Lookup-Table Computing Accelerator for Faster AI Multiplication

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Solution Overview

Problem

Existing artificial intelligence systems, particularly neural network systems, face performance bottlenecks due to the time-consuming nature of operations like multiplication and matrix multiplication, which significantly impact overall system efficiency.

Innovation Solution

A computing accelerator utilizing a lookup table to accelerate floating-point multiplications and other operations by retrieving the product of floating-point operands or dot products from a lookup table, leveraging approximation and symmetry to improve performance, and employing a three-dimensional memory assembly for efficient calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional multiplication operations are used in neural network systems, then computational accuracy is maintained, but system performance and processing speed deteriorate due to time-consuming calculations

Engineering Contradiction:
Improvesystem performanceVSAvoidcomputational time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores multiplication results in lookup tables before runtime. During neural network inference, the system retrieves pre-computed values from the lookup table based on input quantized values, avoiding real-time multiplication operations and significantly reducing computational time while maintaining acceptable accuracy through controlled approximation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates simplified copies of multiplication operations by storing results in lookup tables. Instead of performing actual multiplication computations during inference, the system uses table lookups with quantized indices, effectively replacing complex arithmetic operations with simpler memory access operations that are much faster to execute.

Inventive Principle:
Principle #26Copying

2Speed

If lookup tables are used to accelerate floating-point multiplications, then computational speed is improved, but memory requirements and device complexity increase

Engineering Contradiction:
Improvecomputational speedVSAvoidmemory assembly complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent divides the lookup table into multiple segments or banks organized in a three-dimensional memory structure. This segmentation allows parallel access to different portions of the lookup table, improves memory utilization efficiency, and reduces access conflicts. The segmented structure also enables better distribution of memory resources and facilitates hierarchical memory organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from traditional two-dimensional lookup tables to a three-dimensional memory assembly structure. This dimensional change enables more efficient memory organization, allows for better spatial locality exploitation, and provides additional degrees of freedom for memory access patterns. The third dimension can represent different precision levels, different operation types, or different data groups, enabling multi-functional access from a single memory structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If full precision floating-point multiplication is performed, then calculation accuracy is maintained, but processing time increases significantly affecting overall system efficiency

Engineering Contradiction:
Improvecalculation accuracyVSAvoidprocessing efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent changes the precision parameter dynamically by using different quantization levels for different input ranges or different neural network layers. For less critical computations, lower precision (fewer bits) is used to maximize speed, while for more critical computations requiring higher accuracy, the system uses higher precision levels. This adaptive parameter change allows the system to optimize the trade-off between accuracy and speed based on specific computational requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses partial precision instead of full precision for lookup table operations. By storing and retrieving only the most significant bits of multiplication results, the system achieves sufficient accuracy for neural network inference while dramatically reducing the memory footprint and access time. This partial action approach recognizes that full precision is often unnecessary for the approximate nature of neural network computations.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11262980B2Computing accelerator using a lookup table
Publication Date: 2022.03.01 SAMSUNG ELECTRONICS CO LTD
  • US11262980B2 patent drawing
  • US11262980B2 patent drawing
  • US11262980B2 patent drawing

AI summary

A computing accelerator using a lookup table. The accelerator may accelerate floating point multiplications by retrieving the fraction portion of the product of two floating-point operands from a lookup table, or by retrieving the product of two floating-point operands of two floating-point operands from a lookup table, or it may retrieve dot products of floating point vectors from a lookup table. The accelerator may be implemented in a three-dimensional memory assembly. It may use approximation, the symmetry of a multiplication lookup table, and zero-skipping to improve performance.