[strong] Implement strong mode semantics for the count operation.

src/x64/full-codegen-x64.cc

 // Copyright 2012 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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 4959 matching lines @@
     mode.Add(PRESERVE_SOURCE_REGISTER);
     mode.Add(BAILOUT_ON_NO_OVERFLOW);
     if (expr->op() == Token::INC) {
       __ SmiAddConstant(rax, rax, Smi::FromInt(1), mode, &done, Label::kNear);
     } else {
       __ SmiSubConstant(rax, rax, Smi::FromInt(1), mode, &done, Label::kNear);
     }
     __ jmp(&stub_call, Label::kNear);
     __ bind(&slow);
   }
-
-  ToNumberStub convert_stub(isolate());
-  __ CallStub(&convert_stub);
-  PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  if (!is_strong(language_mode())) {
+    ToNumberStub convert_stub(isolate());
+    __ CallStub(&convert_stub);
+    PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  }
 
   // Save result for postfix expressions.
   if (expr->is_postfix()) {
     if (!context()->IsEffect()) {
       // Save the result on the stack. If we have a named or keyed property
       // we store the result under the receiver that is currently on top
       // of the stack.
       switch (assign_type) {
         case VARIABLE:
           __ Push(rax);
@@ skipping 20 matching lines @@
   // Call stub for +1/-1.
   __ bind(&stub_call);
   __ movp(rdx, rax);
   __ Move(rax, Smi::FromInt(1));
   Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), expr->binary_op(),
                                               strength(language_mode())).code();
   CallIC(code, expr->CountBinOpFeedbackId());
   patch_site.EmitPatchInfo();
   __ bind(&done);
 
+  if (is_strong(language_mode())) {
+    PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  }
   // Store the value returned in rax.
   switch (assign_type) {
     case VARIABLE:
       if (expr->is_postfix()) {
         // Perform the assignment as if via '='.
         { EffectContext context(this);
           EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
                                  Token::ASSIGN, expr->CountSlot());
           PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
           context.Plug(rax);
@@ skipping 481 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64