| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 708502000 | Reciprocal | 7 |
| 20080208945 | METHOD TO COMPUTE AN APPROXIMATION TO THE RECIPROCAL OF THE SQUARE ROOT OF A FLOATING POINT NUMBER IN IEEE FORMAT - Approximations of reciprocal square roots are provided in IEEE floating point binary format by obtaining an index from an input value, accessing a pair of table values and performing a limited number of simple and rapidly performed manipulations. The maximum relative error in the approximation thus provided is less than 0.75/2 | 08-28-2008 |
| 20080243985 | Method and apparatus for performing multiplicative functions - A new function for calculating the reciprocal residual of a floating-point number X is defined as recip_residual(X)=1−X*recip(X), where recip(X) represents the reciprocal of X. The function may be implemented using a fused multiply-add unit in a processor. The reciprocal value of X, recip(X), may be obtained from a lookup table. The recip_residual function may help reduce the latency of many multiplicative functions that are based on products of multiple numbers and can be expressed in simple terms of functions on each individual number (e.g., log(U*V)=log(U)+log(V)). | 10-02-2008 |
| 20080301213 | DIVISION WITH RECTANGULAR MULTIPLIER SUPPORTING MULTIPLE PRECISIONS AND OPERAND TYPES - A division method includes determining a precision indicator for the division operation that indicates whether the quotient should be a single precision, double precision, or extended precision floating-point number. The division is performed at a rectangular multiplier using the Goldschmidt or Newton-Raphson algorithm. Each algorithm calculates one or more intermediate values in order to determine the quotient. For example, the Goldschmidt algorithm calculates a complement of a product of the dividend and an estimate of the reciprocal of the divisor. The quotient is determined based on a portion of one or more of these intermediate values. Because only a portion of the intermediate value is used, the division can be performed efficiently at the rectangular multiplier, and therefore the quotient can be determined more quickly and still achieve the desired level of precision. | 12-04-2008 |
| 20090164543 | APPARATUS AND METHOD TO COMPUTE RECIPROCAL APPROXIMATIONS - A method and apparatus for reducing memory required to store reciprocal approximations as specified in Institute of Electrical and Electronic Engineers (IEEE) standards such as IEEE 754 is presented. Monotonic properties of the reciprocal function are used to bound groups of values. Efficient bit-vectors are used to represent information in groups resulting in a very compact table representation about four times smaller than storing all of the reciprocal approximations in a table. | 06-25-2009 |
| 20110276614 | DATA PROCESSING APPARATUS AND METHOD FOR PERFORMING A RECIPROCAL OPERATION ON AN INPUT VALUE TO PRODUCE A RESULT VALUE - A data processing apparatus and method are provided for performing a reciprocal operation on an input value d to produce a result value X. The reciprocal operation involves iterative execution of a refinement step to converge on the result value, the refinement step performing the computation: X | 11-10-2011 |
| 20120166509 | Performing Reciprocal Instructions With High Accuracy - In one embodiment, the present invention includes a method for receiving a reciprocal instruction and an operand in a processor, accessing an entry of a lookup table based on a portion of the operand and the instruction, generating an encoder output based on a type of the reciprocal instruction and whether the reciprocal instruction is a legacy instruction, and selecting portions of the lookup table entry and input operand to be provided to a reciprocal logic unit based on the encoder output. Other embodiments are described and claimed. | 06-28-2012 |
| 20160110161 | APPARATUS AND METHOD FOR PERFORMING RECIPROCAL ESTIMATION OPERATION - A data processing apparatus has floating-point add circuitry for performing a floating-point add operation for adding or subtracting two floating-point operands. The apparatus also has reciprocal estimation circuitry for performing a reciprocal estimation operation on a first operand to generate a reciprocal estimate value which represents an estimate of a reciprocal of a first operand or an estimate or a reciprocal of the square root of the first operand. The reciprocal estimation circuitry is physically distinct from the floating-point adder circuitry, which allows both the reciprocal estimate and the add operations to be faster. | 04-21-2016 |
