diff --git a/.gitmodules b/.gitmodules
index 31ad04ace0..edfd14ccb9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -19,3 +19,6 @@
 [submodule "third_party/wxWidgets"]
 	path = third_party/wxWidgets
 	url = https://github.com/wxWidgets/wxWidgets.git
+[submodule "third_party/catch"]
+	path = third_party/catch
+	url = https://github.com/philsquared/Catch.git
diff --git a/src/alloy/frontend/ppc/ppc_translator.cc b/src/alloy/frontend/ppc/ppc_translator.cc
index b894978852..008ba8948b 100644
--- a/src/alloy/frontend/ppc/ppc_translator.cc
+++ b/src/alloy/frontend/ppc/ppc_translator.cc
@@ -10,13 +10,13 @@
 #include <alloy/frontend/ppc/ppc_translator.h>
 
 #include <alloy/alloy-private.h>
-#include <alloy/reset_scope.h>
 #include <alloy/compiler/compiler_passes.h>
 #include <alloy/frontend/ppc/ppc_disasm.h>
 #include <alloy/frontend/ppc/ppc_frontend.h>
 #include <alloy/frontend/ppc/ppc_hir_builder.h>
 #include <alloy/frontend/ppc/ppc_instr.h>
 #include <alloy/frontend/ppc/ppc_scanner.h>
+#include <alloy/reset_scope.h>
 #include <alloy/runtime/runtime.h>
 #include <xenia/profiling.h>
 
diff --git a/src/alloy/runtime/module.h b/src/alloy/runtime/module.h
index 88a1c4b94c..6bd50b6f0c 100644
--- a/src/alloy/runtime/module.h
+++ b/src/alloy/runtime/module.h
@@ -37,10 +37,10 @@ class Module {
   virtual bool ContainsAddress(uint64_t address);
 
   SymbolInfo* LookupSymbol(uint64_t address, bool wait = true);
-  SymbolInfo::Status DeclareFunction(uint64_t address,
-                                     FunctionInfo** out_symbol_info);
-  SymbolInfo::Status DeclareVariable(uint64_t address,
-                                     VariableInfo** out_symbol_info);
+  virtual SymbolInfo::Status DeclareFunction(uint64_t address,
+                                             FunctionInfo** out_symbol_info);
+  virtual SymbolInfo::Status DeclareVariable(uint64_t address,
+                                             VariableInfo** out_symbol_info);
 
   SymbolInfo::Status DefineFunction(FunctionInfo* symbol_info);
   SymbolInfo::Status DefineVariable(VariableInfo* symbol_info);
diff --git a/src/alloy/runtime/sources.gypi b/src/alloy/runtime/sources.gypi
index d1d7648b52..283b16c793 100644
--- a/src/alloy/runtime/sources.gypi
+++ b/src/alloy/runtime/sources.gypi
@@ -19,6 +19,8 @@
     'runtime.h',
     'symbol_info.cc',
     'symbol_info.h',
+    'test_module.cc',
+    'test_module.h',
     'thread_state.cc',
     'thread_state.h',
   ],
diff --git a/src/alloy/runtime/test_module.cc b/src/alloy/runtime/test_module.cc
new file mode 100644
index 0000000000..8ed7662173
--- /dev/null
+++ b/src/alloy/runtime/test_module.cc
@@ -0,0 +1,103 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <alloy/runtime/test_module.h>
+
+#include <alloy/compiler/compiler_passes.h>
+#include <alloy/reset_scope.h>
+#include <alloy/runtime/runtime.h>
+#include <poly/platform.h>
+#include <poly/string.h>
+
+namespace alloy {
+namespace runtime {
+
+using alloy::backend::Backend;
+using alloy::compiler::Compiler;
+using alloy::hir::HIRBuilder;
+using alloy::runtime::Function;
+using alloy::runtime::FunctionInfo;
+namespace passes = alloy::compiler::passes;
+
+TestModule::TestModule(Runtime* runtime, const std::string& name,
+                       std::function<bool(uint64_t)> contains_address,
+                       std::function<bool(hir::HIRBuilder&)> generate)
+    : Module(runtime),
+      name_(name),
+      contains_address_(contains_address),
+      generate_(generate) {
+  builder_.reset(new HIRBuilder());
+  compiler_.reset(new Compiler(runtime));
+  assembler_ = std::move(runtime->backend()->CreateAssembler());
+  assembler_->Initialize();
+
+  // Merge blocks early. This will let us use more context in other passes.
+  // The CFG is required for simplification and dirtied by it.
+  compiler_->AddPass(std::make_unique<passes::ControlFlowAnalysisPass>());
+  compiler_->AddPass(std::make_unique<passes::ControlFlowSimplificationPass>());
+  compiler_->AddPass(std::make_unique<passes::ControlFlowAnalysisPass>());
+
+  // Passes are executed in the order they are added. Multiple of the same
+  // pass type may be used.
+  compiler_->AddPass(std::make_unique<passes::ContextPromotionPass>());
+  compiler_->AddPass(std::make_unique<passes::SimplificationPass>());
+  compiler_->AddPass(std::make_unique<passes::ConstantPropagationPass>());
+  compiler_->AddPass(std::make_unique<passes::SimplificationPass>());
+  // compiler_->AddPass(std::make_unique<passes::DeadStoreEliminationPass>());
+  compiler_->AddPass(std::make_unique<passes::DeadCodeEliminationPass>());
+
+  //// Removes all unneeded variables. Try not to add new ones after this.
+  // compiler_->AddPass(new passes::ValueReductionPass());
+
+  // Register allocation for the target backend.
+  // Will modify the HIR to add loads/stores.
+  // This should be the last pass before finalization, as after this all
+  // registers are assigned and ready to be emitted.
+  compiler_->AddPass(std::make_unique<passes::RegisterAllocationPass>(
+      runtime->backend()->machine_info()));
+
+  // Must come last. The HIR is not really HIR after this.
+  compiler_->AddPass(std::make_unique<passes::FinalizationPass>());
+}
+
+TestModule::~TestModule() = default;
+
+bool TestModule::ContainsAddress(uint64_t address) {
+  return contains_address_(address);
+}
+
+SymbolInfo::Status TestModule::DeclareFunction(uint64_t address,
+                                               FunctionInfo** out_symbol_info) {
+  SymbolInfo::Status status = Module::DeclareFunction(address, out_symbol_info);
+  if (status == SymbolInfo::STATUS_NEW) {
+    auto symbol_info = *out_symbol_info;
+
+    // Reset() all caching when we leave.
+    make_reset_scope(compiler_);
+    make_reset_scope(assembler_);
+
+    if (!generate_(*builder_.get())) {
+      symbol_info->set_status(SymbolInfo::STATUS_FAILED);
+      return SymbolInfo::STATUS_FAILED;
+    }
+
+    compiler_->Compile(builder_.get());
+
+    Function* fn = nullptr;
+    assembler_->Assemble(symbol_info, builder_.get(), 0, nullptr, 0, &fn);
+
+    symbol_info->set_function(fn);
+    status = SymbolInfo::STATUS_DEFINED;
+    symbol_info->set_status(status);
+  }
+  return status;
+}
+
+}  // namespace runtime
+}  // namespace alloy
diff --git a/src/alloy/runtime/test_module.h b/src/alloy/runtime/test_module.h
new file mode 100644
index 0000000000..822509e408
--- /dev/null
+++ b/src/alloy/runtime/test_module.h
@@ -0,0 +1,52 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef ALLOY_RUNTIME_TEST_MODULE_H_
+#define ALLOY_RUNTIME_TEST_MODULE_H_
+
+#include <functional>
+#include <memory>
+#include <string>
+
+#include <alloy/backend/assembler.h>
+#include <alloy/compiler/compiler.h>
+#include <alloy/hir/hir_builder.h>
+#include <alloy/runtime/module.h>
+
+namespace alloy {
+namespace runtime {
+
+class TestModule : public Module {
+ public:
+  TestModule(Runtime* runtime, const std::string& name,
+             std::function<bool(uint64_t)> contains_address,
+             std::function<bool(hir::HIRBuilder&)> generate);
+  ~TestModule() override;
+
+  const std::string& name() const override { return name_; }
+
+  bool ContainsAddress(uint64_t address) override;
+
+  SymbolInfo::Status DeclareFunction(uint64_t address,
+                                     FunctionInfo** out_symbol_info) override;
+
+ private:
+  std::string name_;
+  std::function<bool(uint64_t)> contains_address_;
+  std::function<bool(hir::HIRBuilder&)> generate_;
+
+  std::unique_ptr<hir::HIRBuilder> builder_;
+  std::unique_ptr<compiler::Compiler> compiler_;
+  std::unique_ptr<backend::Assembler> assembler_;
+};
+
+}  // namespace runtime
+}  // namespace alloy
+
+#endif  // ALLOY_RUNTIME_TEST_MODULE_H_
diff --git a/third_party/catch b/third_party/catch
new file mode 160000
index 0000000000..85d33e2cbd
--- /dev/null
+++ b/third_party/catch
@@ -0,0 +1 @@
+Subproject commit 85d33e2cbd5354c36000424f823fc87707a24c3c
diff --git a/tools/alloy-test/alloy-test.cc b/tools/alloy-test/alloy-test.cc
new file mode 100644
index 0000000000..da558735a8
--- /dev/null
+++ b/tools/alloy-test/alloy-test.cc
@@ -0,0 +1,47 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#define CATCH_CONFIG_RUNNER
+#include <third_party/catch/single_include/catch.hpp>
+
+#include <tools/alloy-test/test_util.h>
+
+using namespace alloy;
+using namespace alloy::hir;
+using namespace alloy::runtime;
+using alloy::frontend::ppc::PPCContext;
+
+TEST_CASE("Meta test", "[test]") {
+  alloy::test::TestFunction test([](hir::HIRBuilder& b) {
+    auto r = b.Add(b.LoadContext(offsetof(PPCContext, r) + 5 * 8, INT64_TYPE),
+                   b.LoadContext(offsetof(PPCContext, r) + 25 * 8, INT64_TYPE));
+    b.StoreContext(offsetof(PPCContext, r) + 11 * 8, r);
+    b.Return();
+    return true;
+  });
+
+  test.Run([](PPCContext* ctx) {
+             ctx->r[5] = 10;
+             ctx->r[25] = 25;
+           },
+           [](PPCContext* ctx) {
+             auto result = ctx->r[11];
+             REQUIRE(result == 0x23);
+           });
+  test.Run([](PPCContext* ctx) {
+             ctx->r[5] = 10;
+             ctx->r[25] = 25;
+           },
+           [](PPCContext* ctx) {
+             auto result = ctx->r[11];
+             REQUIRE(result == 0x24);
+           });
+}
+
+DEFINE_ENTRY_POINT(L"alloy-test", L"?", alloy::test::main);
diff --git a/tools/alloy-test/alloy-test.gypi b/tools/alloy-test/alloy-test.gypi
new file mode 100644
index 0000000000..36de70cd8d
--- /dev/null
+++ b/tools/alloy-test/alloy-test.gypi
@@ -0,0 +1,29 @@
+# Copyright 2014 Ben Vanik. All Rights Reserved.
+{
+  'targets': [
+    {
+      'target_name': 'alloy-test',
+      'type': 'executable',
+
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'SubSystem': '1'
+        },
+      },
+
+      'dependencies': [
+        'alloy',
+        'xenia',
+      ],
+
+      'include_dirs': [
+        '.',
+      ],
+
+      'sources': [
+        'alloy-test.cc',
+        'test_util.h',
+      ],
+    },
+  ],
+}
diff --git a/tools/alloy-test/test_util.h b/tools/alloy-test/test_util.h
new file mode 100644
index 0000000000..34f4964b4a
--- /dev/null
+++ b/tools/alloy-test/test_util.h
@@ -0,0 +1,148 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef ALLOY_TEST_TEST_UTIL_H_
+#define ALLOY_TEST_TEST_UTIL_H_
+
+#include <alloy/alloy.h>
+#include <alloy/backend/ivm/ivm_backend.h>
+#include <alloy/backend/x64/x64_backend.h>
+#include <alloy/frontend/ppc/ppc_context.h>
+#include <alloy/frontend/ppc/ppc_frontend.h>
+#include <alloy/hir/hir_builder.h>
+#include <alloy/runtime/test_module.h>
+#include <poly/main.h>
+#include <poly/poly.h>
+
+#include <third_party/catch/single_include/catch.hpp>
+
+namespace alloy {
+namespace test {
+
+using alloy::frontend::ppc::PPCContext;
+using alloy::runtime::Runtime;
+
+int main(std::vector<std::wstring>& args) {
+  std::vector<std::string> narrow_args;
+  auto narrow_argv = new char* [args.size()];
+  for (size_t i = 0; i < args.size(); ++i) {
+    auto narrow_arg = poly::to_string(args[i]);
+    narrow_argv[i] = const_cast<char*>(narrow_arg.data());
+    narrow_args.push_back(std::move(narrow_arg));
+  }
+  return Catch::Session().run(int(args.size()), narrow_argv);
+}
+
+class ThreadState : public alloy::runtime::ThreadState {
+ public:
+  ThreadState(Runtime* runtime, uint32_t thread_id, uint64_t stack_address,
+              size_t stack_size, uint64_t thread_state_address)
+      : alloy::runtime::ThreadState(runtime, thread_id),
+        stack_address_(stack_address),
+        stack_size_(stack_size),
+        thread_state_address_(thread_state_address) {
+    memset(memory_->Translate(stack_address_), 0, stack_size_);
+
+    // Allocate with 64b alignment.
+    context_ = (PPCContext*)calloc(1, sizeof(PPCContext));
+    assert_true((reinterpret_cast<uint64_t>(context_) & 0xF) == 0);
+
+    // Stash pointers to common structures that callbacks may need.
+    context_->reserve_address = memory_->reserve_address();
+    context_->membase = memory_->membase();
+    context_->runtime = runtime;
+    context_->thread_state = this;
+
+    // Set initial registers.
+    context_->r[1] = stack_address_ + stack_size;
+    context_->r[13] = thread_state_address_;
+
+    // Pad out stack a bit, as some games seem to overwrite the caller by about
+    // 16 to 32b.
+    context_->r[1] -= 64;
+
+    raw_context_ = context_;
+
+    runtime_->debugger()->OnThreadCreated(this);
+  }
+  ~ThreadState() override {
+    runtime_->debugger()->OnThreadDestroyed(this);
+    free(context_);
+  }
+
+  PPCContext* context() const { return context_; }
+
+ private:
+  uint64_t stack_address_;
+  size_t stack_size_;
+  uint64_t thread_state_address_;
+
+  // NOTE: must be 64b aligned for SSE ops.
+  PPCContext* context_;
+};
+
+class TestFunction {
+ public:
+  TestFunction(std::function<bool(hir::HIRBuilder& b)> generator) {
+    memory_size = 16 * 1024 * 1024;
+    memory.reset(new SimpleMemory(memory_size));
+    runtime.reset(new Runtime(memory.get()));
+
+    auto frontend =
+        std::make_unique<alloy::frontend::ppc::PPCFrontend>(runtime.get());
+    std::unique_ptr<alloy::backend::Backend> backend;
+    // backend =
+    //     std::make_unique<alloy::backend::ivm::IVMBackend>(runtime.get());
+    // backend =
+    //     std::make_unique<alloy::backend::x64::X64Backend>(runtime.get());
+    runtime->Initialize(std::move(frontend), std::move(backend));
+
+    auto module = std::make_unique<alloy::runtime::TestModule>(
+        runtime.get(), "Test",
+        [](uint64_t address) { return address == 0x1000; },
+        [generator](hir::HIRBuilder& b) { return generator(b); });
+    runtime->AddModule(std::move(module));
+
+    runtime->ResolveFunction(0x1000, &fn);
+  }
+
+  ~TestFunction() {
+    runtime.reset();
+    memory.reset();
+  }
+
+  void Run(std::function<void(PPCContext*)> pre_call,
+           std::function<void(PPCContext*)> post_call) {
+    memory->Zero(0, memory_size);
+
+    uint64_t stack_size = 64 * 1024;
+    uint64_t stack_address = memory_size - stack_size;
+    uint64_t thread_state_address = stack_address - 0x1000;
+    auto thread_state = std::make_unique<ThreadState>(
+        runtime.get(), 100, stack_address, stack_size, thread_state_address);
+    auto ctx = thread_state->context();
+    ctx->lr = 0xBEBEBEBE;
+
+    pre_call(ctx);
+
+    fn->Call(thread_state.get(), ctx->lr);
+
+    post_call(ctx);
+  }
+
+  size_t memory_size;
+  std::unique_ptr<Memory> memory;
+  std::unique_ptr<Runtime> runtime;
+  alloy::runtime::Function* fn;
+};
+
+}  // namespace test
+}  // namespace alloy
+
+#endif  // ALLOY_TEST_TEST_UTIL_H_
diff --git a/tools/tools.gypi b/tools/tools.gypi
index 3e6a56ffdb..26b5fba732 100644
--- a/tools/tools.gypi
+++ b/tools/tools.gypi
@@ -2,6 +2,7 @@
 {
   'includes': [
     'alloy-sandbox/alloy-sandbox.gypi',
+    'alloy-test/alloy-test.gypi',
     'xenia-compare/xenia-compare.gypi',
     'xenia-debug/xenia-debug.gypi',
     'xenia-run/xenia-run.gypi',