Add range information to external array loads.

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 1321 matching lines @@
           : new Range();
       result->Shl(c->Integer32Value());
       result->set_can_be_minus_zero(false);
       return result;
     }
   }
   return HValue::InferRange();
 }
 
 
+Range* HLoadKeyedSpecializedArrayElement::InferRange() {
+  switch (elements_kind()) {
+    case EXTERNAL_PIXEL_ELEMENTS:
+      return new Range(0, 255);
+    case EXTERNAL_BYTE_ELEMENTS:
+      return new Range(-128, 127);
+    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
+      return new Range(0, 255);
+    case EXTERNAL_SHORT_ELEMENTS:
+      return new Range(-32768, 32767);
+    case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
+      return new Range(0, 65535);
+    default:
+      return HValue::InferRange();
+  }
+}
+
 
 void HCompareGeneric::PrintDataTo(StringStream* stream) {
   stream->Add(Token::Name(token()));
   stream->Add(" ");
   HBinaryOperation::PrintDataTo(stream);
 }
 
 
 void HStringCompareAndBranch::PrintDataTo(StringStream* stream) {
   stream->Add(Token::Name(token()));
@@ skipping 777 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal