International Business Machines Corporation

Jinwook Oh

Sunil K Shukla

Vijayalakshmi Srinivasan

Kailash Gopalakrishnan

Bruce Martin Fleischer

Chia-Yu Chen

Jungwook Choi

Silvia Melitta Mueller

Brian William Curran

Swagath Venkataramani

Ankur Agrawal

Kailash Gopalakrishan

Lee M Saltzman

A reduced precision based programmable and single instruction multiple data (SIMD) dataflow architecture includes reduced precision execution units with a majority of the execution units operating at reduced precision and a minority of the execution units are capable of operating at higher precision. The execution units operate in parallel within a programmable execution element to share instruction fetch, decode, and issue pipelines and operate on the same instruction in lock-step to minimize instruction-related overhead.

Reduced precision based programmable and SIMD dataflow architecture

Various embodiments are provided for facilitating data processing by one or more processors in a computing system. An instruction to be executed may be obtained. The instruction is a single instruction multiple data (SIMD) reduction operation of an operand vector with a plurality of vector elements. The SIMD reduction operation may be executed to produce a result vector with a plurality of alternative vector elements. One or more reduction functions may be performed on each of a pair of vector elements from the plurality of vector elements of the operand vector and a result of the one or more reduction functions may be placed in a corresponding vector element of the result vector.

Facilitating data processing using SIMD reduction operations across SIMD lanes

Embodiments of the present invention include a computer system that manages execution of one or more programs with one or more loops where each loop having a loop level. Embodiments that manage loops that can skip execution and the number of loops changing during execution are also disclosed. A loop level register (LLEV) stores the loop level for a currently executing loop. A Loop-Back Program Counter Register (LBPR) has a table of one or more Loop-Back Registers. Each Loop-Back Register stores the loop level for a LBPR respective loop and a loop back PC location for the LBPR respective loop. A Program Counter points back to the PC location for each iteration of the loop. A Loop Current Count Register table (LCCR) tracks a number of iterations remaining to executed for of the loop. A loop management process causes one of the CPUs to execute all the one or more instructions of an iteration of the currently executing program loop. When all iterations of the executing loop are complete, the LLEV is decremented to a next loop level that contained the executed loop.

Loop management in multi-processor dataflow architecture

Embodiments for implementing a communicating memory between a plurality of computing components are provided. In one embodiment, an apparatus comprises a plurality of memory components residing on a processing chip, the plurality of memory components interconnected between a plurality of processing elements of at least one processing core of the processing chip and at least one external memory component external to the processing chip. The apparatus further comprises a plurality of load agents and a plurality of store agents on the processing chip, each interfacing with the plurality of memory components. Each of the plurality of load agents and the plurality of store agents execute an independent program specifying a destination of data transacted between the plurality of memory components, the at least one external memory component, and the plurality of processing elements.

Programmable data delivery by load and store agents on a processing chip interfacing with on-chip memory components and directing data to external memory components

An apparatus and method for supporting simultaneous multiple iterations (SMI) and iteration level commits (ILC) in a course grained reconfigurable architecture (CGRA). The apparatus includes: Hardware structures that connect all of multiple processing engines (PEs) to a load-store unit (LSU) configured to keep track of which compiled program code iterations have completed, which ones are in flight and which are yet to begin, and a control unit including hardware structures that are used to maintain synchronization and initiate and terminate loops within the PEs. The PEs, LSU and control unit are configured to commit instructions, and save and restore context at loop iteration boundaries. In doing so, the apparatus tracks and buffers state of in-flight iterations, and detects conditions that prevent an iteration from completing. In support of ILC functions, the LSU is iteration aware and includes: iteration-interleaved load-store queue (LSQ) banks; a Bloom Filter for filtering instructions; and a load coalescing buffer.

Tightly coupled processor arrays using coarse grained reconfigurable architecture with iteration level commits

An apparatus and method for supporting simultaneous multiple iterations (SMI) in a course grained reconfigurable architecture (CGRA). In support of SMI, the apparatus includes: Hardware structures that connect all of multiple processing engines (PEs) to a load-store unit (LSU) configured to keep track of which compiled program code iterations have completed, which ones are in flight and which are yet to begin, and a control unit including hardware structures that are used to maintain synchronization and initiate and terminate loops within the PEs. SMI permits execution of the next instruction within any iteration (in flight). If instructions from multiple iterations are ready for execution (and are pre-decoded), then the hardware selects the lowest iteration number ready for execution. If in a particular clock cycle, a loop iteration with a lower iteration number is stalled (i.e., is waiting for data), the instruction from the next highest iteration number that is ready thereby will be automatically executed automatically allowing the CGRA to have high ILP by overlapping concurrent loop iterations.

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Fort Lee, NJ, United States of America

Jinwook Oh