Language Standards

WebAssembly Standard

• https://webassembly.github.io/spec/core/

WebAssembly-JavaScript API Standard

• https://webassembly.github.io/spec/js-api/index.html

WASI (WebAssembly System Interface) API

• https://github.com/WebAssembly/WASI

Test Suites

• WebAssembly/spec
  • https://github.com/WebAssembly/spec/tree/main/test
• WebAssembly/testsuite
  • https://github.com/WebAssembly/testsuite
• WebAssembly/testsuite-js (JS API)
  • https://github.com/WebAssembly/testsuite-js

Current Issues

1. Code Duplication from Memory64 Support

• Excessive class duplication in ByteCode.h
• Increased code size and reduced maintainability
• Solution: introduce base classes and helper macros
• Refactor incrementally

2. Excessive Stack Usage in Debug Mode

• interpret() uses ~8KB stack (vs. a few hundred bytes in release)
• Problematic for recursive call tests
• Cause: too many local variables with no stack slot reuse
• Solution: reuse variables for uint32/uint64 indices and offsets

3. Missing WASI Preview1 Functions

• Many WASI Preview1 APIs are not implemented
• Low complexity (mainly interface additions)
• Can be implemented quickly

4. Apple Clang Optimization Breaking Bytecode Mapping

• Compiler merges interpreter loop paths
• Breaks computed goto → bytecode mapping
• Critical issue for JIT compilation
• Current workaround: swap src/dst operands in some bytecodes
• Required actions:
  • Verify the issue is fully resolved
  • Add release assert to prevent regression

Optimizations

Interpreter-JIT Hybrid Runtime Execution

• Use interpretation for cold functions and JIT compilation for hot functions