Patent classifications
G06F9/30116
Inferring future value for speculative branch resolution
Aspects of the invention include includes determining a first instruction in a processing pipeline, wherein the first instruction includes a compare instruction, determining a second instruction in the processing pipeline, wherein the second instruction includes a conditional branch instruction relying on the compare instruction, determining a predicted result of the compare instruction, and completing the conditional branch instruction using the predicted result prior to executing the compare instruction.
Bit width reconfiguration using a shadow-latch configured register file
A processor includes a front-end with an instruction set that operates at a first bit width and a floating point unit coupled to receive the instruction set in the processor that operates at the first bit width. The floating point unit operates at a second bit width and, based upon a bit width assessment of the instruction set provided to the floating point unit, the floating point unit employs a shadow-latch configured floating point register file to perform bit width reconfiguration. The shadow-latch configured floating point register file includes a plurality of regular latches and a plurality of shadow latches for storing data that is to be either read from or written to the shadow latches. The bit width reconfiguration enables the floating point unit that operates at the second bit width to operate on the instruction set received at the first bit width.
AN APPARATUS AND METHOD FOR CONTROLLING ACCESS TO A SET OF MEMORY MAPPED CONTROL REGISTERS
A technique for controlling access to a set of memory mapped control registers. The apparatus has processing circuitry for executing program code to perform data processing operations, and a set of memory mapped control registers for storing control information used to control operation of the processing circuitry. Further, a lockdown register used to store a lockdown value. The processing circuitry is arranged to execute store instructions to perform write operations to a memory address space . Thethe processing circuitry is arranged to prevent a write operation being performed to change the control information in the memory mapped control registers . This significantly reduces the prospect of an attacker seeking to exploit a software vulnerability to change the control information in the memory mapped control registers.
DOMAIN TRANSITION DISABLE CONFIGURATION PARAMETER
A processing circuitry having a secure domain and a less secure domain. A control storage location stores a domain transition disable configuration parameter specifying whether domain transitions between the secure domain and the less secure domain are enabled or disabled in at least one mode of the process-ing circuitry. In the at least one mode of the processing circuitry, when the domain transition disable configuration parameter specifies that said domain transitions are disabled in said at least one mode, a disabled domain transition fault is signalled in response to an attempt to transition between domains in either direction. This can help support lazy configuration of resources for the secure domain or less secure domain for a thread expected only to need the other domain.
MANAGING RETURN PARAMETER ALLOCATION
A hybrid threading processor (HTP) supports thread creation by executing an instruction that indicates an amount of storage space to reserve for return values. Before a thread is created, the indicated amount of space is reserved. The newly created child thread sends a return packet back to the parent thread when the child thread completes. The thread writes its return information into the reserved space and waits for the parent thread to execute a thread join instruction. The thread join instruction takes the returned information from the reserved space and transfers it to the parent thread's register state. The reserved space is released once the child thread is joined. Using a configurable amount of space for each child thread may allow for more child threads to be executed simultaneously.
INFERRING FUTURE VALUE FOR SPECULATIVE BRANCH RESOLUTION
Aspects of the invention include includes determining a first instruction in a processing pipeline, wherein the first instruction includes a compare instruction, determining a second instruction in the processing pipeline, wherein the second instruction includes a conditional branch instruction relying on the compare instruction, determining a predicted result of the compare instruction, and completing the conditional branch instruction using the predicted result prior to executing the compare instruction.
User mode event handling
A method includes asserting a field of an event flag mask register configured to inhibit an event handler. The method also includes, responsive to an event that corresponds to the field of the event flag mask register being triggered: asserting a field of an event flag register associated with the event; and based the field in the event flag register being asserted, taking an action by a task being executed by the data processor core.
DATA PROCESSING SYSTEM, DATA TRANSFER DEVICE, AND CONTEXT SWITCHING METHOD
A processing section executes processes concerning a plurality of applications in a time division manner. A CSDMA engine detects a switching timing of an application to be executed in the processing section. When detecting the switching timing, the CSDMA engine saves a context of an application that is being executed in the processing section 46, to a main memory from the processing section, and installs a context of an application to be subsequently executed in the processing section, from the main memory to the processing section, not through a process by software managing the plurality of applications.
TECHNIQUES FOR RECOVERING FROM ERRORS WHEN EXECUTING SOFTWARE APPLICATIONS ON PARALLEL PROCESSORS
In various embodiments, a software program uses hardware features of a parallel processor to checkpoint a context associated with an execution of a software application on the parallel processor. The software program uses a preemption feature of the parallel processor to cause the parallel processor to stop executing instructions in accordance with the context. The software program then causes the parallel processor to collect state data associated with the context. After generating a checkpoint based on the state data, the software program causes the parallel processor to resume executing instructions in accordance with the context.
Methods and systems for utilizing a master-shadow physical register file based on verified activation
A processor in a data processing system includes a master-shadow physical register file and a renaming unit. The master-shadow physical register file has a master storage coupled to shadow storage. The renaming unit is coupled to the master-shadow physical register file. Based on an occurrence of shadow transfer activation conditions verified by the renaming unit, data in the master storage is transferred from the master storage to the shadow storage for storage. Data is transferred from the shadow storage back to the master storage based on the occurrence of a shadow-to-master transfer event, which includes, for example, a flush of the master storage by the processor.