Processing circuitry supports a first type of vector arithmetic instruction specifying at least a first input vector. When at least one exceptional condition is detected for an arithmetic operation performed for a first active data element of the first input vector in a predetermined sequence, the processing circuitry performs at least one response action. When the at least one exceptional condition is detected for a given active data element other than the first active data element in the predetermined sequence, the processing circuitry suppresses the at least one response action and stores elements identifying information identifying which data element is the given active data element which triggered the exceptional condition. This can be useful for reducing the amount of hardware resource for tracking the occurrence of the exceptional conditions and/or supporting speculative execution of vector instructions.

According to one or more embodiments of the present invention, a computer implemented method includes initiating, by a non-secure entity that is executing on a host server, a secure entity, the non-secure entity prohibited from directly accessing any data of the secure entity. The method further includes injecting, into the secure entity, an interrupt that is generated by the host server. The injecting includes adding, by the non-secure entity, information about the interrupt into a portion of non-secure storage, which is then associated with the secure entity. The injecting further includes injecting, by a secure interface control of the host server, the interrupt into the secure entity.

The invention is notably directed to a computer-implemented method for performing safety check operations. The method comprises steps that are implemented while executing a computer program, which is instrumented with safety check operations. As a result, this computer program forms a sequence of ordered instructions. Such instructions comprise safety check operation instructions, in addition to generic execution instructions and system inputs. System inputs allow the executing program to interact with an operating system, which manages resources for the computer program to execute. A series of instructions are identified while executing the computer program. Namely, a first instruction is identified in the sequence, as one of the safety check operation instructions, in view of its subsequent execution. After having identified the first instruction, a second instruction is identified in the sequence. The second instruction is identified as one of the generic computer program instructions. Execution of the second instruction identified is started, irrespective of a completion status of the first instruction. Next, and after having identified the second instruction, a third instruction is identified in the sequence. The third instruction is identified as one as one of the system inputs. There, completion of execution of the first instruction (the safety check operation instruction) is required prior to completing execution of the third instruction (the system input). The invention is further directed to related computerized systems and computer program products.

Systems, apparatuses, and methods for processing load instructions are disclosed. A processor includes at least a data cache and a load queue for storing load instructions. The load queue includes poison indicators for load instructions waiting to reach non-speculative status. When a non-cacheable load instruction is speculatively executed, then the poison bit is automatically set for the load instruction. If a cacheable load instruction is speculatively executed, then the processor waits until detecting a first condition before setting the poison bit for the load instruction. The first condition may be detecting a cache line with data for the load instruction being evicted from the cache. If an ordering event occurs for a load instruction with a set poison bit, then the load instruction may be flushed and replayed. An ordering event may be a data barrier or a hazard on an older load targeting the same address as the load.

A method of controlling a data processor to perform data processing operations is disclosed in which a host processor prepares one or more queue(s) of operations for execution by the data processor. When an error is encountered in the processing of an operation for one of the one or more queue(s), a queue can be set into an error state in which instructions that may have a data dependency on another operation are not executed. The host processor includes in the queues error barrier instructions that divide the respective queues into sets of operations between which there are no data processing dependencies. An error state for a queue can thus be cleared when its processing reaches the next error barrier instruction in the queue.

Instruction interrupt suppression for an overflow condition. An instruction is executed, and a determination is made that an overflow condition occurred. Based on a per-instruction overflow interrupt indicator being set to a defined value, interrupt processing for the overflow condition is performed, and based on the per-instruction overflow interrupt indicator being set to another defined value, the interrupt processing for the overflow condition is bypassed.

A data processing system (2) supports non-speculative execution of vector load instructions that perform at least one contingent load of a data value. Fault detection circuitry (26) serves to detect whether a contingent load is fault-generating contingent load or a fault-free contingent load. Contingent load suppression circuitry (28) detects and suppresses a fault-free contingent load that matches a predetermined criteria that may result in an undesired change of architectural state (undesired side-effect). Examples of such predetermined criteria are that the contingent load is to a non-memory device or that the contingent load will trigger a diagnostic response such as entry of a halting debug halting mode or triggering of a debug exception.

A processor includes an execution unit and a processing logic operatively coupled to the execution unit, the processing logic to: enter a first execution state and transition to a second execution state responsive to executing a control transfer instruction. Responsive to executing a target instruction of the control transfer instruction, the processing logic further transitions to the first execution state responsive to the target instruction being a control transfer termination instruction of a mode identical to a mode of the processing logic following the execution of the control transfer instruction; and raises an execution exception responsive to the target instruction being a control transfer termination instruction of a mode different than the mode of the processing logic following the execution of the control transfer instruction.

Livelock recovery circuits configured to detect livelock in a processor, and cause the processor to transition to a known safe state when livelock is detected. The livelock recovery circuits include detection logic configured to detect that the processor is in livelock when the processor has illegally repeated an instruction; and transition logic configured to cause the processor to transition to a safe state when livelock has been detected by the detection logic.

Embodiments are generally directed to a multithreaded processor for executing a plurality of threads, as well as an associated method and system. The multithreaded processor comprises a first control register configured to store a stack limit value, and instruction decode logic configured to, upon receiving a procedure entry instruction for a stack associated with a first thread, determine whether to throw a stack limit exception based on the stack limit value and a first predefined stack region size associated with the stack.