公开(公告)号：US09753694B2

公开(公告)日：2017-09-05

申请号：US14692071

申请日：2015-04-21

Applicant: QUALCOMM Incorporated

Inventor： Kenneth Alan Dockser ,  Michael Thomas Dibrino ,  Pathik Sunil Lall

IPC: G06F7/537 ,  G06F7/535 ,  G06F5/01 ,  G06F7/487

CPC classification number: G06F7/535 ,  G06F5/01 ,  G06F7/4873 ,  G06F7/5375 ,  G06F2205/003 ,  G06F2207/535

Abstract: Systems and methods relate to division of a dividend by a divisor, with fast result formatting. Counts of leading sign bits of the dividend and the divisor are determined. The dividend and the divisor are normalized based on their respective counts of leading sign bits to obtain a normalized dividend and a normalized divisor, respectively. An exact number of significant quotient bits of a quotient of the division, based on the normalized dividend, the normalized divisor, and the counts of leading sign bits of the dividend and the divisor and used to determine a correct position of a leading bit of the quotient based on this exact number. The quotient is developed by placing the leading bit at or near the correct position and appending less significant bits to the right of the leading bit. Thus, left-shifts in each iteration and large final shifts are avoided in formatting the result.

公开(公告)号：US20130218938A1

公开(公告)日：2013-08-22

申请号：US13768698

申请日：2013-02-15

Applicant: Qualcomm Incorporated

Inventor： Kenneth Alan Dockser ,  Pathik Sunil Lall

IPC: G06F7/485

CPC classification number: G06F7/485

Abstract: Provided are a floating-point adder and methods for implementing a floating-point adder with operand shifting based on a predicted exponent difference when performing an effective subtraction on normal or subnormal numbers. In an aspect, two least significant bits (LSBs) of a first floating-point operand's exponent are compared with two LSBs of a second floating-point operand's exponent to estimate a difference between the two exponents. A first shift of up to one of the first and the second operands is performed, based on the estimated difference. A prospective result is then produced by subtracting the first operand and the second operand. Contemporaneously, one of the first operand's exponent and the second operand's exponent is subtracted from the other of the first operand's exponent and the second operand's exponent to determine if the exponents actually differ by one or less. If the first operand's exponent and the second operand's exponent differ by one or less, the prospective result is provided as the raw difference of the operands.

Abstract translation: 提供了一种浮点加法器和用于在对正常或正常数进行有效减法时基于预测指数差来实现具有操作数移位的浮点加法器的方法。 在一方面，将第一浮点运算数的指数的两个最低有效位（LSB）与第二浮点运算指数的两个LSB进行比较，以估计两个指数之间的差。 基于估计的差异，执行高达第一和第二操作数之一的第一移位。 然后通过减去第一操作数和第二操作数产生预期结果。 同时，第一个操作数的指数和第二个操作数的指数之一从第一个操作数的指数和第二个操作数的指数的另一个中减去，以确定指数实际上是否相差一个或更少。 如果第一个操作数的指数和第二个操作数的指数相差一个或多个，则预期结果作为操作数的原始差异提供。