Consistently use HStringAdd instead of HCallStub with CodeStub::StringAdd.

Previously there were two ways to actually use the StringAddStub
from Hydrogen:

- Either using HStringAdd (which implied NO_STRING_CHECK_IN_STUB
  and and does the argument handling internally),
- or using HCallStub with CodeStub::StringAdd (which implied
  NO_STRING_ADD_FLAGS and expected the arguments to be on the
  stack already).

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/19541003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15771 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-codegen-arm.cc

@@ -1041,11 +1041,6 @@ void LCodeGen::DoCallStub(LCallStub* instr) {
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
       break;
     }
-    case CodeStub::StringAdd: {
-      StringAddStub stub(NO_STRING_ADD_FLAGS);
-      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
     case CodeStub::StringCompare: {
       StringCompareStub stub;
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
@@ -4539,7 +4534,7 @@ void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
 void LCodeGen::DoStringAdd(LStringAdd* instr) {
   __ push(ToRegister(instr->left()));
   __ push(ToRegister(instr->right()));
-  StringAddStub stub(NO_STRING_CHECK_IN_STUB);
+  StringAddStub stub(instr->hydrogen()->flags());
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
 }
 

src/hydrogen-instructions.cc

@@ -3451,8 +3451,11 @@ DEFINE_NEW_H_SIMPLE_ARITHMETIC_INSTR(HSub, -)
 #undef DEFINE_NEW_H_SIMPLE_ARITHMETIC_INSTR
 
 
-HInstruction* HStringAdd::New(
-    Zone* zone, HValue* context, HValue* left, HValue* right) {
+HInstruction* HStringAdd::New(Zone* zone,
+                              HValue* context,
+                              HValue* left,
+                              HValue* right,
+                              StringAddFlags flags) {
   if (FLAG_fold_constants && left->IsConstant() && right->IsConstant()) {
     HConstant* c_right = HConstant::cast(right);
     HConstant* c_left = HConstant::cast(left);
@@ -3462,7 +3465,7 @@ HInstruction* HStringAdd::New(
       return new(zone) HConstant(concat, Representation::Tagged());
     }
   }
-  return new(zone) HStringAdd(context, left, right);
+  return new(zone) HStringAdd(context, left, right, flags);
 }
 
 

src/hydrogen-instructions.h

@@ -6181,7 +6181,10 @@ class HStringAdd: public HBinaryOperation {
   static HInstruction* New(Zone* zone,
                            HValue* context,
                            HValue* left,
-                           HValue* right);
+                           HValue* right,
+                           StringAddFlags flags = NO_STRING_CHECK_IN_STUB);
+
+  StringAddFlags flags() const { return flags_; }
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
@@ -6196,10 +6199,9 @@ class HStringAdd: public HBinaryOperation {
  protected:
   virtual bool DataEquals(HValue* other) { return true; }
 
-
  private:
-  HStringAdd(HValue* context, HValue* left, HValue* right)
-      : HBinaryOperation(context, left, right) {
+  HStringAdd(HValue* context, HValue* left, HValue* right, StringAddFlags flags)
+      : HBinaryOperation(context, left, right), flags_(flags) {
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnMaps);
@@ -6208,6 +6210,8 @@ class HStringAdd: public HBinaryOperation {
 
   // TODO(svenpanne) Might be safe, but leave it out until we know for sure.
   //  virtual bool IsDeletable() const { return true; }
+
+  const StringAddFlags flags_;
 };
 
 

src/hydrogen.cc

@@ -9077,10 +9077,13 @@ void HOptimizedGraphBuilder::GenerateRandomHeapNumber(CallRuntime* call) {
 // Fast support for StringAdd.
 void HOptimizedGraphBuilder::GenerateStringAdd(CallRuntime* call) {
   ASSERT_EQ(2, call->arguments()->length());
-  CHECK_ALIVE(VisitArgumentList(call->arguments()));
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
+  HValue* right = Pop();
+  HValue* left = Pop();
   HValue* context = environment()->LookupContext();
-  HCallStub* result = new(zone()) HCallStub(context, CodeStub::StringAdd, 2);
-  Drop(2);
+  HInstruction* result = HStringAdd::New(
+      zone(), context, left, right, NO_STRING_ADD_FLAGS);
   return ast_context()->ReturnInstruction(result, call->id());
 }
 

src/ia32/lithium-codegen-ia32.cc

@@ -1222,11 +1222,6 @@ void LCodeGen::DoCallStub(LCallStub* instr) {
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
       break;
     }
-    case CodeStub::StringAdd: {
-      StringAddStub stub(NO_STRING_ADD_FLAGS);
-      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
     case CodeStub::StringCompare: {
       StringCompareStub stub;
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
@@ -4873,7 +4868,7 @@ void LCodeGen::DoStringLength(LStringLength* instr) {
 void LCodeGen::DoStringAdd(LStringAdd* instr) {
   EmitPushTaggedOperand(instr->left());
   EmitPushTaggedOperand(instr->right());
-  StringAddStub stub(NO_STRING_CHECK_IN_STUB);
+  StringAddStub stub(instr->hydrogen()->flags());
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
 }
 

src/mips/lithium-codegen-mips.cc

@@ -1024,11 +1024,6 @@ void LCodeGen::DoCallStub(LCallStub* instr) {
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
       break;
     }
-    case CodeStub::StringAdd: {
-      StringAddStub stub(NO_STRING_ADD_FLAGS);
-      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
     case CodeStub::StringCompare: {
       StringCompareStub stub;
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
@@ -4478,7 +4473,7 @@ void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
 void LCodeGen::DoStringAdd(LStringAdd* instr) {
   __ push(ToRegister(instr->left()));
   __ push(ToRegister(instr->right()));
-  StringAddStub stub(NO_STRING_CHECK_IN_STUB);
+  StringAddStub stub(instr->hydrogen()->flags());
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
 }
 

src/x64/lithium-codegen-x64.cc

@@ -921,11 +921,6 @@ void LCodeGen::DoCallStub(LCallStub* instr) {
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
       break;
     }
-    case CodeStub::StringAdd: {
-      StringAddStub stub(NO_STRING_ADD_FLAGS);
-      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
-      break;
-    }
     case CodeStub::StringCompare: {
       StringCompareStub stub;
       CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
@@ -4324,7 +4319,7 @@ void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
 void LCodeGen::DoStringAdd(LStringAdd* instr) {
   EmitPushTaggedOperand(instr->left());
   EmitPushTaggedOperand(instr->right());
-  StringAddStub stub(NO_STRING_CHECK_IN_STUB);
+  StringAddStub stub(instr->hydrogen()->flags());
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
 }