[strong] Implement strong property access semantics

src/ic/mips/ic-mips.cc

Index: src/ic/mips/ic-mips.cc
diff --git a/src/ic/mips/ic-mips.cc b/src/ic/mips/ic-mips.cc
index a888e0b43d3d0561281d69dec233abf310284e04..5a6f95a231e5c257c4381a8bb9fa7871bd412125 100644
--- a/src/ic/mips/ic-mips.cc
+++ b/src/ic/mips/ic-mips.cc
@@ -163,7 +163,8 @@ static void GenerateKeyedLoadReceiverCheck(MacroAssembler* masm,
 static void GenerateFastArrayLoad(MacroAssembler* masm, Register receiver,
                                   Register key, Register elements,
                                   Register scratch1, Register scratch2,
-                                  Register result, Label* slow) {
+                                  Register result, Label* slow,
+                                  LanguageMode language_mode) {
   // Register use:
   //
   // receiver - holds the receiver on entry.
@@ -185,7 +186,7 @@ static void GenerateFastArrayLoad(MacroAssembler* masm, Register receiver,
   //
   // scratch2 - used to hold maps, prototypes, and the loaded value.
   Label check_prototypes, check_next_prototype;
-  Label done, in_bounds, return_undefined;
+  Label done, in_bounds, absent;
 
   __ lw(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
   __ AssertFastElements(elements);
@@ -203,7 +204,7 @@ static void GenerateFastArrayLoad(MacroAssembler* masm, Register receiver,
   __ lw(scratch2, FieldMemOperand(scratch2, Map::kPrototypeOffset));
   // scratch2: current prototype
   __ LoadRoot(at, Heap::kNullValueRootIndex);
-  __ Branch(&return_undefined, eq, scratch2, Operand(at));
+  __ Branch(&absent, eq, scratch2, Operand(at));
   __ lw(elements, FieldMemOperand(scratch2, JSObject::kElementsOffset));
   __ lw(scratch2, FieldMemOperand(scratch2, HeapObject::kMapOffset));
   // elements: elements of current prototype
@@ -218,9 +219,14 @@ static void GenerateFastArrayLoad(MacroAssembler* masm, Register receiver,
   __ Branch(slow, ne, elements, Operand(at));
   __ Branch(&check_next_prototype);
 
-  __ bind(&return_undefined);
-  __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
-  __ Branch(&done);
+  __ bind(&absent);
+  if (is_strong(language_mode)) {
+    // Strong mode accesses must throw in this case, so call the runtime.
+    __ Branch(slow);
+  } else {
+    __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
+    __ Branch(&done);
+  }
 
   __ bind(&in_bounds);
   // Fast case: Do the load.
@@ -270,7 +276,7 @@ static void GenerateKeyNameCheck(MacroAssembler* masm, Register key,
 }
 
 
-void LoadIC::GenerateNormal(MacroAssembler* masm) {
+void LoadIC::GenerateNormal(MacroAssembler* masm, LanguageMode language_mode) {
   Register dictionary = a0;
   DCHECK(!dictionary.is(LoadDescriptor::ReceiverRegister()));
   DCHECK(!dictionary.is(LoadDescriptor::NameRegister()));
@@ -285,7 +291,7 @@ void LoadIC::GenerateNormal(MacroAssembler* masm) {
 
   // Dictionary load failed, go slow (but don't miss).
   __ bind(&slow);
-  GenerateRuntimeGetProperty(masm);
+  GenerateRuntimeGetProperty(masm, language_mode);
 }
 
 
@@ -320,13 +326,17 @@ void LoadIC::GenerateMiss(MacroAssembler* masm) {
 }
 
 
-void LoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
+void LoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm,
+                                        LanguageMode language_mode) {
   // The return address is in ra.
 
   __ mov(LoadIC_TempRegister(), LoadDescriptor::ReceiverRegister());
   __ Push(LoadIC_TempRegister(), LoadDescriptor::NameRegister());
 
-  __ TailCallRuntime(Runtime::kGetProperty, 2, 1);
+  // Do tail-call to runtime routine.
+  __ TailCallRuntime(is_strong(language_mode) ? Runtime::kGetPropertyStrong
+                                              : Runtime::kGetProperty,
+                     2, 1);
 }
 
 
@@ -349,16 +359,21 @@ void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
 }
 
 
-void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
+void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm,
+                                             LanguageMode language_mode) {
   // The return address is in ra.
 
   __ Push(LoadDescriptor::ReceiverRegister(), LoadDescriptor::NameRegister());
 
-  __ TailCallRuntime(Runtime::kKeyedGetProperty, 2, 1);
+  // Do tail-call to runtime routine.
+  __ TailCallRuntime(is_strong(language_mode) ? Runtime::kKeyedGetPropertyStrong
+                                              : Runtime::kKeyedGetProperty,
+                     2, 1);
 }
 
 
-void KeyedLoadIC::GenerateMegamorphic(MacroAssembler* masm) {
+void KeyedLoadIC::GenerateMegamorphic(MacroAssembler* masm,
+                                      LanguageMode language_mode) {
   // The return address is in ra.
   Label slow, check_name, index_smi, index_name, property_array_property;
   Label probe_dictionary, check_number_dictionary;
@@ -382,7 +397,8 @@ void KeyedLoadIC::GenerateMegamorphic(MacroAssembler* masm) {
   // Check the receiver's map to see if it has fast elements.
   __ CheckFastElements(a0, a3, &check_number_dictionary);
 
-  GenerateFastArrayLoad(masm, receiver, key, a0, a3, t0, v0, &slow);
+  GenerateFastArrayLoad(masm, receiver, key, a0, a3, t0, v0, &slow,
+                        language_mode);
   __ IncrementCounter(isolate->counters()->keyed_load_generic_smi(), 1, t0, a3);
   __ Ret();
 
@@ -403,7 +419,7 @@ void KeyedLoadIC::GenerateMegamorphic(MacroAssembler* masm) {
   __ bind(&slow);
   __ IncrementCounter(isolate->counters()->keyed_load_generic_slow(), 1, t0,
                       a3);
-  GenerateRuntimeGetProperty(masm);
+  GenerateRuntimeGetProperty(masm, language_mode);
 
   __ bind(&check_name);
   GenerateKeyNameCheck(masm, key, a0, a3, &index_name, &slow);