Abstract: Methods and apparatuses relating to mitigations for speculative execution side channels are described. Speculative execution hardware and environments that utilize the mitigations are also described. For example, three indirect branch control mechanisms and their associated hardware are discussed herein: (i) indirect branch restricted speculation (IBRS) to restrict speculation of indirect branches, (ii) single thread indirect branch predictors (STIBP) to prevent indirect branch predictions from being controlled by a sibling thread, and (iii) indirect branch predictor barrier (IBPB) to prevent indirect branch predictions after the barrier from being controlled by software executed before the barrier.

Abstract: A data processing apparatus comprises operand routing circuitry configured to prepare operands for processing, and a plurality of processing elements. Each processing element comprises receiving circuitry, processing circuitry, and transmitting circuitry. A group of coupled processing elements comprises a first processing element configured to receive operands from the operand routing circuitry and one or more further processing elements for which the receiving circuitry is coupled to the transmitting circuitry of another processing element in the group. The apparatus also comprises timing circuitry, configured to selectively delay transmission of operands within the group of coupled processing elements to cause operations performed by the group of coupled processing elements to be staggered.

Abstract: Techniques related to executing a plurality of instructions by a processor comprising a method for executing a plurality of instructions by a processor. The method comprises detecting a pipeline hazard based on one or more instructions provided for execution by an instruction execution pipeline, beginning execution of an instruction, of the one or more instructions on the instruction execution pipeline, stalling a portion of the instruction execution pipeline based on the detected pipeline hazard, storing a register state associated with the execution of the instruction based on the stalling, determining that the pipeline hazard has been resolved, and restoring the register state to the instruction execution pipeline based on the determination.

Abstract: Representative apparatus, method, and system embodiments are disclosed for configurable computing. In a representative embodiment, a system includes an interconnection network, a processor, a host interface, and a configurable circuit cluster. The configurable circuit cluster may include a plurality of configurable circuits arranged in an array; an asynchronous packet network and a synchronous network coupled to each configurable circuit of the array; and a memory interface circuit and a dispatch interface circuit coupled to the asynchronous packet network and to the interconnection network. Each configurable circuit includes instruction or configuration memories for selection of a current data path configuration, a master synchronous network input, and a data path configuration for a next configurable circuit.

Abstract: A computer-implemented method includes fetching a fetch-packet containing a first hyper-block from a first address of a memory. The fetch-packet contains a bitwise distance from an entry point of the first hyper-block to a predicted exit point. A first branch instruction of the first hyper-block is executed that corresponds to a first exit point. The first branch instruction includes an address corresponding to an entry point of a second hyper-block. Responsive to executing the first branch instruction, a bitwise distance from the entry point of the first hyper-block to the first exit point is stored. A program counter is moved from the first exit point of the first hyper-block to the entry point of the second hyper-block.

Abstract: Parallel instruction demarcators and methods for parallel instruction demarcation are included, wherein an instruction syllable sequence comprising a plurality of instruction syllables is received and stored at an instruction buffer. It is determined, using one or more logic blocks arranged in a sequence, a size of an instruction and at least one boundary at which the instruction is demarcated. Additionally, using a controlling logic block a restart point is determined from where the sequence of instruction syllables is examined and demarcated into individual instructions.

Abstract: A processor includes a time counter and a time-resource matrix and provides a method for statically dispatching instructions if the resources are available based on data stored in the time-resource matrix, and wherein execution times for the instructions use a time count from the time counter to specify when the instructions may be provided to an execution pipeline. The execution times are based on fixed latency times of instructions with exception of the load instruction which is based on the data cache hit latency time. A data cache miss causes the load instruction and subsequent dependent instructions to be statically replayed at a later time using the same time count.

Abstract: Techniques are provided for allocating registers for a processor. The techniques include identifying a first instruction of an instruction dispatch set that meets all register allocation suppression criteria of a first set of register allocation suppression criteria, suppressing register allocation for the first instruction, identifying a second instruction of the instruction dispatch set that does not meet all register allocation suppression criteria of a second set of register allocation suppression criteria, and allocating a register for the second instruction.

Abstract: A data processing apparatus comprises: a physical register array, prediction circuitry, register rename circuitry, and hardware execution circuitry. The physical register array comprises a plurality of sectors having one or more different access properties, each of the plurality of sectors having one or more different access properties compared to other sectors of the plurality of sectors, each sector of the plurality of sectors comprising at least one physical register. The prediction circuitry to predict, for a given instruction, a sector identifier identifying one of the sectors of the physical register array to be used for a destination register of the given instruction. The prediction circuitry is configured to select the sector identifier in dependence on prediction information learnt from performance monitoring information indicative of performance achieved for a sequence of instructions when using different sector identifiers for the given instruction.

Abstract: Techniques are disclosed relating to instruction scheduling in the context of instruction cache misses. In some embodiments, first-stage scheduler circuitry is configured to assign threads to channels and second-stage scheduler circuitry is configured to assign an operation from a given channel to a given execution pipeline based on decode of an operation for that channel. In some embodiments, thread replacement circuitry is configured to, in response to an instruction cache miss for an operation of a first thread assigned to a first channel, deactivate the first thread from the first channel.

Abstract: An electronic device receives a single instruction to apply a neural network operation to a set of M-bit elements stored in one or more input vector registers to initiate a sequence of computational operations related to a neural network. In response to the single instruction, the electronic device implements the neural network operation on the set of M-bit elements to generate a set of P-bit elements by obtaining the set of M-bit elements from the one or more input vector registers, quantizing each of the set of M-bit elements from M bits to P bits, and packing the set of P-bit elements into an output vector register. P is smaller than M. In some embodiments, the neural network operation is a quantization operation including at least a multiplication with a quantization factor and an addition with a zero point.

Abstract: A processor includes a plurality of execution units. At least one of the execution units is configured to determine, based on a first field of a first instruction, a number of additional instructions to execute in conjunction with the first instruction and prior to execution of the first instruction. The at least one of the execution units is further configured to determine, based on a second field of the first instruction, a subset of the additional instructions to execute atomically.

Abstract: An apparatus includes an array processor to process array data in response to a set of macro-instructions. A macro-instruction in the set of macro-instructions performs loop operations, array iteration operations, and/or arithmetic logic unit (ALU) operations.

Abstract: An apparatus has processing circuitry with execution units to perform operations, physical registers to store data, and forwarding circuitry to forward the data from the physical registers to the execution units. The forwarding circuitry provides an incomplete set of connections between the physical registers and the execution units such that, for each of at least some of the physical registers, the physical register is connected to only a subset of the execution units. The apparatus also has register renaming circuitry to map logical registers identified by the operations to respective physical registers and register reorganisation circuitry to monitor upcoming operations and to determine, based on the upcoming operations and the connections provided by the forwarding circuitry, whether to perform a register reorganisation procedure to change a mapping between the logical registers and the physical registers.

Abstract: A processing-in-memory (PIM) system includes a host and a PIM controller. The host is configured to generate a request for a memory access operation or a multiplication/accumulation (MAC) operation of a PIM device and also to generate a mode definition signal defining an operation mode of the PIM device. The PIM controller is configured to generate a command corresponding to the request to control the memory access operation or the MAC operation of the PIM device. When the operation mode of the PIM device is inconsistent with a mode set defined by the mode definition signal, the PIM controller controls the memory access operation or the MAC operation of the PIM device after changing the operation mode of the PIM device.

Abstract: Software instructions are executed on a processor within a computer system to configure a streaming engine with stream parameters to define a multidimensional array. The stream parameters define a size for each dimension of the multidimensional array and a specified width for a selected dimension of the array. Data is fetched from a memory coupled to the streaming engine responsive to the stream parameters. A stream of vectors is formed for the multidimensional array responsive to the stream parameters from the data fetched from memory. When the selected dimension in the stream of vectors exceeds the specified width, the streaming engine inserts null elements into each portion of a respective vector for the selected dimension that exceeds the specified width in the stream of vectors. Stream vectors that are completely null are formed by the streaming engine without accessing the system memory for respective data.

Abstract: An apparatus includes an array processor to process at least one array. The apparatus further includes a memory coupled to the array processor. The at least one array is stored in memory with programmable per-dimension size and stride values.

Abstract: An apparatus has processing circuitry, an instruction decoder, and capability registers, each capability register to store a capability comprising a pointer and constraint metadata for constraining valid use of the pointer/capability. In response to a capability-generating address calculating instruction specifying an offset value, a reference capability register is selected as one of a program counter capability register and a further capability register. A result capability is generated for which the pointer of the result capability indicates a window address identifying a selected window within an address space, the selected window being offset from a reference window by a number of windows determined based on the offset value of the capability-generating address calculating instruction. The reference window comprises the window comprising an address indicated by the pointer of the reference capability register.

Abstract: An apparatus includes an array processor to process array data. The array data are arranged in a memory. The array data are specified with programmable per-dimension size and stride values.

Abstract: Processing circuitry has a handler mode and a thread mode. In response to an exception condition, a switch to handler mode is made. In response to an intermodal calling branch instruction specifying a branch target address when the processing circuitry is in the handler mode, an instruction decoder controls the processing circuitry to save a function return address to a function return address storage location; switch a current mode of the processing circuitry to the thread mode; and branch to an instruction identified by the branch target address. This can be useful for deprivileging of exceptions.