Compiler-Guaranteed Safety in Code-Copying Virtual Machines

1 Virtual Machine authors face a difficult choice between low performance, cheap interpreters, or specialized and costly compilers. A method able to bridge this wide gap is the existing code-copying technique that reuses chunks of the VM's binary code to create a simple JIT. This technique is not reliable without a compiler guaranteeing that copied chunks are still functionally equivalent despite aggressive optimizations. We present a proof-of-concept, minimal-impact modification of a highly optimizing compiler, GCC. A VM programmer marks chunks of VM source code as copyable. The chunks of native code resulting from compilation of the marked source become addressable and self-contained. Chunks can be safely copied at VM runtime, concatenated and executed together. This allows code-copying VMs to safely achieve speedup up to

• Type: Conference
• Year: 2008
• Where: CC
• Authors: Gregory B. Prokopski, Clark Verbrugge
• Keywords: CC 2008, Programmer Marks Chunks, System Software, VM Source Code, VM's Binary Code