[wasm] Adding feature to JIT a wasm function at runtime and hook up the compiled code into the indi…

src/runtime/runtime-wasm.cc

Index: src/runtime/runtime-wasm.cc
diff --git a/src/runtime/runtime-wasm.cc b/src/runtime/runtime-wasm.cc
index ff99e242e14610ad28dd029047568f1e358576c8..c883fb7e1a94fee7c4c064a8e1e64bd4e270e6bd 100644
--- a/src/runtime/runtime-wasm.cc
+++ b/src/runtime/runtime-wasm.cc
@@ -6,6 +6,7 @@
 
 #include "src/arguments.h"
 #include "src/assembler.h"
+#include "src/compiler/wasm-compiler.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
 #include "src/factory.h"
@@ -17,6 +18,10 @@
 namespace v8 {
 namespace internal {
 
+namespace {
+const int kWasmMemArrayBuffer = 2;
+}
+
 RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -40,7 +45,6 @@ RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
 
   Address old_mem_start, new_mem_start;
   uint32_t old_size, new_size;
-  const int kWasmMemArrayBuffer = 2;
 
   // Get mem buffer associated with module object
   Handle<Object> obj(module_object->GetInternalField(kWasmMemArrayBuffer),
@@ -110,5 +114,81 @@ RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
                                                 wasm::WasmModule::kPageSize);
 }
 
+RUNTIME_FUNCTION(Runtime_JITSingleFunction) {
+  const int fixed_args = 6;

[titzer, 2016/07/14 08:59:43]

Most of this functionality should somehow be in src/wasm, since it uses lots of
internal details.

[ritesht, 2016/07/14 18:10:00]

Acknowledged.

+
+  HandleScope scope(isolate);
+  DCHECK_LE(fixed_args, args.length());
+  CONVERT_SMI_ARG_CHECKED(base, 0);
+  CONVERT_SMI_ARG_CHECKED(length, 1);
+  CONVERT_SMI_ARG_CHECKED(index, 2);
+  CONVERT_ARG_HANDLE_CHECKED(FixedArray, function_table, 3);
+  CONVERT_UINT32_ARG_CHECKED(sig_index, 4);
+  CONVERT_SMI_ARG_CHECKED(return_count, 5);
+
+  Handle<JSObject> module_object;
+
+  {
+    // Get the module JSObject
+    DisallowHeapAllocation no_allocation;
+    const Address entry = Isolate::c_entry_fp(isolate->thread_local_top());
+    Address pc =
+        Memory::Address_at(entry + StandardFrameConstants::kCallerPCOffset);
+    Code* code =
+        isolate->inner_pointer_to_code_cache()->GetCacheEntry(pc)->code;
+    FixedArray* deopt_data = code->deoptimization_data();
+    DCHECK(deopt_data->length() == 2);
+    module_object = Handle<JSObject>::cast(handle(deopt_data->get(0), isolate));
+    CHECK(!module_object->IsNull(isolate));
+  }
+
+  // Get mem buffer associated with module object
+  Handle<Object> obj(module_object->GetInternalField(kWasmMemArrayBuffer),
+                     isolate);
+
+  if (obj->IsUndefined(isolate)) {
+    return isolate->heap()->undefined_value();
+  }
+
+  Handle<JSArrayBuffer> mem_buffer = Handle<JSArrayBuffer>::cast(obj);
+
+  wasm::WasmModule module(reinterpret_cast<byte*>(mem_buffer->backing_store()));
+  wasm::ErrorThrower thrower(isolate, "JITSingleFunction");
+  wasm::ModuleEnv module_env;
+  module_env.module = &module;
+  module_env.instance = nullptr;
+  module_env.origin = wasm::kWasmOrigin;
+
+  uint32_t signature_size = args.length() - fixed_args;
+  wasm::LocalType* sig_types = new wasm::LocalType[signature_size];
+
+  for (uint32_t i = 0; i < signature_size; ++i) {
+    CONVERT_SMI_ARG_CHECKED(sig_type, i + fixed_args);
+    sig_types[i] = static_cast<wasm::LocalType>(sig_type);
+  }
+  wasm::FunctionSig sig(return_count, signature_size - return_count, sig_types);
+
+  wasm::WasmFunction func;
+  func.sig = &sig;
+  func.func_index = index;
+  func.sig_index = sig_index;
+  func.name_offset = 0;
+  func.name_length = 0;
+  func.code_start_offset = base;
+  func.code_end_offset = base + length;
+
+  Handle<Code> code = compiler::WasmCompilationUnit::CompileWasmFunction(
+      &thrower, isolate, &module_env, &func);
+
+  delete[] sig_types;
+  if (thrower.error()) {
+    return isolate->heap()->undefined_value();
+  }
+
+  function_table->set(index, Smi::FromInt(sig_index));
+  function_table->set(index + function_table->length() / 2, *code);
+
+  return isolate->heap()->undefined_value();
+}
 }  // namespace internal
 }  // namespace v8