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Overview

VLIW (Very Long Instruction Word) and SIMD (Single Instruction, Multiple Data) are processor architecture techniques that enable parallel execution of multiple operations.

This guide covers the key concepts needed to understand and optimize for VLIW SIMD architectures.

Documents

  1. Scalar vs Vector - Understanding the difference between processing one value vs eight values at once

  2. ALU and Engines - What ALU means and the five execution engines in this architecture

  3. VLIW Architecture - How Very Long Instruction Word architectures work

  4. Instruction Set Reference - Complete list of available instructions

  5. Optimization Strategies - Techniques to reduce cycle count


Key Concepts

ConceptDescription
VLIWExplicit instruction-level parallelism scheduled by compiler/programmer
SIMDData-level parallelism via vector operations
Vector LengthNumber of elements processed simultaneously (commonly 4, 8, or 16)
Instruction BundleGroup of operations executed in one cycle

Learning Path

Start with Scalar vs Vector to understand data parallelism, then proceed through the documents in order.

Related Project

These notes were developed while studying the Anthropic Performance Take-Home challenge, which provides a hands-on way to apply these concepts.