Crate multiversed 

Attribute macros wrapping multiversion with predefined SIMD target presets.

This crate provides the #[multiversed] attribute that wraps #[multiversion::multiversion] with carefully curated target sets for each architecture.

Usage

use multiversed::multiversed;

// Use targets from enabled cargo features (default: x86-64-v3, x86-64-v4x, arm64-v2)
#[multiversed]
pub fn dot_product(a: &[f32], b: &[f32]) -> f32 {
    a.iter().zip(b).map(|(x, y)| x * y).sum()
}

// Explicit presets
#[multiversed("x86-64-v4", "arm64-v2")]
pub fn optimized_sum(data: &[f32]) -> f32 {
    data.iter().sum()
}

// Mix presets with custom raw target strings
#[multiversed("x86-64-v3", "aarch64+neon+dotprod")]
pub fn custom_targets(data: &[f32]) -> f32 {
    data.iter().sum()
}

Cargo Features (Presets)

Feature lists match the archmage token registry — the source of truth. Each feature is a complete, non-cumulative preset based on the x86-64 psABI microarchitecture levels and ARM architecture versions.

x86/x86_64

Feature	Archmage Token	Key Features	Hardware
x86-64-v2	X64V2Token	SSE4.2, POPCNT	Nehalem 2008+, Bulldozer 2011+
x86-64-v3	X64V3Token	AVX2, FMA, BMI1/2	Haswell 2013+, Zen 1 2017+
x86-64-v4	X64V4Token	AVX-512 (F/BW/DQ/VL/CD)	Skylake-X 2017+, Zen 4 2022+
x86-64-v4-modern / x86-64-v4x	X64V4xToken	+ VNNI, VBMI2, GFNI, VAES	Ice Lake 2019+, Zen 4 2022+

Note: Intel consumer CPUs (Alder Lake 12th gen through Arrow Lake) do NOT have AVX-512 due to E-core limitations. Only Xeon server, i9-X workstation, and AMD Zen 4+ have AVX-512.

aarch64

Feature	Archmage Token	Key Features	Hardware
arm64 / arm64-v2	Arm64V2Token	NEON, CRC, DotProd, FP16, AES	Cortex-A55+, Apple M1+, Graviton 2+
arm64-v3	Arm64V3Token	+ SHA3, I8MM, BF16	Cortex-A510+, Apple M2+, Graviton 3+

wasm32

Feature	Archmage Token	Notes
wasm32-simd128	Wasm128Token	No-op (multiversion elides on wasm32)

Attribute Arguments

The #[multiversed] attribute accepts:

• No arguments: Uses targets from enabled cargo features
• Preset names: "x86-64-v3", "arm64", etc.
• Raw target strings: Any string containing + is passed through as-is

Multiple arguments are comma-separated and all are included in the target list.

Attribute Macros

multiversed

Apply multiversion with SIMD target presets.