Eliminate redundant smi checks

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 1694 matching lines @@
   stream->Add(".");
   stream->Add(*String::cast(*name())->ToCString());
 }
 
 
 void HLoadKeyedFastElement::PrintDataTo(StringStream* stream) {
   object()->PrintNameTo(stream);
   stream->Add("[");
   key()->PrintNameTo(stream);
   stream->Add("]");
-  if (hole_check_mode_ == PERFORM_HOLE_CHECK) {
+  if (IsFastHoleyElementsKind(elements_kind())) {

[Michael Starzinger, 2012/06/12 08:10:43]

It seems as if we don't need the hole_check_mode flag for this instruction
anymore, because it solely depends on the elements kind. Can we get rid of the
flag, move the IsFastHoleyElementsKind() into a
HLoadKeyedFastElements::MightHaveHoles() helper method and use this helper
method here?

[danno, 2012/06/12 09:59:22]

Done.

     stream->Add(" check_hole");
   }
 }
 
 
 bool HLoadKeyedFastElement::RequiresHoleCheck() {
-  if (hole_check_mode_ == OMIT_HOLE_CHECK) {
+  if (IsFastPackedElementsKind(elements_kind())) {

[Michael Starzinger, 2012/06/12 08:10:43]

Likewise.

[danno, 2012/06/12 09:59:22]

The hole check value is gone, but we still need to answer the question by
implementing this function, so this code still seems necessary.
On 2012/06/12 08:10:43, Michael Starzinger wrote:

     return false;
   }
-
+  
   for (HUseIterator it(uses()); !it.Done(); it.Advance()) {
     HValue* use = it.value();
     if (!use->IsChange()) return true;
   }
-
+  
   return false;
 }
 
 
 void HLoadKeyedFastDoubleElement::PrintDataTo(StringStream* stream) {
   elements()->PrintNameTo(stream);
   stream->Add("[");
   key()->PrintNameTo(stream);
   stream->Add("]");
 }
@@ skipping 737 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal