Improve representation inference for HUnknownOSRValue.

src/hydrogen-instructions.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2244 matching lines @@
   stream->Add(" ");
   object()->PrintNameTo(stream);
 }
 
 
 Representation HPhi::InferredRepresentation() {
   bool double_occurred = false;
   bool int32_occurred = false;
   for (int i = 0; i < OperandCount(); ++i) {
     HValue* value = OperandAt(i);
-    if (value->IsUnknownOSRValue()) continue;
+    if (value->IsUnknownOSRValue()) {
+      HPhi* hint_value = HUnknownOSRValue::cast(value)->incoming_value();
+      if (hint_value != NULL) {
+        Representation hint = hint_value->representation();
+        if (hint.IsDouble()) double_occurred = true;
+        if (hint.IsInteger32()) int32_occurred = true;
+      }
+      continue;
+    }
     if (value->representation().IsDouble()) double_occurred = true;
     if (value->representation().IsInteger32()) int32_occurred = true;
     if (value->representation().IsTagged()) {
       if (value->IsConstant()) {
         HConstant* constant = HConstant::cast(value);
         if (constant->IsConvertibleToInteger()) {
           int32_occurred = true;
         } else if (constant->HasNumberValue()) {
           double_occurred = true;
         } else {
@@ skipping 53 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal