Using SubtypeTestCache object instead of an array, that way we do not need to patch and can communi…

runtime/vm/code_generator_ia32.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/code_generator.h"
 
 #include "lib/error.h"
@@ skipping 1247 matching lines @@
   return &cls;
 }
 
 
 // Instance to test is in EAX. Test if its class is in subtype test cache array
 // and use the result in the array to jump to one of the labels. Fall through
 // if the instance is not in the cache array.
 // TODO(srdjan): Implement a quicker subtype check, as type test
 // arrays can grow too high, but they may be useful when optimizing
 // code (type-feedback).
-void CodeGenerator::GenerateSubtype1TestCacheLookup(
+RawSubtypeTestCache* CodeGenerator::GenerateSubtype1TestCacheLookup(
     intptr_t node_id,
     intptr_t token_index,
     const Class& type_class,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
+  const SubtypeTestCache& type_test_cache =
+      SubtypeTestCache::ZoneHandle(SubtypeTestCache::New());
   const Bool& bool_true = Bool::ZoneHandle(Bool::True());
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   Label loop, found_in_cache, runtime_call;
   // Check immediate equality.
   __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
   // ECX: instance class.
   __ CompareObject(ECX, type_class);
   __ j(EQUAL, is_instance_lbl);
 
   // Check immediate superclass equality.
   __ movl(EDI, FieldAddress(ECX, Class::super_type_offset()));
   __ movl(EDI, FieldAddress(EDI, Type::type_class_offset()));
   __ CompareObject(EDI, type_class);
   __ j(EQUAL, is_instance_lbl);
 
-  AddCurrentDescriptor(PcDescriptors::kTypeTest, node_id, token_index);
-  __ LoadObject(EDX, Array::ZoneHandle(
-      Array::New(SubTypeTestCache::kNumEntries)));
+  __ LoadObject(EDX, type_test_cache);
   __ pushl(EDX);  // Cache array.
   __ pushl(EAX);  // Instance.
   __ pushl(raw_null);  // Unused
   __ call(&StubCode::Subtype1TestCacheLabel());
   __ popl(EAX);  // Discard.
   __ popl(EAX);  // Restore receiver.
   __ popl(EDX);  // Discard.
   // Result is in ECX: null -> not found, otherwise Bool::True or Bool::False.
 
   __ cmpl(ECX, raw_null);
   __ j(EQUAL, &runtime_call, Assembler::kNearJump);
   __ CompareObject(ECX, bool_true);
   __ j(EQUAL, is_instance_lbl);
   __ jmp(is_not_instance_lbl);
   __ Bind(&runtime_call);
+  return type_test_cache.raw();
 }
 
 
 // Inline tests according to the 'type' being tested. Jump to labels
 // if we can compute the type-test, otherwise fallthrough.
 // EAX: instance to be tested, must be preserved.
 // Clobbers many registers.
-void CodeGenerator::GenerateInlineInstanceof(intptr_t node_id,
-                                             intptr_t token_index,
-                                             const AbstractType& type,
-                                             Label* is_instance_lbl,
-                                             Label* is_not_instance_lbl) {
+RawSubtypeTestCache* CodeGenerator::GenerateInlineInstanceof(
+    intptr_t node_id,
+    intptr_t token_index,
+    const AbstractType& type,
+    Label* is_instance_lbl,
+    Label* is_not_instance_lbl) {
   if (type.IsInstantiated()) {
     const Class& type_class = Class::ZoneHandle(type.type_class());
     // A Smi object cannot be the instance of a parameterized class.
     // A class equality check is only applicable with a dst type of a
     // non-parameterized class or with a raw dst type of a parameterized class.
     if (type_class.HasTypeArguments()) {
-      GenerateInstantiatedTypeWithArgumentsTest(node_id,
-                                                token_index,
-                                                type,
-                                                is_instance_lbl,
-                                                is_not_instance_lbl);
+      return GenerateInstantiatedTypeWithArgumentsTest(node_id,
+                                                       token_index,
+                                                       type,
+                                                       is_instance_lbl,
+                                                       is_not_instance_lbl);
       // Fall through to runtime call.
     } else {
       GenerateInstantiatedTypeNoArgumentsTest(node_id,
                                               token_index,
                                               type,
                                               is_instance_lbl,
                                               is_not_instance_lbl);
       // If test non-conclusive so far, try the inlined type-test cache.
       // 'type' is known at compile time.
-      GenerateSubtype1TestCacheLookup(node_id, token_index, type_class,
-                                      is_instance_lbl, is_not_instance_lbl);
+      return GenerateSubtype1TestCacheLookup(
+          node_id, token_index, type_class,
+          is_instance_lbl, is_not_instance_lbl);
     }
   } else {
     GenerateUninstantiatedTypeTest(type,
                                    token_index,
                                    is_instance_lbl);
   }
+  return SubtypeTestCache::null();
 }
 
 
 // If instanceof type test cannot be performed successfully at compile time and
 // therefore eliminated, optimize it by adding inlined tests for:
 // - NULL -> return false.
 // - Smi -> compile time subtype check (only if dst class is not parameterized).
 // - Class equality (only if class is not parameterized).
 // Inputs:
 // - EAX: object.
@@ skipping 60 matching lines @@
     // We can only inline this null check if the type is instantiated at compile
     // time, since an uninstantiated type at compile time could be Object or
     // Dynamic at run time.
     Label non_null;
     __ cmpl(EAX, raw_null);
     __ j(NOT_EQUAL, &non_null, Assembler::kNearJump);
     __ PushObject(negate_result ? bool_true : bool_false);
     __ jmp(&done);
     __ Bind(&non_null);
   }
-
-  GenerateInlineInstanceof(node_id, token_index, type,
-                           &is_instance_of, &is_not_instance_of);
+  SubtypeTestCache& test_cache = SubtypeTestCache::ZoneHandle();
+  test_cache = GenerateInlineInstanceof(node_id, token_index, type,
+                                        &is_instance_of, &is_not_instance_of);
 
   __ PushObject(Object::ZoneHandle());  // Make room for the result.
   const Immediate location = Immediate(Smi::RawValue(token_index));
   const Immediate node_id_as_smi = Immediate(Smi::RawValue(node_id));
   __ pushl(location);  // Push the source location.
   __ pushl(node_id_as_smi);  // node-id.
   __ pushl(EAX);  // Push the instance.
   __ PushObject(type);  // Push the type.
   if (!type.IsInstantiated()) {
     GenerateInstantiatorTypeArguments(token_index);
   } else {
     __ pushl(raw_null);  // Null instantiator.
   }
+  __ LoadObject(EAX, test_cache);
+  __ pushl(EAX);
   GenerateCallRuntime(node_id, token_index, kInstanceofRuntimeEntry);
   // Pop the two parameters supplied to the runtime entry. The result of the
   // instanceof runtime call will be left as the result of the operation.
-  __ addl(ESP, Immediate(5 * kWordSize));
+  __ addl(ESP, Immediate(6 * kWordSize));
   if (negate_result) {
     __ popl(EDX);
     __ CompareObject(EDX, bool_false);
     __ j(EQUAL, &is_not_instance_of, Assembler::kNearJump);
     // Fall through to is_instance_of.
   } else {
     __ jmp(&done);
   }
 
   __ Bind(&is_instance_of);
   __ PushObject(negate_result ? bool_false: bool_true);
   __ jmp(&done, Assembler::kNearJump);
   __ Bind(&is_not_instance_of);
   __ PushObject(negate_result ? bool_true: bool_false);
   __ Bind(&done);
 }
 
 
 // EAX: instance to test.
 // Clobbers: ECX.
 // Jumps to labels 'is_instance' or 'is_not_instance' respectively, if
 // type test is conclusive, otherwise fallthrough if a type test could not
 // be completed.
-void CodeGenerator::GenerateInstantiatedTypeWithArgumentsTest(
+RawSubtypeTestCache* CodeGenerator::GenerateInstantiatedTypeWithArgumentsTest(
     intptr_t node_id,
     intptr_t token_index,
     const AbstractType& type,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   ASSERT(type.IsInstantiated());
   const Class& type_class = Class::ZoneHandle(type.type_class());
   ASSERT(type_class.HasTypeArguments());
   // A Smi object cannot be the instance of a parameterized class.
   // A class equality check is only applicable with a dst type of a
   // non-parameterized class or with a raw dst type of a parameterized class.
   __ testl(EAX, Immediate(kSmiTagMask));
   __ j(ZERO, is_not_instance_lbl);
   const AbstractTypeArguments& type_arguments =
       AbstractTypeArguments::ZoneHandle(type.arguments());
   const bool is_raw_type = type_arguments.IsNull() ||
       type_arguments.IsRaw(type_arguments.Length());
   if (is_raw_type) {
     // Dynamic type argument, check only classes.
     __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
     if (type.IsListInterface()) {
       // TODO(srdjan) also accept List<Object>.
       __ CompareObject(ECX, *CoreClass("ObjectArray"));
       __ j(EQUAL, is_instance_lbl);
       __ CompareObject(ECX, *CoreClass("GrowableObjectArray"));
       __ j(EQUAL, is_instance_lbl);
     }
-    GenerateSubtype1TestCacheLookup(node_id, token_index, type_class,
-                                    is_instance_lbl, is_not_instance_lbl);
-    return;
+    return
+        GenerateSubtype1TestCacheLookup(node_id, token_index, type_class,
+                                        is_instance_lbl, is_not_instance_lbl);
   }
   // Note that the test below must be synced with the tests in
   // CodeGenerator::UpdateTestCache.
   // Inline checks for one type argument only.
   if (type_arguments.Length() != 1) {
-    return;
+    return SubtypeTestCache::null();
   }
   const AbstractType& tp_argument =
       AbstractType::ZoneHandle(type_arguments.TypeAt(0));
   if (!tp_argument.IsType()) {
     // E.g., it is a TypeParameter.
-    return;
+    return SubtypeTestCache::null();
   }
   // Malformed type has been caught in the caller chain of this function.
   ASSERT(tp_argument.HasResolvedTypeClass());
   // Check if type argument is dynamic or Object.
   const Type& object_type =
       Type::Handle(Isolate::Current()->object_store()->object_type());
   Error& malformed_error = Error::Handle();
   if (object_type.IsSubtypeOf(tp_argument, &malformed_error)) {
     // Instance class test only necessary.
-    GenerateSubtype1TestCacheLookup(node_id, token_index, type_class,
-                                    is_instance_lbl, is_not_instance_lbl);
-    return;
+    return GenerateSubtype1TestCacheLookup(
+        node_id, token_index, type_class, is_instance_lbl, is_not_instance_lbl);
   }
+  const SubtypeTestCache& type_test_cache =
+      SubtypeTestCache::ZoneHandle(SubtypeTestCache::New());
   Label inlined_check, fall_through;
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
-  AddCurrentDescriptor(PcDescriptors::kTypeTest, node_id, token_index);
-  __ LoadObject(EDX, Array::ZoneHandle(
-      Array::New(SubTypeTestCache::kNumEntries)));
+  __ LoadObject(EDX, type_test_cache);
   __ pushl(EDX);  // Cache array.
   __ pushl(EAX);  // Instance.
   __ pushl(raw_null);  // Unused.
   __ call(&StubCode::Subtype2TestCacheLabel());
   __ popl(EAX);  // Discard.
   __ popl(EAX);  // Restore receiver.
   __ popl(EDX);  // Discard.
   // Result is in ECX: null -> not found, otherwise Bool::True or Bool::False.
 
   __ cmpl(ECX, raw_null);
   __ j(EQUAL, &fall_through, Assembler::kNearJump);
   const Bool& bool_true = Bool::ZoneHandle(Bool::True());
   __ CompareObject(ECX, bool_true);
   __ j(EQUAL, is_instance_lbl);
   __ jmp(is_not_instance_lbl);
   __ Bind(&fall_through);
+  return type_test_cache.raw();
 }
 
 
 // EAX: instance to test.
 // Clobbers: EBX, ECX, EDX.
 void CodeGenerator::GenerateInstantiatedTypeNoArgumentsTest(
     intptr_t node_id,
     intptr_t token_index,
     const AbstractType& type,
     Label* is_instance_lbl,
@@ skipping 239 matching lines @@
     __ PushObject(dst_name);  // Push the name of the destination.
     __ PushObject(error_message);
     GenerateCallRuntime(node_id, token_index, kMalformedTypeErrorRuntimeEntry);
     // We should never return here.
     __ int3();
 
     __ Bind(&done);  // For a null object.
     return;
   }
 
-  GenerateInlineInstanceof(node_id, token_index, dst_type,
-                           &done, &runtime_call);
+  SubtypeTestCache& test_cache = SubtypeTestCache::ZoneHandle();
+  test_cache = GenerateInlineInstanceof(node_id, token_index, dst_type,
+                                        &done, &runtime_call);
 
   __ Bind(&runtime_call);
   __ PushObject(Object::ZoneHandle());  // Make room for the result.
   __ pushl(Immediate(Smi::RawValue(token_index)));  // Source location.
   __ pushl(Immediate(Smi::RawValue(node_id)));  // node-id.
   __ pushl(EAX);  // Push the source object.
   __ PushObject(dst_type);  // Push the type of the destination.
   if (dst_type.IsInstantiated()) {
     __ pushl(raw_null);  // Null instantiator.
   } else {
     GenerateInstantiatorTypeArguments(token_index);
   }
   __ PushObject(dst_name);  // Push the name of the destination.
+  __ LoadObject(EAX, test_cache);
+  __ pushl(EAX);
   GenerateCallRuntime(node_id, token_index, kTypeCheckRuntimeEntry);
   // Pop the parameters supplied to the runtime entry. The result of the
   // type check runtime call is the checked value.
-  __ addl(ESP, Immediate(6 * kWordSize));
+  __ addl(ESP, Immediate(7 * kWordSize));
   __ popl(EAX);
 
   // EAX: value.
   __ Bind(&done);
 }
 
 
 void CodeGenerator::GenerateArgumentTypeChecks() {
   const Function& function = parsed_function_.function();
   const SequenceNode& sequence_node = *parsed_function_.node_sequence();
@@ skipping 1128 matching lines @@
   const Error& error = Error::Handle(
       Parser::FormatError(script, token_index, "Error", format, args));
   va_end(args);
   Isolate::Current()->long_jump_base()->Jump(1, error);
   UNREACHABLE();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32