[builtins] implement Array.prototype.includes in TurboFan

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index eb7e49da46d352883ccad891f19f348217b8cdec..497caddd11b86edb533de43ce1a3c5d9149cbe55 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -471,6 +471,32 @@ Node* CodeStubAssembler::WordIsPositiveSmi(Node* a) {
                    IntPtrConstant(0));
 }
 
+void CodeStubAssembler::BranchIfSameValueZero(Node* a, Node* b, Node* context,
+                                              Label* if_true, Label* if_false) {
+  Label if_noteq(this), if_a_isnan(this);
+  Node* heap_number_type = Int32Constant(HEAP_NUMBER_TYPE);
+  BranchIf(CallRuntime(Runtime::kInlineStrictEqual, context, a, b), if_true,

[caitp, 2016/07/15 17:24:35]

this was the problem --- fixing this made the perf results a lot worse, so I
implemented a more proper SameValueZero here in the next patchset.

The spec does not say anything about SameValueZero equating SIMD objects, so I'm
not sure if it should or not. At the moment, it doesn't.

Another option is to just call the StrictEquals stub and then fix the NaN stuff
after, but that's probably still a slow path.

With the change, the fast path is significantly faster, but not as fast as it
could be maybe.

+           &if_noteq);
+
+  Bind(&if_noteq);
+  GotoIf(WordIsSmi(a), if_false);
+
+  Node* a_type = LoadInstanceType(a);
+  GotoIf(WordNotEqual(a_type, heap_number_type), if_false);
+
+  Node* a_value = LoadHeapNumberValue(a);
+  BranchIfFloat64IsNaN(a_value, &if_a_isnan, if_false);
+
+  Bind(&if_a_isnan);
+  GotoIf(WordIsSmi(b), if_false);
+
+  Node* b_type = LoadInstanceType(b);
+  GotoIf(WordNotEqual(b_type, heap_number_type), if_false);
+
+  Node* b_value = LoadHeapNumberValue(b);
+  BranchIfFloat64IsNaN(b_value, if_true, if_false);
+}
+
 Node* CodeStubAssembler::AllocateRawUnaligned(Node* size_in_bytes,
                                               AllocationFlags flags,
                                               Node* top_address,