[wasm] Avoid double-serializing the wire bytes

src/wasm/wasm-module.cc

Index: src/wasm/wasm-module.cc
diff --git a/src/wasm/wasm-module.cc b/src/wasm/wasm-module.cc
index e789982ba8b58b75f469cab1f7d1dd7d11a849d7..7f20dd8b34c6ed42797989717de8b00f3136f103 100644
--- a/src/wasm/wasm-module.cc
+++ b/src/wasm/wasm-module.cc
@@ -439,10 +439,11 @@ void PatchDirectCalls(Handle<FixedArray> old_functions,
   DCHECK_EQ(new_functions->length(), old_functions->length());
 
   DisallowHeapAllocation no_gc;
-  std::map<Code*, Code*> old_to_new_code;
+  std::map<Code*, HeapObject*> old_to_new_code;
   for (int i = 0; i < new_functions->length(); ++i) {
-    old_to_new_code.insert(std::make_pair(Code::cast(old_functions->get(i)),
-                                          Code::cast(new_functions->get(i))));
+    old_to_new_code.insert(
+        std::make_pair(Code::cast(old_functions->get(i)),
+                       HeapObject::cast(new_functions->get(i))));
   }
   int mode_mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
   AllowDeferredHandleDereference embedding_raw_address;
@@ -455,11 +456,21 @@ void PatchDirectCalls(Handle<FixedArray> old_functions,
           old_code->kind() == Code::WASM_FUNCTION) {
         auto found = old_to_new_code.find(old_code);
         DCHECK(found != old_to_new_code.end());
-        Code* new_code = found->second;
+        HeapObject* new_code = found->second;
         if (new_code != old_code) {
-          it.rinfo()->set_target_address(new_code->instruction_start(),
-                                         UPDATE_WRITE_BARRIER,
-                                         SKIP_ICACHE_FLUSH);
+          if (new_code->IsCode()) {
+            it.rinfo()->set_target_address(
+                Code::cast(new_code)->instruction_start(), UPDATE_WRITE_BARRIER,
+                SKIP_ICACHE_FLUSH);
+          } else {
+            DCHECK(new_code->IsForeign());
+            it.rinfo()->set_target_address(
+                ExternalReference(Foreign::cast(new_code)->foreign_address(),
+                                  it.rinfo()->isolate(),
+                                  ExternalReference::BUILTIN_FP_FP_CALL)
+                    .address(),
+                UPDATE_WRITE_BARRIER, SKIP_ICACHE_FLUSH);
+          }
         }
       }
     }
@@ -1383,12 +1394,25 @@ class WasmInstanceBuilder {
                            module_name, function_name);
             return -1;
           }
-
-          Handle<Code> import_wrapper = CompileImportWrapper(
-              index, import, Handle<JSReceiver>::cast(function), module_name,
-              function_name);
-          code_table->set(num_imported_functions, *import_wrapper);
-          RecordStats(isolate_, *import_wrapper);
+          Handle<JSReceiver> function_as_receiver =
+              Handle<JSReceiver>::cast(function);
+          Handle<String> native_variant_key =
+              isolate_->factory()->InternalizeUtf8String("native_variant");
+          MaybeHandle<Object> maybeObj =
+              JSReceiver::GetProperty(function_as_receiver, native_variant_key);
+          Handle<Object> native_variant;
+          if (maybeObj.ToHandle(&native_variant) &&
+              native_variant->IsJSObject()) {
+            Handle<Foreign> foreign(Foreign::cast(
+                JSObject::cast(*native_variant)->GetInternalField(0)));
+            code_table->set(num_imported_functions, *foreign);
+          } else {
+            Handle<Code> import_wrapper =
+                CompileImportWrapper(index, import, function_as_receiver,
+                                     module_name, function_name);
+            code_table->set(num_imported_functions, *import_wrapper);
+            RecordStats(isolate_, *import_wrapper);
+          }
           num_imported_functions++;
           break;
         }