Apparatus and methods are disclosed for controlling execution of memory access instructions in a block-based processor architecture using a hardware structure that indicates a relative ordering of memory access instruction in an instruction block. In one example of the disclosed technology, a method of executing an instruction block having a plurality of memory load and/or memory store instructions includes selecting a next memory load or memory store instruction to execute based on dependencies encoded within the block, and on a store vector that stores data indicating which memory load and memory store instructions in the instruction block have executed. The store vector can be masked using a store mask. The store mask can be generated when decoding the instruction block, or copied from an instruction block header. Based on the encoded dependencies and the masked store vector, the next instruction can issue when its dependencies are available.

Operation of a multi-slice processor implementing datapath steering, where the multi-slice processor includes a plurality of execution slices. Operation of such a multi-slice processor includes: identifying, from a set of instructions, a second instruction that is dependent upon a first instruction in the set of instructions; and responsive to the second instruction being dependent upon the first instruction in the set of instructions, issuing each of the instructions in the set of instructions to a particular set of execution slices configured with bypass logic between execution slices that reduces execution latencies between dependent instructions.

In an embodiment, a coprocessor may include a bypass indication which identifies execution circuitry that is not used by a given processor instruction, and thus may be bypassed. The corresponding circuitry may be disabled during execution, preventing evaluation when the output of the circuitry will not be used for the instruction. In another embodiment, the coprocessor may implement a grid of processing elements in rows and columns, where a given coprocessor instruction may specify an operation that causes up to all of the processing elements to operate on vectors of input operands to produce results. Implementations of the coprocessor may implement a portion of the processing elements. The coprocessor control circuitry may be designed to operate with the full grid or partial grid, reissuing instructions in the partial grid case to perform the requested operation. In still another embodiment, the coprocessor may be able to fuse vector mode operations.

Functional units disposed in one or more processor cores are communicatively coupled using both a shared bypass network and a switched network. The shared bypass network enables the functional units to be operated conventionally for general processing while the switched network enables specialized processing in which the functional units are configured as a spatial array. In the spatial array configuration, operands produced by one functional unit can only be sent to a subset of functional units to which dependent instructions have been mapped a priori. The functional units may be dynamically reconfigured at runtime to toggle between operating in the general configuration and operating as the spatial array. Information to control the toggling between operating configurations may be provided in instructions received by the functional units.

Methods and apparatus of delegating instructions or data from a CU to an NOC node in a network on chip (NOC) is disclosed. The NOC node executes the delegated instructions or processes the delegated data. An NOC controller (NCC), which is operatively coupled to the CU and the NOC node, facilitates delegating the instructions or data from the CU to the NOC node.

Techniques are disclosed relating to sharing operands among SIMD threads for a larger arithmetic operation. In some embodiments, a set of multiple hardware pipelines is configured to execute single-instruction multiple-data (SIMD) instructions for multiple threads in parallel, where ones of the hardware pipelines include execution circuitry configured to perform floating-point operations using one or more pipeline stages of the pipeline and first routing circuitry configured to select, from among thread-specific operands stored for the hardware pipeline and from one or more other pipelines in the set, a first input operand for an operation by the execution circuitry. In some embodiments, a device is configured to perform a mathematical operation on source input data structures stored across thread-specific storage for the set of hardware pipelines, by executing multiple SIMD floating-point operations using the execution circuitry and the first routing circuitry. This may improve performance and reduce power consumption for matrix multiply and reduction operations, for example.

A processor core includes even and odd execution slices each having a register file. The slices are each configured to perform operations specified in a first set of instructions on data from its respective register file, and together configured to perform operations specified in a second set of instructions on data stored across both register files. During utilization, the processor receives a first instruction of the first set specifying an operation, a target register, and a source register. Next, a second instruction upon which content of the source register depends is identified as being of the second set. In response, the first instruction is dispatched to the even slice. In accordance with the operation specified in the first instruction, the even slice uses content of the source register in its register file to produce a result. Copies of the result are written to the target register in both register files.

In an embodiment, a coprocessor may include a bypass indication which identifies execution circuitry that is not used by a given processor instruction, and thus may be bypassed. The corresponding circuitry may be disabled during execution, preventing evaluation when the output of the circuitry will not be used for the instruction. In another embodiment, the coprocessor may implement a grid of processing elements in rows and columns, where a given coprocessor instruction may specify an operation that causes up to all of the processing elements to operate on vectors of input operands to produce results. Implementations of the coprocessor may implement a portion of the processing elements. The coprocessor control circuitry may be designed to operate with the full grid or partial grid, reissuing instructions in the partial grid case to perform the requested operation. In still another embodiment, the coprocessor may be able to fuse vector mode operations.

The invention relates to a method for processing instructions out-of-order on a processor comprising an arrangement of execution units. The inventive method comprises looking up operand sources in a Register Positioning Table and setting operand input references of the instruction to be issued accordingly, checking for an Execution Unit (EXU) available for receiving a new instruction, and issuing the instruction to the available Execution Unit and entering a reference of the result register addressed by the instruction to be issued to the Execution Unit into the Register Positioning Table (RPT).

A data processing system including a data processor which is operable to execute programs to perform data processing operations and in which execution threads executing a program to perform data processing operations may be grouped together into thread groups. The data processor comprises a cross-lane permutation circuit which is operable to perform processing for cross-lane instructions which require data to be permuted (copied or moved) between the threads of a thread group. The cross-lane permutation circuit has plural data lanes between which data may be permuted (moved or copied). The number of data lanes is fewer than the number of threads in a thread group.