ARM ISA

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Helium or M-Profile Vector Extension (MVE) is an optional vector architectural extension introduced as part of the ARMv8.1-M architecture. Implementations that include MVE also include the DSP extension.

Overview

The M-Profile Vector Extension (MVE) is a vector architectural extension introduced by Arm as part of the ARMv8.1-M architecture. For Arm Cortex-M processors, MVE goes by the brand name Helium. The extension is optional and heavily repurposes the FPU extension in order to maximize the implementation area and power. MVE was introduced in order to enable more efficient DSP-like operations on the Cortex-M family of cores.

MVE instructions comes in two distinct flavors: MVE-I and MVE-F:

• MVE-I operates on 32-bit, 16-bit, and 8-bit data types
• MVE-F operates on half-precision and single-precision floating-point values

All vector instructions operate on a fixed vector width of 128 bits. It's worth pointing out that MVE-I instructions can be implemented with or without the MVE-F scalar floating-point extension.