Implement first D-specific optimization pass: -simplify-drtcalls. It uses the machinery of the standard -simplify-libcalls pass, but optimizes calls to the D runtime instead of calls to C libraries. At the moment, these optimizations are implemented by this pass: - Avoid the runtime call for `arr.length = newlen` if it can determine that the new length isn't longer than the old one. - Ditto for `cast(T[]) arr` if it will clearly always succeed. (e.g. if the length of the original array is zero, or if the old element size is a multiple of the new element size)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gen/passes/Passes.h	Tue Apr 28 21:58:06 2009 +0200
@@ -0,0 +1,12 @@
+#ifndef LDC_PASSES_H
+#define LDC_PASSES_H
+
+namespace llvm {
+    class FunctionPass;
+}
+
+// Performs simplifications on runtime calls.
+llvm::FunctionPass* createSimplifyDRuntimeCalls();
+
+
+#endif