ARM & MIPS: Try to use the object pool before trying to embed a pointer, like ARM64 and X64.

runtime/vm/assembler_mips.cc

 // Copyright (c) 2013, 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"  // NOLINT
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/longjump.h"
 #include "vm/runtime_entry.h"
@@ skipping 488 matching lines @@
                            Patchability patchable) {
   BranchLink(&stub_entry.label(), patchable);
 }
 
 
 void Assembler::BranchLinkPatchable(const StubEntry& stub_entry) {
   BranchLink(&stub_entry.label(), kPatchable);
 }
 
 
+bool Assembler::CanLoadFromObjectPool(const Object& object) const {
+  ASSERT(!Thread::CanLoadFromThread(object));
+  if (!constant_pool_allowed()) {
+    return false;
+  }
+
+  ASSERT(object.IsNotTemporaryScopedHandle());
+  ASSERT(object.IsOld());
+  return true;
+}
+
+
 void Assembler::LoadObjectHelper(Register rd,
                                  const Object& object,
                                  bool is_unique) {
-  // Load common VM constants from the thread. This works also in places where
-  // no constant pool is set up (e.g. intrinsic code).
+  ASSERT(!in_delay_slot_);
   if (Thread::CanLoadFromThread(object)) {
+    // Load common VM constants from the thread. This works also in places where
+    // no constant pool is set up (e.g. intrinsic code).
     lw(rd, Address(THR, Thread::OffsetFromThread(object)));
-    return;
-  }
-  ASSERT(!in_delay_slot_);
-  // Smis and VM heap objects are never relocated; do not use object pool.
-  if (object.IsSmi()) {
+  } else if (object.IsSmi()) {
+    // Relocation doesn't apply to Smis.
     LoadImmediate(rd, reinterpret_cast<int32_t>(object.raw()));
-  } else if (object.InVMHeap() || !constant_pool_allowed()) {
+  } else if (CanLoadFromObjectPool(object)) {
+    // Make sure that class CallPattern is able to decode this load from the
+    // object pool.
+    const int32_t offset = ObjectPool::element_offset(
+        is_unique ? object_pool_wrapper_.AddObject(object)
+                  : object_pool_wrapper_.FindObject(object));
+    LoadWordFromPoolOffset(rd, offset - kHeapObjectTag);
+  } else {
     ASSERT(FLAG_allow_absolute_addresses);
+    ASSERT(object.IsOld());
     // Make sure that class CallPattern is able to decode this load immediate.

[Florian Schneider, 2015/09/16 08:00:05]

Comment does not apply here.

     int32_t object_raw = reinterpret_cast<int32_t>(object.raw());
     const uint16_t object_low = Utils::Low16Bits(object_raw);
     const uint16_t object_high = Utils::High16Bits(object_raw);
     lui(rd, Immediate(object_high));
     ori(rd, rd, Immediate(object_low));
-  } else {
-    // Make sure that class CallPattern is able to decode this load from the
-    // object pool.
-    const int32_t offset = ObjectPool::element_offset(
-        is_unique ? object_pool_wrapper_.AddObject(object)
-                  : object_pool_wrapper_.FindObject(object));
-    LoadWordFromPoolOffset(rd, offset - kHeapObjectTag);
   }
 }
 
 
 void Assembler::LoadObject(Register rd, const Object& object) {
   LoadObjectHelper(rd, object, false);
 }
 
 
 void Assembler::LoadUniqueObject(Register rd, const Object& object) {
@@ skipping 787 matching lines @@
   Label stop;
   b(&stop);
   Emit(reinterpret_cast<int32_t>(message));
   Bind(&stop);
   break_(Instr::kStopMessageCode);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS