International Business Machines Corporation

Rensselaer Polytechnic Institute

John G Rell, Jr

Fadi Y Busaba

David S Hutton

Eric M Schwarz

Christopher A Krygowski

Patrick M West, Jr

Edward Thomas Malley

James Raymond Cuffney

Chung-Lung K Shum

Steven R Carlough

Khary J Alexander

Timothy John Slegel

Brian Robert Prasky

Sheryll H Veneracion

Brian William Curran

Timothy J Koprowski

Jeffrey S Plate

Mark S Farrell

Bruce C Giamei

Aaron Tsai

Vimal M Kapadia

Michael T Huffer

Anthony Saporito

Charles Franklin Webb

James J Bonanno

Mark Anthony Check

Scott Barnett Swaney

Michael Billeci

Michael James Mack

Christine C Harty

James J Parslow

Frank Tanzi

Saleem A Ali

Franz A Bronnimann

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 relate to a hardware circuit that is operable as a fixed point adder and a checksum adder. An aspect includes a driving of a multifunction compression tree disposed on a circuit path based on a control bit to execute one of first and second schemes of vector input addition and a driving of a multifunction adder disposed on the circuit path based on the control bit to perform the one of the first and second schemes of vector input addition.

Checksum adder

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

An apparatus for comparing strings comprises a first and a second set of input registers, a matrix of comparator circuits wherein rows of the matrix correspond to the first set of input registers and columns of the matrix correspond to the second set of input registers, a set of row control registers wherein each register corresponds to a row of the matrix of the comparator circuits, the matrix of comparator circuits configured to compare data provided by the first set of registers with data provided by the second set of registers according to the row control registers, and an error detection circuit configured to compare results from four comparator circuits corresponding to two adjacent rows and two columns of the matrix of comparator circuits. A method that invokes the above mentioned apparatus is also disclosed herein, along with a computer program product corresponding to the method.

String dataflow error detection

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

Execution of threads in a processor core is controlled. The processor core supports simultaneous multi-threading (SMT) such that there can be effectively multiple logical central processing units (CPUs) operating simultaneously on the same physical processor hardware. Each of these logical CPUs is considered a thread. In such a multi-threading environment, it may be desirous for one thread to stop other threads on the processor core from executing. This may be in response to running a critical sequence or other sequence that needs the processor core resources or is manipulating processor core resources in a way that other threads would interfere with its execution.

Controlling execution of threads in a multi-threaded processor

Embodiments relate to vectorized Galois field multiplication. An aspect includes an input of first and second input operands of equal sizes into a single hardware tree, a calculation of a predicted parity as a parity of the first input operand ANDed with a parity of the second input operand, a comparison of the predicted parity with a parity generated on a final result of a Galois field multiplication of the first and second operands and a raising of an error based on a mismatch between the predicted parity and the generated parity.

Vectorized Galois field multiplication

Embodiments relate to vectorized Galois field multiplication. An aspect includes a subdivision of first and second input operands into vector elements of equal sizes with multiple modes defined such that a base mode has a size corresponding to a smallest vector element size, which is a factor of a size of the first and second input operands, and a higher mode has a size that is a multiple of the base mode size. The vector elements of the first input operand are modified with a bit mask based on a size of the vector elements. The modified vector elements of the first input operand and the vector elements of the second input operand are input into a single hardware tree configured for subdivision into staggered subtrees a size of each of which being based on the base mode size.

Growing community of inventors

Saugerties, NY, United States of America

John G Rell, Jr