DBC: Adds DecodeLoadObjectFromPoolOrThread, enables tests

runtime/vm/instructions_dbc.cc

 // Copyright (c) 2016, 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_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/instructions.h"
 #include "vm/instructions_dbc.h"
 
@@ skipping 91 matching lines @@
 // and the index in the pool being read from in the output parameters 'reg'
 // and 'index' respectively.
 uword InstructionPattern::DecodeLoadWordFromPool(uword end,
                                                  Register* reg,
                                                  intptr_t* index) {
   UNIMPLEMENTED();
   return 0;
 }
 
 
+static bool HasLoadFromPool(Instr instr) {
+  switch (Bytecode::DecodeOpcode(instr)) {
+    case Bytecode::kLoadConstant:
+    case Bytecode::kPushConstant:
+    case Bytecode::kStaticCall:
+    case Bytecode::kInstanceCall:
+    case Bytecode::kInstanceCall2:
+    case Bytecode::kInstanceCall3:
+    case Bytecode::kStoreStaticTOS:
+    case Bytecode::kPushStatic:
+    case Bytecode::kAllocate:
+    case Bytecode::kInstantiateType:
+    case Bytecode::kInstantiateTypeArgumentsTOS:
+    case Bytecode::kAssertAssignable:
+      return true;
+    default:
+      return false;
+  }
+}
+
+
 bool DecodeLoadObjectFromPoolOrThread(uword pc,
                                       const Code& code,
                                       Object* obj) {
-  UNIMPLEMENTED();
+  ASSERT(code.ContainsInstructionAt(pc));
+  Instr instr = Bytecode::At(pc);
+  if (HasLoadFromPool(instr)) {
+    uint16_t index = Bytecode::DecodeD(instr);
+    const ObjectPool& pool = ObjectPool::Handle(code.object_pool());
+    if (pool.InfoAt(index) == ObjectPool::kTaggedObject) {
+      *obj = pool.ObjectAt(index);
+      return true;
+    }
+  }
   return false;
 }
 
 
 RawICData* CallPattern::IcData() {
   UNIMPLEMENTED();
   return ICData::null();
 }
 
 
@@ skipping 45 matching lines @@
 
 
 bool ReturnPattern::IsValid() const {
   UNIMPLEMENTED();
   return false;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC