Abstract: A method, circuit arrangement, and program product for selectively predicating instructions in an instruction stream by determining a first register address from an instruction, determining a second register address based on a value stored at the first register address, and determining whether to predicate the instruction based at least in part on a value stored at the second register address. Predication logic may analyze the instruction to determine the first register address, analyze a register corresponding to the first register address to determine the second register address, and communicate a predication signal to an execution unit based at least in part on the value stored at the second register address.

Abstract: A method and circuit arrangement tightly couple together decode logic associated with multiple types of execution units and having varying priorities to enable instructions that are decoded as valid instructions for multiple types of execution units to be forwarded to a highest priority type of execution unit among the multiple types of execution units. Among other benefits, when an auxiliary execution unit is coupled to a general purpose processing core with the decode logic for the auxiliary execution unit tightly coupled with the decode logic for the general purpose processing core, the auxiliary execution unit may be used to effectively overlay new functionality for an existing instruction that is normally executed by the general purpose processing core, e.g., to patch a design flaw in the general purpose processing core or to provide improved performance for specialized applications.

Abstract: A method and circuit arrangement maintain power usage prediction information for one or more functional units in branch prediction logic for a processing unit such that the power consumption of a functional unit may be selectively reduced in association with the execution of branch instructions when it is predicted that the functional unit will be idle subsequent to the execution of such branch instructions.

Abstract: A method and circuit arrangement tightly couple together decode logic associated with multiple types of execution units and having varying priorities to enable instructions that are decoded as valid instructions for multiple types of execution units to be forwarded to a highest priority type of execution unit among the multiple types of execution units. Among other benefits, when an auxiliary execution unit is coupled to a general purpose processing core with the decode logic for the auxiliary execution unit tightly coupled with the decode logic for the general purpose processing core, the auxiliary execution unit may be used to effectively overlay new functionality for an existing instruction that is normally executed by the general purpose processing core, e.g., to patch a design flaw in the general purpose processing core or to provide improved performance for specialized applications.

Abstract: A method and circuit arrangement utilize secure clear instructions defined in an instruction set architecture (ISA) for a processing unit to clear, overwrite or otherwise restrict unauthorized access to the internal architected state of the processing unit in association with context switch operations. The secure clear instructions are executable by a hypervisor, operating system, or other supervisory program code in connection with a context switch operation, and the processing unit includes security logic that is responsive to such instructions to restrict access by an operating system or process associated with an incoming context to architected state information associated with an operating system or process associated with an outgoing context.

Abstract: A method and circuit arrangement utilize a register file of an execution unit as a local instruction loop buffer to enable suitable algorithms, such as DSP algorithms, to be fetched and executed directly within the execution unit, and often enabling other logic circuits utilized for other, general purpose workloads to either be powered down or freed up to handle other workloads.

Abstract: Load latency speculation in an out-of-order computer processor, including: issuing a load instruction for execution, wherein the load instruction has a predetermined expected execution latency; issuing a dependent instruction wakeup signal on an instruction wakeup bus, wherein the dependent instruction wakeup signal indicates that the load instruction will be completed upon the expiration of the expected execution latency; determining, upon the expiration of the expected execution latency, whether the load instruction has completed; and responsive to determining that the load instruction has not completed upon the expiration of the expected execution latency, issuing a negative dependent instruction wakeup signal on the instruction wakeup bus, wherein the negative dependent instruction wakeup signal indicates that the load instruction has not completed upon the expiration of the expected execution latency.

Abstract: Load latency speculation in an out-of-order computer processor, including: issuing a load instruction for execution, wherein the load instruction has a predetermined expected execution latency; issuing a dependent instruction wakeup signal on an instruction wakeup bus, wherein the dependent instruction wakeup signal indicates that the load instruction will be completed upon the expiration of the expected execution latency; determining, upon the expiration of the expected execution latency, whether the load instruction has completed; and responsive to determining that the load instruction has not completed upon the expiration of the expected execution latency, issuing a negative dependent instruction wakeup signal on the instruction wakeup bus, wherein the negative dependent instruction wakeup signal indicates that the load instruction has not completed upon the expiration of the expected execution latency.

Abstract: A circuit arrangement, method, and program product communicate data over a communication bus by selectively encoding data values queued for communication over the communication bus based at least in part on at least one data value queued to be communicated thereafter and at least one previously communicated encoded data value to reduce bit transitions for communication of the encoded data values. By reducing bit transitions in the data communicated over the communication bus, power consumption by the communication bus is likewise reduced.

Abstract: A circuit arrangement, method, and program product communicate data over a communication bus by selectively encoding data values queued for communication over the communication bus based at least in part on at least one data value queued to be communicated thereafter and at least one previously communicated encoded data value to reduce bit transitions for communication of the encoded data values. By reducing bit transitions in the data communicated over the communication bus, power consumption by the communication bus is likewise reduced.

Abstract: A method and circuit arrangement utilize inactive non-pipelined operation resources in one processing core of a multi-core processing unit to execute non-pipelined instructions on behalf of another processing core in the same processing unit. Adjacent processing cores in a processing unit may be coupled together such that, for example, when one processing core's non-pipelined execution sequencer is busy, that processing core may issue into another processing core's non-pipelined execution sequencer if that other processing core's non-pipelined execution sequencer is idle, thereby providing intermittent concurrent execution of multiple non-pipelined instructions within each individual processing core.

Abstract: Translation management instructions are used in a multi-node data processing system to facilitate remote management of address translation data structures distributed throughout such a system. Thus, in multi-node data processing systems where multiple processing nodes collectively handle a workload, the address translation data structures for such nodes may be collectively managed to minimize translation misses and the performance penalties typically associated therewith.

Abstract: A method, circuit arrangement, and program product for executing instructions including denormal values for one or more operands in a vector execution unit. A denormal value operand may be prenormalized by a first processing lane of the vector execution unit upon detecting the denormal value. The prenormalized value and any other operands of the instruction may be communicated to a dot product adder of the vector execution unit. The dot product adder performs at least a portion of the floating point operation with the prenormalized value and any other operands of the instruction.

Abstract: A method, circuit arrangement, and program product for executing instructions including denormal values for one or more operands in a vector execution unit. A denormal value operand may be prenormalized by a first processing lane of the vector execution unit upon detecting the denormal value. The prenormalized value and any other operands of the instruction may be communicated to a dot product adder of the vector execution unit. The dot product adder performs at least a portion of the floating point operation with the prenormalized value and any other operands of the instruction.

Abstract: A method and circuit arrangement selectively stream data to an encryption or compression engine based upon encryption and/or compression-related page attributes stored in a memory address translation data structure such as an Effective To Real Translation (ERAT) or Translation Lookaside Buffer (TLB). A memory address translation data structure may be accessed, for example, in connection with a memory access request for data in a memory page, such that attributes associated with the memory page in the data structure may be used to control whether data is encrypted/decrypted and/or compressed/decompressed in association with handling the memory access request.

Abstract: A method and circuit arrangement provide support for packed sum of absolute difference operations in a floating point execution unit, e.g., a scalar or vector floating point execution unit. Existing adders in a floating point execution unit may be utilized along with minimal additional logic in the floating point execution unit to support efficient execution of a fixed point packed sum of absolute differences instruction within the floating point execution unit, often eliminating the need for a separate vector fixed point execution unit in a processor architecture, and thereby leading to less logic and circuit area, lower power consumption and lower cost.

Abstract: A circuit arrangement and method utilize existing redundant execution pipelines in a processing unit to execute multiple instances of stability critical instructions in parallel so that the results of the multiple instances of the instructions can be compared for the purpose of detecting errors. For other types of instructions for which fault tolerant or stability critical execution is not required or desired, the redundant execution pipelines are utilized in a more conventional manner, enabling multiple non-stability critical instructions to be concurrently issued to and executed by the redundant execution pipelines. As such, for non-stability critical program code, the performance benefits of having multiple redundant execution units are preserved, yet in the instances where fault tolerant or stability critical execution is desired for certain program code, the redundant execution units may be repurposed to provide greater assurances as to the fault-free execution of such instructions.

Abstract: A method includes receiving packed data corresponding to pixel components to be processed at a graphics pipeline. The method includes unpacking the packed data to generate floating point numbers that correspond to the pixel components. The method also includes routing each of the floating point numbers to a separate lane of the graphics pipeline. Each of the floating point numbers are to be processed by multiplier units of the graphics pipeline.

Abstract: Register file soft error recovery including a system that includes a first register file and a second register file that mirrors the first register file. The system also includes an arithmetic pipeline for receiving data read from the first register file, and error detection circuitry to detect whether the data read from the first register file includes corrupted data. The system further includes error recovery circuitry to insert an error recovery instruction into the arithmetic pipeline in response to detecting the corrupted data. The inserted error recovery instruction replaces the corrupted data in the first register file with a copy of the data from the second register file.

Abstract: A circuit arrangement and method support efficient indexing into large register files by utilizing register address sequence detection, wherein register addresses to be used by an instruction are produced by concatenating a portion of the address that is contained in the instruction with another portion that is speculatively produced by sequence detection logic. The portion of the correct full address that is not contained in the instruction is stored in a software accessible special purpose register. If the end of a particular sequence of addresses is detected by the sequence detection logic, the invention speculatively assumes that the next address in the sequence will be used. Since only a portion of the full addresses are stored in the instruction, they occupy less instruction space than the full address widths. An instruction may include at least one address portion that identifies a register address.