International Business Machines Corporation

Daniel Arthur Prener

Ravi Nair

Kathryn Mary O'Brien

John Kevin O'Brien

Peter Howland Oden

Hans Mikael Jacobson

Bruce Martin Fleischer

Thomas Winters Fox

Erik Richter Altman

Sumedh Wasudeo Sathaye

Thomas R Puzak

John Kevin Patrick O'Brien

Mark Jay Charney

Michael K Gschwind

David Arnold Luick

Tong Chen

Jude A Rivers

Zehra Noman Sura

Allan Mark Hartstein

John-David Wellman

Jaime Humberto Moreno

Arpith C Jacob

Kevin John Patrick O'Brien

Pradip Bose

Philip George Emma

Vijayalakshmi Srinivasan

Christos J Georgiou

Prabhakar Nandavar Kudva

Meeta S Gupta

Sumeda Wasudeo Sathaye

A processor core includes a storage device which stores a composite very large instruction word (VLIW) instruction, an instruction unit which obtains the composite VLIW instruction from the storage device and decodes the composite VLIW instruction to determine an operation to perform, and a composite VLIW instruction execution unit which executes the composite VLIW instruction to perform the operation.

Executing a composite scalar-vector VLIW instruction having a repeat field

Methods and systems for optimizing an application for a computing system having multiple distinct memory locations that are interconnected by one or more communication channels include determining one or more data handling properties for a data region in an application. One or more data handling policies for the data region are determined based on the one or more data handling properties. Data setup costs are determined for a scope in the application that uses the data region in different memory locations based on the one or more data handling properties. The application is optimized in accordance with the one or more data handling policies and the data setup costs for the different memory locations.

Flexible optimized data handling in systems with multiple memories

A processor core includes a storage device which stores a composite very large instruction word (VLIW) instruction, an instruction unit which obtains the composite VLIW instruction from the storage device and decodes the composite VLIW instruction to determine an operation to perform, and a composite VLIW instruction execution unit which executes the decoded composite VLIW instruction to perform the operation.

Executing a composite VLIW instruction having a scalar atom that indicates an iteration of execution

Embodiments relate to packed loading and storing of data. An aspect includes a system for packed loading and storing of distributed data. The system includes memory and a processing element configured to communicate with the memory. The processing element is configured to perform a method including fetching and decoding an instruction for execution by the processing element. A plurality of individually addressable data elements is gathered from non-contiguous locations in the memory which are narrower than a nominal width of register file elements in the processing element based on the instruction. The processing element packs and loads the data elements into register file elements of a register file entry based on the instruction, such that at least two of the data elements gathered from the non-contiguous locations in the memory are packed and loaded into a single register file element of the register file entry.

Gather/scatter of multiple data elements with packed loading/storing into /from a register file entry

Embodiments relate to packed loading and storing of data. An aspect includes a method for packed loading and storing of data distributed in a system that includes memory and a processing element. The method includes fetching and decoding an instruction for execution by the processing element. The processing element gathers a plurality of individually addressable data elements from non-contiguous locations in the memory which are narrower than a nominal width of register file elements in the processing element based on the instruction. The data elements are packed and loaded into register file elements of a register file entry by the processing element based on the instruction, such that at least two of the data elements gathered from the non-contiguous locations in the memory are packed and loaded into a single register file element of the register file entry.

Gather/scatter of multiple data elements with packed loading/storing into/from a register file entry

Embodiments relate to vector processing in an active memory device. An aspect includes a method for vector processing in an active memory device that includes memory and a processing element. The method includes decoding, in the processing element, an instruction including a plurality of sub-instructions to execute in parallel. An iteration count to repeat execution of the sub-instructions in parallel is determined. Based on the iteration count, execution of the sub-instructions in parallel is repeated for multiple iterations by the processing element. Multiple locations in the memory are accessed in parallel based on the execution of the sub-instructions.

Vector processing in an active memory device

Embodiments relate to vector processing in an active memory device. An aspect includes a system for vector processing in an active memory device. The system includes memory in the active memory device and a processing element in the active memory device. The processing element is configured to perform a method including decoding an instruction with a plurality of sub-instructions to execute in parallel. An iteration count to repeat execution of the sub-instructions in parallel is determined. Execution of the sub-instructions is repeated in parallel for multiple iterations, by the processing element, based on the iteration count. Multiple locations in the memory are accessed in parallel based on the execution of the sub-instructions.

A method (and system) of emulation in a multiprocessor system, includes performing an emulation in which a host multiprocessing system of the multiprocessor system supports a weak consistency model, and the target multiprocessing system of the multiprocessor system supports a strong consistency model.

Method and system for efficient emulation of multiprocessor memory consistency

Partitioning programs between a general purpose core and one or more accelerators is provided. A compiler front end is provided for converting a program source code in a corresponding high level programming language into an intermediate code representation. This intermediate code representation is provided to an interprocedural optimizer which determines which core processor or accelerator each portion of the program should execute on and partitions the program into sub-programs based on this set of decisions. The interprocedural optimizer may further add instructions to the partitions to coordinate and synchronize the sub-programs as required. Each sub-program is compiled on an appropriate compiler backend for the instruction set architecture of the particular core processor or accelerator selected to execute the sub-program. The compiled sub-programs and then linked to thereby generate an executable program.

Method for partitioning programs between a general purpose core and one or more accelerators

An aspect includes providing rollback support in an exposed-pipeline processing element. A method for providing rollback support in an exposed-pipeline processing element includes detecting, by rollback support logic, an error associated with execution of an instruction in the exposed-pipeline processing element. The rollback support logic determines whether the exposed-pipeline processing element supports replay of the instruction for a predetermined number of cycles. Based on determining that the exposed-pipeline processing element supports replay of the instruction, a rollback action is performed in the exposed-pipeline processing element to attempt recovery from the error.

Exposed-pipeline processing element with rollback

Mechanisms are provided for predicting effects of soft errors on an integrated circuit device design. A data processing system is configured to implement a unified derating tool that includes a machine derating front-end engine used to generate machine derating information, and an application derating front-end engine used to generate application derating information, for the integrated circuit device design. The machine derating front-end engine executes a simulation of the integrated circuit device design to generate the machine derating information. The application derating front-end engine executes an application workload on existing hardware similar in architecture to the integrated circuit device design and injects a fault into the existing hardware during execution of the application workload to generate application derating information. The machine derating information is combined with the application derating information to generate at least one soft error rate value for the integrated circuit device design.

Hardware execution driven application level derating calculation for soft error rate analysis

A method (and structure) of mapping a memory addressing of a multiprocessing system when it is emulated using a virtual memory addressing of another multiprocessing system includes accessing a local lookaside table (LLT) on a target processor with a target virtual memory address. Whether there is a 'miss' in the LLT is determined and, with the miss determined in the LLT, a lock for a global page table is obtained.

Method and system for efficient emulation of multiprocessor address translation on a multiprocessor

In a host system, a method for using instruction scheduling to efficiently emulate the operation of a target computing system includes preparing, on the host system, an instruction sequence to interpret an instruction written for execution on the target computing system. An instruction scheduling on the instruction sequence is performed, to achieve an efficient instruction level parallelism, for the host system. A separate and independent instruction sequence is inserted, which, when executed simultaneously with the instruction sequence, performs to copy to a separate location a minimum instruction sequence necessary to execute an intent of an interpreted target instruction, the interpreted target instruction being a translation; and modifies the interpreter code such that a next interpretation of the target instruction results in execution of the translated version, thereby removing execution of interpreter overhead.

Hybrid mechanism for more efficient emulation and method therefor

An mechanism is provided for partitioning programs between a general purpose core and one or more accelerators. With the apparatus and method, a compiler front end is provided for converting a program source code in a corresponding high level programming language into an intermediate code representation. This intermediate code representation is provided to an interprocedural optimizer which determines which core processor or accelerator each portion of the program should execute on and partitions the program into sub-programs based on this set of decisions. The interprocedural optimizer may further add instructions to the partitions to coordinate and synchronize the sub-programs as required. Each sub-program is compiled on an appropriate compiler backend for the instruction set architecture of the particular core processor or accelerator selected to execute the sub-program. The compiled sub-programs and then linked to thereby generate an executable program.

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Croton-on-Hudson, NY, United States of America

Daniel Arthur Prener