International Business Machines Corporation

Other

David S Hutton

Fadi Y Busaba

John G Rell, Jr

Chung-Lung K Shum

Eric M Schwarz

Edward Thomas Malley

Khary J Alexander

Bruce C Giamei

Brian Robert Prasky

Anthony Saporito

Christian Jacobi

Gregory William Alexander

Christopher A Krygowski

Brian William Curran

Wen H Li

Kathryn Marie Jackson

Keith N Langston

Steven R Carlough

James J Bonanno

Pak-kin Mak

Sheryll H Veneracion

Aaron Tsai

Jane Helen Bartik

Michael Billeci

Somin Song

Michael T Huffer

Jeffrey S Plate

Stephen Duffy

Timothy John Slegel

Charles Franklin Webb

Robert J Sonnelitter, Iii

Phil C Yeh

Lee Evan Eisen

Craig Raymond Walters

Jang-Soo Lee

Hanno Ulrich

Bruce A Wagar

Michael P Mullen

John J McNeely

Fadi Y Basuba

Fadi Y Busada

Embodiments include load-balancing a plurality of simultaneous threads of a processor. An example method includes computing a minimum group count for a thread from the plurality of threads. The minimum group count indicates a minimum number of groups of instructions to be assigned to the thread. The method further includes computing a maximum allowed group count for the thread. The maximum allowed group count indicates a maximum number of groups of instructions to be assigned to the thread. The method further includes issuing one or more groups of instructions for execution by the thread based on the minimum group count and the maximum allowed group count for the thread.

Infinite processor thread balancing

Embodiments of the present invention provide a system for balancing a global completion table (GCT) in a microprocessor via frontend steering or stalls. A non-limiting example of the system includes an instruction dispatch unit (IDU) that includes an instruction queue and the system includes an instruction sequencing unit (ISU) that includes a GCT having a first area and a second area. The IDU is configured to determine whether a full group of instructions exist in the instruction queue and to determine whether additional instructions will be received by the instruction queue in a subsequent cycle. The IDU is configured to stall the instruction queue for at least one cycle until a full group of instructions is accumulated at the instruction queue upon determining that additional instructions will be received by the instruction queue in subsequent cycle.

Managing backend resources via frontend steering or stalls

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.

Accelerated execution of execute instruction target

Embodiments of the invention are directed to methods for handling scratch registers in a processor. The method includes receiving a cracked instruction in an instruction dispatch unit of the processor. The method further includes decoding the cracked instruction into a group of micro-operations. Based on a determination that the instruction group uses a scratch register, determining if the scratch register is used in other groups of micro-operations. Based on a determination that the scratch register is not used in other instruction groups, allocating a physical register for use as the scratch register without creating a mapper entry for the scratch register.

Suppress unnecessary mapping for scratch register

Embodiments relate to register comparison for register comparison for operand store compare (OSC) prediction. An aspect includes, for each instruction in an instruction group of a processor pipeline: determining a base register value of the instruction; determining an index register value of the instruction; and determining a displacement of the instruction. Another aspect includes comparing the base register value, index register value, and displacement of each instruction in the instruction group to the base register value, index register value, and displacement of all other instructions in the instruction group. Another aspect includes based on the comparison, determining that a load instruction of the instruction group has a probable OSC conflict with a store instruction of the instruction group. Yet another aspect includes delaying the load instruction based on the determined probable OSC conflict.

Register comparison for operand store compare (OSC) prediction

Embodiments include optimizing the grouping of instructions in a microprocessor. Aspects include receiving a first clump of instructions from a streaming buffer, pre-decoding each of instructions for select information and sending the instructions to an instruction queue. Aspects further include storing initial grouping information for the instructions in a local register, wherein the initial grouping information is based on the select information. Aspects further include updating the initial group information stored in the local register when additional pre-decode information becomes available and grouping the instructions that are ready to be dispatched into a dispatch group based on the grouping information stored in the local register. Aspects further include dispatching the dispatch group to an issue unit.

Optimizing grouping of instructions

Embodiments relate to reducing operand store compare penalties by detecting potential unit of operation (UOP) dependencies. An aspect includes a computer system for reducing operation store compare penalties. The system includes memory and a processor. The system performs a method including cracking an instruction into units of operation, where each UOP includes instruction text and address determination fields. The method includes identifying a load UOP among the plurality of UOPs and comparing values of the address determination fields of the load UOP with values of address determination fields of one or more previously-decoded store UOPs. The method also includes forcing, prior to issuance of the instruction to an execution unit, a dependency between the load UOP and the one or more previously-decoded store UOPs based on the comparing.

Reducing operand store compare penalties

Accelerated execution of target of execute instruction

A method, information processing system, and computer program product manage instruction execution based on machine state. At least one instruction is received. The at least one instruction is decoded. A current machine state is determined in response to the decoding. The at least one instruction is organized into a set of unit of operations based on the current machine state that has been determined. The set of unit of operations is executed.

Instruction cracking based on machine state

Growing community of inventors

Tallahassee, FL, United States of America

David S Hutton