摘要:
A method in a computer system of performing a butterfly stage of a complex fast fourier transform of two input signals. First, a packed multiply add is performed on a first packed complex value generated from a first input signal and a set of trigonometric values to generate a first product. Then, a second product is generated which comprises the first product with a sign inverted. A packed add of the second product and a second complex value generated from a second input signal is performed to generate a first result, and the first product and the second complex value to generate a second result.
摘要:
The invention provides a method and apparatus for performing complex digital filters. According to one aspect of the invention, a method for performing a complex digital filter is described. The complex digital filter is performed using a set of data samples and a set of complex coefficients. In addition, the complex digital filter is performed using a inner and outer loop. The outer loop steps through a number of corresponding relationships between the set of complex coefficients and the set of data samples. The inner loop steps thorough each complex coefficient in the set of complex coefficients. Within the inner loop, the data sample corresponding to the current complex coefficient (the complex coefficient currently identified by the inner loop) is determined according to the current corresponding relationship (the corresponding relationship currently identified by the outer loop). Then, in response to receiving an instruction, eight data elements are read and used to generate a currently calculated complex number. These eight data elements were previously stored as packed data and include two representations of each of the components of the current complex coefficient and its current corresponding data sample. Each of these data elements is either the positive or negative of the component they represent. As a result of the manner in which these eight data elements are stored, the currently calculated complex number represents the product of the current complex coefficient and its current corresponding data sample. The currently calculated complex number is then added to the current output packed data.
摘要:
A method and apparatus for performing complex digital filters. According to one aspect of the invention, a method for performing a complex digital filter is described. The complex digital filter is performed using a set of data samples and a set of complex coefficients. In addition, the complex digital filter is performed using a inner and outer loop. The outer loop steps through a number of corresponding relationships between the set of complex coefficients and the set of data samples. The inner loop steps thorough each complex coefficient in the set of complex coefficients. Within the inner loop, the data sample corresponding to the current complex coefficient (the complex coefficient currently identified by the inner loop) is determined according to the current corresponding relationship (the corresponding relationship currently identified by the outer loop). Then, in response to receiving an instruction, eight data elements are read and used to generate a currently calculated complex number. These eight data elements were previously stored as packed data and include two representations of each of the components of the current complex coefficient and its current corresponding data sample. Each of these data elements is either the positive or negative of the component they represent. As a result of the manner in which these eight data elements are stored, the currently calculated complex number represents the product of the current complex coefficient and its current corresponding data sample. The currently calculated complex number is then added to the current output packed data.
摘要:
A method and apparatus for performing complex digital filters. According to one aspect of the invention, a computer system generally having a transmitting unit, a processor, and a storage device is described. The storage device is coupled to the processor and has stored therein a routine. When executed by the processor, the routine causes the processor to perform a digital filter on unfiltered data items using complex coefficients to generate an output data stream. Execution of the routine causes the processor to perform outer and inner loops. The outer loop steps through corresponding relationships between the complex coefficients and the unfiltered data items. Each of these corresponding relationships is used by the digital filter to generate the output data stream. The inner loop steps the complex coefficients. Within the inner loop, the unfiltered data item corresponding to the current complex coefficient is determined according to the current corresponding relationship. Then, in response to receiving an instruction, eight data elements are read and used to generate a currently calculated complex number. As a result of the manner in which these eight data elements are stored, the currently calculated complex number represents the product of the current complex coefficient and its corresponding unfiltered data item. The currently calculated complex number is then added to the current output packed data. As a result, the current output packed data stores the sum of the complex numbers generated in the current inner loop.
摘要:
The invention provides a method and apparatus for performing complex digital filters. According to one aspect of the invention, a method for performing a complex digital filter is described. The complex digital filter is performed using a set of data samples and a set of complex coefficients. In addition, the complex digital filter is performed using a inner and outer loop. The outer loop steps through a number of corresponding relationships between the set of complex coefficients and the set of data samples. The inner loop steps thorough each complex coefficient in the set of complex coefficients. Within the inner loop, the data sample corresponding to the current complex coefficient (the complex coefficient currently identified by the inner loop) is determined according to the current corresponding relationship (the corresponding relationship currently identified by the outer loop). Then, in response to receiving an instruction, eight data elements are read and used to generate a currently calculated complex number. These eight data elements were previously stored as packed data and include two representations of each of the components of the current complex coefficient and its current corresponding data sample. Each of these data elements is either the positive or negative of the component they represent. As a result of the manner in which these eight data elements are stored, the currently calculated complex number represents the product of the current complex coefficient and its current corresponding data sample. The currently calculated complex number is then added to the current output packed data.
摘要:
A computer system which includes a multimedia input device which generates an audio or video input signal and a processor coupled to the multimedia input device. The system further includes a storage device coupled to the processor and having stored therein a signal processing routine for multiplying and accumulating input values representative of the audio or video input signal. The signal processing routine, when executed by the processor, causes the processor to perform several steps. These steps include performing a packed multiply add on a first set of values packed into a first source and a second set of values packed into a second source each representing input signals to generate a packed intermediate result. The packed intermediate result is added to an accumulator to generate a packed accumulated result in the accumulator. These steps may be iterated with the first set of values and portions of the second set of values to the accumulator to generate the packed accumulated result. Subsequent thereto, the packed accumulated result in the accumulator is unpacked into a first result and a second result and the first result and the second result are added together to generate an accumulated result.
摘要:
The invention provides a method and apparatus for performing complex digital filters. According to one aspect of the invention, a method for performing a complex digital filter is described. The complex digital filter is performed using a set of data samples and a set of complex coefficients. In addition, the complex digital filter is performed using a inner and outer loop. The outer loop steps through a number of corresponding relationships between the set of complex coefficients and the set of data samples. The inner loop steps thorough each complex coefficient in the set of complex coefficients. Within the inner loop, the data sample corresponding to the current complex coefficient (the complex coefficient currently identified by the inner loop) is determined according to the current corresponding relationship (the corresponding relationship currently identified by the outer loop). Then, in response to receiving an instruction, eight data elements are read and used to generate a currently calculated complex number. These eight data elements were previously stored as packed data and include two representations of each of the components of the current complex coefficient and its current corresponding data sample. Each of these data elements is either the positive or negative of the component they represent. As a result of the manner in which these eight data elements are stored, the currently calculated complex number represents the product of the current complex coefficient and its current corresponding data sample. The currently calculated complex number is then added to the current output packed data.
摘要:
The invention provides a method and apparatus for storing complex data in formats which allow efficient complex multiplication operations to be performed and for performing such complex multiplication operations. According to one aspect of the invention, a method for multiplying complex numbers is provided for use in a data processing system. In response to receiving an instruction, eight data elements are read and used to generate a resulting complex number. These eight data elements were previously stored as packed data and include two representations of each of the components of a first and second complex number. Each of these representations is signed such that it represents either the positive or negative of said component. As a result of the manner in which these eight data elements are stored, the resulting complex number represents the product of the first and second complex numbers. According to another aspect of the invention, a machine-readable medium is described. This machine-readable medium has stored thereon data representing sequences of instructions which, when executed by a processor, cause that processor to perform the above described method.
摘要:
A method and apparatus for including in a processor instructions for performing multiply-add operations on packed data. In one embodiment, a processor is coupled to a memory. The memory has stored therein a first packed data and a second packed data. The processor performs operations on data elements in said first packed data and said second packed data to generate a third packed data in response to receiving an instruction. At least two of the data elements in this third packed data storing the result of performing multiply-add operations on data elements in the first and second packed data.
摘要:
A method and apparatus for including in a processor instructions for performing multiply-add operations on packed data. In one embodiment, a processor is coupled to a memory. The memory has stored therein a first packed data and a second packed data. The processor performs operations on data elements in said first packed data and said second packed data to generate a third packed data in response to receiving an instruction. At least two of the data elements in this third packed data storing the result of performing multiply-add operations on data elements in the first and second packed data.