1 files changed, 65 insertions, 0 deletions
diff --git a/llvm/tools/jello/VM.cpp b/llvm/tools/jello/VM.cpp
new file mode 100644
index 00000000000..497c42ef90e
--- /dev/null
+++ b/llvm/tools/jello/VM.cpp
@@ -0,0 +1,65 @@
+//===-- jello.cpp - LLVM Just in Time Compiler ----------------------------===//
+//
+// This tool implements a just-in-time compiler for LLVM, allowing direct
+// execution of LLVM bytecode in an efficient manner.
+//
+//===----------------------------------------------------------------------===//
+
+#include "VM.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/Function.h"
+#include <iostream>
+
+
+VM::~VM() {
+  delete MCE;
+}
+
+/// setupPassManager - Initialize the VM PassManager object with all of the
+/// passes needed for the target to generate code.
+///
+void VM::setupPassManager() {
+  // Compile LLVM Code down to machine code in the intermediate representation
+  if (TM.addPassesToJITCompile(PM)) {
+    std::cerr << ExeName << ": target '" << TM.getName()
+              << "' doesn't support JIT compilation!\n";
+    abort();
+  }
+
+  // Turn the machine code intermediate representation into bytes in memory that
+  // may be executed.
+  //
+  if (TM.addPassesToEmitMachineCode(PM, *MCE)) {
+    std::cerr << ExeName << ": target '" << TM.getName()
+              << "' doesn't support machine code emission!\n";
+    abort();
+  }
+}
+
+int VM::run(Function *F) {
+  int(*PF)() = (int(*)())getPointerToFunction(F);
+  assert(PF != 0 && "Null pointer to function?");
+  return PF();
+}
+
+
+/// getPointerToFunction - This method is used to get the address of the
+/// specified function, compiling it if neccesary.
+///
+void *VM::getPointerToFunction(Function *F) {
+  void *&Addr = GlobalAddress[F];   // Function already code gen'd
+  if (Addr) return Addr;
+
+  if (F->isExternal()) {
+    assert(0 && "VM::getPointerToFunction: Doesn't handle external fn's yet!");
+  }
+
+  // JIT all of the functions in the module.  Eventually this will JIT functions
+  // on demand.  This has the effect of populating all of the non-external
+  // functions into the GlobalAddress table.
+  PM.run(M);
+
+  assert(Addr && "Code generation didn't add function to GlobalAddress table!");
+  return Addr;
+}