37 results about "Sign extension" patented technology

A data processing apparatus execution unit includes a multiplexer having inputs receiving data from sections of a source data register or registers. The multiplexer selects data from one section to store in a destination data register. The execution unit may zero extend or sign extend the remaining most significant bits of the destination data. In an alternative embodiment, the execution unit includes plural multiplexers, one for each section of the destination data. Each multiplexer received data from each section of the source data register or registers. Special codes in the sections of the second source data register may select 0 fill, 1 fill or sign extension from the next most significant section for each multiplexer.

A programmable logic integrated circuit device has at least one function-specific circuit block (e.g., a parallel multiplier, a parallel barrel shifter, a parallel arithmetic logic unit, etc.) in addition to the usual multiple regions of programmable logic and the usual programmable interconnection circuit resources. To reduce the impact of use of the function-specific block (“FSB”) on the general purpose interconnection resources of the device, inputs and/or outputs of the FSB may be coupled relatively directly to a subset of the logic regions. In addition to conserving general purpose interconnect, resources of the logic regions to which the FSB are connected can be used by the FSB to reduce the amount of circuitry that must be dedicated to the FSB. If the FSB is a multiplier, additional features include facilitating accumulation of successive multiplier outputs (using either addition or subtraction and with sign extension if desired) and/or arithmetically combining the outputs of multiple multipliers.

Addressing memory includes receiving a first operand to a memory addressing operator, receiving a second operand to the memory addressing operator, performing sign extension on the first operand to provide a sign-extended operand, shifting the sign-extended operand to provide a shifted, sign-extended operand, and adding the shifted, sign-extended operand to the second operand. The second operand has a different bit length than the first operand.

A method of discovering a fault in a circuit is disclosed. The method comprises generating a first result of a selected function by performing the selected function on an operand, wherein the selected function employs a mask. Once the function is performed, an antimask of the mask is created, and the modulo of the antimask is calculated. A modulo function of the first result of the selected function is calculated to obtain a third result. A modulo of the operand is then calculated to obtain a fourth result, and a second function is then performed on the second result and the third result to obtain a fifth result. In response to comparing the fifth result to the fourth result, a signal is propagated to indicate a fault in the circuit.

The invention discloses a method and device for extending an immediate operand in a computer instruction. At least one immediate operand extending instruction is newly increased in an RISC instruction system, during the programming process, an immediate operand the digit number of which is larger than the length of an immediate operand domain of an execution instruction is divided into a high-order immediate operand field and a low-order immediate operand field, the high-order immediate operand field is subjected to signed extension or unsigned extension and then is stored in the immediate operand domain of the immediate operand extending instruction, and the low-order immediate operand field just fills up the immediate operand domain of the execution instruction; during the instruction fetching process, the newly-increased immediate operand extending instruction and the execution instruction following closely are sent into respective decoders synchronously to carry out decoding; during the decoding process, the immediate operand output by the immediate operand extending instruction decoder is subjected to logical left shift and then is merged with the immediate operand output by the execution instruction decoder, after the merging process, the immediate operand the digit number of which is larger than the length of the immediate operand domain of the execution instruction is obtained. By employing the method for extending the immediate operand in the computer instruction, the program execution efficiency can be greatly improved, and time and space are saved.

The present invention provides methods, apparatus, and systems to remove a redundant, sign extension instruction from a program and to improve the execution efficiency of the program. In an example embodiment, a conversion program for controlling a computer for the conversion of an execution program, especially a compiler, permits the computer to perform: a function for analyzing a sign extension instruction issued in order to perform the sign extension of a value defined in the execution program; and a function for, in accordance with analysis results, removing a predetermined sign extension instruction from those included in the execution program.

A multiplier sign extension method and architecture are used for encoding operations of a multiplier of a digital signal processor. The multiplier sign extension method comprises the steps of: determining the width of the multiplier to obtain a sign extension bit total value; encoding a multiplier by means of the modified Booth algorithm; calculating out a plurality of layers of partial product terms by multiplying a multiplicand by the encoded multiplier to form a first stepwise bit table; setting a plurality of complementary bits, a first correction bit and a second correction bit to form a second stepwise bit table; and summing up the plurality of layers of the second stepwise bit table. Without increasing critical paths, a plurality of complementary bits is provided for encoding of sign extension to reduce waste of chip area and make the multiplier smaller.

A streaming engine employed in a digital data processor specifies a fixed read only data stream recalled memory. Streams are started by one of two types of stream start instructions. A stream start ordinary instruction specifies a register storing a stream start address and a register of storing a stream definition template which specifies stream parameters. A stream start short-cut instruction specifies a register storing a stream start address and an implied stream definition template. A functional unit is responsive to a stream operand instruction to receive at least one operand from a stream head register. The stream template supports plural nested loops with short-cut start instructions limited to a single loop. The stream template supports data element promotion to larger data element size with sign extension or zero extension. A set of allowed stream short-cut start instructions includes various data sizes and promotion factors.

In an arithmetic circuit, every time a numerical value is stored in a register, a partial solution is predicted on the basis of the numerical value, an intermediate value is generated by a predetermined calculation using one or more predicted partial solutions, an extended sign bit is appended to the intermediate value by sign extension, and the intermediate value to which the extended sign bit is appended is stored in the register. In addition, the solution is generated on the basis of the one or more partial solutions. A value of a sign bit constituting the intermediate value stored in the register is compared with a value of the extended sign bit stored in the register, and an error signal is outputted when the value of the sign bit is different from the value of the extended sign bit.

Floating point Multiply-Add, Accumulate Unit, supporting BF16 format for Multiply-Accumulate operations, and FP32 Single-Precision Addition complying with the IEEE 754 Standard. The Multiply-Accumulate unit uses higher radix and longer internal 2's complement significand representation to facilitate precision as well as comparison and operation with negative numbers. The addition can be performed using Carry-Save format to avoid long carry propagation and speed up the operation. The circuit uses early exponent comparison to shorten the accumulate pipeline stage. Operations including overflow detection, zero detection and sign extension are adopted for 2s complement and Carry-Save format.

The disclosed optimization method separates data signal from pilot signal, which pass through sign extension portion and IFFT portion respectively. The data portion passes through clipping module then. Optimizing process module carries out optimizing process for data signal. The purpose of the optimizing process is to eliminate influence on the pilot signal by the clipping operation. FFT is carried out for data after self-adapting amplitude limiting in advance so as to convert signal in time domain into signal in frequency domain. Afterwards, the signal in frequency domain passes through module for limiting and eliminating amplitude of noise. Finally, the method superposes the portion of optimizing processed data signal with the portion of pilot signal, and outputs the superposed signal. Through iterative algorithm, the invention reduces influence on the pilot signal caused by amplitude-limited noise, raises precision for estimating channel so as to raise transmission performance.

A multiply accumulator performs a multiplication-and-addition operation for a first multiplier with N bits, a second multiplier with N bits, and an addend with M bits, wherein M is larger than 2N. The multiply accumulator includes a modified Booth encoder and a multiplication-and-addition unit. The modified Booth encoder performs a Booth encoding to either the first multiplier or its bit inversion by supplementing a multiplier sign bit behind a least significant bit of either the first multiplier or its bit inversion. The multiplication-and-addition unit includes a carry save adder tree and a sign extension adder and achieves a high speed of the multiplication-and-addition operation by simultaneously performing the multiplication and addition.

An arrangement is provided for using 2's complement arithmetic without the high switching activity of the prior art. In particular, the invention operates to exploit the sign-extension property of a 2's complement number. A reduced representation for 2's complement numbers is provided to avoid sign-extension and the switching of sign-extension bits. The maximum magnitude of a 2's complement number is detected and its reduced representation is dynamically generated to represent the signal. A constant error introduced by the reduced representation is also dynamically compensated.