[stubs] remove unused BranchIfSameValueZero from CodeStubAssembler

BUG=v8:5268, v8:5162
R=ishell@chromium.org

Review-Url: https://codereview.chromium.org/2374703002
Cr-Commit-Position: refs/heads/master@{#39766}

src/code-stub-assembler.cc

@@ -497,80 +497,6 @@ Node* CodeStubAssembler::WordIsPositiveSmi(Node* a) {
                    IntPtrConstant(0));
 }
 
-void CodeStubAssembler::BranchIfSameValueZero(Node* a, Node* b, Node* context,
-                                              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(Word32Or(WordIsSmi(a), WordIsSmi(b)), if_false);
-  // GotoIf(WordIsSmi(b), if_false);
-
-  Node* a_map = LoadMap(a);
-  Node* b_map = LoadMap(b);
-  Branch(WordEqual(a_map, 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(b_map, 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), a_isnotstring(this);
-    Node* a_instance_type = LoadMapInstanceType(a_map);
-
-    Branch(Int32LessThan(a_instance_type, Int32Constant(FIRST_NONSTRING_TYPE)),
-           &a_isstring, &a_isnotstring);
-
-    Bind(&a_isstring);
-    {
-      Label b_isstring(this), b_isnotstring(this);
-      Node* b_instance_type = LoadInstanceType(b_map);
-
-      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);
-      }
-    }
-
-    Bind(&a_isnotstring);
-    {
-      // Check if {lhs} is a Simd128Value.
-      Label a_issimd128value(this);
-      Branch(Word32Equal(a_instance_type, Int32Constant(SIMD128_VALUE_TYPE)),
-             &a_issimd128value, if_false);
-
-      Bind(&a_issimd128value);
-      {
-        // Load the map of {rhs}.
-        BranchIfSimd128Equal(a, a_map, b, b_map, if_true, if_false);
-      }
-    }
-  }
-}
-
 void CodeStubAssembler::BranchIfSimd128Equal(Node* lhs, Node* lhs_map,
                                              Node* rhs, Node* rhs_map,
                                              Label* if_equal,

src/code-stub-assembler.h

@@ -177,10 +177,6 @@ class CodeStubAssembler : public compiler::CodeAssembler {
                          if_notequal);
   }
 
-  void BranchIfSameValueZero(compiler::Node* a, compiler::Node* b,
-                             compiler::Node* context, Label* if_true,
-                             Label* if_false);
-
   void BranchIfFastJSArray(compiler::Node* object, compiler::Node* context,
                            Label* if_true, Label* if_false);