Always create deopt data when using full-codegen if the function is optimizable

src/compiler.cc

 // Copyright 2011 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 150 matching lines @@
            compiled_functions,
            code_size,
            compilation_time);
   }
 }
 
 
 static bool MakeCrankshaftCode(CompilationInfo* info) {
   // Test if we can optimize this function when asked to. We can only
   // do this after the scopes are computed.
-  if (!info->AllowOptimize()) info->DisableOptimization();
+  if (!info->AllowOptimize()) {
+    info->DisableOptimization();
+  } else if (info->IsOptimizable()) {
+    info->EnableDeoptimizationSupport();
+  }
 
   // In case we are not optimizing simply return the code from
   // the full code generator.
   if (!info->IsOptimizing()) {
     return FullCodeGenerator::MakeCode(info);
   }
 
   // We should never arrive here if there is not code object on the
   // shared function object.
   Handle<Code> code(info->shared_info()->code());
@@ skipping 52 matching lines @@
   if (!match) {
     info->SetCode(code);
     return true;
   }
 
   // Recompile the unoptimized version of the code if the current version
   // doesn't have deoptimization support. Alternatively, we may decide to
   // run the full code generator to get a baseline for the compile-time
   // performance of the hydrogen-based compiler.
   int64_t start = OS::Ticks();
   bool should_recompile = !info->shared_info()->has_deoptimization_support();

[Kevin Millikin (Chromium), 2011/11/21 13:47:25]

So is all this dead code now?  Can we just assert that the unoptimized code has
deoptimization support?

[Rico, 2011/11/21 14:00:12]

I think that we can get in here if we had a function that had the
CompilingForDebugging set, in that case we only generate deopt data if the
function already has optimized code. I could change that to also always generate
deopt data - in all the cases where we could potentially later optimize.

   if (should_recompile || FLAG_hydrogen_stats) {
     HPhase phase(HPhase::kFullCodeGen);
     CompilationInfo unoptimized(info->shared_info());
     // Note that we use the same AST that we will use for generating the
     // optimized code.
     unoptimized.SetFunction(info->function());
     unoptimized.SetScope(info->scope());
     if (should_recompile) unoptimized.EnableDeoptimizationSupport();
     bool succeeded = FullCodeGenerator::MakeCode(&unoptimized);
     if (should_recompile) {
@@ skipping 537 matching lines @@
     }
   }
 
   GDBJIT(AddCode(Handle<String>(shared->DebugName()),
                  Handle<Script>(info->script()),
                  Handle<Code>(info->code()),
                  info));
 }
 
 } }  // namespace v8::internal