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

runtime/vm/stub_code_ia32.cc

 // Copyright (c) 2011, 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"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
 #include "vm/object_store.h"
@@ skipping 1804 matching lines @@
   __ cmpl(EDX, ECX);
   __ j(NOT_EQUAL, &super_loop, Assembler::kNearJump);
   __ jmp(&found, Assembler::kNearJump);
 }
 
 
 // Used to check class and type arguments. Arguments passed on stack:
 // TOS + 0: return address.
 // TOS + 1: instantiator type arguments (can be NULL).
 // TOS + 2: instance.
-// TOS + 3: cache array.
+// TOS + 3: SubtypeTestCache.
 // Result in ECX: null -> not found, otherwise result (true or false).
 static void GenerateSubtypeNTestCacheStub(Assembler* assembler, int n) {
   ASSERT((1 <= n) && (n <= 3));
   const intptr_t kInstantiatorTypeArgumentsInBytes = 1 * kWordSize;
   const intptr_t kInstanceOffsetInBytes = 2 * kWordSize;
-  const intptr_t kCacheArrayOffsetInBytes = 3 * kWordSize;
+  const intptr_t kCacheOffsetInBytes = 3 * kWordSize;
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   Label not_found;
   __ movl(EAX, Address(ESP, kInstanceOffsetInBytes));
   __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
   // EAX: instance, ECX: instance-class.
   // Get instance type arguments
   if (n > 1) {
     // Compute instance type arguments into EBX.
     Label has_no_type_arguments;
     __ movl(EBX, raw_null);
     __ movl(EDI, FieldAddress(ECX,
         Class::type_arguments_instance_field_offset_offset()));
     __ cmpl(EDI, Immediate(Class::kNoTypeArguments));
     __ j(EQUAL, &has_no_type_arguments, Assembler::kNearJump);
     __ movl(EBX, FieldAddress(EAX, EDI, TIMES_1, 0));
     __ Bind(&has_no_type_arguments);
   }
   // EBX: instance type arguments (null if none).
-  __ movl(EDX, Address(ESP, kCacheArrayOffsetInBytes));
-  // EDX: cache.
+  __ movl(EDX, Address(ESP, kCacheOffsetInBytes));
+  // EDX: SubtypeTestCache.
+  __ movl(EDX, FieldAddress(EDX, SubtypeTestCache::cache_offset()));
   __ addl(EDX, Immediate(Array::data_offset() - kHeapObjectTag));
 
   Label loop, found, next_iteration;
   // EDX: Entry start.
   // ECX: instance class.
   // EBX: instance type arguments
   __ Bind(&loop);
-  __ movl(EDI, Address(EDX, kWordSize * SubTypeTestCache::kInstanceClass));
+  __ movl(EDI, Address(EDX, kWordSize * SubtypeTestCache::kInstanceClass));
   __ cmpl(EDI, raw_null);
   __ j(EQUAL, &not_found, Assembler::kNearJump);
   __ cmpl(EDI, ECX);
   if (n == 1) {
     __ j(EQUAL, &found, Assembler::kNearJump);
   } else {
     __ j(NOT_EQUAL, &next_iteration, Assembler::kNearJump);
     __ movl(EDI,
-          Address(EDX, kWordSize * SubTypeTestCache::kInstanceTypeArguments));
+          Address(EDX, kWordSize * SubtypeTestCache::kInstanceTypeArguments));
     __ cmpl(EDI, EBX);
     if (n == 2) {
       __ j(EQUAL, &found, Assembler::kNearJump);
     } else {
       __ j(NOT_EQUAL, &next_iteration, Assembler::kNearJump);
       __ movl(EDI,
               Address(EDX, kWordSize *
-                           SubTypeTestCache::kInstantiatorTypeArguments));
+                           SubtypeTestCache::kInstantiatorTypeArguments));
       __ cmpl(EDI, Address(ESP, kInstantiatorTypeArgumentsInBytes));
       __ j(EQUAL, &found, Assembler::kNearJump);
     }
   }
   __ Bind(&next_iteration);
-  __ addl(EDX, Immediate(kWordSize * SubTypeTestCache::kNumEntries));
+  __ addl(EDX, Immediate(kWordSize * SubtypeTestCache::kTestEntryLength));
   __ jmp(&loop, Assembler::kNearJump);
   // Fall through to not found.
   __ Bind(&not_found);
   __ movl(ECX, raw_null);
   __ ret();
 
   __ Bind(&found);
-  __ movl(ECX, Address(EDX, kWordSize * SubTypeTestCache::kTestResult));
+  __ movl(ECX, Address(EDX, kWordSize * SubtypeTestCache::kTestResult));
   __ ret();
 }
 
 
 // Used to check class and type arguments. Arguments passed on stack:
 // TOS + 0: return address.
 // TOS + 1: instantiator type arguments or NULL.
 // TOS + 2: instance.
 // TOS + 3: cache array.
 // Result in ECX: null -> not found, otherwise result (true or false).
@@ skipping 19 matching lines @@
 // TOS + 2: instance.
 // TOS + 3: cache array.
 // Result in ECX: null -> not found, otherwise result (true or false).
 void StubCode::GenerateSubtype3TestCacheStub(Assembler* assembler) {
   GenerateSubtypeNTestCacheStub(assembler, 3);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32