Abstract: A data processing system 2 supporting vector processing operations uses scaling vector length querying instructions. The scaling vector length querying instructions return a result which is dependent upon a number of elements in a vector for a variable vector element size specified by the instruction and multiplied by a scaling value specified by the instruction. The scaling vector length querying instructions may be in the form of count instructions, increment instructions or decrement instructions. The instructions may include a pattern constraint applying a constraint, such as modulo(M) or power of 2 to the partial result value representing the number of vector elements provided for the register element size specified for the instruction.

Abstract: Address collisions are managed when performing vector operations. A register store stores vector operands. Execution circuitry performs memory access operations to move the vector operands between the register store and memory and data processing operations using the vector operands. The execution circuitry may iteratively execute a vector loop, where during each iteration the execution circuitry executes a sequence of instructions to implement the vector loop. The sequence includes a check instruction identifying a plurality of memory addresses. The execution circuitry responds to the check instruction to determine whether an address hazard condition exists among the plurality of memory addresses. For each iteration of the vector loop, the execution circuitry responds to the check instruction determining an absence of the hazard address condition to employ a default level of vectorization when executing the sequence of instructions to implement the vector loop.

Abstract: Data processing apparatus comprises processing circuitry to selectively apply a vector processing operation to data items at positions within data vectors according to the states of a set of respective predicate flags associated with the positions, the data vectors having a data vector processing order, each data vector comprising a plurality of data items having a data item order, the processing circuitry comprising: instruction decoder circuitry to decode program instructions; and instruction processing circuitry to execute instructions decoded by the instruction decoder circuitry; wherein the instruction decoder circuitry is responsive to a propagation instruction to control the instruction processing circuitry to derive a set of predicate flags applicable to a current data vector in dependence upon a set of predicate flags applicable to a preceding data vector in the data vector processing order, wherein when one or more last-most predicate flags of the set applicable to the preceding data vector are inac

Abstract: An apparatus and method of operating the apparatus are provided for performing a count operation. Instruction decoder circuitry is responsive to a count instruction specifying an input data item to generate control signals to control the data processing circuitry to perform a count operation. The count operation determines a count value indicative of a number of input elements of a subset of elements in the specified input data item which have a value which matches a reference value in a reference element in a reference data item. A plurality of count operations may be performed to determine a count data item corresponding to the input data item. A register scatter storage instruction, a gather index generation instruction, and respective apparatuses responsive to them, as well as simulator implementations, are also provided.

Abstract: An apparatus and a method of operating the apparatus are provided for performing a comparison operation to match a given sequence of values within an input vector. Instruction decoder circuitry is responsive to a string match instruction specifying a segment of an input vector to generate control signals to control the data processing circuitry to perform a comparison operation. The comparison operation determines a comparison value indicative of whether each input element of a required set of consecutive input elements of the segment has a value which matches a respective value in consecutive reference elements of the reference data item. A plurality of comparison operations may be performed to determine a match vector corresponding to the segment of the input vector to indicate the start position of the substring in the input vector. A string match instruction, as well as simulator virtual machine implementations, are also provided.

Abstract: Data processing apparatus comprises processing circuitry to selectively apply vector processing operations to one or more data items of a data vector comprising a plurality of data items at respective positions in the data vector, according to the state of respective predicate flags associated with the positions; the processing circuitry comprising: instruction decoder circuitry to decode program instructions; and instruction processing circuitry to execute instructions decoded by the instruction decoder circuitry; wherein the instruction decoder circuitry is responsive to a WHILE instruction and a CHANGE instruction, to control the instruction processing dependent upon a number of the predicate flags.

Abstract: An apparatus and method are provided for managing address collisions when performing vector operations. The apparatus has a register store for storing vector operands, each vector operand comprising a plurality of elements, and execution circuitry for executing instructions in order to perform operations specified by the instructions. The execution circuitry has access circuitry for performing memory access operations in order to move the vector operands between the register store and memory, and processing circuitry for performing data processing operations using the vector operands. The execution circuitry may be arranged to iteratively execute a vector loop, where during each iteration the execution circuitry executes a sequence of instructions to implement the vector loop.

Abstract: An apparatus and a method of operating the apparatus are provided for performing a comparison operation to match a given sequence of values within an input vector. Instruction decoder circuitry is responsive to a string match instruction specifying a segment of an input vector to generate control signals to control the data processing circuitry to perform a comparison operation. The comparison operation determines a comparison value indicative of whether each input element of a required set of consecutive input elements of the segment has a value which matches a respective value in consecutive reference elements of the reference data item. A plurality of comparison operations may be performed to determine a match vector corresponding to the segment of the input vector to indicate the start position of the substring in the input vector. A string match instruction, as well as simulator virtual machine implementations, are also provided.

Abstract: An apparatus and method of operating the apparatus are provided for performing a count operation. Instruction decoder circuitry is responsive to a count instruction specifying an input data item to generate control signals to control the data processing circuitry to perform a count operation. The count operation determines a count value indicative of a number of input elements of a subset of elements in the specified input data item which have a value which matches a reference value in a reference element in a reference data item. A plurality of count operations may be performed to determine a count data item corresponding to the input data item. A register scatter storage instruction, a gather index generation instruction, and respective apparatuses responsive to them, as well as simulator implementations, are also provided.

Abstract: Data processing apparatus comprises processing circuitry to selectively apply vector processing operations to one or more data items of a data vector comprising a plurality of data items at respective positions in the data vector, according to the state of respective predicate flags associated with the positions; the processing circuitry comprising: instruction decoder circuitry to decode program instructions; and instruction processing circuitry to execute instructions decoded by the instruction decoder circuitry; wherein the instruction decoder circuitry is responsive to a WHILE instruction and a CHANGE instruction, to control the instruction processing dependent upon a number of the predicate flags.

Abstract: A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.

Abstract: Data processing apparatus comprises processing circuitry to selectively apply a vector processing operation to data items at positions within data vectors according to the states of a set of respective predicate flags associated with the positions, the data vectors having a data vector processing order, each data vector comprising a plurality of data items having a data item order, the processing circuitry comprising: instruction decoder circuitry to decode program instructions; and instruction processing circuitry to execute instructions decoded by the instruction decoder circuitry; wherein the instruction decoder circuitry is responsive to a propagation instruction to control the instruction processing circuitry to derive a set of predicate flags applicable to a current data vector in dependence upon a set of predicate flags applicable to a preceding data vector in the data vector processing order, wherein when one or more last-most predicate flags of the set applicable to the preceding data vector are inac

Abstract: A data processing system 2 supporting vector processing operations uses scaling vector length querying instructions. The scaling vector length querying instructions return a result which is dependent upon a number of elements in a vector for a variable vector element size specified by the instruction and multiplied by a scaling value specified by the instruction. The scaling vector length querying instructions may be in the form of count instructions, increment instructions or decrement instructions. The instructions may include a pattern constraint applying a constraint, such as modulo(M) or power of 2 to the partial result value representing the number of vector elements provided for the register element size specified for the instruction.

Abstract: A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.

Abstract: Disclosed is an apparatus and method to manage instruction cache prefetching from an instruction cache. A processor may comprise: a prefetch engine; a branch prediction engine to predict the outcome of a branch; and dynamic optimizer. The dynamic optimizer may be used to control: identifying common instruction cache misses and inserting a prefetch instruction from the prefetch engine to the instruction cache.

Abstract: A mechanism for generating a path profile is disclosed. A profiling module may insert profiling instructions into instruction blocks. The profiling instructions may generate a path identifier as a processor executes an execution path executes a sequence or path of instruction blocks). A path identifier module may add path identifiers to path identifier data, such as a table, and may track the number of times an execution path associated with the path identifier is executed.

Abstract: Techniques and mechanisms for a processor to determine whether a commit action is to be performed. In an embodiment, a processor performs operations to determine whether a commit instruction is for contingent performance of a commit action. In another embodiment, one or more conditions of processor state are evaluated in response to determining that the commit instruction is for contingent performance of the commit action, where the evaluation is performed to determine whether the commit action indicated by the commit instruction is to be performed.

Abstract: Disclosed is an apparatus and method to manage instruction cache prefetching from an instruction cache. A processor may comprise: a prefetch engine; a branch prediction engine to predict the outcome of a branch; and dynamic optimizer. The dynamic optimizer may be used to control: indentifying common instruction cache misses and inserting a prefetch instruction from the prefetch engine to the instruction cache.

Abstract: A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.

Abstract: Disclosed is an apparatus and method generally related to controlling a multimedia extension control and status register (MXCSR). A processor core may include a floating point unit (FPU) to perform arithmetic functions; and a multimedia extension control register (MXCR) to provide control bits to the FPU. Further an optimizer may be used to select a speculative multimedia extension status register (SPEC_MXSR) from a plurality of SPEC_MXSRs to update a multimedia extension status register (MXSR) based upon an instruction.