Drop unnecessary receiver validity checks from {Load,Store}IC_Normal.

src/arm64/ic-arm64.cc

Index: src/arm64/ic-arm64.cc
diff --git a/src/arm64/ic-arm64.cc b/src/arm64/ic-arm64.cc
index 5a2dde53ff64fc969e8ba549cfa655ee6d37d992..9244b4adf7d83065030c85edc62a978890268c78 100644
--- a/src/arm64/ic-arm64.cc
+++ b/src/arm64/ic-arm64.cc
@@ -34,51 +34,6 @@ static void GenerateGlobalInstanceTypeCheck(MacroAssembler* masm,
 }
 
 
-// Generated code falls through if the receiver is a regular non-global
-// JS object with slow properties and no interceptors.
-//
-// "receiver" holds the receiver on entry and is unchanged.
-// "elements" holds the property dictionary on fall through.
-static void GenerateNameDictionaryReceiverCheck(MacroAssembler* masm,
-                                                Register receiver,
-                                                Register elements,
-                                                Register scratch0,
-                                                Register scratch1,
-                                                Label* miss) {
-  ASSERT(!AreAliased(receiver, elements, scratch0, scratch1));
-
-  // Check that the receiver isn't a smi.
-  __ JumpIfSmi(receiver, miss);
-
-  // Check that the receiver is a valid JS object.
-  // Let t be the object instance type, we want:
-  //   FIRST_SPEC_OBJECT_TYPE <= t <= LAST_SPEC_OBJECT_TYPE.
-  // Since LAST_SPEC_OBJECT_TYPE is the last possible instance type we only
-  // check the lower bound.
-  STATIC_ASSERT(LAST_TYPE == LAST_SPEC_OBJECT_TYPE);
-
-  __ JumpIfObjectType(receiver, scratch0, scratch1, FIRST_SPEC_OBJECT_TYPE,
-                      miss, lt);
-
-  // scratch0 now contains the map of the receiver and scratch1 the object type.
-  Register map = scratch0;
-  Register type = scratch1;
-
-  // Check if the receiver is a global JS object.
-  GenerateGlobalInstanceTypeCheck(masm, type, miss);
-
-  // Check that the object does not require access checks.
-  __ Ldrb(scratch1, FieldMemOperand(map, Map::kBitFieldOffset));
-  __ Tbnz(scratch1, Map::kIsAccessCheckNeeded, miss);
-  __ Tbnz(scratch1, Map::kHasNamedInterceptor, miss);
-
-  // Check that the properties dictionary is valid.
-  __ Ldr(elements, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
-  __ Ldr(scratch1, FieldMemOperand(elements, HeapObject::kMapOffset));
-  __ JumpIfNotRoot(scratch1, Heap::kHashTableMapRootIndex, miss);
-}
-
-
 // Helper function used from LoadIC GenerateNormal.
 //
 // elements: Property dictionary. It is not clobbered if a jump to the miss
@@ -424,28 +379,19 @@ void LoadIC::GenerateMegamorphic(MacroAssembler* masm) {
 
 
 void LoadIC::GenerateNormal(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- x2    : name
-  //  -- lr    : return address
-  //  -- x1    : receiver
-  // -----------------------------------
-  ASSERT(x1.is(ReceiverRegister()));
-  ASSERT(x2.is(NameRegister()));
-  Label miss, slow;
-
-  GenerateNameDictionaryReceiverCheck(masm, x1, x0, x3, x4, &miss);
+  Register dictionary = x0;
+  ASSERT(!dictionary.is(ReceiverRegister()));
+  ASSERT(!dictionary.is(NameRegister()));
+  Label slow;
 
-  // x0 now holds the property dictionary.
-  GenerateDictionaryLoad(masm, &slow, x0, x2, x0, x3, x4);
+  __ Ldr(dictionary,
+         FieldMemOperand(ReceiverRegister(), JSObject::kPropertiesOffset));
+  GenerateDictionaryLoad(masm, &slow, dictionary, NameRegister(), x0, x3, x4);
   __ Ret();
 
   // Dictionary load failed, go slow (but don't miss).
   __ Bind(&slow);
   GenerateRuntimeGetProperty(masm);
-
-  // Cache miss: Jump to runtime.
-  __ Bind(&miss);
-  GenerateMiss(masm);
 }
 
 
@@ -1187,8 +1133,7 @@ void StoreIC::GenerateNormal(MacroAssembler* masm) {
   Register dictionary = x3;
   ASSERT(!AreAliased(value, receiver, name, x3, x4, x5));
 
-  GenerateNameDictionaryReceiverCheck(
-      masm, receiver, dictionary, x4, x5, &miss);
+  __ Ldr(dictionary, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
 
   GenerateDictionaryStore(masm, &miss, dictionary, name, value, x4, x5);
   Counters* counters = masm->isolate()->counters();