Ensure consistency of representations when replacing integer ops with constants

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/bootstrap.h"
 #include "vm/compiler.h"
 #include "vm/constant_propagator.h"
@@ skipping 1717 matching lines @@
       // specialized instructions that use this value under this assumption.
       return Integer::null();
     }
     result ^= result.CheckAndCanonicalize(NULL);
   }
 
   return result.raw();
 }
 
 
+Definition* BinaryIntegerOpInstr::CreateConstantResult(FlowGraph* flow_graph,
+                                                       const Integer& result) {
+  Definition* result_defn = flow_graph->GetConstant(result);
+  if (representation() != kTagged) {
+    result_defn = UnboxInstr::Create(representation(),
+                                     new Value(result_defn),
+                                     GetDeoptId());
+    flow_graph->InsertBefore(this, result_defn, env(), FlowGraph::kValue);
+  }
+  return result_defn;
+}
+
+
 Definition* BinaryIntegerOpInstr::Canonicalize(FlowGraph* flow_graph) {
   // If both operands are constants evaluate this expression. Might
   // occur due to load forwarding after constant propagation pass
   // have already been run.
   if (left()->BindsToConstant() &&
       left()->BoundConstant().IsInteger() &&
       right()->BindsToConstant() &&
       right()->BoundConstant().IsInteger()) {
     const Integer& result = Integer::Handle(
         Evaluate(Integer::Cast(left()->BoundConstant()),
                  Integer::Cast(right()->BoundConstant())));
     if (!result.IsNull()) {
-      return flow_graph->GetConstant(result);
+      return CreateConstantResult(flow_graph, result);
     }
   }
 
   if (left()->BindsToConstant() &&
       !right()->BindsToConstant() &&
       IsCommutative(op_kind())) {
     Value* l = left();
     Value* r = right();
     SetInputAt(0, r);
     SetInputAt(1, l);
@@ skipping 104 matching lines @@
       }
       break;
 
     case Token::kSHR:
       if (rhs == 0) {
         return left()->definition();
       } else if (rhs < 0) {
         DeoptimizeInstr* deopt =
             new DeoptimizeInstr(ICData::kDeoptBinarySmiOp, GetDeoptId());
         flow_graph->InsertBefore(this, deopt, env(), FlowGraph::kEffect);
-        return flow_graph->GetConstant(Smi::Handle(Smi::New(0)));
+        return CreateConstantResult(flow_graph, Integer::Handle(Smi::New(0)));
       }
       break;
 
     case Token::kSHL: {
       const intptr_t kMaxShift = RepresentationBits(representation()) - 1;
       if (rhs == 0) {
         return left()->definition();
       } else if ((rhs < 0) || (rhs >= kMaxShift)) {
         if ((rhs < 0) || !is_truncating()) {
           DeoptimizeInstr* deopt =
               new DeoptimizeInstr(ICData::kDeoptBinarySmiOp, GetDeoptId());
           flow_graph->InsertBefore(this, deopt, env(), FlowGraph::kEffect);
         }
-        return flow_graph->GetConstant(Smi::Handle(Smi::New(0)));
+        return CreateConstantResult(flow_graph, Integer::Handle(Smi::New(0)));
       }
       break;
     }
 
     default:
       break;
   }
 
   return this;
 }
@@ skipping 295 matching lines @@
   return this;
 }
 
 
 Definition* UnboxIntegerInstr::Canonicalize(FlowGraph* flow_graph) {
   if (!HasUses() && !CanDeoptimize()) return NULL;
 
   // Fold away UnboxInteger<rep_to>(BoxInteger<rep_from>(v)).
   BoxIntegerInstr* box_defn = value()->definition()->AsBoxInteger();
   if (box_defn != NULL) {
-    if (box_defn->value()->definition()->representation() == representation()) {
+    Representation from_representation =
+        box_defn->value()->definition()->representation();
+    if (from_representation == representation()) {
       return box_defn->value()->definition();
     } else {
       UnboxedIntConverterInstr* converter = new UnboxedIntConverterInstr(
-          box_defn->value()->definition()->representation(),
+          from_representation,
           representation(),
           box_defn->value()->CopyWithType(),
           (representation() == kUnboxedInt32) ?
               GetDeoptId() : Thread::kNoDeoptId);
       // TODO(vegorov): marking resulting converter as truncating when
       // unboxing can't deoptimize is a workaround for the missing
       // deoptimization environment when we insert converter after
       // EliminateEnvironments and there is a mismatch between predicates
       // UnboxIntConverterInstr::CanDeoptimize and UnboxInt32::CanDeoptimize.
       if ((representation() == kUnboxedInt32) &&
@@ skipping 1458 matching lines @@
   set_native_c_function(native_function);
   function().SetIsNativeAutoSetupScope(auto_setup_scope);
   Dart_NativeEntryResolver resolver = library.native_entry_resolver();
   bool is_bootstrap_native = Bootstrap::IsBootstapResolver(resolver);
   set_is_bootstrap_native(is_bootstrap_native);
 }
 
 #undef __
 
 }  // namespace dart