X87: Remove the obsolete OverwriteMode optimization.

port 634b0f20 (r26454).

original commit message:

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/880743005

Cr-Commit-Position: refs/heads/master@{#26520}

src/x87/full-codegen-x87.cc

@@ -1951,18 +1951,14 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
     __ push(eax);  // Left operand goes on the stack.
     VisitForAccumulatorValue(expr->value());
 
-    OverwriteMode mode = expr->value()->ResultOverwriteAllowed()
-        ? OVERWRITE_RIGHT
-        : NO_OVERWRITE;
     SetSourcePosition(expr->position() + 1);
     if (ShouldInlineSmiCase(op)) {
       EmitInlineSmiBinaryOp(expr->binary_operation(),
                             op,
-                            mode,
                             expr->target(),
                             expr->value());
     } else {
-      EmitBinaryOp(expr->binary_operation(), op, mode);
+      EmitBinaryOp(expr->binary_operation(), op);
     }
 
     // Deoptimization point in case the binary operation may have side effects.
@@ -2343,7 +2339,6 @@ void FullCodeGenerator::EmitKeyedSuperPropertyLoad(Property* prop) {
 
 void FullCodeGenerator::EmitInlineSmiBinaryOp(BinaryOperation* expr,
                                               Token::Value op,
-                                              OverwriteMode mode,
                                               Expression* left,
                                               Expression* right) {
   // Do combined smi check of the operands. Left operand is on the
@@ -2357,7 +2352,7 @@ void FullCodeGenerator::EmitInlineSmiBinaryOp(BinaryOperation* expr,
 
   __ bind(&stub_call);
   __ mov(eax, ecx);
-  Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op, mode).code();
+  Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op).code();
   CallIC(code, expr->BinaryOperationFeedbackId());
   patch_site.EmitPatchInfo();
   __ jmp(&done, Label::kNear);
@@ -2489,11 +2484,9 @@ void FullCodeGenerator::EmitClassDefineProperties(ClassLiteral* lit) {
 }
 
 
-void FullCodeGenerator::EmitBinaryOp(BinaryOperation* expr,
-                                     Token::Value op,
-                                     OverwriteMode mode) {
+void FullCodeGenerator::EmitBinaryOp(BinaryOperation* expr, Token::Value op) {
   __ pop(edx);
-  Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op, mode).code();
+  Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), op).code();
   JumpPatchSite patch_site(masm_);    // unbound, signals no inlined smi code.
   CallIC(code, expr->BinaryOperationFeedbackId());
   patch_site.EmitPatchInfo();
@@ -4764,8 +4757,8 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   __ bind(&stub_call);
   __ mov(edx, eax);
   __ mov(eax, Immediate(Smi::FromInt(1)));
-  Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), expr->binary_op(),
-                                              NO_OVERWRITE).code();
+  Handle<Code> code =
+      CodeFactory::BinaryOpIC(isolate(), expr->binary_op()).code();
   CallIC(code, expr->CountBinOpFeedbackId());
   patch_site.EmitPatchInfo();
   __ bind(&done);

src/x87/lithium-codegen-x87.cc

@@ -2317,8 +2317,7 @@ void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
   DCHECK(ToRegister(instr->right()).is(eax));
   DCHECK(ToRegister(instr->result()).is(eax));
 
-  Handle<Code> code =
-      CodeFactory::BinaryOpIC(isolate(), instr->op(), NO_OVERWRITE).code();
+  Handle<Code> code = CodeFactory::BinaryOpIC(isolate(), instr->op()).code();
   CallCode(code, RelocInfo::CODE_TARGET, instr);
 }