公开(公告)号：GB2530990A

公开(公告)日：2016-04-13

申请号：GB201417582

申请日：2014-10-06

Applicant: IBM

Inventor： MICHAEL KROENER ,  SILVIA MELITTA MUELLER ,  STEVEN R CARLOUGH ,  MICHAEL KLEIN ,  KERSTIN SCHELM ,  PETRA LEBER ,  JUERGEN HAESS

IPC: G06F7/485 ,  G06F7/491

Abstract: A decimal floating point unit for performing add or subtract calculations on a first (100) and second operand (101) comprising unpacking S200 the first and second operand such as by formatting 128 bit width mantissa to be 136 bit wide; conditionally swapping S202 the first and second operand, if an exponent (104) of the first operand is less than an exponent (105) of the second operand, and aligning S204, S206 the operands based on the exponent difference and a number of leading zeroes in the operand with the larger exponent. Adding or subtracting the operands S208 is performed on the aligned operands with normalizing and rounding of the result which is then packed S210. Binary floating point arithmetic can also be performed on the decimal floating point unit which may be pipelined.