[wasm] Implement an interpreter for WASM.

test/cctest/wasm/wasm-run-utils.h

Index: test/cctest/wasm/wasm-run-utils.h
diff --git a/test/cctest/wasm/wasm-run-utils.h b/test/cctest/wasm/wasm-run-utils.h
index c0747b44c4f490bf234b3bb805b0dad615ecbe46..436dab88d079810e603b6694e6c15f81b80c4a74 100644
--- a/test/cctest/wasm/wasm-run-utils.h
+++ b/test/cctest/wasm/wasm-run-utils.h
@@ -9,6 +9,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "src/base/accounting-allocator.h"
 #include "src/base/utils/random-number-generator.h"
 
 #include "src/compiler/graph-visualizer.h"
@@ -20,6 +21,7 @@
 #include "src/compiler/zone-pool.h"
 
 #include "src/wasm/ast-decoder.h"
+#include "src/wasm/wasm-interpreter.h"
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-macro-gen.h"
 #include "src/wasm/wasm-module.h"
@@ -39,6 +41,9 @@
 #endif
 
 static const uint32_t kMaxFunctions = 10;
+#define WASM_INTERPRETER 1

[Clemens Hammacher, 2016/05/24 12:47:03]

This can be removed now.

[titzer, 2016/05/24 14:50:48]

Done.

+
+enum WasmExecutionMode { kExecuteInterpreted, kExecuteCompiled };
 
 // TODO(titzer): check traps more robustly in tests.
 // Currently, in tests, we just return 0xdeadbeef from the function in which
@@ -72,10 +77,14 @@ const uint32_t kMaxGlobalsSize = 128;
 // {WasmModuleInstance}.
 class TestingModule : public ModuleEnv {
  public:
-  TestingModule()
-      : instance_(&module_),
+  explicit TestingModule(WasmExecutionMode mode = kExecuteCompiled)
+      : execution_mode_(mode),
+        instance_(&module_),
         isolate_(CcTest::InitIsolateOnce()),
-        global_offset(0) {
+        global_offset(0),
+        interpreter_(mode == kExecuteInterpreted
+                         ? new WasmInterpreter(&instance_, &allocator_)
+                         : nullptr) {
     module = &module_;
     instance = &instance_;
     instance->module = &module_;
@@ -92,6 +101,7 @@ class TestingModule : public ModuleEnv {
     if (instance->mem_start) {
       free(instance->mem_start);
     }
+    if (interpreter_) delete interpreter_;
   }
 
   byte* AddMemory(size_t size) {
@@ -172,6 +182,11 @@ class TestingModule : public ModuleEnv {
     uint32_t index = static_cast<uint32_t>(module->functions.size());
     module->functions.push_back({sig, index, 0, 0, 0, 0, 0, false});
     instance->function_code.push_back(code);
+    WasmFunction* function = &module->functions.back();

[Clemens Hammacher, 2016/05/24 12:47:03]

This can be moved inside the if.

[titzer, 2016/05/24 14:50:48]

Done.

+    if (interpreter_) {
+      int interpreter_index = interpreter_->AddFunctionForTesting(function);
+      CHECK_EQ(index, static_cast<uint32_t>(interpreter_index));
+    }
     DCHECK_LT(index, kMaxFunctions);  // limited for testing.
     return index;
   }
@@ -224,12 +239,18 @@ class TestingModule : public ModuleEnv {
     }
   }
 
+  WasmInterpreter* interpreter() { return interpreter_; }
+  WasmExecutionMode execution_mode() { return execution_mode_; }
+
  private:
+  WasmExecutionMode execution_mode_;
   WasmModule module_;
   WasmModuleInstance instance_;
   Isolate* isolate_;
+  v8::base::AccountingAllocator allocator_;
   uint32_t global_offset;
   V8_ALIGNED(8) byte global_data[kMaxGlobalsSize];  // preallocated global data.
+  WasmInterpreter* interpreter_;
 
   WasmGlobal* AddGlobal(MachineType mem_type) {
     byte size = WasmOpcodes::MemSize(mem_type);
@@ -408,14 +429,41 @@ class WasmFunctionWrapper : public HandleAndZoneScope,
 // A helper for compiling WASM functions for testing. This class can create a
 // standalone function if {module} is NULL or a function within a
 // {TestingModule}. It contains the internal state for compilation (i.e.
-// TurboFan graph) and, later, interpretation.
+// TurboFan graph) and interpretation (by adding to the interpreter manually).
 class WasmFunctionCompiler : public HandleAndZoneScope,
                              private GraphAndBuilders {
  public:
   explicit WasmFunctionCompiler(
+      FunctionSig* sig, WasmExecutionMode mode,
+      Vector<const char> debug_name = ArrayVector("<WASM UNNAMED>"))
+      : GraphAndBuilders(main_zone()),
+        execution_mode_(mode),
+        jsgraph(this->isolate(), this->graph(), this->common(), nullptr,
+                nullptr, this->machine()),
+        sig(sig),
+        descriptor_(nullptr),
+        testing_module_(nullptr),
+        debug_name_(debug_name),
+        local_decls(main_zone(), sig),
+        source_position_table_(this->graph()),
+        interpreter_(nullptr) {
+    // Create our own function.
+    function_ = new WasmFunction();
+    function_->sig = sig;
+    function_->func_index = 0;
+    function_->sig_index = 0;
+    if (mode == kExecuteInterpreted) {
+      interpreter_ = new WasmInterpreter(nullptr, zone()->allocator());
+      int index = interpreter_->AddFunctionForTesting(function_);
+      CHECK_EQ(0, index);
+    }
+  }
+
+  explicit WasmFunctionCompiler(
       FunctionSig* sig, TestingModule* module,
       Vector<const char> debug_name = ArrayVector("<WASM UNNAMED>"))
       : GraphAndBuilders(main_zone()),
+        execution_mode_(module->execution_mode()),
         jsgraph(this->isolate(), this->graph(), this->common(), nullptr,
                 nullptr, this->machine()),
         sig(sig),
@@ -423,23 +471,20 @@ class WasmFunctionCompiler : public HandleAndZoneScope,
         testing_module_(module),
         debug_name_(debug_name),
         local_decls(main_zone(), sig),
-        source_position_table_(this->graph()) {
-    if (module) {
-      // Get a new function from the testing module.
-      function_ = nullptr;
-      function_index_ = module->AddFunction(sig, Handle<Code>::null());
-    } else {
-      // Create our own function.
-      function_ = new WasmFunction();
-      function_->sig = sig;
-      function_index_ = 0;
-    }
+        source_position_table_(this->graph()),
+        interpreter_(module->interpreter()) {
+    // Get a new function from the testing module.
+    int index = module->AddFunction(sig, Handle<Code>::null());
+    function_ = &testing_module_->module->functions[index];
   }
 
   ~WasmFunctionCompiler() {
-    if (function_) delete function_;
+    if (testing_module_) return;  // testing module owns the below things.
+    delete function_;
+    if (interpreter_) delete interpreter_;
   }
 
+  WasmExecutionMode execution_mode_;
   JSGraph jsgraph;
   FunctionSig* sig;
   // The call descriptor is initialized when the function is compiled.
@@ -447,9 +492,9 @@ class WasmFunctionCompiler : public HandleAndZoneScope,
   TestingModule* testing_module_;
   Vector<const char> debug_name_;
   WasmFunction* function_;
-  int function_index_;
   LocalDeclEncoder local_decls;
   SourcePositionTable source_position_table_;
+  WasmInterpreter* interpreter_;
 
   Isolate* isolate() { return main_isolate(); }
   Graph* graph() const { return main_graph_; }
@@ -462,13 +507,17 @@ class WasmFunctionCompiler : public HandleAndZoneScope,
     }
   }
   CallDescriptor* descriptor() { return descriptor_; }
+  int function_index() { return static_cast<int>(function_->func_index); }

[Clemens Hammacher, 2016/05/24 12:47:03]

You could use this function in all the code below.

[titzer, 2016/05/24 14:50:47]

Done.

 
   void Build(const byte* start, const byte* end) {
     // Build the TurboFan graph.
-    local_decls.Prepend(&start, &end);
+    local_decls.Prepend(main_zone(), &start, &end);
     TestBuildingGraph(main_zone(), &jsgraph, testing_module_, sig,
                       &source_position_table_, start, end);
-    delete[] start;
+    if (interpreter_) {
+      // Add the code to the interpreter.
+      CHECK(interpreter_->SetFunctionCodeForTesting(function_, start, end));
+    }
   }
 
   byte AllocateLocal(LocalType type) {
@@ -494,13 +543,14 @@ class WasmFunctionCompiler : public HandleAndZoneScope,
 
     Handle<Code> code = info.code();
 
-    // Length is always 2, since usually <wasm_obj, func_index> is stored in the
+    // Length is always 2, since usually <wasm_obj, func_index> is stored in
+    // the

[Clemens Hammacher, 2016/05/24 12:47:03]

Huh, what happened here? The "the" should still fit in the first line.

[ahaas, 2016/05/24 14:48:27]

Fix the line break.

[titzer, 2016/05/24 14:50:48]

Done.

     // deopt data. Here, we only store the function index.
     DCHECK(code->deoptimization_data() == nullptr ||
            code->deoptimization_data()->length() == 0);
     Handle<FixedArray> deopt_data =
         isolate()->factory()->NewFixedArray(2, TENURED);
-    deopt_data->set(1, Smi::FromInt(function_index_));
+    deopt_data->set(1, Smi::FromInt(function_->func_index));
     deopt_data->set_length(2);
     code->set_deoptimization_data(*deopt_data);
 
@@ -516,15 +566,10 @@ class WasmFunctionCompiler : public HandleAndZoneScope,
 
   uint32_t CompileAndAdd(uint16_t sig_index = 0) {
     CHECK(testing_module_);
-    function()->sig_index = sig_index;
+    function_->sig_index = sig_index;
     Handle<Code> code = Compile();
-    testing_module_->SetFunctionCode(function_index_, code);
-    return static_cast<uint32_t>(function_index_);
-  }
-
-  WasmFunction* function() {
-    if (function_) return function_;
-    return &testing_module_->module->functions[function_index_];
+    testing_module_->SetFunctionCode(function_->func_index, code);
+    return static_cast<uint32_t>(function_->func_index);
   }
 
   // Set the context, such that e.g. runtime functions can be called.
@@ -543,7 +588,8 @@ class WasmFunctionCompiler : public HandleAndZoneScope,
 template <typename ReturnType>
 class WasmRunner {
  public:
-  WasmRunner(MachineType p0 = MachineType::None(),
+  WasmRunner(WasmExecutionMode execution_mode,
+             MachineType p0 = MachineType::None(),
              MachineType p1 = MachineType::None(),
              MachineType p2 = MachineType::None(),
              MachineType p3 = MachineType::None())
@@ -551,7 +597,7 @@ class WasmRunner {
         compiled_(false),
         signature_(MachineTypeForC<ReturnType>() == MachineType::None() ? 0 : 1,
                    GetParameterCount(p0, p1, p2, p3), storage_),
-        compiler_(&signature_, nullptr) {
+        compiler_(&signature_, execution_mode) {
     InitSigStorage(p0, p1, p2, p3);
   }
 
@@ -594,51 +640,102 @@ class WasmRunner {
   void Build(const byte* start, const byte* end) {
     CHECK(!compiled_);
     compiled_ = true;
-
-    // Build the TF graph within the compiler.
     compiler_.Build(start, end);
-    // Generate code.
-    Handle<Code> code = compiler_.Compile();
 
-    if (compiler_.testing_module_) {
-      // Update the table of function code in the module.
-      compiler_.testing_module_->SetFunctionCode(compiler_.function_index_,
-                                                 code);
-    }
+    if (!interpret()) {
+      // Compile machine code and install it into the module.
+      Handle<Code> code = compiler_.Compile();
+
+      if (compiler_.testing_module_) {
+        // Update the table of function code in the module.
+        compiler_.testing_module_->SetFunctionCode(
+            compiler_.function_->func_index, code);
+      }
 
-    wrapper_.SetInnerCode(code);
+      wrapper_.SetInnerCode(code);
+    }
   }
 
-  ReturnType Call() { return Call(0, 0, 0, 0); }
+  ReturnType Call() {
+    if (interpret()) {
+      return CallInterpreter(nullptr, 0);
+    } else {
+      return Call(0, 0, 0, 0);
+    }
+  }
 
   template <typename P0>
   ReturnType Call(P0 p0) {
-    return Call(p0, 0, 0, 0);
+    if (interpret()) {
+      WasmVal args[] = {WasmVal(p0)};
+      return CallInterpreter(args, 1);
+    } else {
+      return Call(p0, 0, 0, 0);
+    }
   }
 
   template <typename P0, typename P1>
   ReturnType Call(P0 p0, P1 p1) {
-    return Call(p0, p1, 0, 0);
+    if (interpret()) {
+      WasmVal args[] = {WasmVal(p0), WasmVal(p1)};
+      return CallInterpreter(args, 2);
+    } else {
+      return Call(p0, p1, 0, 0);
+    }
   }
 
   template <typename P0, typename P1, typename P2>
   ReturnType Call(P0 p0, P1 p1, P2 p2) {
-    return Call(p0, p1, p2, 0);
+    if (interpret()) {
+      WasmVal args[] = {WasmVal(p0), WasmVal(p1), WasmVal(p2)};
+      return CallInterpreter(args, 3);
+    } else {
+      return Call(p0, p1, p2, 0);
+    }
   }
 
   template <typename P0, typename P1, typename P2, typename P3>
   ReturnType Call(P0 p0, P1 p1, P2 p2, P3 p3) {
-    CodeRunner<int32_t> runner(CcTest::InitIsolateOnce(),
-                               wrapper_.GetWrapperCode(), wrapper_.signature());
-    ReturnType return_value;
-    int32_t result = runner.Call<void*, void*, void*, void*, void*>(
-        &p0, &p1, &p2, &p3, &return_value);
-    CHECK_EQ(WASM_WRAPPER_RETURN_VALUE, result);
-    return return_value;
+    if (interpret()) {
+      WasmVal args[] = {WasmVal(p0), WasmVal(p1), WasmVal(p2), WasmVal(p3)};
+      return CallInterpreter(args, 4);
+    } else {
+      CodeRunner<int32_t> runner(CcTest::InitIsolateOnce(),
+                                 wrapper_.GetWrapperCode(),
+                                 wrapper_.signature());
+      ReturnType return_value;
+      int32_t result = runner.Call<void*, void*, void*, void*, void*>(
+          &p0, &p1, &p2, &p3, &return_value);
+      CHECK_EQ(WASM_WRAPPER_RETURN_VALUE, result);
+      return return_value;
+    }
+  }
+
+  ReturnType CallInterpreter(WasmVal* args, int count) {

[Clemens Hammacher, 2016/05/24 12:47:03]

Looks like a candidate for Vector<WasmVal*>.

[titzer, 2016/05/24 14:50:48]

Done.

+    CHECK_EQ(count,
+             static_cast<int>(compiler_.function_->sig->parameter_count()));
+    WasmInterpreter::Thread& thread = interpreter()->GetThread(0);
+    thread.Reset();
+    thread.PushFrame(compiler_.function_, args);
+    if (thread.Run() == WasmInterpreter::FINISHED) {
+      WasmVal val = thread.GetReturnValue();
+      return val.to<ReturnType>();
+    } else if (thread.state() == WasmInterpreter::TRAPPED) {
+      // TODO(titzer): return the correct trap code
+      int64_t result = 0xdeadbeefdeadbeef;
+      return static_cast<ReturnType>(result);
+    } else {
+      // TODO(titzer): falling off end
+      ReturnType val = 0;
+      return val;
+    }
   }
 
   byte AllocateLocal(LocalType type) { return compiler_.AllocateLocal(type); }
 
+  WasmFunction* function() { return compiler_.function_; }
+  WasmInterpreter* interpreter() { return compiler_.interpreter_; }
+
  protected:
   v8::base::AccountingAllocator allocator_;
   Zone zone;
@@ -648,6 +745,8 @@ class WasmRunner {
   WasmFunctionCompiler compiler_;
   WasmFunctionWrapper<ReturnType> wrapper_;
 
+  bool interpret() { return compiler_.execution_mode_ == kExecuteInterpreted; }
+
   static size_t GetParameterCount(MachineType p0, MachineType p1,
                                   MachineType p2, MachineType p3) {
     if (p0 == MachineType::None()) return 0;
@@ -662,10 +761,11 @@ class WasmRunner {
 // Currently only supports compiled tests, but a future
 // RunWasmInterpreted_##name version will allow each test to also run in the
 // interpreter.
-#define WASM_EXEC_TEST(name)                         \
-  void RunWasm_##name();                             \
-  TEST(RunWasmCompiled_##name) { RunWasm_##name(); } \
-  void RunWasm_##name()
+#define WASM_EXEC_TEST(name)                                               \
+  void RunWasm_##name(WasmExecutionMode execution_mode);                   \
+  TEST(RunWasmCompiled_##name) { RunWasm_##name(kExecuteCompiled); }       \
+  TEST(RunWasmInterpreted_##name) { RunWasm_##name(kExecuteInterpreted); } \
+  void RunWasm_##name(WasmExecutionMode execution_mode)

[Clemens Hammacher, 2016/05/24 12:47:03]

Passing this execution_mode explicitely adds a ton of code, and can easily be
forgotton. How about setting some static field somewhere, maybe scoped, and then
using this in WasmRunner and TestingModule when no execution mode is explicitely
given?

[titzer, 2016/05/24 14:50:48]

Explicit is better than relying on global state, even if that state is scoped.

 
 }  // namespace