[Builtins] Provide a code-stub impl. of Array.prototype.map

BUG=

Review-Url: https://codereview.chromium.org/2765293002
Cr-Commit-Position: refs/heads/master@{#44093}

src/bootstrapper.cc

@@ -3714,6 +3714,7 @@ void Genesis::InitializeGlobal_experimental_fast_array_builtins() {
 
   // Insert experimental fast array builtins here.
   InstallOneBuiltinFunction("Array", "filter", Builtins::kArrayFilter);
+  InstallOneBuiltinFunction("Array", "map", Builtins::kArrayMap);
 }
 
 void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {

src/builtins/builtins-array-gen.cc

@@ -129,24 +129,42 @@ class ArrayBuiltinCodeStubAssembler : public CodeStubAssembler {
   }
 
   Node* FilterProcessor(Node* k_value, Node* k) {
-    Node* callback_result = CallJS(CodeFactory::Call(isolate()), context(),
-                                   callbackfn(), this_arg(), k_value, k, o());
+    // ii. Let selected be ToBoolean(? Call(callbackfn, T, kValue, k, O)).
+    Node* selected = CallJS(CodeFactory::Call(isolate()), context(),
+                            callbackfn(), this_arg(), k_value, k, o());
     Label true_continue(this, &to_), false_continue(this);
-    BranchIfToBooleanIsTrue(callback_result, &true_continue, &false_continue);
+    BranchIfToBooleanIsTrue(selected, &true_continue, &false_continue);
     Bind(&true_continue);
+    // iii. If selected is true, then...
+    {
+      // 1. Perform ? CreateDataPropertyOrThrow(A, ToString(to), kValue).
+      CallRuntime(Runtime::kCreateDataProperty, context(), a(), to_.value(),
+                  k_value);
 
-    // 1. let status be CreateDataPropertyOrThrow(A, ToString(to), kValue).
-    // 2. ReturnIfAbrupt(status)
-    Node* const p_to = ToString(context(), to_.value());
-    CallRuntime(Runtime::kCreateDataProperty, context(), a(), p_to, k_value);
-
-    // 3. Increase to by 1.
-    to_.Bind(NumberInc(to_.value()));
-    Goto(&false_continue);
+      // 2. Increase to by 1.
+      to_.Bind(NumberInc(to_.value()));
+      Goto(&false_continue);
+    }
     Bind(&false_continue);
     return a();
   }
 
+  Node* MapResultGenerator() {
+    // 5. Let A be ? ArraySpeciesCreate(O, len).
+    return ArraySpeciesCreate(context(), o(), len_);
+  }
+
+  Node* MapProcessor(Node* k_value, Node* k) {
+    //  i. Let kValue be ? Get(O, Pk). Performed by the caller of MapProcessor.
+    // ii. Let mappedValue be ? Call(callbackfn, T, kValue, k, O).
+    Node* mappedValue = CallJS(CodeFactory::Call(isolate()), context(),
+                               callbackfn(), this_arg(), k_value, k, o());
+
+    // iii. Perform ? CreateDataPropertyOrThrow(A, Pk, mappedValue).
+    CallRuntime(Runtime::kCreateDataProperty, context(), a(), k, mappedValue);
+    return a();
+  }
+
   void NullPostLoopAction() {}
 
  protected:
@@ -770,13 +788,50 @@ TF_BUILTIN(ArrayFilter, ArrayBuiltinCodeStubAssembler) {
                                 new_target);
 
   GenerateIteratingArrayBuiltinBody(
-      "Array.prototype.reduce",
+      "Array.prototype.filter",
       &ArrayBuiltinCodeStubAssembler::FilterResultGenerator,
       &ArrayBuiltinCodeStubAssembler::FilterProcessor,
       &ArrayBuiltinCodeStubAssembler::NullPostLoopAction,
       CodeFactory::ArrayFilterLoopContinuation(isolate()));
 }
 
+TF_BUILTIN(ArrayMapLoopContinuation, ArrayBuiltinCodeStubAssembler) {
+  Node* context = Parameter(Descriptor::kContext);
+  Node* receiver = Parameter(Descriptor::kReceiver);
+  Node* callbackfn = Parameter(Descriptor::kCallbackFn);
+  Node* this_arg = Parameter(Descriptor::kThisArg);
+  Node* array = Parameter(Descriptor::kArray);
+  Node* object = Parameter(Descriptor::kObject);
+  Node* initial_k = Parameter(Descriptor::kInitialK);
+  Node* len = Parameter(Descriptor::kLength);
+  Node* to = Parameter(Descriptor::kTo);
+
+  InitIteratingArrayBuiltinLoopContinuation(context, receiver, callbackfn,
+                                            this_arg, array, object, initial_k,
+                                            len, to);
+
+  GenerateIteratingArrayBuiltinLoopContinuation(
+      &ArrayBuiltinCodeStubAssembler::MapProcessor,
+      &ArrayBuiltinCodeStubAssembler::NullPostLoopAction);
+}
+
+TF_BUILTIN(ArrayMap, ArrayBuiltinCodeStubAssembler) {
+  Node* context = Parameter(Descriptor::kContext);
+  Node* receiver = Parameter(Descriptor::kReceiver);
+  Node* callbackfn = Parameter(Descriptor::kCallbackFn);
+  Node* this_arg = Parameter(Descriptor::kThisArg);
+  Node* new_target = Parameter(Descriptor::kNewTarget);
+
+  InitIteratingArrayBuiltinBody(context, receiver, callbackfn, this_arg,
+                                new_target);
+
+  GenerateIteratingArrayBuiltinBody(
+      "Array.prototype.map", &ArrayBuiltinCodeStubAssembler::MapResultGenerator,
+      &ArrayBuiltinCodeStubAssembler::MapProcessor,
+      &ArrayBuiltinCodeStubAssembler::NullPostLoopAction,
+      CodeFactory::ArrayMapLoopContinuation(isolate()));
+}
+
 TF_BUILTIN(ArrayIsArray, CodeStubAssembler) {
   Node* object = Parameter(Descriptor::kArg);
   Node* context = Parameter(Descriptor::kContext);

src/builtins/builtins.h

@@ -300,6 +300,10 @@ class Isolate;
   TFJ(ArrayFilterLoopContinuation, 7, kCallbackFn, kThisArg, kArray, kObject,  \
       kInitialK, kLength, kTo)                                                 \
   TFJ(ArrayFilter, 2, kCallbackFn, kThisArg)                                   \
+  /* ES6 #sec-array.prototype.foreach */                                       \
+  TFJ(ArrayMapLoopContinuation, 7, kCallbackFn, kThisArg, kArray, kObject,     \
+      kInitialK, kLength, kTo)                                                 \
+  TFJ(ArrayMap, 2, kCallbackFn, kThisArg)                                      \
   /* ES6 #sec-array.prototype.reduce */                                        \
   TFJ(ArrayReduceLoopContinuation, 7, kCallbackFn, kThisArg, kAccumulator,     \
       kObject, kInitialK, kLength, kTo)                                        \

src/code-factory.cc

@@ -513,6 +513,12 @@ Callable CodeFactory::ArrayFilterLoopContinuation(Isolate* isolate) {
                   IteratingArrayBuiltinLoopContinuationDescriptor(isolate));
 }
 
+// static
+Callable CodeFactory::ArrayMapLoopContinuation(Isolate* isolate) {
+  return Callable(isolate->builtins()->ArrayMapLoopContinuation(),
+                  IteratingArrayBuiltinLoopContinuationDescriptor(isolate));
+}
+
 // static
 Callable CodeFactory::ArrayForEachLoopContinuation(Isolate* isolate) {
   return Callable(isolate->builtins()->ArrayForEachLoopContinuation(),

src/code-factory.h

@@ -185,6 +185,7 @@ class V8_EXPORT_PRIVATE CodeFactory final {
   static Callable ArrayConstructor(Isolate* isolate);
   static Callable ArrayPush(Isolate* isolate);
   static Callable ArrayFilterLoopContinuation(Isolate* isolate);
+  static Callable ArrayMapLoopContinuation(Isolate* isolate);
   static Callable ArrayForEachLoopContinuation(Isolate* isolate);
   static Callable ArraySomeLoopContinuation(Isolate* isolate);
   static Callable ArrayEveryLoopContinuation(Isolate* isolate);