Port prototype-call-stubs for normal objects (http://codereview.chromium.org/...

src/arm/stub-cache-arm.cc

 // Copyright 2006-2009 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 65 matching lines @@
   // Jump to the first instruction in the code stub.
   __ add(offset, offset, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ Jump(offset);
 
   // Miss: Restore offset and fall through.
   __ bind(&miss);
   __ pop(offset);
 }
 
 
+// Helper function used to check that the dictionary doesn't contain
+// the property. This function may return false negatives, so miss_label
+// must always call a backup property check that is complete.
+// This function is safe to call if the receiver has fast properties.
+// Name must be a symbol and receiver must be a heap object.
+static void GenerateDictionaryNegativeLookup(MacroAssembler* masm,
+                                             Label* miss_label,
+                                             Register receiver,
+                                             String* name,
+                                             Register r0,
+                                             Register extra) {
+  ASSERT(name->IsSymbol());
+  if (!extra.is(no_reg)) {
+    __ IncrementCounter(&Counters::negative_lookups, 1, r0, extra);
+    __ IncrementCounter(&Counters::negative_lookups_miss, 1, r0, extra);
+  }
+
+  Label done;
+
+  const int kInterceptorOrAccessCheckNeededMask =
+      (1 << Map::kHasNamedInterceptor) | (1 << Map::kIsAccessCheckNeeded);
+
+  // Bail out if the receiver has a named interceptor or requires access checks.
+  Register map = extra.is(no_reg) ? r0 : extra;
+  __ ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ ldrb(r0, FieldMemOperand(map, Map::kBitFieldOffset));
+  __ tst(r0, Operand(kInterceptorOrAccessCheckNeededMask));
+  __ b(ne, miss_label);
+
+  // Check that receiver is a JSObject.
+  if (extra.is(no_reg)) {
+     __ ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  }
+  __ ldrb(r0, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  __ cmp(r0, Operand(FIRST_JS_OBJECT_TYPE));
+  __ b(lt, miss_label);
+
+  // Load properties array.
+  Register properties = r0;
+  __ ldr(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+  // Check that the properties array is a dictionary.
+  if (!extra.is(no_reg)) {
+    __ ldr(extra, FieldMemOperand(properties, HeapObject::kMapOffset));
+    Register tmp = properties;
+    __ LoadRoot(tmp, Heap::kHashTableMapRootIndex);
+    __ cmp(extra, tmp);
+  } else {
+    Register tmp1 = receiver;
+    Register tmp2 = properties;
+    __ push(tmp1);
+    __ ldr(tmp1, FieldMemOperand(properties, HeapObject::kMapOffset));
+    __ LoadRoot(tmp2, Heap::kHashTableMapRootIndex);
+    __ cmp(tmp1, tmp2);
+    __ pop(tmp1);
+  }
+  __ b(ne, miss_label);
+
+  // Restore the temporarily used register.
+  __ ldr(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+
+  // Compute the capacity mask.
+  const int kCapacityOffset =
+      StringDictionary::kHeaderSize +
+      StringDictionary::kCapacityIndex * kPointerSize;
+
+  // Generate an unrolled loop that performs a few probes before
+  // giving up.
+  static const int kProbes = 4;
+  const int kElementsStartOffset =
+      StringDictionary::kHeaderSize +
+      StringDictionary::kElementsStartIndex * kPointerSize;
+
+  // If names of slots in range from 1 to kProbes - 1 for the hash value are
+  // not equal to the name and kProbes-th slot is not used (its name is the
+  // undefined value), it guarantees the hash table doesn't contain the
+  // property. It's true even if some slots represent deleted properties
+  // (their names are the null value).
+  for (int i = 0; i < kProbes; i++) {
+    // r0 points to properties hash.
+    // Compute the masked index: (hash + i + i * i) & mask.
+    if (extra.is(no_reg)) {
+      __ push(receiver);
+    }
+    Register index = extra.is(no_reg) ? receiver : extra;
+    // Capacity is smi 2^n.
+    __ ldr(index, FieldMemOperand(properties, kCapacityOffset));
+    __ sub(index, index, Operand(1));
+    __ and_(index, index, Operand(
+        Smi::FromInt(name->Hash() + StringDictionary::GetProbeOffset(i))));
+
+    // Scale the index by multiplying by the entry size.
+    ASSERT(StringDictionary::kEntrySize == 3);
+    __ add(index, index, Operand(index, LSL, 1));  // index *= 3.
+
+    Register entity_name = extra.is(no_reg) ? properties : extra;
+    // Having undefined at this place means the name is not contained.
+    ASSERT_EQ(kSmiTagSize, 1);
+    Register tmp = extra.is(no_reg) ? receiver : properties;
+    __ add(tmp, properties, Operand(index, LSL, 1));
+    __ ldr(entity_name, FieldMemOperand(tmp, kElementsStartOffset));
+
+    ASSERT(!tmp.is(entity_name));
+    __ LoadRoot(tmp, Heap::kUndefinedValueRootIndex);
+    __ cmp(entity_name, tmp);
+    if (extra.is(no_reg)) {
+      // 'receiver' shares a register with 'entity_name'.
+      __ pop(receiver);
+    }
+    if (i != kProbes - 1) {
+      __ b(eq, &done);
+
+      // Stop if found the property.
+      __ cmp(entity_name, Operand(Handle<String>(name)));
+      __ b(eq, miss_label);
+
+      // Restore the properties.
+      __ ldr(properties,
+             FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+    } else {
+      // Give up probing if still not found the undefined value.
+      __ b(ne, miss_label);
+    }
+  }
+  __ bind(&done);
+  if (!extra.is(no_reg)) {
+    __ DecrementCounter(&Counters::negative_lookups_miss, 1, r0, extra);
+  }
+}
+
+
 void StubCache::GenerateProbe(MacroAssembler* masm,
                               Code::Flags flags,
                               Register receiver,
                               Register name,
                               Register scratch,
                               Register extra) {
   Label miss;
 
   // Make sure that code is valid. The shifting code relies on the
   // entry size being 8.
@@ skipping 640 matching lines @@
 
 Register StubCompiler::CheckPrototypes(JSObject* object,
                                        Register object_reg,
                                        JSObject* holder,
                                        Register holder_reg,
                                        Register scratch,
                                        String* name,
                                        int save_at_depth,
                                        Label* miss,
                                        Register extra) {
-  // Check that the maps haven't changed.
-  Register result =
-      masm()->CheckMaps(object, object_reg, holder, holder_reg, scratch,
-                        save_at_depth, miss);
+  // Make sure there's no overlap between scratch and the other
+  // registers.
+  ASSERT(!scratch.is(object_reg) && !scratch.is(holder_reg));
+
+  // Keep track of the current object in register reg.
+  Register reg = object_reg;
+  int depth = 0;
+
+  if (save_at_depth == depth) {
+    __ str(reg, MemOperand(sp));
+  }
+
+  // Check the maps in the prototype chain.
+  // Traverse the prototype chain from the object and do map checks.
+  JSObject* current = object;
+  while (current != holder) {
+    depth++;
+
+    // Only global objects and objects that do not require access
+    // checks are allowed in stubs.
+    ASSERT(current->IsJSGlobalProxy() || !current->IsAccessCheckNeeded());
+
+    JSObject* prototype = JSObject::cast(current->GetPrototype());
+    if (!current->HasFastProperties() &&
+        !current->IsJSGlobalObject() &&
+        !current->IsJSGlobalProxy()) {
+      if (!name->IsSymbol()) {
+        Object* lookup_result = Heap::LookupSymbol(name);
+        if (lookup_result->IsFailure()) {
+          set_failure(Failure::cast(lookup_result));
+          return reg;
+        } else {
+          name = String::cast(lookup_result);
+        }
+      }
+      ASSERT(current->property_dictionary()->FindEntry(name) ==
+             StringDictionary::kNotFound);
+
+      GenerateDictionaryNegativeLookup(masm(),
+                                       miss,
+                                       reg,
+                                       name,
+                                       scratch,
+                                       extra);
+      __ ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+      reg = holder_reg;  // from now the object is in holder_reg
+      __ ldr(reg, FieldMemOperand(scratch, Map::kPrototypeOffset));
+    } else {
+      // Get the map of the current object.
+      __ ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+      __ cmp(scratch, Operand(Handle<Map>(current->map())));
+
+      // Branch on the result of the map check.
+      __ b(ne, miss);
+
+      // Check access rights to the global object.  This has to happen
+      // after the map check so that we know that the object is
+      // actually a global object.
+      if (current->IsJSGlobalProxy()) {
+        __ CheckAccessGlobalProxy(reg, scratch, miss);
+        // Restore scratch register to be the map of the object.  In the
+        // new space case below, we load the prototype from the map in
+        // the scratch register.
+        __ ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+      }
+
+      reg = holder_reg;  // from now the object is in holder_reg
+      if (Heap::InNewSpace(prototype)) {
+        // The prototype is in new space; we cannot store a reference
+        // to it in the code. Load it from the map.
+        __ ldr(reg, FieldMemOperand(scratch, Map::kPrototypeOffset));
+      } else {
+        // The prototype is in old space; load it directly.
+        __ mov(reg, Operand(Handle<JSObject>(prototype)));
+      }
+    }
+
+    if (save_at_depth == depth) {
+      __ str(reg, MemOperand(sp));
+    }
+
+    // Go to the next object in the prototype chain.
+    current = prototype;
+  }
+
+  // Check the holder map.
+  __ ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
+  __ cmp(scratch, Operand(Handle<Map>(current->map())));
+  __ b(ne, miss);
+
+  // Log the check depth.
+  LOG(IntEvent("check-maps-depth", depth + 1));
+
+  // Perform security check for access to the global object and return
+  // the holder register.
+  ASSERT(current == holder);
+  ASSERT(current->IsJSGlobalProxy() || !current->IsAccessCheckNeeded());
+  if (current->IsJSGlobalProxy()) {
+    __ CheckAccessGlobalProxy(reg, scratch, miss);
+  }
 
   // If we've skipped any global objects, it's not enough to verify
   // that their maps haven't changed.  We also need to check that the
   // property cell for the property is still empty.
-  while (object != holder) {
-    if (object->IsGlobalObject()) {
+  current = object;
+  while (current != holder) {
+    if (current->IsGlobalObject()) {
       Object* cell = GenerateCheckPropertyCell(masm(),
-                                               GlobalObject::cast(object),
+                                               GlobalObject::cast(current),
                                                name,
                                                scratch,
                                                miss);
       if (cell->IsFailure()) {
         set_failure(Failure::cast(cell));
-        return result;
+        return reg;
       }
     }
-    object = JSObject::cast(object->GetPrototype());
+    current = JSObject::cast(current->GetPrototype());
   }
 
   // Return the register containing the holder.
-  return result;
+  return reg;
 }
 
 
 void StubCompiler::GenerateLoadField(JSObject* object,
                                      JSObject* holder,
                                      Register receiver,
                                      Register scratch1,
                                      Register scratch2,
                                      int index,
                                      String* name,
@@ skipping 265 matching lines @@
 
   const int argc = arguments().immediate();
 
   // Get the receiver of the function from the stack into r0.
   __ ldr(r0, MemOperand(sp, argc * kPointerSize));
   // Check that the receiver isn't a smi.
   __ tst(r0, Operand(kSmiTagMask));
   __ b(eq, &miss);
 
   // Do the right check and compute the holder register.
-  Register reg = CheckPrototypes(object, r0, holder, r1, r3, name, &miss);
+  Register reg = CheckPrototypes(object, r0, holder, r1, r3, name, &miss, r4);
   GenerateFastPropertyLoad(masm(), r1, reg, holder, index);
 
   GenerateCallFunction(masm(), object, arguments(), &miss);
 
   // Handle call cache miss.
   __ bind(&miss);
   GenerateMissBranch();
 
   // Return the generated code.
   return GetCode(FIELD, name);
@@ skipping 24 matching lines @@
 
   // Get the receiver from the stack
   const int argc = arguments().immediate();
   __ ldr(r1, MemOperand(sp, argc * kPointerSize));
 
   // Check that the receiver isn't a smi.
   __ tst(r1, Operand(kSmiTagMask));
   __ b(eq, &miss);
 
   // Check that the maps haven't changed.
-  CheckPrototypes(JSObject::cast(object), r1, holder, r3, r0, name, &miss);
+  CheckPrototypes(JSObject::cast(object), r1, holder, r3, r0, name, &miss, r4);
 
   if (object->IsGlobalObject()) {
     __ ldr(r3, FieldMemOperand(r1, GlobalObject::kGlobalReceiverOffset));
     __ str(r3, MemOperand(sp, argc * kPointerSize));
   }
 
   __ TailCallExternalReference(ExternalReference(Builtins::c_ArrayPush),
                                argc + 1,
                                1);
 
@@ skipping 30 matching lines @@
 
   // Get the receiver from the stack
   const int argc = arguments().immediate();
   __ ldr(r1, MemOperand(sp, argc * kPointerSize));
 
   // Check that the receiver isn't a smi.
   __ tst(r1, Operand(kSmiTagMask));
   __ b(eq, &miss);
 
   // Check that the maps haven't changed.
-  CheckPrototypes(JSObject::cast(object), r1, holder, r3, r0, name, &miss);
+  CheckPrototypes(JSObject::cast(object), r1, holder, r3, r0, name, &miss, r4);
 
   if (object->IsGlobalObject()) {
     __ ldr(r3, FieldMemOperand(r1, GlobalObject::kGlobalReceiverOffset));
     __ str(r3, MemOperand(sp, argc * kPointerSize));
   }
 
   __ TailCallExternalReference(ExternalReference(Builtins::c_ArrayPop),
                                argc + 1,
                                1);
 
@@ skipping 77 matching lines @@
             JSObject::cast(object), holder);
       }
 
       if (depth != kInvalidProtoDepth) {
         __ IncrementCounter(&Counters::call_const_fast_api, 1, r0, r3);
         ReserveSpaceForFastApiCall(masm(), r0);
       }
 
       // Check that the maps haven't changed.
       CheckPrototypes(JSObject::cast(object), r1, holder, r0, r3, name,
-                      depth, &miss);
+                      depth, &miss, r4);
 
       // Patch the receiver on the stack with the global proxy if
       // necessary.
       if (object->IsGlobalObject()) {
         ASSERT(depth == kInvalidProtoDepth);
         __ ldr(r3, FieldMemOperand(r1, GlobalObject::kGlobalReceiverOffset));
         __ str(r3, MemOperand(sp, argc * kPointerSize));
       }
       break;
 
     case STRING_CHECK:
       if (!function->IsBuiltin()) {
         // Calling non-builtins with a value as receiver requires boxing.
         __ jmp(&miss);
       } else {
         // Check that the object is a two-byte string or a symbol.
         __ CompareObjectType(r1, r3, r3, FIRST_NONSTRING_TYPE);
         __ b(hs, &miss);
         // Check that the maps starting from the prototype haven't changed.
         GenerateDirectLoadGlobalFunctionPrototype(
             masm(), Context::STRING_FUNCTION_INDEX, r0);
         CheckPrototypes(JSObject::cast(object->GetPrototype()), r0, holder, r3,
-                        r1, name, &miss);
+                        r1, name, &miss, r4);
       }
       break;
 
     case NUMBER_CHECK: {
       if (!function->IsBuiltin()) {
         // Calling non-builtins with a value as receiver requires boxing.
         __ jmp(&miss);
       } else {
         Label fast;
         // Check that the object is a smi or a heap number.
         __ tst(r1, Operand(kSmiTagMask));
         __ b(eq, &fast);
         __ CompareObjectType(r1, r0, r0, HEAP_NUMBER_TYPE);
         __ b(ne, &miss);
         __ bind(&fast);
         // Check that the maps starting from the prototype haven't changed.
         GenerateDirectLoadGlobalFunctionPrototype(
             masm(), Context::NUMBER_FUNCTION_INDEX, r0);
         CheckPrototypes(JSObject::cast(object->GetPrototype()), r0, holder, r3,
-                        r1, name, &miss);
+                        r1, name, &miss, r4);
       }
       break;
     }
 
     case BOOLEAN_CHECK: {
       if (!function->IsBuiltin()) {
         // Calling non-builtins with a value as receiver requires boxing.
         __ jmp(&miss);
       } else {
         Label fast;
         // Check that the object is a boolean.
         __ LoadRoot(ip, Heap::kTrueValueRootIndex);
         __ cmp(r1, ip);
         __ b(eq, &fast);
         __ LoadRoot(ip, Heap::kFalseValueRootIndex);
         __ cmp(r1, ip);
         __ b(ne, &miss);
         __ bind(&fast);
         // Check that the maps starting from the prototype haven't changed.
         GenerateDirectLoadGlobalFunctionPrototype(
             masm(), Context::BOOLEAN_FUNCTION_INDEX, r0);
         CheckPrototypes(JSObject::cast(object->GetPrototype()), r0, holder, r3,
-                        r1, name, &miss);
+                        r1, name, &miss, r4);
       }
       break;
     }
 
     default:
       UNREACHABLE();
   }
 
   if (depth != kInvalidProtoDepth) {
     GenerateFastApiCall(masm(), optimization, argc);
@@ skipping 84 matching lines @@
 
   // If the object is the holder then we know that it's a global
   // object which can only happen for contextual calls. In this case,
   // the receiver cannot be a smi.
   if (object != holder) {
     __ tst(r0, Operand(kSmiTagMask));
     __ b(eq, &miss);
   }
 
   // Check that the maps haven't changed.
-  CheckPrototypes(object, r0, holder, r3, r1, name, &miss);
+  CheckPrototypes(object, r0, holder, r3, r1, name, &miss, r4);
 
   // Get the value from the cell.
   __ mov(r3, Operand(Handle<JSGlobalPropertyCell>(cell)));
   __ ldr(r1, FieldMemOperand(r3, JSGlobalPropertyCell::kValueOffset));
 
   // Check that the cell contains the same function.
   if (Heap::InNewSpace(function)) {
     // We can't embed a pointer to a function in new space so we have
     // to verify that the shared function info is unchanged. This has
     // the nice side effect that multiple closures based on the same
@@ skipping 203 matching lines @@
   //  -- r0    : receiver
   //  -- lr    : return address
   // -----------------------------------
   Label miss;
 
   // Check that receiver is not a smi.
   __ tst(r0, Operand(kSmiTagMask));
   __ b(eq, &miss);
 
   // Check the maps of the full prototype chain.
-  CheckPrototypes(object, r0, last, r3, r1, name, &miss);
+  CheckPrototypes(object, r0, last, r3, r1, name, &miss, r4);
 
   // If the last object in the prototype chain is a global object,
   // check that the global property cell is empty.
   if (last->IsGlobalObject()) {
     Object* cell = GenerateCheckPropertyCell(masm(),
                                              GlobalObject::cast(last),
                                              name,
                                              r1,
                                              &miss);
     if (cell->IsFailure()) return cell;
@@ skipping 119 matching lines @@
 
   // If the object is the holder then we know that it's a global
   // object which can only happen for contextual calls. In this case,
   // the receiver cannot be a smi.
   if (object != holder) {
     __ tst(r0, Operand(kSmiTagMask));
     __ b(eq, &miss);
   }
 
   // Check that the map of the global has not changed.
-  CheckPrototypes(object, r0, holder, r3, r4, name, &miss);
+  CheckPrototypes(object, r0, holder, r3, r4, name, &miss, r1);
 
   // Get the value from the cell.
   __ mov(r3, Operand(Handle<JSGlobalPropertyCell>(cell)));
   __ ldr(r4, FieldMemOperand(r3, JSGlobalPropertyCell::kValueOffset));
 
   // Check for deleted property if property can actually be deleted.
   if (!is_dont_delete) {
     __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
     __ cmp(r4, ip);
     __ b(eq, &miss);
@@ skipping 353 matching lines @@
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM