Remove 6 unused flags.

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 628 matching lines @@
   if (!allocator.Allocate(chunk)) {
     if (FLAG_trace_bailout) {
       PrintF("Not enough virtual registers (regalloc).\n");
     }
     return Handle<Code>::null();
   }
 
   MacroAssembler assembler(info->isolate(), NULL, 0);
   LCodeGen generator(chunk, &assembler, info);
 
-  if (FLAG_eliminate_empty_blocks) {
-    chunk->MarkEmptyBlocks();
-  }
+  chunk->MarkEmptyBlocks();
 
   if (generator.GenerateCode()) {
     if (FLAG_trace_codegen) {
       PrintF("Crankshaft Compiler - ");
     }
     CodeGenerator::MakeCodePrologue(info);
     Code::Flags flags = Code::ComputeFlags(Code::OPTIMIZED_FUNCTION);
     Handle<Code> code =
         CodeGenerator::MakeCodeEpilogue(&assembler, flags, info);
     generator.FinishCode(code);
@@ skipping 1702 matching lines @@
   graph()->PropagateDeoptimizingMark();
   if (!graph()->CheckConstPhiUses()) {
     Bailout("Unsupported phi use of const variable");
     return NULL;
   }
   graph()->EliminateRedundantPhis();
   if (!graph()->CheckArgumentsPhiUses()) {
     Bailout("Unsupported phi use of arguments");
     return NULL;
   }
-  if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis();

[Vyacheslav Egorov (Chromium), 2012/02/08 15:31:12]

please keep this flag it helps debugging.

+  graph()->EliminateUnreachablePhis();
   graph()->CollectPhis();
 
   HInferRepresentation rep(graph());
   rep.Analyze();
 
   graph()->MarkDeoptimizeOnUndefined();
   graph()->InsertRepresentationChanges();
 
   graph()->InitializeInferredTypes();
   graph()->Canonicalize();
@@ skipping 5130 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal