[builtins] implement Array.prototype.includes in TurboFan

src/code-stub-assembler.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 #include "src/ic/stub-cache.h"
 
@@ skipping 453 matching lines @@
 
 Node* CodeStubAssembler::WordIsSmi(Node* a) {
   return WordEqual(WordAnd(a, IntPtrConstant(kSmiTagMask)), IntPtrConstant(0));
 }
 
 Node* CodeStubAssembler::WordIsPositiveSmi(Node* a) {
   return WordEqual(WordAnd(a, IntPtrConstant(kSmiTagMask | kSmiSignMask)),
                    IntPtrConstant(0));
 }
 
+void CodeStubAssembler::BranchIfSameValueZero(Node* a, Node* b, Node* context,

[Benedikt Meurer, 2016/07/15 17:59:55]

Nice, this looks pretty good already. You'll have to handle Simd128Values tho
(the SIMD.js spec defines that).
See the implementation of Object::SameValueZero.

+                                              Label* if_true, Label* if_false) {
+  Node* number_map = HeapNumberMapConstant();
+  Label a_isnumber(this), a_isnotnumber(this), b_isnumber(this), a_isnan(this),
+      float_not_equal(this);
+  // If register A and register B are identical, goto `if_true`
+  GotoIf(WordEqual(a, b), if_true);
+  // If either register A or B are Smis, goto `if_false`
+  GotoIf(WordIsSmi(a), if_false);
+  GotoIf(WordIsSmi(b), if_false);
+
+  Node* map_a = LoadMap(a);
+  Node* map_b = LoadMap(b);
+  Branch(WordEqual(map_a, number_map), &a_isnumber, &a_isnotnumber);
+
+  // If both register A and B are HeapNumbers, return true if they are equal,
+  // or if both are NaN
+  Bind(&a_isnumber);
+  {
+    Branch(WordEqual(map_b, number_map), &b_isnumber, if_false);
+
+    Bind(&b_isnumber);
+    Node* a_value = LoadHeapNumberValue(a);
+    Node* b_value = LoadHeapNumberValue(b);
+    BranchIfFloat64Equal(a_value, b_value, if_true, &float_not_equal);
+
+    Bind(&float_not_equal);
+    BranchIfFloat64IsNaN(a_value, &a_isnan, if_false);
+
+    Bind(&a_isnan);
+    BranchIfFloat64IsNaN(a_value, if_true, if_false);
+  }
+
+  Bind(&a_isnotnumber);
+  {
+    Label a_isstring(this);
+    Node* a_instance_type = LoadMapInstanceType(map_a);
+
+    Branch(Int32LessThan(a_instance_type, Int32Constant(FIRST_NONSTRING_TYPE)),
+           &a_isstring, if_false);

[Benedikt Meurer, 2016/07/15 17:59:55]

Instead of going to if_false here, you can check if a is a Simd128Value and if
so, call to Runtime::kSameValueZero, otherwise go to if_false. The Simd128Value
case doesn't need to be super fast for now (it's still not clear if it will make
it into the ESnext spec).

+
+    Bind(&a_isstring);
+    {
+      Label b_isstring(this), b_isnotstring(this);
+      Node* b_instance_type = LoadInstanceType(map_b);
+
+      Branch(
+          Int32LessThan(b_instance_type, Int32Constant(FIRST_NONSTRING_TYPE)),
+          &b_isstring, if_false);
+
+      Bind(&b_isstring);
+      {
+        Callable callable = CodeFactory::StringEqual(isolate());
+        Node* result = CallStub(callable, context, a, b);
+        Branch(WordEqual(BooleanConstant(true), result), if_true, if_false);
+      }
+    }
+  }
+}
+
 Node* CodeStubAssembler::AllocateRawUnaligned(Node* size_in_bytes,
                                               AllocationFlags flags,
                                               Node* top_address,
                                               Node* limit_address) {
   Node* top = Load(MachineType::Pointer(), top_address);
   Node* limit = Load(MachineType::Pointer(), limit_address);
 
   // If there's not enough space, call the runtime.
   Variable result(this, MachineRepresentation::kTagged);
   Label runtime_call(this, Label::kDeferred), no_runtime_call(this);
@@ skipping 2506 matching lines @@
   }
   Bind(&miss);
   {
     TailCallRuntime(Runtime::kLoadGlobalIC_Miss, p->context, p->slot,
                     p->vector);
   }
 }
 
 }  // namespace internal
 }  // namespace v8