Fixes bug where we would occasionally materialize a corrupted object.

runtime/vm/flow_graph_compiler.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"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
@@ skipping 531 matching lines @@
     }
 
     intptr_t register_bit_count = bitmap->Length() - StackSize();
     stackmap_table_builder_->AddEntry(assembler()->CodeSize(),
                                       bitmap,
                                       register_bit_count);
   }
 }
 
 
-// This function must be in sync with FlowGraphCompiler::RecordSafepoint and
-// FlowGraphCompiler::SaveLiveRegisters.
+// This function must be kept in sync with:
+//
+//     FlowGraphCompiler::RecordSafepoint
+//     FlowGraphCompiler::SaveLiveRegisters
+//     MaterializeObjectInstr::RemapRegisters
+//
 Environment* FlowGraphCompiler::SlowPathEnvironmentFor(
     Instruction* instruction) {
-  if (instruction->env() == NULL) return NULL;
+  if (instruction->env() == NULL) {
+    ASSERT(!is_optimizing());
+    return NULL;
+  }
 
   Environment* env = instruction->env()->DeepCopy();
   // 1. Iterate the registers in the order they will be spilled to compute
   //    the slots they will be spilled to.
   intptr_t next_slot = StackSize();
   RegisterSet* regs = instruction->locs()->live_registers();
   intptr_t fpu_reg_slots[kNumberOfFpuRegisters];
   intptr_t cpu_reg_slots[kNumberOfCpuRegisters];
   const intptr_t kFpuRegisterSpillFactor = kFpuRegisterSize / kWordSize;
   // FPU registers are spilled first from highest to lowest register number.
@@ skipping 37 matching lines @@
           it.SetCurrentLocation(Location::DoubleStackSlot(index));
           break;
         case kUnboxedFloat32x4:
         case kUnboxedInt32x4:
         case kUnboxedFloat64x2:
           it.SetCurrentLocation(Location::QuadStackSlot(index));
           break;
         default:
           UNREACHABLE();
       }
+    } else if (loc.IsInvalid()) {
+      Definition* def =
+          it.CurrentValue()->definition();
+      ASSERT(def != NULL);
+      if (def->IsMaterializeObject()) {
+        def->AsMaterializeObject()->RemapRegisters(fpu_reg_slots,
+                                                   cpu_reg_slots);
+      }
     }
   }
-
   return env;
 }
 
 
 Label* FlowGraphCompiler::AddDeoptStub(intptr_t deopt_id,
                                        DeoptReasonId reason) {
   ASSERT(is_optimizing_);
   CompilerDeoptInfoWithStub* stub =
       new CompilerDeoptInfoWithStub(deopt_id,
                                     reason,
@@ skipping 654 matching lines @@
 
   for (int i = 0; i < len; i++) {
     sorted->Add(CidTarget(ic_data.GetReceiverClassIdAt(i),
                           &Function::ZoneHandle(ic_data.GetTargetAt(i)),
                           ic_data.GetCountAt(i)));
   }
   sorted->Sort(HighestCountFirst);
 }
 
 }  // namespace dart