SPUR: A Trace-Based JIT Compiler for CIL

By Nikolai Tillmann

Tracing just-in-time compilers (TJITs) determine frequently executed traces
(hot paths and loops) in running programs and focus their optimization effort
by emitting optimized machine code specialized to these traces. We designed and
implemented SPUR, a TJIT for Microsoft’s Common Intermediate Language CIL,
thereby supporting C#, VisualBasic, F#, JavaScript, many other languages, and
cross-language scenarios. To achieve best performance, SPUR does not use an
interpreter but always produces machine code, enabling tight coupling with the
garbage collector in the presence of interior pointers, and very efficient
transitions between different code versions. We are currently investigating the
use of automated theorem provers to further optimize traces, and automated code
parallelization by trace analysis.


Biography: Nikolai Tillmann is a Principal Research Software Design Engineer at
Microsoft Research. He works on combining dynamic and static program analysis
techniques. He currently leads the Pex project, a framework for runtime
verification and automatic test-case generation for .NET applications based on
parameterized unit testing and dynamic symbolic execution. Try it in your
browser at www.pexforfun.com. He also works on the Spur project, a tracing
Just-In-Time compiler for .NET and JavaScript code. Previously he worked on
AsmL, an executable modeling language, and the Spec Explorer 2004 model-based
testing tool. He co-developed XRT, a concrete/symbolic state exploration engine
and software model-checker for .NET.