Variable-Length Instruction Steering to Decode Clusters

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Solution Overview

Problem

Current information processing systems face challenges in decoding instructions efficiently, particularly in handling variable-length instructions, which can lead to slower execution and reduced overall processor performance.

Innovation Solution

The implementation of a variable-length instruction steering mechanism that breaks instruction bytes into fixed-size chunks and steers them to multiple decode clusters, allowing for dynamic adjustment of instruction chunks based on instruction length and branch predictions to optimize decoding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If variable-length instructions are decoded using traditional methods, then all instructions can be processed, but decoding speed decreases and processor performance is reduced

Engineering Contradiction:
Improveinstruction decoding speedVSAvoidprocessor performance
Core Design Contradiction:
SpeedVSProductivity

Solution Approach 1:

The patent divides the instruction stream into fixed-size chunks (e.g., 16-byte chunks) and distributes them to multiple decode clusters. Each decode cluster independently processes assigned chunks, enabling parallel decoding operations. This segmentation transforms the sequential decoding bottleneck into a parallel processing architecture, directly improving decoding speed and overall processor performance.

Inventive Principle:
Principle #1Segmentation

2Productivity

If fixed-size chunks are used for instruction steering, then decoding can be parallelized across multiple clusters, but handling variable-length instructions becomes complex

Engineering Contradiction:
Improvedecoding throughputVSAvoidinstruction steering complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a chunk steering unit as an intermediary component that receives variable-length instructions, segments them into fixed-size chunks, and intelligently distributes them to appropriate decode clusters. This mediator handles the complexity of variable-length instruction management, allowing the decode clusters to operate with simple fixed-size chunks while maintaining support for variable-length instruction semantics.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically adjusts chunk distribution parameters based on instruction characteristics. The chunk steering unit modifies how instructions are divided and assigned to decode clusters, changing the segmentation parameters adaptively to handle different instruction lengths and types, thereby simplifying the decoding process while maintaining throughput.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple decode clusters are used, then decoding capacity increases, but distributing instructions efficiently among clusters becomes challenging

Engineering Contradiction:
Improveinstruction distribution flexibilityVSAvoidcluster coordination complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The chunk steering unit implements dynamic instruction distribution to decode clusters. Rather than static assignment, the system adaptively routes instruction chunks to available decode clusters based on current processing state and cluster availability. This dynamic approach maximizes utilization of multiple decode clusters while simplifying coordination through centralized steering logic.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4254179A1Variable-length instruction steering to instruction decode clusters
Publication Date: 2023.10.04 INTEL CORP
  • EP4254179A1 patent drawingFigure 1
  • EP4254179A1 patent drawingFigure 2
  • EP4254179A1 patent drawingFigure 3A

AI summary

Embodiments of apparatuses and methods for variable-length instruction steering to instruction decode clusters are disclosed. In an embodiment, an apparatus includes a decode cluster and chunk steering circuitry. The decode cluster includes multiple instruction decoders. The chunk steering circuitry is to break a sequence of instruction bytes into a plurality of chunks, create a slice from a one or more of the plurality of chunks based on one or more indications of a number of instructions in each of the one or more of the plurality of chunks, wherein the slice has a variable size and includes a plurality of instructions, and steer the slice to the decode cluster.