Invention Application
US20090024643A1 Multi-Level Compressed Look-up Tables Formed by Logical Operations to Compress Selected Index Bits
有权
通过逻辑操作形成的多级压缩查找表来压缩所选择的索引位
- Patent Title: Multi-Level Compressed Look-up Tables Formed by Logical Operations to Compress Selected Index Bits
- Patent Title (中): 通过逻辑操作形成的多级压缩查找表来压缩所选择的索引位
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Application No.: US12190692Application Date: 2008-08-13
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Publication No.: US20090024643A1Publication Date: 2009-01-22
- Inventor: Millind Mittal
- Applicant: Millind Mittal
- Applicant Address: US CA Santa Clara
- Assignee: X-ENGINES, INC
- Current Assignee: X-ENGINES, INC
- Current Assignee Address: US CA Santa Clara
- Main IPC: G06F17/30
- IPC: G06F17/30

Abstract:
A lookup is performed using multiple levels of compressed stride tables in a multi-bit Trie structure. An input lookup key is divided into several strides including a current stride of S bits. A valid entry in a current stride table is located by compressing the S bits to form a compressed index of D bits into the current stride table. A compression function logically combines the S bits to generate the D compressed index bits. An entry in a prior-level table points to the current stride table and has a field indicating which compression function and mask to use. Compression functions can include XOR, shifts, rotates, and multi-bit averaging. Rather than store all 2S entries, the current stride table is compressed to store only 2D entries. Ideally, the number of valid entries in the current stride table is between 2D−1 and 2D for maximum compression. Storage requirements are reduced.
Public/Granted literature
- US08356020B2 Multi-level compressed look-up tables formed by logical operations to compress selected index bits Public/Granted day:2013-01-15
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