Symbols for type cells.

src/arm/code-stubs-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2997 matching lines @@
   // Cache the called function in a feedback vector slot.  Cache states
   // are uninitialized, monomorphic (indicated by a JSFunction), and
   // megamorphic.
   // r0 : number of arguments to the construct function
   // r1 : the function to call
   // r2 : Feedback vector
   // r3 : slot in feedback vector (Smi)
   Label initialize, done, miss, megamorphic, not_array_function;
 
   ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
-            masm->isolate()->heap()->undefined_value());
+            masm->isolate()->heap()->megamorphic_symbol());
   ASSERT_EQ(*TypeFeedbackInfo::UninitializedSentinel(masm->isolate()),
-            masm->isolate()->heap()->the_hole_value());
+            masm->isolate()->heap()->uninitialized_symbol());
 
   // Load the cache state into r4.
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
   __ ldr(r4, FieldMemOperand(r4, FixedArray::kHeaderSize));
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
   __ cmp(r4, r1);
   __ b(eq, &done);
 
   // If we came here, we need to see if we are the array function.
   // If we didn't have a matching function, and we didn't find the megamorph
   // sentinel, then we have in the slot either some other function or an
   // AllocationSite. Do a map check on the object in ecx.
   __ ldr(r5, FieldMemOperand(r4, 0));
   __ CompareRoot(r5, Heap::kAllocationSiteMapRootIndex);
   __ b(ne, &miss);
 
   // Make sure the function is the Array() function
   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r4);
   __ cmp(r1, r4);
   __ b(ne, &megamorphic);
   __ jmp(&done);
 
   __ bind(&miss);
 
   // A monomorphic miss (i.e, here the cache is not uninitialized) goes
   // megamorphic.
-  __ CompareRoot(r4, Heap::kTheHoleValueRootIndex);
+  __ CompareRoot(r4, Heap::kUninitializedSymbolRootIndex);
   __ b(eq, &initialize);
   // MegamorphicSentinel is an immortal immovable object (undefined) so no
   // write-barrier is needed.
   __ bind(&megamorphic);
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
-  __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(ip, Heap::kMegamorphicSymbolRootIndex);
   __ str(ip, FieldMemOperand(r4, FixedArray::kHeaderSize));
   __ jmp(&done);
 
   // An uninitialized cache is patched with the function or sentinel to
   // indicate the ElementsKind if function is the Array constructor.
   __ bind(&initialize);
   // Make sure the function is the Array() function
   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r4);
   __ cmp(r1, r4);
   __ b(ne, &not_array_function);
@@ skipping 26 matching lines @@
                  EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
   __ Pop(r4, r2, r1);
 
   __ bind(&done);
 }
 
 
 void CallFunctionStub::Generate(MacroAssembler* masm) {
   // r1 : the function to call
   // r2 : feedback vector
-  // r3 : (only if r2 is not undefined) slot in feedback vector (Smi)
+  // r3 : (only if r2 is not the megamorphic symbol) slot in feedback
+  //      vector (Smi)
   Label slow, non_function, wrap, cont;
 
   if (NeedsChecks()) {
     // Check that the function is really a JavaScript function.
     // r1: pushed function (to be verified)
     __ JumpIfSmi(r1, &non_function);
 
     // Goto slow case if we do not have a function.
     __ CompareObjectType(r1, r4, r4, JS_FUNCTION_TYPE);
     __ b(ne, &slow);
@@ skipping 35 matching lines @@
     __ bind(&cont);
   }
   __ InvokeFunction(r1, actual, JUMP_FUNCTION, NullCallWrapper());
 
   if (NeedsChecks()) {
     // Slow-case: Non-function called.
     __ bind(&slow);
     if (RecordCallTarget()) {
       // If there is a call target cache, mark it megamorphic in the
       // non-function case.  MegamorphicSentinel is an immortal immovable
-      // object (undefined) so no write barrier is needed.
+      // object (megamorphic symbol) so no write barrier is needed.
       ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
-                masm->isolate()->heap()->undefined_value());
+                masm->isolate()->heap()->megamorphic_symbol());
       __ add(r5, r2, Operand::PointerOffsetFromSmiKey(r3));
-      __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+      __ LoadRoot(ip, Heap::kMegamorphicSymbolRootIndex);
       __ str(ip, FieldMemOperand(r5, FixedArray::kHeaderSize));
     }
     // Check for function proxy.
     __ cmp(r4, Operand(JS_FUNCTION_PROXY_TYPE));
     __ b(ne, &non_function);
     __ push(r1);  // put proxy as additional argument
     __ mov(r0, Operand(argc_ + 1, RelocInfo::NONE32));
     __ mov(r2, Operand::Zero());
     __ GetBuiltinFunction(r1, Builtins::CALL_FUNCTION_PROXY);
     {
@@ skipping 24 matching lines @@
     __ str(r0, MemOperand(sp, argc_ * kPointerSize));
     __ jmp(&cont);
   }
 }
 
 
 void CallConstructStub::Generate(MacroAssembler* masm) {
   // r0 : number of arguments
   // r1 : the function to call
   // r2 : feedback vector
-  // r3 : (only if r2 is not undefined) slot in feedback vector (Smi)
+  // r3 : (only if r2 is not the megamorphic symbol) slot in feedback
+  //      vector (Smi)
   Label slow, non_function_call;
 
   // Check that the function is not a smi.
   __ JumpIfSmi(r1, &non_function_call);
   // Check that the function is a JSFunction.
   __ CompareObjectType(r1, r4, r4, JS_FUNCTION_TYPE);
   __ b(ne, &slow);
 
   if (RecordCallTarget()) {
     GenerateRecordCallTarget(masm);
@@ skipping 2072 matching lines @@
   } else {
     UNREACHABLE();
   }
 }
 
 
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0 : argc (only if argument_count_ == ANY)
   //  -- r1 : constructor
-  //  -- r2 : feedback vector (fixed array or undefined)
+  //  -- r2 : feedback vector (fixed array or megamorphic symbol)
   //  -- r3 : slot index (if r2 is fixed array)
   //  -- sp[0] : return address
   //  -- sp[4] : last argument
   // -----------------------------------
+
+  ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
+            masm->isolate()->heap()->megamorphic_symbol());
+
   if (FLAG_debug_code) {
     // The array construct code is only set for the global and natives
     // builtin Array functions which always have maps.
 
     // Initial map for the builtin Array function should be a map.
     __ ldr(r4, FieldMemOperand(r1, JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ tst(r4, Operand(kSmiTagMask));
     __ Assert(ne, kUnexpectedInitialMapForArrayFunction);
     __ CompareObjectType(r4, r4, r5, MAP_TYPE);
     __ Assert(eq, kUnexpectedInitialMapForArrayFunction);
 
-    // We should either have undefined in ebx or a valid fixed array.
+    // We should either have the megamorphic symbol in ebx or a valid
+    // fixed array.
     Label okay_here;
     Handle<Map> fixed_array_map = masm->isolate()->factory()->fixed_array_map();
-    __ CompareRoot(r2, Heap::kUndefinedValueRootIndex);
+    __ CompareRoot(r2, Heap::kMegamorphicSymbolRootIndex);
     __ b(eq, &okay_here);
     __ ldr(r4, FieldMemOperand(r2, 0));
     __ cmp(r4, Operand(fixed_array_map));
     __ Assert(eq, kExpectedFixedArrayInRegisterR2);
 
     // r3 should be a smi if we don't have undefined in r2
     __ AssertSmi(r3);
 
     __ bind(&okay_here);
   }
 
   Label no_info;
   // Get the elements kind and case on that.
-  __ CompareRoot(r2, Heap::kUndefinedValueRootIndex);
+  __ CompareRoot(r2, Heap::kMegamorphicSymbolRootIndex);
   __ b(eq, &no_info);
   __ add(r2, r2, Operand::PointerOffsetFromSmiKey(r3));
   __ ldr(r2, FieldMemOperand(r2, FixedArray::kHeaderSize));
 
   // If the feedback vector is undefined, or contains anything other than an
   // AllocationSite, call an array constructor that doesn't use AllocationSites.
   __ ldr(r4, FieldMemOperand(r2, 0));
   __ CompareRoot(r4, Heap::kAllocationSiteMapRootIndex);
   __ b(ne, &no_info);
 
@@ skipping 235 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM