Abstract: An apparatus and method is described herein for providing robust speculative code section abort control mechanisms. Hardware is able to track speculative code region abort events, conditions, and/or scenarios, such as an explicit abort instruction, a data conflict, a speculative timer expiration, a disallowed instruction attribute or type, etc. And hardware, firmware, software, or a combination thereof makes an abort determination based on the tracked abort events. As an example, hardware may make an initial abort determination based on one or more predefined events or choose to pass the event information up to a firmware or software handler to make such an abort determination. Upon determining an abort of a speculative code region is to be performed, hardware, firmware, software, or a combination thereof performs the abort, which may include following a fallback path specified by hardware or software.

Abstract: An apparatus and method is described herein for providing robust speculative code section abort control mechanisms. Hardware is able to track speculative code region abort events, conditions, and/or scenarios, such as an explicit abort instruction, a data conflict, a speculative timer expiration, a disallowed instruction attribute or type, etc. And hardware, firmware, software, or a combination thereof makes an abort determination based on the tracked abort events. As an example, hardware may make an initial abort determination based on one or more predefined events or choose to pass the event information up to a firmware or software handler to make such an abort determination. Upon determining an abort of a speculative code region is to be performed, hardware, firmware, software, or a combination thereof performs the abort, which may include following a fallback path specified by hardware or software.

Abstract: In accordance with embodiments disclosed herein, there is provided systems and methods for tracking the mode of processing devices in an instruction tracing system. The method may include receiving an indication of a change in a current execution mode of the processing device. The method may also include determining that the current execution mode of the received indication is different than a value of an execution mode of a first execution mode (EM) packet previously-generated by the IT module. The method may also include generating, based on the determining that the current execution mode is different, a second EM packet that provides a value of the current execution mode of the processing device to indicate the change in the execution mode for an instruction in a trace generated by the IT module. The method may further include generating transactional memory (TMX) packets having n bit mode pattern in the packet log. The n is at least two and the n bit mode indicates transaction status of the TMX operation.

Abstract: Novel instructions, logic, methods and apparatus are disclosed to test transactional execution status. Embodiments include decoding a first instruction to start a transactional region. Responsive to the first instruction, a checkpoint for a set of architecture state registers is generated and memory accesses from a processing element in the transactional region associated with the first instruction are tracked. A second instruction to detect transactional execution of the transactional region is then decoded. An operation is executed, responsive to decoding the second instruction, to determine if an execution context of the second instruction is within the transactional region. Then responsive to the second instruction, a first flag is updated. In some embodiments, a register may optionally be updated and/or a second flag may optionally be updated responsive to the second instruction.

Abstract: Novel instructions, logic, methods and apparatus are disclosed to test transactional execution status. Embodiments include decoding a first instruction to start a transactional region. Responsive to the first instruction, a checkpoint for a set of architecture state registers is generated and memory accesses from a processing element in the transactional region associated with the first instruction are tracked. A second instruction to detect transactional execution of the transactional region is then decoded. An operation is executed, responsive to decoding the second instruction, to determine if an execution context of the second instruction is within the transactional region. Then responsive to the second instruction, a first flag is updated. In some embodiments, a register may optionally be updated and/or a second flag may optionally be updated responsive to the second instruction.

Abstract: Methods and apparatus for throttling an interface that is integrated on the same die as a processor are described. In one embodiment, a signal from an Integrated Input/Output hub (e.g., integrated on the same die as a processor) causes throttling of a link coupled between the IIO and an Input/Output (IO) device. Other embodiments are also disclosed.

Abstract: Novel instructions, logic, methods and apparatus are disclosed to test transactional execution status. Embodiments include decoding a first instruction to start a transactional region. Responsive to the first instruction, a checkpoint for a set of architecture state registers is generated and memory accesses from a processing element in the transactional region associated with the first instruction are tracked. A second instruction to detect transactional execution of the transactional region is then decoded. An operation is executed, responsive to decoding the second instruction, to determine if an execution context of the second instruction is within the transactional region. Then responsive to the second instruction, a first flag is updated. In some embodiments, a register may optionally be updated and/or a second flag may optionally be updated responsive to the second instruction.

Abstract: A method and apparatus for hybrid pre and post-retire tentative access tracking is herein described. Access tracking is often performed during execution of critical sections, which may be defined by traditional locks or transactional memory instructions. Pre-retire accesses to memory are performed to update tracking information for access during execution of a critical section. However, post-retire updates to tracking information are performed for subsequent consecutive critical section accesses in a pipeline when a previous end critical section operation is retired.

Abstract: Novel instructions, logic, methods and apparatus are disclosed to test transactional execution status. Embodiments include decoding a first instruction to start a transactional region. Responsive to the first instruction, a checkpoint for a set of architecture state registers is generated and memory accesses from a processing element in the transactional region associated with the first instruction are tracked. A second instruction to detect transactional execution of the transactional region is then decoded. An operation is executed, responsive to decoding the second instruction, to determine if an execution context of the second instruction is within the transactional region. Then responsive to the second instruction, a first flag is updated. In some embodiments, a register may optionally be updated and/or a second flag may optionally be updated responsive to the second instruction.

Abstract: Novel instructions, logic, methods and apparatus are disclosed to test transactional execution status. Embodiments include decoding a first instruction to start a transactional region. Responsive to the first instruction, a checkpoint for a set of architecture state registers is generated and memory accesses from a processing element in the transactional region associated with the first instruction are tracked. A second instruction to detect transactional execution of the transactional region is then decoded. An operation is executed, responsive to decoding the second instruction, to determine if an execution context of the second instruction is within the transactional region. Then responsive to the second instruction, a first flag is updated. In some embodiments, a register may optionally be updated and/or a second flag may optionally be updated responsive to the second instruction.

Abstract: Novel instructions, logic, methods and apparatus are disclosed to test transactional execution status. Embodiments include decoding a first instruction to start a transactional region. Responsive to the first instruction, a checkpoint for a set of architecture state registers is generated and memory accesses from a processing element in the transactional region associated with the first instruction are tracked. A second instruction to detect transactional execution of the transactional region is then decoded. An operation is executed, responsive to decoding the second instruction, to determine if an execution context of the second instruction is within the transactional region. Then responsive to the second instruction, a first flag is updated. In some embodiments, a register may optionally be updated and/or a second flag may optionally be updated responsive to the second instruction.

Abstract: Suspendable load address tracking inside transactions is disclosed. An example processing device of implementations of the disclosure includes a transactional memory (TM) read set tracking component circuitry to identify a suspend read tracking instruction within a transaction executed by the processing device, mark load instructions occurring in the transaction subsequent to the identified suspend read tracking instruction with a suspend attribute, wherein the addresses corresponding to the marked load instructions are excluded from a read set maintained for the transaction, identify a resume read tracking instruction within the transaction, and stop marking the load instructions occurring subsequent to the identified resume read tracking instruction with the suspend attribute.

Abstract: In one embodiment, a processor includes an execution unit and at least one last branch record (LBR) register to store address information of a branch taken during program execution. This register may further store a transaction indicator to indicate whether the branch was taken during a transactional memory (TM) transaction. This register may further store an abort indicator to indicate whether the branch was caused by a transaction abort. Other embodiments are described and claimed.

Abstract: Suspendable load address tracking inside transactions is disclosed. An example processing device of implementations of the disclosure includes a transactional memory (TM) read set tracking component circuitry to identify a suspend read tracking instruction within a transaction executed by the processing device, mark load instructions occurring in the transaction subsequent to the identified suspend read tracking instruction with a suspend attribute, wherein the addresses corresponding to the marked load instructions are excluded from a read set maintained for the transaction, identify a resume read tracking instruction within the transaction, and stop marking the load instructions occurring subsequent to the identified resume read tracking instruction with the suspend attribute.

Abstract: A method and apparatus for post-retire transaction access tracking is herein described. Load and store buffers are capable of storing senior entries. In the load buffer a first access is scheduled based on a load buffer entry. Tracking information associated with the load is stored in a filter field in the load buffer entry. Upon retirement, the load buffer entry is marked as a senior load entry. A scheduler schedules a post-retire access to update transaction tracking information, if the filter field does not represent that the tracking information has already been updated during a pendency of the transaction. Before evicting a line in a cache, the load buffer is snooped to ensure no load accessed the line to be evicted.

Abstract: A method of analyzing aborts of transactional execution transactions. Starting a transactional execution transaction with a first logical processor. Performing, with a second logical processor, store to memory instructions, while the first logical processor is performing the transactional execution transaction. Capturing memory addresses of, and instruction pointer values associated with, at least a sample of the store to memory instructions. Performing, with the second logical processor, a first store to memory instruction to a first memory address, which is to cause the transactional execution transaction to abort. Capturing the first memory address. Determining an instruction pointer value associated with the first store to memory instruction by correlating at least the captured first memory address with the captured memory addresses of said at least the sample of the store to memory instructions.

Abstract: A method and apparatus for post-retire transaction access tracking is herein described. Load and store buffers are capable of storing senior entries. In the load buffer a first access is scheduled based on a load buffer entry. Tracking information associated with the load is stored in a filter field in the load buffer entry. Upon retirement, the load buffer entry is marked as a senior load entry. A scheduler schedules a post-retire access to update transaction tracking information, if the filter field does not represent that the tracking information has already been updated during a pendency of the transaction. Before evicting a line in a cache, the load buffer is snooped to ensure no load accessed the line to be evicted.

Abstract: An example system for speculative execution event counter checkpointing and restoring may include a plurality of processors, a first interconnect to couple two or more of the plurality of processors, a second interconnect to couple one or more of the plurality of processors to one or more other system components, and a system memory coupled to one or more of the processors.

Abstract: An example system for speculative execution event counter checkpointing and restoring may include a plurality of symmetric cores, at least one of the symmetric cores to simultaneously process a plurality of threads and to perform out-of-order instruction processing for the plurality of threads; at least one shared cache circuit to be shared among two or more the of symmetric cores. The system may further include a memory controller to couple the symmetric cores to a system memory and a data communication interface to couple one or more of the cores to input/output devices.

Abstract: An example processor for speculative execution event counter checkpointing and restoring may include a plurality of symmetric cores, at least one of the symmetric cores to simultaneously process a plurality of threads and to perform out-of-order instruction processing for the plurality of threads; at least one shared cache circuit to be shared among two or more the of symmetric cores. The processor may further include event counter circuitry comprising: a plurality of event counters including programmable event counters and fixed event counters and one or more configuration registers to store configuration data to specify an event type to be counted by the programmable event counters, wherein at least one of the one or more configuration registers is to store configuration data for a plurality of the programmable event counters.