From c23ed104e54a852befc8e13b9cdddda8670f369a Mon Sep 17 00:00:00 2001
From: Andreas Kling <andreas@ladybird.org>
Date: Wed, 15 Oct 2025 11:26:58 +0200
Subject: [PATCH] LibJS: Micro-optimize
 ECMAScriptFunctionObject::internal_construct()

- Add FLATTEN (same as we do for internal_call()).
- Demote nice-to-have VERIFYs to ASSERTs.
- Pass already-known Realm to ordinary_create_from_constructor

1.03x speedup on Octane/earley-boyer.js
---
 Libraries/LibJS/Runtime/AbstractOperations.h         | 10 ++++++++--
 Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp | 12 ++++++------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/Libraries/LibJS/Runtime/AbstractOperations.h b/Libraries/LibJS/Runtime/AbstractOperations.h
index 1b3e0daeac..889834d4e5 100644
--- a/Libraries/LibJS/Runtime/AbstractOperations.h
+++ b/Libraries/LibJS/Runtime/AbstractOperations.h
@@ -157,13 +157,19 @@ ALWAYS_INLINE ThrowCompletionOr<GC::Ref<Object>> construct(VM& vm, FunctionObjec
 
 // 10.1.13 OrdinaryCreateFromConstructor ( constructor, intrinsicDefaultProto [ , internalSlotsList ] ), https://tc39.es/ecma262/#sec-ordinarycreatefromconstructor
 template<typename T, typename... Args>
-ThrowCompletionOr<GC::Ref<T>> ordinary_create_from_constructor(VM& vm, FunctionObject const& constructor, GC::Ref<Object> (Intrinsics::*intrinsic_default_prototype)(), Args&&... args)
+ALWAYS_INLINE ThrowCompletionOr<GC::Ref<T>> ordinary_create_from_constructor(VM& vm, Realm& realm, FunctionObject const& constructor, GC::Ref<Object> (Intrinsics::*intrinsic_default_prototype)(), Args&&... args)
 {
-    auto& realm = *vm.current_realm();
     auto* prototype = TRY(get_prototype_from_constructor(vm, constructor, intrinsic_default_prototype));
     return realm.create<T>(forward<Args>(args)..., *prototype);
 }
 
+// 10.1.13 OrdinaryCreateFromConstructor ( constructor, intrinsicDefaultProto [ , internalSlotsList ] ), https://tc39.es/ecma262/#sec-ordinarycreatefromconstructor
+template<typename T, typename... Args>
+ALWAYS_INLINE ThrowCompletionOr<GC::Ref<T>> ordinary_create_from_constructor(VM& vm, FunctionObject const& constructor, GC::Ref<Object> (Intrinsics::*intrinsic_default_prototype)(), Args&&... args)
+{
+    return ordinary_create_from_constructor<T>(vm, *vm.current_realm(), constructor, intrinsic_default_prototype, forward<Args>(args)...);
+}
+
 // 7.3.35 AddValueToKeyedGroup ( groups, key, value ), https://tc39.es/ecma262/#sec-add-value-to-keyed-group
 template<typename GroupsType, typename KeyType>
 void add_value_to_keyed_group(VM& vm, GroupsType& groups, KeyType key, Value value)
diff --git a/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp b/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
index 52cb283e6c..6789ae3c9d 100644
--- a/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
+++ b/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
@@ -549,7 +549,7 @@ FLATTEN ThrowCompletionOr<Value> ECMAScriptFunctionObject::internal_call(Executi
 }
 
 // 10.2.2 [[Construct]] ( argumentsList, newTarget ), https://tc39.es/ecma262/#sec-ecmascript-function-objects-construct-argumentslist-newtarget
-ThrowCompletionOr<GC::Ref<Object>> ECMAScriptFunctionObject::internal_construct(ExecutionContext& callee_context, FunctionObject& new_target)
+FLATTEN ThrowCompletionOr<GC::Ref<Object>> ECMAScriptFunctionObject::internal_construct(ExecutionContext& callee_context, FunctionObject& new_target)
 {
     auto& vm = this->vm();
 
@@ -566,14 +566,14 @@ ThrowCompletionOr<GC::Ref<Object>> ECMAScriptFunctionObject::internal_construct(
     // 3. If kind is base, then
     if (kind == ConstructorKind::Base) {
         // a. Let thisArgument be ? OrdinaryCreateFromConstructor(newTarget, "%Object.prototype%").
-        this_argument = TRY(ordinary_create_from_constructor<Object>(vm, new_target, &Intrinsics::object_prototype, ConstructWithPrototypeTag::Tag));
+        this_argument = TRY(ordinary_create_from_constructor<Object>(vm, *realm(), new_target, &Intrinsics::object_prototype, ConstructWithPrototypeTag::Tag));
     }
 
     // 4. Let calleeContext be PrepareForOrdinaryCall(F, newTarget).
     prepare_for_ordinary_call(vm, callee_context, &new_target);
 
     // 5. Assert: calleeContext is now the running execution context.
-    VERIFY(&vm.running_execution_context() == &callee_context);
+    ASSERT(&vm.running_execution_context() == &callee_context);
 
     // 6. If kind is base, then
     if (kind == ConstructorKind::Base) {
@@ -628,7 +628,7 @@ ThrowCompletionOr<GC::Ref<Object>> ECMAScriptFunctionObject::internal_construct(
     auto this_binding = TRY(constructor_env->get_this_binding(vm));
 
     // 16. Assert: Type(thisBinding) is Object.
-    VERIFY(this_binding.is_object());
+    ASSERT(this_binding.is_object());
 
     // 17. Return thisBinding.
     return this_binding.as_object();
@@ -765,7 +765,7 @@ void ECMAScriptFunctionObject::ordinary_call_bind_this(VM& vm, ExecutionContext&
             this_value = MUST(this_argument.to_object(vm));
 
             // ii. NOTE: ToObject produces wrapper objects using calleeRealm.
-            VERIFY(vm.current_realm() == callee_realm);
+            ASSERT(vm.current_realm() == callee_realm);
         }
     }
 
@@ -908,7 +908,7 @@ ThrowCompletionOr<Value> ECMAScriptFunctionObject::ordinary_call_evaluate_body(V
     if (kind() == FunctionKind::Async)
         return AsyncFunctionDriverWrapper::create(realm, generator_object);
 
-    VERIFY(kind() == FunctionKind::Generator);
+    ASSERT(kind() == FunctionKind::Generator);
     return generator_object;
 }