Symbols for type cells.

src/a64/code-stubs-a64.cc

 // Copyright 2013 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 3251 matching lines @@
   ASM_LOCATION("GenerateRecordCallTarget");
   // Cache the called function in a feedback vector slot. Cache states are
   // uninitialized, monomorphic (indicated by a JSFunction), and megamorphic.
   //  x0 : number of arguments to the construct function
   //  x1 : the function to call
   //  x2 : feedback vector
   //  x3 : 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.
   __ Add(x4, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
   __ Ldr(x4, FieldMemOperand(x4, FixedArray::kHeaderSize));
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
   __ Cmp(x4, x1);
   __ 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(x5, FieldMemOperand(x4, AllocationSite::kMapOffset));
   __ JumpIfNotRoot(x5, Heap::kAllocationSiteMapRootIndex, &miss);
 
   // Make sure the function is the Array() function
   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, x4);
   __ Cmp(x1, x4);
   __ B(ne, &megamorphic);
   __ B(&done);
 
   __ Bind(&miss);
 
   // A monomorphic miss (i.e, here the cache is not uninitialized) goes
   // megamorphic.
-  __ JumpIfRoot(x4, Heap::kTheHoleValueRootIndex, &initialize);
+  __ JumpIfRoot(x4, Heap::kUninitializedSymbolRootIndex, &initialize);
   // MegamorphicSentinel is an immortal immovable object (undefined) so no
   // write-barrier is needed.
   __ Bind(&megamorphic);
   __ Add(x4, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
-  __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(x10, Heap::kMegamorphicSymbolRootIndex);
   __ Str(x10, FieldMemOperand(x4, FixedArray::kHeaderSize));
   __ B(&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, x4);
   __ Cmp(x1, x4);
   __ B(ne, &not_array_function);
@@ skipping 32 matching lines @@
   // TODO(all): Are x4, x2 and x1 outputs? This isn't clear.
 
   __ Bind(&done);
 }
 
 
 void CallFunctionStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("CallFunctionStub::Generate");
   // x1  function    the function to call
   // x2 : feedback vector
-  // x3 : slot in feedback vector (smi) (if x2 is not undefined)
+  // x3 : slot in feedback vector (smi) (if x2 is not the megamorphic symbol)
   Register function = x1;
   Register cache_cell = x2;
   Register slot = x3;
   Register type = x4;
   Label slow, non_function, wrap, cont;
 
   // TODO(jbramley): This function has a lot of unnamed registers. Name them,
   // and tidy things up a bit.
 
   if (NeedsChecks()) {
@@ skipping 39 matching lines @@
                     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.
+      // (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(x12, cache_cell, Operand::UntagSmiAndScale(slot,
                                                         kPointerSizeLog2));
-      __ LoadRoot(x11, Heap::kUndefinedValueRootIndex);
+      __ LoadRoot(x11, Heap::kMegamorphicSymbolRootIndex);
       __ Str(x11, FieldMemOperand(x12, FixedArray::kHeaderSize));
     }
     // Check for function proxy.
     // x10 : function type.
     __ CompareAndBranch(type, JS_FUNCTION_PROXY_TYPE, ne, &non_function);
     __ Push(function);  // put proxy as additional argument
     __ Mov(x0, argc_ + 1);
     __ Mov(x2, 0);
     __ GetBuiltinFunction(x1, Builtins::CALL_FUNCTION_PROXY);
     {
@@ skipping 25 matching lines @@
     __ B(&cont);
   }
 }
 
 
 void CallConstructStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("CallConstructStub::Generate");
   // x0 : number of arguments
   // x1 : the function to call
   // x2 : feedback vector
-  // x3 : slot in feedback vector (smi) (if r2 is not undefined)
+  // x3 : slot in feedback vector (smi) (if r2 is not the megamorphic symbol)
   Register function = x1;
   Label slow, non_function_call;
 
   // Check that the function is not a smi.
   __ JumpIfSmi(function, &non_function_call);
   // Check that the function is a JSFunction.
   Register object_type = x10;
   __ JumpIfNotObjectType(function, object_type, object_type, JS_FUNCTION_TYPE,
                          &slow);
 
@@ skipping 1993 matching lines @@
     UNREACHABLE();
   }
 }
 
 
 void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   ASM_LOCATION("ArrayConstructorStub::Generate");
   // ----------- S t a t e -------------
   //  -- x0 : argc (only if argument_count_ == ANY)
   //  -- x1 : constructor
-  //  -- x2 : feedback vector (fixed array or undefined)
+  //  -- x2 : feedback vector (fixed array or the megamorphic symbol)
   //  -- x3 : slot index (if x2 is fixed array)
   //  -- sp[0] : return address
   //  -- sp[4] : last argument
   // -----------------------------------
   Register constructor = x1;
   Register feedback_vector = x2;
   Register slot_index = x3;
 
+  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.
 
     Label unexpected_map, map_ok;
     // Initial map for the builtin Array function should be a map.
     __ Ldr(x10, FieldMemOperand(constructor,
                                 JSFunction::kPrototypeOrInitialMapOffset));
     // Will both indicate a NULL and a Smi.
     __ JumpIfSmi(x10, &unexpected_map);
     __ JumpIfObjectType(x10, x10, x11, MAP_TYPE, &map_ok);
     __ Bind(&unexpected_map);
     __ Abort(kUnexpectedInitialMapForArrayFunction);
     __ Bind(&map_ok);
 
-    // In feedback_vector, we expect either undefined or a valid fixed array.
+    // In feedback_vector, we expect either the megamorphic symbol or a valid
+    // fixed array.
     Label okay_here;
     Handle<Map> fixed_array_map = masm->isolate()->factory()->fixed_array_map();
-    __ JumpIfRoot(feedback_vector, Heap::kUndefinedValueRootIndex, &okay_here);
+    __ JumpIfRoot(feedback_vector, Heap::kMegamorphicSymbolRootIndex,
+                  &okay_here);
     __ Ldr(x10, FieldMemOperand(feedback_vector, FixedArray::kMapOffset));
     __ Cmp(x10, Operand(fixed_array_map));
     __ Assert(eq, kExpectedFixedArrayInFeedbackVector);
 
     // slot_index should be a smi if we don't have undefined in feedback_vector.
     __ AssertSmi(slot_index);
 
     __ Bind(&okay_here);
   }
 
   Register allocation_site = x2;  // Overwrites feedback_vector.
   Register kind = x3;
   Label no_info;
   // Get the elements kind and case on that.
-  __ JumpIfRoot(feedback_vector, Heap::kUndefinedValueRootIndex, &no_info);
+  __ JumpIfRoot(feedback_vector, Heap::kMegamorphicSymbolRootIndex, &no_info);
   __ Add(feedback_vector, feedback_vector,
          Operand::UntagSmiAndScale(slot_index, kPointerSizeLog2));
   __ Ldr(allocation_site, FieldMemOperand(feedback_vector,
                                           FixedArray::kHeaderSize));
 
-  // If the feedback vector is undefined, or contains anything other than an
-  // AllocationSite, call an array constructor that doesn't use AllocationSites.
+  // If the feedback vector is the megamorphic symbol, or contains anything
+  // other than an AllocationSite, call an array constructor that doesn't
+  // use AllocationSites.
   __ Ldr(x10, FieldMemOperand(allocation_site, AllocationSite::kMapOffset));
   __ JumpIfNotRoot(x10, Heap::kAllocationSiteMapRootIndex, &no_info);
 
   __ Ldrsw(kind,
            UntagSmiFieldMemOperand(allocation_site,
                                    AllocationSite::kTransitionInfoOffset));
   __ And(kind, kind, AllocationSite::ElementsKindBits::kMask);
   GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
   __ Bind(&no_info);
@@ skipping 251 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_A64