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VLIW

Very Long Instruction Word; a CPU architecture where the compiler bundles multiple independent operations into a single, very long instruction.

AbbreviationVLIW
Categoryhardware

Overview

VLIW shifts the complexity of identifying parallel instructions from the hardware (as in superscalar CPUs) to the compiler. The compiler analyzes the code and packs operations that can run in parallel into a single instruction word.

Pros and Cons

  • Pros: Simpler hardware design, lower power consumption.
  • Cons: Extremely complex compiler design; code is not binary-compatible across different VLIW implementations.

Examples

  • Intel Itanium (IA-64).
  • Many modern Digital Signal Processors (DSPs).

Related Terms

Superscalar Architecture