The present disclosure relates to a mechanism for issuing instructions in a processor (e.g., a vector processor) implemented as an overlay on programmable hardware (e.g., a field programmable gate array (FPGA) device). Implementations described herein include features for optimizing resource availability on programmable hardware units and enabling superscalar execution when coupled with a temporal single-instruction multiple data (SIMD). Systems described herein involve an issue component of a processor controller (e.g., a vector processor controller) that enables fast and efficient instruction issue while verifying that structural and data hazards between instructions have been resolved.

There is provided execution circuitry. Storage circuitry retains a stored state of the execution circuitry. Operation receiving circuitry receives, from issue circuitry, an operation signal corresponding to an operation to be performed that accesses the stored state of the execution circuitry from the storage circuitry. Functional circuitry seeks to perform the operation in response to the operation signal by accessing the stored state of the execution circuitry from the storage circuitry. Delete request receiving circuitry receives a deletion signal and in response to the deletion signal, deletes the stored state of the execution circuitry from the storage circuitry. State loss indicating circuitry responds to the operation signal when the stored state of the execution circuitry is not present and is required for the operation by indicating an error. In addition, there is provided a data processing apparatus comprising issue circuitry to issue an operation to execution circuitry. The execution circuitry stores a stored state that is accessed during performance of the operation and error detecting circuitry detects an indication of an error from the execution circuitry that the stored state is required for performance of the operation and that the stored state has been deleted.

There is provided a data processing apparatus comprising decode circuitry responsive to receipt of a block of instructions to generate control signals indicative of each of the block of instructions, and to analyse the block of instructions to detect a potential hazard instruction. The data processing apparatus is provided with decode circuitry to encode information indicative of a clean restart point into the control signals associated with the potential hazard instruction. The data processing apparatus is provided with data processing circuitry to perform out-of-order execution of at least some of the block of instructions, and control circuitry responsive to a determination, at execution of the potential hazard instruction, that data values used as operands for the potential hazard instruction have been modified by out-of-order execution of a subsequent instruction, to restart execution from the clean restart point and to flush held data values from the data processing circuitry.

Techniques related to executing a plurality of instructions by a processor comprising receiving a first instruction for execution on an instruction execution pipeline, beginning execution of the first instruction, receiving one or more second instructions for execution on the instruction execution pipeline, the one or more second instructions associated with a higher priority task than the first instruction, storing a register state associated with the execution of the first instruction in one or more registers of a capture queue associated with the instruction execution pipeline, copying the register state from the capture queue to a memory, determining that the one or more second instructions have been executed, copying the register state from the memory to the one or more registers of the capture queue, and restoring the register state to the instruction execution pipeline from the capture queue.

A predicated-loop-terminating branch instruction controls, based on whether a loop termination condition is satisfied, whether the processing circuitry should process a further iteration of a predicated loop body or process a following instruction. If at least one unnecessary iteration of the predicated loop body is processed following a mispredicted-non-termination branch misprediction when the loop termination condition is mispredicted as unsatisfied for a given iteration when it should have been satisfied, processing of the at least one unnecessary iteration of the predicated loop body is predicated to suppress an effect of the at least one unnecessary iteration. When the mispredicted-non-termination branch misprediction is detected for the given iteration of the predicated-loop-terminating branch instruction, in response to determining that a flush suppressing condition is satisfied, flushing of the at least one unnecessary iteration of the predicated loop body is suppressed as a response to the mispredicted-non-termination branch misprediction.

A streaming engine employed in a digital data processor specifies a fixed read only data stream defined by plural nested loops. An address generator produces addresses of data elements. A steam head register stores data elements next to be supplied to functional units for use as operands. Stream metadata is stored in response to a stream store instruction. Stored stream metadata is restored to the stream engine in response to a stream restore instruction. An interrupt changes an open stream to a frozen state discarding stored stream data. A return from interrupt changes a frozen stream to an active state.

An exception summary is provided for an invalid value detected during instruction execution. An indication that a value determined to be invalid was included in input data to a computation of one or more computations or in output data resulting from the one or more computations is obtained. The value is determined to be invalid due to one exception of a plurality of exceptions. Based on obtaining the indication that the value is determined to be invalid, a summary indicator is set. The summary indicator represents the plurality of exceptions collectively.

Techniques for operating on an indirect memory access instruction, where the instruction accesses a memory location via at least one indirect address. A pipeline processes the instruction and a memory operation engine generates a first access to the at least one indirect address and a second access to a target address determined by the at least one indirect address. A cache memory used with the pipeline and the memory operation engine caches pointers. In response to a cache hit when executing the indirect memory access instruction, operations dereference a pointer to obtain the at least one indirect address, not set a cache bit, and return data for the instruction without storing the data in the cache memory; and in response to a cache miss, operations set the cache bit, obtain, and store a cache line for a missed pointer, and return data without storing the data in the cache memory.

An apparatus comprises decoder circuitry to decode an instruction that includes an opcode to indicate a protected load operation, a source field for source memory address information, and a destination field to identify a destination register. The apparatus also comprises memory to store an allocate load-protect (LP) data structure with an entry for the identified destination register. The entry comprises an IP field and a status field. The apparatus also comprises load elision circuitry to (a) use the allocate LP data structure to determine whether the identified destination register has active status for the IP; (b) in response to determining that the identified destination register has active status for the IP, cause the instruction to be elided; and (c) in response to determining that the identified destination register does not have active status for the IP, cause the instruction to be executed. Other embodiments are described and claimed.

An embodiment of an integrated circuit may comprise a return stack buffer (RSB), a speculative return stack buffer (SRSB), and circuitry coupled to the RSB and the SRSB, the circuitry to track a count until the SRSB is empty at a time of a prediction by a branch prediction unit, and return an output from the branch prediction unit that corresponds to one of the RSB and the SRSB based at least in part on the count until the SRSB is empty. Other embodiments are disclosed and claimed.