SpawnDev.ILGPU.WebGPU

Run ILGPU kernels directly in the browser using WebGPU!

SpawnDev.ILGPU.WebGPU is a WebGPU backend for ILGPU that enables GPU-accelerated compute in Blazor WebAssembly applications. Write your GPU kernels once in C# and run them on any WebGPU-capable browser.

Features

• ILGPU-compatible - Use familiar ILGPU APIs (ArrayView, Index1D/2D/3D, math intrinsics, etc.)
• WGSL transpilation - C# kernels are automatically compiled to WebGPU Shading Language (WGSL)
• Blazor WebAssembly - Seamless integration via SpawnDev.BlazorJS
• Shared memory & atomics - Supports workgroup shared memory, barriers, and atomic operations
• No native dependencies - Entirely written in C#

Installation

dotnet add package SpawnDev.ILGPU.WebGPU

Quick Start

using ILGPU;
using ILGPU.Runtime;
using SpawnDev.ILGPU.WebGPU;

// Initialize ILGPU context with WebGPU backend
var builder = Context.Create();
await builder.WebGPUAsync();
using var context = builder.ToContext();

// Get WebGPU device and create accelerator
var devices = context.GetWebGPUDevices();
var device = devices[0];
using var accelerator = await device.CreateAcceleratorAsync(context);

// Allocate buffers
int length = 64;
var a = Enumerable.Range(0, length).Select(i => (float)i).ToArray();
var b = Enumerable.Range(0, length).Select(i => (float)i * 2.0f).ToArray();

using var bufA = accelerator.Allocate1D(a);
using var bufB = accelerator.Allocate1D(b);
using var bufC = accelerator.Allocate1D<float>(length);

// Load and execute kernel
var kernel = accelerator.LoadAutoGroupedStreamKernel<Index1D, ArrayView<float>, ArrayView<float>, ArrayView<float>>(VectorAddKernel);
kernel((Index1D)length, bufA.View, bufB.View, bufC.View);

// Wait for GPU to complete (async required in Blazor WASM)
await accelerator.SynchronizeAsync();

// Define the kernel
static void VectorAddKernel(Index1D index, ArrayView<float> a, ArrayView<float> b, ArrayView<float> c)
{
    c[index] = a[index] + b[index];
}

Demo Application

The demo application is located in SpawnDev.ILGPU.WebGPU.Demo and showcases:

• GPU compute tasks running in Blazor WebAssembly
• Interactive Mandelbrot renderer
• Comprehensive unit tests at /tests

Running the Demo

cd SpawnDev.ILGPU.WebGPU.Demo
dotnet run

Navigate to https://localhost:5181 in a WebGPU-capable browser (Chrome, Edge, or Firefox Nightly).

Testing

Browser Tests

Start the demo app and navigate to /tests to run the unit test suite.

Automated Tests (Playwright)

# Windows
_test.bat

# Linux/macOS
./_test.sh

The PlaywrightTestRunner runs tests in a headless browser. To view the browser during tests, uncomment Environment.SetEnvironmentVariable("HEADED", "1"); in PlaywrightTestRunner/GlobalSetup.cs.

Browser Requirements

WebGPU is required. Supported browsers:

• Chrome 113+
• Edge 113+
• Firefox Nightly (with dom.webgpu.enabled flag)

Known Limitations

• Some advanced ILGPU features may not yet be supported
• Subgroups extension not available in all browsers
• Dynamic shared memory requires Pipeline Overridable Constants (not yet implemented)

Async Synchronization

In Blazor WebAssembly, the main thread cannot block. Use SynchronizeAsync() instead of Synchronize():

// ❌ Don't use - non-blocking in Blazor WASM
accelerator.Synchronize();

// ✅ Use async version
await accelerator.SynchronizeAsync();

The standard Synchronize() method will log a warning and return immediately without waiting.

License

This project is licensed under the same terms as ILGPU. See LICENSE for details.

Resources

• ILGPU Documentation
• WebGPU Specification
• SpawnDev.BlazorJS