includes an indication of the pipeline slice that performed the AGN operation. In response to receiving the confirmation and a source operand for the data operation being ready, the issue queue issues the data operation to data logic associated with the pipeline slice indicated by the confirmation. The data logic is configured to format data for 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: 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: Techniques are disclosed for receiving an instruction for processing data that includes a plurality of sectors. A method includes decoding the instruction to determine which of the plurality of sectors are needed to process the instruction and fetching at least one of the plurality of sectors from memory. The method includes determining whether each sector that is needed to process the instruction has been fetched. If all sectors needed to process the instruction have been fetched, the method includes transmitting a sector valid signal and processing the instruction. If all sectors needed to process the instruction have not been fetched, the method includes blocking a data valid signal from being transmitted, fetching an additional one or more of the plurality of sectors until all sectors needed to process the instruction have been fetched, transmitting a sector valid signal, and reissuing and processing the instruction using the fetched sectors.

Abstract: Accessing partial cachelines in a data cache including storing a first portion of a cacheline in a cache entry of the data cache; relaunching a load instruction targeting a second portion of the cacheline, wherein the second portion of the cacheline is not stored in the data cache; determining that the load instruction targets a portion of the cacheline not stored in the cache entry; storing the second portion of the cacheline in the data cache; and reading the second portion of the cacheline from the data cache according to the load instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices, a plurality of load/store slices, and one or more instruction sequencing units, where operation includes: receiving, at a load/store slice from an instruction sequencing unit, a instruction to be issued; determining, at the load/store slice, a rejection condition for the instruction; and responsive to determining the rejection condition for the instruction, maintaining state information for the instruction in the load/store slice instead of notifying the instruction sequencing unit of a rejection of the instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices, a plurality of load/store slices, and one or more instruction sequencing units, where operation includes: receiving, at a load/store slice from an instruction sequencing unit, a instruction to be issued; determining, at the load/store slice, a rejection condition for the instruction; and responsive to determining the rejection condition for the instruction, maintaining state information for the instruction in the load/store slice instead of notifying the instruction sequencing unit of a rejection of the instruction.

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: Preventing hazard flushes in an instruction sequencing unit of a multi-slice processor including receiving a load instruction in a load reorder queue, wherein the load instruction is an instruction to load data from a memory location; subsequent to receiving the load instruction, receiving a store instruction in a store reorder queue, wherein the store instruction is an instruction to store data in the memory location; determining that the store instruction causes a hazard against the load instruction; preventing a flush of the load reorder queue based on a state of the load instruction; and re-executing the load instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices and a plurality of load/store slices, where each load/store slice includes a load miss queue and a load reorder queue, includes: receiving, at a load reorder queue, a load instruction requesting data; responsive to the data not being stored in a data cache, determining whether a previous load instruction is pending a fetch of a cache line comprising the data; if the cache line does not comprise the data, allocating an entry for the load instruction in the load miss queue; and if the cache line does comprise the data: merging, in the load reorder queue, the load instruction with an entry for the previous load instruction.

Abstract: Operation of a multi-slice processor that includes a plurality of execution slices, a plurality of load/store slices, and an instruction sequencing unit, where operation includes: receiving, at a load/store slice, a load instruction to be issued; determining, at the load/store slice, that the load instruction has not completed and is to be reissued; and responsive to determining that the load instruction is to be reissued, delaying a signal, from the load/store slice to the instruction sequencing unit, that allows the instruction sequencing unit to issue one or more instructions dependent upon the load instruction.