This project is part of the @thi.ng/umbrella monorepo and anti-framework.
WebAssembly SIMD vector operations for array/batch processing, written in AssemblyScript. These functions use the CPU's vector instructions to process 128bit words at once, which is the equivalent width of a 4D vector with 4x 32bit components. Several of the provided functions can also be used to process 2D vectors.
See /assembly for sources:
abs4_f32
add4_f32
addn4_f32
clamp4_f32
clampn4_f32
div4_f32
divn4_f32
dot2_f32_aos
(2)dot4_f32_aos
dot4_f32_soa
invsqrt4_f32
madd4_f32
maddn4_f32
mag2_f32_aos
mag4_f32_aos
magsq2_f32_aos
magsq4_f32_aos
max4_f32
min4_f32
mix4_f32
mixn4_f32
msub4_f32
msubn4_f32
mul4_f32
muln4_f32
mul_m22v2_aos
(2)mul_m23v2_aos
(2)mul_m44v4_aos
neg4_f32
normalize2_f32_aos
(2)normalize4_f32_aos
sqrt4_f32
sub4_f32
subn4_f32
sum4_f32
swizzle4_32
(f32 and u32)
(2) 2x vec2 per iteration
Also see src/api.ts for documentation about the exposed TS/JS API...
ALPHA - bleeding edge / work-in-progress
Search or submit any issues for this package
The WebAssembly SIMD spec is still WIP and (at the time of writing) only partially implemented and hidden behind feature flags. Currently only fully tested (& testable for me) on Node 14.6+.
- SIMD implementation status
- Node (v12.10+):
node --experimental-wasm-simd
- Chrome: Enable SIMD support via chrome://flags
Due to the opcode renumbering of SIMD operations proposed in April 2020, the WASM module will only work on engines released after 2020-05-21 when that change was committed to the WASM spec. For NodeJS this means only v14.6.0 or newer will be supported. This was an external change and outside our control...
- @thi.ng/malloc - ArrayBuffer based malloc() impl for hybrid JS/WASM use cases, based on thi.ng/tinyalloc
- @thi.ng/soa - SOA & AOS memory mapped structured views with optional & extensible serialization
- @thi.ng/vectors - Optimized 2d/3d/4d and arbitrary length vector operations, support for memory mapping/layouts
- @thi.ng/vector-pools - Data structures for managing & working with strided, memory mapped vectors
yarn add @thi.ng/simd
ES module import:
<script type="module" src="https://cdn.skypack.dev/@thi.ng/simd"></script>
For Node.js REPL:
const simd = await import("@thi.ng/simd");
Package sizes (brotli'd, pre-treeshake): ESM: 2.16 KB
import { init } from "@thi.ng/simd";
// the WASM module doesn't specify any own memory and it must be provided by user
// the returned object contains all available vector functions & memory views
// (an error will be thrown if WASM isn't available or SIMD unsupported)
const simd = init(new WebAssembly.Memory({ initial: 1 }));
// input data: 3x vec4 buffers
const a = simd.f32.subarray(0, 4);
const b = simd.f32.subarray(4, 16);
const out = simd.f32.subarray(16, 18);
a.set([1, 2, 3, 4])
b.set([10, 20, 30, 40, 40, 30, 20, 10]);
// compute dot products: dot(A[i], B[i])
// by using 0 as stride for A, all dot products are using the same vec
simd.dot4_f32_aos(
out.byteOffset, // output addr / pointer
a.byteOffset, // vector A addr
b.byteOffset, // vector B addr
2, // number of vectors to process
1, // output stride (floats)
0, // A stride (floats)
4 // B stride (floats)
);
// results for [dot(a0, b0), dot(a0, b1)]
out
// [300, 200]
// mat4 * vec4 matrix-vector multiplies
const mat = simd.f32.subarray(0, 16);
const points = simd.f32.subarray(16, 24);
// mat4 (col major)
mat.set([
10, 0, 0, 0,
0, 20, 0, 0,
0, 0, 30, 0,
100, 200, 300, 1
]);
// vec4 array
points.set([
1, 2, 3, 1,
4, 5, 6, 1,
]);
simd.mul_m44v4_aos(
points.byteOffset, // output addr / pointer
mat.byteOffset, // mat4 addr
points.byteOffset, // vec4 addr
2, // number of vectors to process
4, // output stride (float)
4 // vec stride (float)
);
// transformed points
points
// [110, 240, 390, 1, 140, 300, 480, 1]
If this project contributes to an academic publication, please cite it as:
@misc{thing-simd,
title = "@thi.ng/simd",
author = "Karsten Schmidt",
note = "https://thi.ng/simd",
year = 2019
}
© 2019 - 2023 Karsten Schmidt // Apache License 2.0