Abstract: An “early exit” of an iterative refinement algorithm is implemented by effectively disabling read after write dependency stalls of newer instructions, as well as disabling the register write enable of these instructions, for the remainder of the algorithm, in addition to disabling the register write enable of these instructions. By doing so, the latency of the algorithm is reduced and the performance is increased without the complexity and potential poor performance of compare and branch instructions that might otherwise be required.

Abstract: Persistent vector multiplexer control is used in a vector-based execution unit to control the shuffling of words in operand vectors processed by the execution unit. In addition, a persistent swizzle instruction is defined in an instruction set for the vector-based execution unit and is used to cause state information to be persisted such that the operand vectors processed by subsequent vector instructions executed by the vector-based execution unit will be selectively shuffled using the persisted state information. As a result, when multiple vector instructions require a common custom word ordering for one or more operand vectors, a single persistent swizzle instruction may be used to select the desired custom word ordering for all of the vector instructions.

Abstract: A multirate execution unit is capable of being operated in a plurality of modes, with the execution unit being capable of clocked at multiple different rates relative to a multithreaded issue unit such that, in applications where maximum performance is desired, the execution unit can be clocked at a rate that is faster than the clock rate for the multithreaded issue unit, and in applications where a lower power profile is desired, the execution unit can be throttled back to a slower rate to reduce the power consumption of the execution unit. When the execution unit is clocked at a faster rate than the multithreaded issue unit, the issue unit is permitted to issue more instructions per cycle than when the execution unit is throttled to the slower rate to increase overall instruction throughput.

Abstract: A circuit arrangement and method bypass the storage of requested data in a higher level cache of a multi-level memory architecture during the return of the requested data to a requester, while caching the requested data in a lower level cache. For certain types of data, e.g., data that is only used once and/or that is rarely modified or written back to memory, bypassing storage in a higher level cache reduces the likelihood of the requested data casting out frequently used data from the higher level cache. By caching the data in a lower level cache, however, the lower level cache can still snoop data requests and return requested data in the event the data is already cached in the lower level cache.

Abstract: A vectorizable execution unit is capable of being operated in a plurality of modes, with the processing lanes in the vectorizable execution unit grouped into different combinations of logical execution units in different modes. By doing so, processing lanes can be selectively grouped together to operate as different types of vector execution units and/or scalar execution units, and if desired, dynamically switched during runtime to process various types of instruction streams in a manner that is best suited for each type of instruction stream. As a consequence, a single vectorizable execution unit may be configurable, e.g., via software control, to operate either as a vector execution or a plurality of scalar execution units.

Abstract: A method and apparatus for executing instructions in a processor are provided. In one embodiment of the invention, the method includes receiving a plurality of instructions. The plurality of instructions includes first instructions in a first thread and second instructions in a second thread. The method further includes forming a common issue group including an instruction of a first instruction type and an instruction of a second instruction type. The method also includes issuing the common issue group to a first execution unit and a second execution unit. The instruction of the first instruction type is issued to the first execution unit and the instruction of the second instruction type is issued to the second execution unit.

Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design for image processing, and more specifically to vector units for supporting image processing is provided. A combined vector/scalar unit is provided wherein one or more processing lanes of the vector unit are used for performing scalar operations. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated and a significant amount of chip area is saved.

Abstract: Embodiments of the invention are generally related to image processing, and more specifically to vector units for supporting image processing. A combined vector/scalar unit is provided wherein one or more processing lanes of the vector unit are used for performing scalar operations. An integrated register file is also provided for storing vector and scalar data. Therefore, the transfer of data to memory to exchange data between independent vector and scalar units is obviated and a significant amount of chip area is saved.

Abstract: A method, computer-readable medium, and an apparatus for implementing a floating point weighted average function. The method includes receiving an input containing 2N input values, 2N weights, and an opcode, where N is a positive integer number and each of the input values corresponds to one of the weights. Furthermore, the method also includes using existing dot product circuit function to generate 2N addends by multiplying each of the input values with the corresponding weight. In addition, the method includes generating a sum value by adding the 2N addends, where the sum value includes an exponent value, and generating the weighted average value based on the sum value by decreasing the exponent value by N. In this fashion, the same circuit area may be used to carry out both dot product and weighted average calculations, leading to greater circuit area savings and performance advantages.

Abstract: A method, computer-readable medium, and an apparatus for generating a transcendental value. The method includes receiving an input containing an input value and an opcode and determining whether the opcode corresponds to a trigonometric operation or a power-of-two operation. The method also includes calculating a fractional value and an integer value from the input value, generating the transcendental value based on the fractional value by adding at least a portion of the fractional value with at least one of a shifted fractional value produced by shifting the portion of the fractional value and a constant value, and providing the transcendental value in response to the request. In this fashion, the same circuit area may be used to carry out both trigonometric and power-of-two calculations, leading to greater circuit area savings and performance advantages while not sacrificing significant accuracy.

Abstract: Embodiments of the invention are generally related to the field of image processing, and more specifically to vector units for supporting image processing. A vector unit may comprise a plurality of operand multiplexers associated with each vector processing lane of the vector unit. The operand multiplexers may select vector operands from one or more register files for performing a cross product operation. A first multiply operation may be performed in a first pipeline stage by multiplying a first set of operands in a multiplier. In a second pipeline stage, a second multiply operation may be performed by multiplying a second set of operands. The results of the first multiply operation and the second multiply operation may be transferred to an adder to complete the cross product instruction.

Abstract: Embodiments of the invention provide methods and apparatus for executing a multiple operand instruction. Executing the multiple operand instruction comprises computing an arithmetic result of a pair of operands in each processing lane of a vector unit. The arithmetic results generated in each processing lane of the vector unit may be transferred to a dot product unit. The dot product unit may compute an arithmetic result using the arithmetic result computed by each processing lane of the vector unit to generate an arithmetic result of more than two operands.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: Embodiments of the invention provide logic within the store data path between a processor and a memory array. The logic may be configured to misalign vector data as it is stored to memory. By misaligning vector data as it is stored to memory, memory bandwidth may be maximized while processing bandwidth required to store vector data misaligned is minimized. Furthermore, embodiments of the invention provide logic within the load data path which allows vector data which is stored misaligned to be aligned as it is loaded into a vector register. By aligning misaligned vector data as it is loaded into a vector register, memory bandwidth may be maximized while processing bandwidth required to align misaligned vector data may be minimized.

Abstract: The present invention is generally related to the field of image processing, and more specifically to an instruction set for processing images. Vector processing may involve rearranging vector operands in one or more source registers prior to performing vector operations. Typically, rearranging of operands in source registers is done by issuing a plurality of permute instructions that require excessive usage of temporary registers. Furthermore, the permute instructions may cause dependencies between instructions executing in a pipeline, thereby adversely affecting performance. Embodiments of the invention provide a level of muxing between a register file and a vector unit that allow for rearrangement of vector operands in source registers prior to providing the operands to the vector unit, thereby obviating the need for permute instructions.

Abstract: The present invention is generally related to integrated circuit devices, and more particularly, to methods, systems and design structures for the field of image processing, and more specifically to an instruction set for processing images. Vector processing may involve rearranging vector operands in one or more source registers prior to performing vector operations. Typically, rearranging of operands in source registers is done by issuing a plurality of permute instructions that require excessive usage of temporary registers. Furthermore, the permute instructions may cause dependencies between instructions executing in a pipeline, thereby adversely affecting performance. Embodiments of the invention provide a level of muxing between a register file and a vector unit that allow for rearrangement of vector operands in source registers prior to providing the operands to the vector unit, thereby obviating the need for permute instructions.

Abstract: The present invention is generally related to the field of image processing, and more specifically to an instruction set for processing images. Vector processing may involve performing a plurality of dot product operations to generate operands for generating operands for a new vector. The dot product operations may require the issue of a plurality of permute instructions to arrange the vector operands in desired locations of a target register. Embodiments of the invention provide a dot product instruction wherein a mask field may be used to specify a particular location of a target register in which to transfer data, thereby avoiding the need for permute instructions for arranging data, reducing dependencies between instructions, and the usage of temporary registers.

Abstract: The present invention is generally related to the field of image processing, and more specifically to an instruction set for processing images. Vector processing may involve performing a plurality of permute operations to arrange vector operands in desired locations of a register prior to performing vector operation, for example, a cross product. The permute instructions may be dependent on one another and may require the use of temporary registers. Embodiments of the invention provide a permute instruction wherein a mask field may be used to specify a particular location of a target register in which to transfer data, thereby reducing the number of instructions for arranging data, reducing dependencies between instructions, and the usage of temporary registers.

Abstract: The present invention is generally related to integrated circuit devices, and more particularly, to methods, systems and design structures for the field of image processing, and more specifically to an instruction set for processing images. Vector processing may involve performing a plurality of permute operations to arrange vector operands in desired locations of a register prior to performing vector operation, for example, a cross product. The permute instructions may be dependent on one another and may require the use of temporary registers. Embodiments of the invention provide a permute instruction wherein a mask field may be used to specify a particular location of a target register in which to transfer data, thereby reducing the number of instructions for arranging data, reducing dependencies between instructions, and the usage of temporary registers.

Abstract: The present invention is generally related to integrated circuit devices, and more particularly, to methods, systems and design structures for the field of image processing, and more specifically to vector units for supporting image processing. A dual vector unit implementation is described wherein two vector units are configured receive data from a common register file. The vector units may independently and simultaneously process instructions. Furthermore, the vector units may be adapted to perform scalar operations thereby integrating the vector and scalar processing. The vector units may also be configured to share resources to perform an operation, for example, a cross product operation.