Methods, systems and apparatuses may provide for technology that triggers an idle state in a first command streamer in response to a request to reset a second command streamer that shares graphics hardware with the first command streamer. The technology may also determine an event type associated with the request and conduct the request based on the event type.

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.

Disclosed in some examples, are methods, systems, computing devices, and machine readable mediums which define an instruction for a programmable atomic transaction that is executed as the last instruction and that terminates the executing thread, waits for all outstanding store operations to finish, clears the programmable atomic lock, and sends a completion response back to the issuing process. This guarantees that the programmable atomic lock is cleared when the transaction completes. By coupling thread termination with clearing the lock bit, this guarantees that the thread cannot terminate without clearing the lock.

Devices and techniques for low-latency register error correction are described herein. A register is read as part of an instruction when that instruction is the currently executing instruction in a processor. A correctable error in data produced from reading the register can be detected. In response to detecting the correctable error, the currently executing instruction in the processor can be changed into a register update instruction that is executed to overwrite the data in the register with corrected data. Then, the original (e.g. unchanged) instruction can be rescheduled.

A data processing system includes a processor operable to execute a program partitioned into a number of discrete instructions, the processor having multiple processing elements each capable of executing more than one instruction per cycle, and an interface configured to read a first program and, on detecting a branch operation by that program creating m number of branches each having a different sequence of instructions, combine an instruction from one of the branches with an instruction from at least one other branch so as to cause a processing element to execute the combined instructions during a single cycle.

A processor and a method are disclosed that mitigate side channel attacks (SCAs) that exploit store-to-load forwarding operations. In one embodiment, the processor detects a translation context change from a first translation context (TC) to a second TC and responsively disallows store-to-load forwarding until all store instructions older than the TC change are committed. The TC comprises an address space identifier (ASID), a virtual machine identifier (VMID), a privilege mode (PM) or a combination of two or more of the ASID, VMID and PM, or a derivative thereof, such as a TC hash, TC generation value, or a RobID associated with the last TC-updating instruction. In other embodiments, TC generation values of load and store instructions are compared or RobIDs of the load and store instructions are compared with the RobID associated with the last TC-updating instruction. If the instructions' RobIDs straddle the TC boundary, store-to-load forwarding is not allowed.

An apparatus and method are provided for handling prediction information. The apparatus has processing circuitry for performing data processing operations in response to instructions, the processing circuitry comprising transactional memory support circuitry to support execution of a transaction comprising a sequence of instructions. Prediction circuitry is used to generate predictions in relation to instruction flow changing instructions, and prediction storage is provided to store a plurality of items of prediction information that are referenced by the prediction circuitry when generating the predictions. The items of prediction information maintained by the prediction storage change based on the instructions being executed by the processing circuitry. A recovery storage is activated by the transactional memory support circuitry at a transaction start point to store a restore pointer identifying a chosen location in the prediction storage. Between the transaction start point and the transaction end point, the recovery storage receives any item of prediction information removed from the prediction storage that was present in the prediction storage at the transaction start point. In response to the transaction being aborted, the restore pointer is used in order to discard from the prediction storage any items of prediction information added to the prediction storage after the transaction start point, and in addition any items of prediction information stored in the recovery storage are stored back into the prediction storage. This can significantly improve prediction accuracy in systems that may need to retry transactions due to a transaction abort, without requiring the entire prediction storage state to be captured at the transaction start point.

A computer processor is provided that employs a plurality of operand storage elements that store operand data values and associated meta-data as unitary operand data elements as well as at least one functional unit that performs operations that produce and access the unitary operand data elements stored in the plurality of operand storage elements. The meta-data associated with a given operand data value as part of a unitary operand data element can specify type of the unitary operand data element (e.g., vector or scalar), elemental width and floating-point error flags. The meta-data can also be used to define special operand data values (e.g., Not-a-Result and None). The meta-data is useful in optimizing execution, such as in speculation and vectorized SIMD operations. The computer processor can also support a number of particular vector operations that are useful in optimizing execution of vectorized SIMD operations.

According to at least one aspect, a hardware system include a host processor, a policy engine, and an interlock is provided. These components can interoperate to enforce security policies. The host processor can execute an instruction and provide instruction information to the policy engine and the result of the executed instruction to the interlock. The policy engine can determine whether the executed instruction is allowable according to one or more security policies using the instruction information. The interlock can buffer the result of the executed instruction until an indication is received from the policy engine that the instruction was allowable. The interlock can then release the result of the executed instruction. The policy engine can be configured to transform instructions received from the host processor or add inserted instructions to the policy evaluation pipeline to increase the flexibility of the policy engine and enable enforcement of the security policies.

An apparatus is described with support for transactional memory and load/store-exclusive instructions using an exclusive monitor indication to track exclusive access to a given address. In response to a predetermined type of load instruction specifying a load target address, which is executed within a given transaction, any exclusive monitor indication previously set for the load target address is cleared. In response to a load-exclusive instruction, an abort is triggered for a transaction for which the given address is specified as one of its working set of addresses. This helps to maintain mutual exclusion between transactional and non-transactional threads even if there is load speculation in the non-transactional thread.