VM: Fix bugs with missing deoptimization environment and int32x4 constructor

runtime/vm/intermediate_language_x64.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_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 3419 matching lines @@
   const intptr_t value_cid = value()->Type()->ToCid();
   const Register value = locs()->in(0).reg();
   Label* deopt = CanDeoptimize() ?
       compiler->AddDeoptStub(GetDeoptId(), ICData::kDeoptUnboxInteger) : NULL;
   ASSERT(value == locs()->out(0).reg());
 
   if (value_cid == kSmiCid) {
     __ SmiUntag(value);
   } else if (value_cid == kMintCid) {
     __ movq(value, FieldAddress(value, Mint::value_offset()));
+  } else if (!CanDeoptimize()) {
+    // Type information is not conclusive, but range analysis found
+    // the value to be in int64 range. Therefore it must be a smi
+    // or mint value.
+    ASSERT(is_truncating());
+    Label done;
+    __ SmiUntag(value);
+    __ j(NOT_CARRY, &done, Assembler::kNearJump);
+    __ movq(value, Address(value, TIMES_2, Mint::value_offset()));
+    __ Bind(&done);
+    return;
   } else {
     Label done;
     // Optimistically untag value.
     __ SmiUntagOrCheckClass(value, kMintCid, &done);
     __ j(NOT_EQUAL, deopt);
     // Undo untagging by multiplying value with 2.
     __ movq(value, Address(value, TIMES_2, Mint::value_offset()));
     __ Bind(&done);
   }
 
@@ skipping 3001 matching lines @@
   __ Drop(1);
   __ popq(result);
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64