diff --git a/tools/llvm-diff/llvm-diff.cpp b/tools/llvm-diff/llvm-diff.cpp
index b932ccc..76853f1 100644
--- a/tools/llvm-diff/llvm-diff.cpp
+++ b/tools/llvm-diff/llvm-diff.cpp
@@ -11,9 +11,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "DiffLog.h"
 #include "DifferenceEngine.h"
 
-#include "llvm/Instructions.h"
 #include "llvm/LLVMContext.h"
 #include "llvm/Module.h"
 #include "llvm/Type.h"
@@ -21,7 +21,6 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/CommandLine.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/IRReader.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
@@ -43,221 +42,6 @@
   return M;
 }
 
-namespace {
-  struct DiffContext {
-    DiffContext(Value *L, Value *R)
-      : L(L), R(R), Differences(false), IsFunction(isa<Function>(L)) {}
-    Value *L;
-    Value *R;
-    bool Differences;
-    bool IsFunction;
-    DenseMap<Value*,unsigned> LNumbering;
-    DenseMap<Value*,unsigned> RNumbering;
-  };
-}
-
-static void ComputeNumbering(Function *F, DenseMap<Value*,unsigned> &Numbering){
-  unsigned IN = 0;
-
-  // Arguments get the first numbers.
-  for (Function::arg_iterator
-         AI = F->arg_begin(), AE = F->arg_end(); AI != AE; ++AI)
-    if (!AI->hasName())
-      Numbering[&*AI] = IN++;
-
-  // Walk the basic blocks in order.
-  for (Function::iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI) {
-    if (!FI->hasName())
-      Numbering[&*FI] = IN++;
-
-    // Walk the instructions in order.
-    for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ++BI)
-      // void instructions don't get numbers.
-      if (!BI->hasName() && !BI->getType()->isVoidTy())
-        Numbering[&*BI] = IN++;
-  }
-
-  assert(!Numbering.empty() && "asked for numbering but numbering was no-op");
-}
-
-namespace {
-class DiffConsumer : public DifferenceEngine::Consumer {
-private:
-  raw_ostream &out;
-  Module *LModule;
-  Module *RModule;
-  SmallVector<DiffContext, 5> contexts;
-  bool Differences;
-  unsigned Indent;
-
-  void printValue(Value *V, bool isL) {
-    if (V->hasName()) {
-      out << (isa<GlobalValue>(V) ? '@' : '%') << V->getName();
-      return;
-    }
-    if (V->getType()->isVoidTy()) {
-      if (isa<StoreInst>(V)) {
-        out << "store to ";
-        printValue(cast<StoreInst>(V)->getPointerOperand(), isL);
-      } else if (isa<CallInst>(V)) {
-        out << "call to ";
-        printValue(cast<CallInst>(V)->getCalledValue(), isL);
-      } else if (isa<InvokeInst>(V)) {
-        out << "invoke to ";
-        printValue(cast<InvokeInst>(V)->getCalledValue(), isL);
-      } else {
-        out << *V;
-      }
-      return;
-    }
-
-    unsigned N = contexts.size();
-    while (N > 0) {
-      --N;
-      DiffContext &ctxt = contexts[N];
-      if (!ctxt.IsFunction) continue;
-      if (isL) {
-        if (ctxt.LNumbering.empty())
-          ComputeNumbering(cast<Function>(ctxt.L), ctxt.LNumbering);
-        out << '%' << ctxt.LNumbering[V];
-        return;
-      } else {
-        if (ctxt.RNumbering.empty())
-          ComputeNumbering(cast<Function>(ctxt.R), ctxt.RNumbering);
-        out << '%' << ctxt.RNumbering[V];
-        return;
-      }
-    }
-
-    out << "<anonymous>";
-  }
-
-  void header() {
-    if (contexts.empty()) return;
-    for (SmallVectorImpl<DiffContext>::iterator
-           I = contexts.begin(), E = contexts.end(); I != E; ++I) {
-      if (I->Differences) continue;
-      if (isa<Function>(I->L)) {
-        // Extra newline between functions.
-        if (Differences) out << "\n";
-
-        Function *L = cast<Function>(I->L);
-        Function *R = cast<Function>(I->R);
-        if (L->getName() != R->getName())
-          out << "in function " << L->getName()
-              << " / " << R->getName() << ":\n";
-        else
-          out << "in function " << L->getName() << ":\n";
-      } else if (isa<BasicBlock>(I->L)) {
-        BasicBlock *L = cast<BasicBlock>(I->L);
-        BasicBlock *R = cast<BasicBlock>(I->R);
-        if (L->hasName() && R->hasName() && L->getName() == R->getName())
-          out << "  in block %" << L->getName() << ":\n";
-        else {
-          out << "  in block ";
-          printValue(L, true);
-          out << " / ";
-          printValue(R, false);
-          out << ":\n";
-        }
-      } else if (isa<Instruction>(I->L)) {
-        out << "    in instruction ";
-        printValue(I->L, true);
-        out << " / ";
-        printValue(I->R, false);
-        out << ":\n";
-      }
-
-      I->Differences = true;
-    }
-  }
-
-  void indent() {
-    unsigned N = Indent;
-    while (N--) out << ' ';
-  }
-
-public:
-  DiffConsumer(Module *L, Module *R)
-    : out(errs()), LModule(L), RModule(R), Differences(false), Indent(0) {}
-
-  bool hadDifferences() const { return Differences; }
-
-  void enterContext(Value *L, Value *R) {
-    contexts.push_back(DiffContext(L, R));
-    Indent += 2;
-  }
-  void exitContext() {
-    Differences |= contexts.back().Differences;
-    contexts.pop_back();
-    Indent -= 2;
-  }
-
-  void log(StringRef text) {
-    header();
-    indent();
-    out << text << '\n';
-  }
-
-  void logf(const DifferenceEngine::LogBuilder &Log) {
-    header();
-    indent();
-
-    unsigned arg = 0;
-
-    StringRef format = Log.getFormat();
-    while (true) {
-      size_t percent = format.find('%');
-      if (percent == StringRef::npos) {
-        out << format;
-        break;
-      }
-      assert(format[percent] == '%');
-
-      if (percent > 0) out << format.substr(0, percent);
-
-      switch (format[percent+1]) {
-      case '%': out << '%'; break;
-      case 'l': printValue(Log.getArgument(arg++), true); break;
-      case 'r': printValue(Log.getArgument(arg++), false); break;
-      default: llvm_unreachable("unknown format character");
-      }
-
-      format = format.substr(percent+2);
-    }
-
-    out << '\n';
-  }
-
-  void logd(const DifferenceEngine::DiffLogBuilder &Log) {
-    header();
-
-    for (unsigned I = 0, E = Log.getNumLines(); I != E; ++I) {
-      indent();
-      switch (Log.getLineKind(I)) {
-      case DifferenceEngine::DC_match:
-        out << "  ";
-        Log.getLeft(I)->dump();
-        //printValue(Log.getLeft(I), true);
-        break;
-      case DifferenceEngine::DC_left:
-        out << "< ";
-        Log.getLeft(I)->dump();
-        //printValue(Log.getLeft(I), true);
-        break;
-      case DifferenceEngine::DC_right:
-        out << "> ";
-        Log.getRight(I)->dump();
-        //printValue(Log.getRight(I), false);
-        break;
-      }
-      //out << "\n";
-    }
-  }
-  
-};
-} // end anonymous namespace
-
 static void diffGlobal(DifferenceEngine &Engine, Module *L, Module *R,
                        StringRef Name) {
   // Drop leading sigils from the global name.