摘要:
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.
摘要:
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.
摘要:
A circuit arrangement and method couple a hardware-based pseudorandom number generator (PRNG) to an execution unit in such a manner that pseudorandom numbers generated by the PRNG may be selectively output to the execution unit for use as an operand during the execution of instructions by the execution unit. A PRNG may be coupled to an input of an operand multiplexer that outputs to an operand input of an execution unit so that operands provided by instructions supplied to the execution unit are selectively overridden with pseudorandom numbers generated by the PRNG. Furthermore, overridden operands provided by instructions supplied to the execution unit may be used as seed values for the PRNG.
摘要:
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.
摘要:
An execution unit supports data dependent conditional write instructions that write data to a target only when a particular condition is met. In one implementation, a data dependent conditional write instruction identifies a condition as well as data to be tested against that condition. The data is tested against that condition, and the result of the test is used to selectively enable or disable a write to a target associated with the data dependent conditional write instruction. Then, a write is attempted while the write to the target is enabled or disabled such that the write will update the contents of the target only when the write is selectively enabled as a result of the test. By doing so, dependencies are typically avoided, as is use of an architected condition register that might otherwise introduce branch prediction mispredict penalties, enabling improved performance with z-buffer test and similar types of algorithms.
摘要:
A circuit arrangement and method couple a hardware-based pseudorandom number generator (PRNG) to an execution unit in such a manner that pseudorandom numbers generated by the PRNG may be selectively output to the execution unit for use as an operand during the execution of instructions by the execution unit. A PRNG may be coupled to an input of an operand multiplexer that outputs to an operand input of an execution unit so that operands provided by instructions supplied to the execution unit are selectively overridden with pseudorandom numbers generated by the PRNG. Furthermore, overridden operands provided by instructions supplied to the execution unit may be used as seed values for the PRNG. In many instances, an instruction executed by an execution unit may be able to perform an arithmetic operation using both an operand specified by the instruction and a pseudorandom number generated by the PRNG during the execution of the instruction, so that the generation of the pseudorandom number and the performance of the arithmetic operation occur during a single pass of an execution unit.
摘要:
A circuit arrangement and method support instruction target history based register address indexing, whereby register addresses to be used by an instruction are decoded using a target history table of previous target register addresses, and an index into the target history table supplied by an index value in the instruction. An instruction may include at least one index value that identifies a previously used register address. During execution of the instruction, the index is retrieved from the instruction, and then a register address is retrieved from the target history table using the index.
摘要:
A floating point execution unit calculates a one minus dot product value in a single pass. As such, the dependency that otherwise would be required to perform the calculations is eliminated, resulting in a substantially faster performance of such calculations. The floating point execution unit may be used, for example, to accelerate pixel shading algorithms such as Fresnel and electron microscope effects.
摘要:
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.
摘要:
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.