DBC: Enables unboxed doubles

runtime/vm/deopt_instructions.h

 // 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.
 
 #ifndef VM_DEOPT_INSTRUCTIONS_H_
 #define VM_DEOPT_INSTRUCTIONS_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
@@ skipping 68 matching lines @@
     // On DBC registers and stack slots are the same.
     const intptr_t stack_index = num_args_ + kDartFrameFixedSize + reg;
     return *GetSourceFrameAddressAt(stack_index);
 #endif  // !defined(TARGET_ARCH_DBC)
   }
 
   double FpuRegisterValue(FpuRegister reg) const {
     ASSERT(FlowGraphCompiler::SupportsUnboxedDoubles());
     ASSERT(fpu_registers_ != NULL);
     ASSERT(reg >= 0);
+#if !defined(TARGET_ARCH_DBC)
     ASSERT(reg < kNumberOfFpuRegisters);
     return *reinterpret_cast<double*>(&fpu_registers_[reg]);
+#else
+    // On DBC registers and stack slots are the same.
+    const intptr_t stack_index = num_args_ + kDartFrameFixedSize + reg;
+    return *reinterpret_cast<double*>(GetSourceFrameAddressAt(stack_index));
+#endif
   }
 
   simd128_value_t FpuRegisterValueAsSimd128(FpuRegister reg) const {
     ASSERT(FlowGraphCompiler::SupportsUnboxedSimd128());
     ASSERT(fpu_registers_ != NULL);
     ASSERT(reg >= 0);
     ASSERT(reg < kNumberOfFpuRegisters);
     const float* address = reinterpret_cast<float*>(&fpu_registers_[reg]);
     return simd128_value_t().readFrom(address);
   }
@@ skipping 492 matching lines @@
       public BitField<intptr_t, ICData::DeoptReasonId, 0, 8> { };
   class FlagsField : public BitField<intptr_t, uint32_t, 8, 8> { };
 
  private:
   static const intptr_t kEntrySize = 3;
 };
 
 }  // namespace dart
 
 #endif  // VM_DEOPT_INSTRUCTIONS_H_