+ The JIT engine works on Linux and Win32, although you
+ will need to install the CygWin32 development tools to get a
+ Unix-like compilation environment (mostly we use GNU make in
+ a few of the makefiles).
+
+** JIT Engine (<b>updated, July 8th, 2002</b>)
+
+ The JIT engine uses a code-generator generator approach for
+ compilation. Given the properties of CIL byte codes, we can
+ take full advantage of a real instruction selector for our
+ code generator.
+
+ The JIT engine implements a number of optimizations:
+
+ <ul>
+ * Opcode cost estimates (our architecture allows
+ us to generate different code paths depending
+ on the target CPU dynamically).
+
+ * Inlining.
+
+ * Constant folding.
+
+ Although compilers typically do
+ constant folding, the combination of inlining with
+ constant folding gives some very good results.
+
+ * Linear scan register allocation. In the past,
+ register allocation was our achilles heel, but now
+ we have left this problem behind.
+ </ul>
+
+ There are a couple of books that deal with this technique: "A
+ Retargetable C Compiler" and "Advanced Compiler Design and
+ Implementation" are good references. You can also get a
+ technical description of <a
+ href="http://research.microsoft.com/copyright/accept.asp?path=http://www.research.microsoft.com/~drh/pubs/iburg.pdf&pub=ACM">lbrug</a>.
+
+ A few papers that describe the instruction selector:
+
+ <ul>
+ * <a href="http://research.microsoft.com/copyright/accept.asp?path=http://www.research.microsoft.com/~drh/pubs/interface.pdf&pub=wiley">A code generation interface for ANSI C</a>
+
+
+ * <a href="http://research.microsoft.com/copyright/accept.asp?path=http://www.research.microsoft.com/~drh/pubs/iburg.pdf&pub=ACM">Engineering efficient code generators using tree matching and dynamic programming.</a>
+
+ </ul>
+
+** Future plans
+
+ We are evaluating the future directions for the JIT engine:
+ both from our needs (optimizations like inlining, better register allocation,
+ instruction scheduling, and porting to other CPUs).
+
+ We have not yet decided how we will evolve the JIT engine. We
+ might just upgrade our current architecture, and provide optimizations as
+ an extra layer.