Fix code gen bug on arm and mips; SeqStringSetChar overwrites a register; Add better default PrintD…

src/hydrogen.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 5421 matching lines @@
   // Transitively mark all inputs of live instructions live.
   while (!worklist.is_empty()) {
     HValue* instr = worklist.RemoveLast();
     for (int i = 0; i < instr->OperandCount(); ++i) {
       MarkLive(instr, instr->OperandAt(i), &worklist);
     }
   }
 }
 
 
 void HGraph::MarkLive(HValue *ref, HValue* instr,

[Jakob Kummerow, 2013/05/16 13:18:57]

nit: while you're here: "HValue* ref", and if all parameters in a
method/function declaration/definition don't fit on one line, they each get
their own, as in:
void HGraph::MarkLive(HValue* ref,
                      HValue* instr,
                      ZoneList<HValue*>* worklist) {

[titzer, 2013/05/16 14:28:44]

Fits :)

     ZoneList<HValue*>* worklist) {
   if (!instr->CheckFlag(HValue::kIsLive)) {
     instr->SetFlag(HValue::kIsLive);
     worklist->Add(instr, zone());
 
     if (FLAG_trace_dead_code_elimination) {
       HeapStringAllocator allocator;
       StringStream stream(&allocator);
+      ALLOW_HANDLE_DEREF(isolate(), "debug mode printing");

[Jakob Kummerow, 2013/05/16 13:18:57]

I don't see any handle being dereferenced?

[titzer, 2013/05/16 14:28:44]

Yeah, it can happen if you try to print an instruction which is a HConstant of a
map.

       if (ref != NULL) {
         ref->PrintTo(&stream);
       } else {
         stream.Add("root ");
       }
       stream.Add(" -> ");
       instr->PrintTo(&stream);
       PrintF("[MarkLive %s]\n", *stream.ToCString());
     }
   }
@@ skipping 6998 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal