[stubs] Add TruncationMode argument to ToInteger

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/handler-configuration.h"
 #include "src/ic/stub-cache.h"
@@ skipping 2967 matching lines @@
     {
       var_result.Bind(NonNumberToNumber(context, input));
       Goto(&end);
     }
   }
 
   Bind(&end);
   return var_result.value();
 }
 
-Node* CodeStubAssembler::ToInteger(Node* context, Node* input) {
+Node* CodeStubAssembler::ToInteger(Node* context, Node* input,
+                                   ToIntegerTruncationMode mode) {
   // We might need to loop once for ToNumber conversion.
   Variable var_arg(this, MachineRepresentation::kTagged);
   Label loop(this, &var_arg), out(this);
   var_arg.Bind(input);
   Goto(&loop);
   Bind(&loop);
   {
     // Shared entry points.
     Label return_zero(this, Label::kDeferred);
 
@@ skipping 12 matching lines @@
     Bind(&if_argisheapnumber);
     {
       // Load the floating-point value of {arg}.
       Node* arg_value = LoadHeapNumberValue(arg);
 
       // Check if {arg} is NaN.
       GotoUnless(Float64Equal(arg_value, arg_value), &return_zero);
 
       // Truncate {arg} towards zero.
       Node* value = Float64Trunc(arg_value);
+
+      if (mode == kTruncateMinusZero) {
+        // Truncate -0.0 to 0.
+        GotoIf(Float64Equal(value, Float64Constant(0.0)), &return_zero);
+      }
+
       var_arg.Bind(ChangeFloat64ToTagged(value));
       Goto(&out);
     }
 
     Bind(&if_argisnotheapnumber);
     {
       // Need to convert {arg} to a Number first.
       Callable callable = CodeFactory::NonNumberToNumber(isolate());
       var_arg.Bind(CallStub(callable, context, arg));
       Goto(&loop);
@@ skipping 2556 matching lines @@
                        Heap::kTheHoleValueRootIndex);
 
   // Store the WeakCell in the feedback vector.
   StoreFixedArrayElement(feedback_vector, slot, cell, UPDATE_WRITE_BARRIER,
                          CodeStubAssembler::SMI_PARAMETERS);
   return cell;
 }
 
 }  // namespace internal
 }  // namespace v8