Method and apparatus are provided for synchronising execution of a plurality of threads on a multi-threaded processor. A program executed by a thread can have a number of synchronisation points corresponding to points where execution is to be synchronised with another thread. Execution of a thread is paused when it reaches a synchronisation point until at least one other thread with which it is intended to be synchronised reaches a corresponding synchronisation point. Execution is subsequently resumed. A control core maintains status data for threads and can cause a thread that is ready to run to use execution resources that were occupied by a thread that is waiting for a synchronisation event.

A data processing apparatus 10 for executing an access instruction for n threads in order to access data values for the n threads includes storage circuitry 100 that stores data values associated with the n threads in groups defined by storage boundaries. The data processing apparatus also includes processing circuitry 80 that processes the access instruction for a set of threads at a time (where each set of threads comprises fewer than n threads) and splitting circuitry 110, responsive to the access instruction, to divide the n threads into multiple sets of threads, and to generate at least one control signal identifying the multiple sets. For each of the sets, the processing circuitry responds to the at least one control signal by issuing at least one access request to the storage circuitry in order to access the data values for that set. The splitting circuitry determines into which set each of the n threads is allocated having regards to the storage boundaries.

A method, system, and computer program product synchronize a group of workitems executing an instruction stream on a processor. The processor is yielded by a first workitem responsive to a synchronization instruction in the instruction stream. A first one of a plurality of program counters is updated to point to a next instruction following the synchronization instruction in the instruction stream to be executed by the first workitem. A second workitem is run on the processor after the yielding.

A compiler parses a multithreaded application into cohesive blocks of instructions. Cohesive blocks include instructions that do not diverge or converge. Each cohesive block is associated with one or more uniform registers. When a set of threads executes the instructions in a given cohesive block, each thread in the set may access the uniform register independently of the other threads in the set. Accordingly, the uniform register may store a single copy of data on behalf of all threads in the set of threads, thereby conserving resources.

A just-in-time (JIT) compiler binds constants to specific memory locations at runtime. The JIT compiler parses program code derived from a multithreaded application and identifies an instruction that references a uniform constant. The JIT compiler then determines a chain of pointers that originates within a root table specified in the multithreaded application and terminates at the uniform constant. The JIT compiler generates additional instructions for traversing the chain of pointers and inserts these instructions into the program code. A parallel processor executes this compiled code and, in doing so, causes a thread to traverse the chain of pointers and bind the uniform constant to a uniform register at runtime. Each thread in a group of threads executing on the parallel processor may then access the uniform constant.

This invention provides a high performance processor system and a method based on a common general purpose unit, it may be configured into a variety of different processor architectures; before the processor executes instructions, the instruction is filled into the instruction read buffer, which is directly accessed by the processor core, then instruction read buffer actively provides instructions to processor core to execute, achieving a high cache hit rate.

One embodiment provides for a parallel processor comprising a processing array within the parallel processor, the processing array including multiple compute blocks, each compute block including multiple processing clusters configured for parallel operation, wherein each of the multiple compute blocks is independently preemptable. In one embodiment a preemption hint can be generated for source code during compilation to enable a compute unit to determine an efficient point for preemption.

An apparatus that includes a program controller to fetch and issue instructions. The apparatus includes an execution lane having at least one execution unit to execute the instructions. The execution lane is part of an execution lane array that is coupled to a two dimensional shift register array structure, wherein, execution lane s of the execution lane array are located at respective array locations and are coupled to dedicated registers at same respective array locations in the two-dimensional shift register array.

Systems, apparatuses, and methods for implementing register compaction with early release are disclosed. A processor includes at least a command processor, a plurality of compute units, a plurality of registers, and a control unit. Registers are statically allocated to wavefronts by the control unit when wavefronts are launched by the command processor on the compute units. In response to determining that a first set of registers, previously allocated to a first wavefront, are no longer needed, the first wavefront executes an instruction to release the first set of registers. The control unit detects the executed instruction and releases the first set of registers to the available pool of registers to potentially be used by other wavefronts. Then, the control unit can allocate the first set of registers to a second wavefront for use by threads of the second wavefront while the first wavefront is still active.

Devices and methods for partial sorting for coherence recovery are provided. The partial sorting is efficiently executed by utilizing existing hardware along the memory path (e.g., memory local to the compute unit). The devices include an accelerated processing device which comprises memory and a processor. The processor is, for example, a compute unit of a GPU which comprises a plurality of SIMD units and is configured to determine, for data entries each comprising a plurality of bits, a number of occurrences of different types of the data entries by storing the number of occurrences in one or more portions of the memory local to the processor, sort the data entries based on the determined number of occurrences stored in the one or more portions of the memory local to the processor and execute the sorted data entries.