Invention Grant
US08671129B2 System and method of bypassing unrounded results in a multiply-add pipeline unit
有权
在多重加法管道单元中绕过未包围结果的系统和方法
- Patent Title: System and method of bypassing unrounded results in a multiply-add pipeline unit
- Patent Title (中): 在多重加法管道单元中绕过未包围结果的系统和方法
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Application No.: US13043101Application Date: 2011-03-08
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Publication No.: US08671129B2Publication Date: 2014-03-11
- Inventor: Jeffrey S. Brooks , Christopher H. Olson
- Applicant: Jeffrey S. Brooks , Christopher H. Olson
- Applicant Address: US CA Redwood City
- Assignee: Oracle International Corporation
- Current Assignee: Oracle International Corporation
- Current Assignee Address: US CA Redwood City
- Agency: Meyertons, Hood, Kivlin, Kowert & Goetzel, P.C.
- Agent Rory D. Rankin
- Main IPC: G06F7/32
- IPC: G06F7/32

Abstract:
A processing unit, system, and method for performing a multiply operation in a multiply-add pipeline. To reduce the pipeline latency, the unrounded result of a multiply-add operation is bypassed to the inputs of the multiply-add pipeline for use in a subsequent operation. If it is determined that rounding is required for the prior operation, then the rounding will occur during the subsequent operation. During the subsequent operation, a Booth encoder not utilized by the multiply operation will output a rounding correction factor as a selection input to a Booth multiplexer not utilized by the multiply operation. When the Booth multiplexer receives the rounding correction factor, the Booth multiplexer will output a rounding correction value to a carry save adder (CSA) tree, and the CSA tree will generate the correct sum from the rounding correction value and the other partial products.
Public/Granted literature
- US20120233234A1 SYSTEM AND METHOD OF BYPASSING UNROUNDED RESULTS IN A MULTIPLY-ADD PIPELINE UNIT Public/Granted day:2012-09-13
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