- Correctly handle negative constant indices when

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 "lib/error.h"
@@ skipping 3924 matching lines @@
 }
 
 
 void CheckArrayBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptCheckArrayBound);
 
   Location length_loc = locs()->in(kLengthPos);
   Location index_loc = locs()->in(kIndexPos);
 
   if (length_loc.IsConstant() && index_loc.IsConstant()) {
+    // TODO(srdjan): remove this code once failures are fixed.
+    if ((Smi::Cast(length_loc.constant()).Value() >
+         Smi::Cast(index_loc.constant()).Value()) &&
+        (Smi::Cast(index_loc.constant()).Value() >= 0)) {
+      // This CheckArrayBoundInstr should have been eliminated.
+      return;
+    }
     ASSERT((Smi::Cast(length_loc.constant()).Value() <=
             Smi::Cast(index_loc.constant()).Value()) ||
            (Smi::Cast(index_loc.constant()).Value() < 0));
     // Unconditionally deoptimize for constant bounds checks because they
     // only occur only when index is out-of-bounds.
     __ jmp(deopt);
     return;
   }
 
   if (index_loc.IsConstant()) {
@@ skipping 364 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64