Dynamic Fixed-Point Conversion for LSTM Neural Networks

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Solution Overview

Problem

Deep neural networks face challenges in maintaining accuracy during compression, particularly when converting floating-point numbers to fixed-point numbers, which affects computation speed and resource efficiency.

Innovation Solution

A dynamic fixed-point conversion scheme is proposed for LSTM neural networks, where weights and intermediate calculations are converted to fixed-point numbers during the fine-tuning process, with adaptive conversion schemes determined based on data inputs to minimize accuracy loss and prevent overflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If floating-point numbers are converted to fixed-point numbers for compression, then computation speed and resource efficiency are improved, but accuracy is degraded

Engineering Contradiction:
Improvecomputation speedVSAvoidaccuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the fixed-point conversion scheme adaptive rather than static. The system dynamically determines the number of decimal bits based on the actual data distribution and value ranges observed during training, allowing the precision to adjust to the specific requirements of different layers and operations, thereby maintaining accuracy while optimizing for fixed-point computation efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of decimal bit length in the fixed-point conversion scheme from a fixed value to a dynamically determined value. By adjusting this parameter based on the actual data characteristics and requirements of different neural network components, the system achieves optimal balance between precision and computation speed

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a static fixed-point conversion scheme is used, then device complexity is reduced, but overflow occurs during training

Engineering Contradiction:
Improveconversion scheme complexityVSAvoidoverflow prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system transitions from a static conversion scheme to a dynamic one where the decimal bit length is determined based on the actual data characteristics. This dynamic adaptation allows the system to prevent overflow by adjusting precision to match the actual data requirements, rather than using a fixed scheme that may be either too conservative or insufficient

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent performs preliminary analysis of data distribution and value ranges before finalizing the fixed-point conversion scheme. By examining the actual data characteristics in advance and determining appropriate decimal bit lengths based on observed requirements, the system prevents overflow issues before they occur during training

Inventive Principle:
Principle #10Preliminary action

3Reliability

If precision is increased to prevent overflow, then reliability is improved, but computation speed decreases

Engineering Contradiction:
Improveoverflow preventionVSAvoidcomputation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system optimizes the decimal bit length parameter dynamically based on actual data requirements rather than using excessive precision. By adjusting this parameter to match the specific needs of each layer and operation, the system achieves sufficient precision for reliability while avoiding the computational overhead of unnecessarily high precision

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10929744B2Fixed-point training method for deep neural networks based on dynamic fixed-point conversion scheme
Publication Date: 2021.02.23 XILINX TECH BEIJING LTD
  • US10929744B2 patent drawing
  • US10929744B2 patent drawing
  • US10929744B2 patent drawing

AI summary

The present disclosure proposes a fixed-point training method and apparatus based on dynamic fixed-point conversion scheme. More specifically, the present disclosure proposes a fixed-point training method for LSTM neural network. According to this method, during the fine-tuning process of the neural network, it uses fixed-point numbers to conduct forward calculation. Accordingly, within several training cycles, the network accuracy may returned to the desired accuracy level under floating point calculation.