Fix bug with missing unboxed mint-to-double conversion.

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2012, 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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 62 matching lines @@
         // For non-definitions Canonicalize should return either NULL or
         // this.
         ASSERT((replacement == NULL) || current->IsDefinition());
         ReplaceCurrentInstruction(&it, current, replacement);
       }
     }
   }
 }
 
 
-static Definition* CreateConversion(Representation from,
-                                    Representation to,
-                                    Definition* def,
-                                    Instruction* deopt_target) {
+void FlowGraphOptimizer::InsertConversion(Representation from,
+                                          Representation to,
+                                          Instruction* instr,
+                                          Value* use,
+                                          Definition* def,
+                                          Instruction* deopt_target) {
+  Definition* converted = NULL;
   if ((from == kTagged) && (to == kUnboxedMint)) {
     const intptr_t deopt_id = (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
     ASSERT((deopt_target != NULL) || (def->GetPropagatedCid() == kDoubleCid));
-    return new UnboxIntegerInstr(new Value(def), deopt_id);
+    converted = new UnboxIntegerInstr(new Value(def), deopt_id);
   } else if ((from == kUnboxedMint) && (to == kTagged)) {
-    return new BoxIntegerInstr(new Value(def));
+    converted = new BoxIntegerInstr(new Value(def));
+  } else if (from == kUnboxedMint && to == kUnboxedDouble) {
+    // Convert by boxing/unboxing.
+    // TODO(fschneider): Implement direct unboxed mint-to-double conversion.
+    BoxIntegerInstr* boxed = new BoxIntegerInstr(new Value(def));
+    InsertBefore(instr, boxed, NULL, Definition::kValue);
+    const intptr_t deopt_id = (deopt_target != NULL) ?
+        deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
+    converted = new UnboxDoubleInstr(new Value(boxed), deopt_id);
   } else if ((from == kUnboxedDouble) && (to == kTagged)) {
-    return new BoxDoubleInstr(new Value(def), NULL);
+    converted = new BoxDoubleInstr(new Value(def), NULL);
   } else if ((from == kTagged) && (to == kUnboxedDouble)) {
     const intptr_t deopt_id = (deopt_target != NULL) ?
         deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
     ASSERT((deopt_target != NULL) || (def->GetPropagatedCid() == kDoubleCid));
-    return new UnboxDoubleInstr(new Value(def), deopt_id);
-  } else {
-    UNREACHABLE();
-    return NULL;
+    converted = new UnboxDoubleInstr(new Value(def), deopt_id);
   }
+  ASSERT(converted != NULL);
+  InsertBefore(instr, converted, use->instruction()->env(),
+               Definition::kValue);
+  use->set_definition(converted);
 }
 
 
 void FlowGraphOptimizer::InsertConversionsFor(Definition* def) {
   const Representation from_rep = def->representation();
 
   for (Value* use = def->input_use_list();
        use != NULL;
        use = use->next_use()) {
     const Representation to_rep =
         use->instruction()->RequiredInputRepresentation(use->use_index());
     if (from_rep == to_rep) {
       continue;
     }
 
     Instruction* deopt_target = NULL;
     Instruction* instr = use->instruction();
     if (instr->IsPhi()) {
       if (!instr->AsPhi()->is_alive()) continue;
 
       // For phis conversions have to be inserted in the predecessor.
       const BlockEntryInstr* pred =
           instr->AsPhi()->block()->PredecessorAt(use->use_index());
       instr = pred->last_instruction();
     } else {
       deopt_target = instr;
     }
 
-    Definition* converted =
-        CreateConversion(from_rep, to_rep, def, deopt_target);
-    InsertBefore(instr, converted, use->instruction()->env(),
-                 Definition::kValue);
-    use->set_definition(converted);
+    InsertConversion(from_rep, to_rep, instr, use, def, deopt_target);
   }
 }
 
 
 void FlowGraphOptimizer::SelectRepresentations() {
   // Convervatively unbox all phis that were proven to be of type Double.
   for (intptr_t i = 0; i < block_order_.length(); ++i) {
     JoinEntryInstr* join_entry = block_order_[i]->AsJoinEntry();
     if (join_entry == NULL) continue;
 
@@ skipping 3101 matching lines @@
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 
 }  // namespace dart