International Business Machines Corporation

Juergen Haess

Silvia Melitta Mueller

Steven R Carlough

Michael Klaus Kroener

Kerstin Claudia Schelm

Michael Klein

Klaus Michael Kroener

Erez Barak

Son Trong Dao

Eyal Gonen

Eric M Schwarz

Stefan Payer

Maarten Jakob Boersma

Jochen Preiss

Guenter Gerwig

Cédric Lichtenau

Son Dao Trong

Son Dao-Trong

Christian Jacobi

Dung Q Nguyen

Cedric Lichtenau

Bruce Martin Fleischer

Erwin F Pfeffer

Petra Leber

Martin Stanley Schmookler

Raymond Cheung Yeung

Lawrence Joseph Powell, Jr

Rolf B Hilgendorf

Ingemar Holm

Gerhard Zilles

Hartmut Ulland

A method is provided. The method is executable by a processor. The method includes receiving, by an instruction issue unit of the processor as an input, a preferred instruction variant from an instruction variant selection logic. The method includes executing, by an execution unit of the processor, the preferred instruction variant. The method includes providing, by the execution unit of the processor, quality feedback to the instruction variant selection logic and evaluating, by the instruction variant selection logic of the processor, the preferred instruction variant based on the quality feedback.

Cognitive binary coded decimal to binary number conversion hardware for evaluating a preferred instruction variant based on feedback

A system and a method of clock-gating for multicycle instructions are provided. For example, the method includes enabling a plurality of logic blocks that include a subset of multicycle (MC) logic blocks and a subset of pipeline logic blocks. The method also includes computing a precise enable computation value after a plurality of cycles of executing an instruction, and disabling one or more of the subset of multicycle (MC) logic blocks based on the precise enable computation value. Also, at least the subset of pipeline logic blocks needed to compute the instruction remains on.

Clock-gating for multicycle instructions

Logic is provided for performing decimal and binary floating point arithmetic calculations on first and second operands. The method includes: receiving the first and second operands in packed format; unpacking the first and second operands; swapping the first operand to a fourth operand and the second operand to a third operand, if an exponent of the first operand is less than an exponent of the second operand, otherwise storing the first operand to the third operand and the second operand to the fourth operand; aligning the third operand and the fourth operands based on the exponent difference of the third and fourth operand and a number of leading zeroes of the third operand; performing an add/subtract operation on the aligned third and fourth operands with normalizing and rounding between the operands; and packing the result obtained from the add/subtract.

Decimal and binary floating point arithmetic calculations

Embodiments include a method for temporary pipeline marking for processor error workarounds. The method includes monitoring an execution unit pipeline of a processor for an event associated with a programmable instruction operational code that is predetermined to cause a stuck state resulting in an errant instruction execution. The execution unit pipeline is marked for a workaround action based on detecting the event. A clearing action is triggered based on the marking, where the triggering is conditionally triggered by a next instruction in the execution unit pipeline having a same instruction type as the programmable instruction operational code. The marking of the pipeline is cleared based on the triggering of the clearing action, where the clearing action is a subsequent pipeline flush event based on the next instruction having the same instruction type reaching a same pipeline stage that results in a stuck state prior to completion of the next instruction.

Temporary pipeline marking for processor error workarounds

Embodiments include a method for temporary pipeline marking for processor error workarounds. The method includes monitoring a pipeline of a processor for an event that is predetermined to place the processor in a stuck state that results in an errant instruction execution result due to the stuck state or repeated resource contention causing performance degradation. The pipeline is marked for a workaround action based on detecting the event. A clearing action is triggered based on the marking of the pipeline. The marking of the pipeline is cleared based on the triggering of the clearing action.

Embodiments include a computer system for temporary pipeline marking for processor error workarounds, the computer system having a processor configured to perform a method. The method includes monitoring a pipeline of the processor for an event that is predetermined to place the processor in a stuck state that results in an errant instruction execution result due to the stuck state or repeated resource contention causing performance degradation. The pipeline is marked for a workaround action based on detecting the event. A clearing action is triggered based on the marking of the pipeline. The marking of the pipeline is cleared based on the triggering of the clearing action.

Software that combines parity bits with error correcting codes (ECC) such that a subset of ECC bits is also used for parity purposes, by performing the following steps: (i) providing a first set of redundant bit(s) in a data block, where the first set of redundant bit(s) is adapted to detect and/or correct errors in the data block; (ii) providing, within the first set of redundant bit(s), a first sub-set of parity bit(s), where the first sub-set of parity bit(s) is adapted to provide single bit error detection for the data block; and (iii) determining, based, at least in part, on a first set of data read requirements, whether to use the first set of redundant bit(s) and/or the first sub-set of parity bit(s) to detect and/or correct potential errors while reading data on the data block.

Using error correcting codes for parity purposes

A residue generating circuit for an execution unit that supports vector operations includes an operand register and a residue generator coupled to the operand register. The residue generator includes a first residue generation tree coupled to a first section of the operand register and a second residue generation tree coupled to a second section of the operand register. The first residue generation tree is configured to generate a first residue for first data included in the first section of the operand register. The second residue generation tree is configured to generate a second residue for second data included in a second section of the operand register. The first section of the operand register includes a different number of register bits than the second section of the operand register.

Residue-based error detection for a processor execution unit that supports vector operations

A method and system for tracing in a data processing system. The method includes receiving a plurality of signals associated with an operation during execution of the operation. The method also includes, in response to an indication that the operation is a multiphase operation, during execution of the operation, selection logic, during a first phase of the multiphase operation, selecting and outputting as a trace signal a first signal of the plurality of signals, and during a second phase of the multiphase operation, selecting and outputting as the trace signal a second signal of the plurality of signals.

Dynamic hardware trace supporting multiphase operations

In a data processing system a plurality of signals associated with an operation are received during execution of the operation. In response to an indication that the operation is a multiphase operation, during execution of the operation, selection logic, during a first phase of the multiphase operation, selects and outputs as a trace signal a first signal of the plurality of signals, and during a second phase of the multiphase operation, selects and outputs as the trace signal a second signal of the plurality of signals.

A distributed residue checking apparatus for a floating point unit having a plurality of functional elements performing floating-point operations on a plurality of operands. The distributed residue checking apparatus includes a plurality of residue generators which generate residue values for the operands and the functional elements, and a plurality of residue checking units distributed throughout the floating point unit. Each residue checking unit receives a first residue value and a second residue value from respective residue generators and compares the first residue value to the second residue value to determine whether an error has occurred in a floating-point operation performed by a respective functional element.

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Schoenaich, Germany

Juergen Haess