MSL Assembler

A Metal Shading Language (MSL) code generator for the Gaia project, enabling cross-compilation of Gaia IR to high-performance GPU shaders for Apple's Metal framework.

🏛️ Architecture

graph TB
    subgraph "Metal Shader Generation"
        A[Gaia Module] --> B[MSL Backend Generator]
        B --> C[Instruction Mapper]
        C --> D[Source Code Emitter]
        D --> E["Metal Source (.metal)"]
        D --> F["Metal Library (.metallib)"]
        
        subgraph "Metal Context"
            G[metal_stdlib]
            H[Device/Constant Memory]
            I[Compute Kernels]
        end
        
        B --> G
        C --> H
        C --> I
    end

🚀 Features

Core Capabilities

• Direct Source Generation: Compiles Gaia IR instructions directly into readable C++14-based Metal Shading Language source code.
• Kernel Abstraction: Automatically wraps Gaia functions into kernel void entry points with standard Metal buffer arguments.
• Resource Binding: Manages the mapping of Gaia memory operands to Metal buffer indexes (e.g., device float* data [[buffer(0)]]).

Advanced Features

• Metal Library Simulation: Generates placeholder .metallib files to satisfy toolchain requirements for offline shader compilation.
• Standard Library Integration: Automatically includes <metal_stdlib> and configures the metal namespace for all generated modules.
• Unified Backend Interface: Implements the Backend trait, allowing seamless integration with the gaia-assembler orchestration layer.

💻 Usage

Generating Metal Shaders via Gaia Assembler

The following example shows how to use the MSL generator as a backend for the main assembler.

use gaia_assembler::assembler::GaiaAssembler;
use msl_assembler::MslGenerator;
use gaia_types::helpers::{Architecture, AbiCompatible, ApiCompatible, CompilationTarget};

fn main() {
    let assembler = GaiaAssembler::new();
    // Register MSL backend (usually done automatically)
    // ...

    let target = CompilationTarget {
        build: Architecture::X86_64,
        host: AbiCompatible::MSL,
        target: ApiCompatible::Metal,
    };

    // program: GaiaModule
    let generated = assembler.compile(&program, &target).expect("Metal generation failed");
    
    if let Some(source) = generated.files.get("module.metal") {
        println!("Generated MSL source:\n{}", String::from_utf8_lossy(source));
    }
}

🛠️ Support Status

Legend: ✅ Supported, 🚧 In Progress, ❌ Not Supported

🔗 Relations

• gaia-assembler: Acts as a specialized backend that plugs into the assembler's dispatcher for Metal-specific targets.
• gaia-types: Uses the CompilationTarget and Architecture definitions to ensure ABI compatibility.