Request for reviews (M): 6873116: Modify reexecute implementation to use pcDesc to record the reexecute bit

[Vladimir Kozlov]

No. What Tom talks about is to do it only in
Deoptimization::fetch_unroll_info_helper().
In other cases we will generate just empty ObjectValue(id).

Vladimir

changpeng fang - Sun Microsystems - Santa Clara United States wrote:
> 
> Is this the approach to make it lazy? Thanks. -- Changpeng
> 
> 
> diff -r d0acbc302e14 src/share/vm/code/scopeDesc.cpp
> --- a/src/share/vm/code/scopeDesc.cpp   Mon Aug 17 14:45:02 2009 -0700
> +++ b/src/share/vm/code/scopeDesc.cpp   Wed Aug 19 14:49:27 2009 -0700
> @@ -90,16 +90,21 @@ GrowableArray<ScopeValue*>* ScopeDesc::d
> 
> GrowableArray<ScopeValue*>* ScopeDesc::decode_object_values(int 
> decode_offset) {
>   if (decode_offset == DebugInformationRecorder::serialized_null) return 
> NULL;
> -  GrowableArray<ScopeValue*>* result = new GrowableArray<ScopeValue*>();
> -  DebugInfoReadStream* stream = new DebugInfoReadStream(_code, 
> decode_offset, result);
> -  int length = stream->read_int();
> -  for (int index = 0; index < length; index++) {
> -    // Objects values are pushed to 'result' array during read so that
> -    // object's fields could reference it (OBJECT_ID_CODE).
> -    (void)ScopeValue::read_from(stream);
> +#ifdef COMPILER2
> +  if (DoEscapeAnalysis && EliminateAllocations) {
> +    GrowableArray<ScopeValue*>* result = new GrowableArray<ScopeValue*>();
> +    DebugInfoReadStream* stream = new DebugInfoReadStream(_code, 
> decode_offset, result);
> +    int length = stream->read_int();
> +    for (int index = 0; index < length; index++) {
> +      // Objects values are pushed to 'result' array during read so that
> +      // object's fields could reference it (OBJECT_ID_CODE).
> +      (void)ScopeValue::read_from(stream);
> +    }
> +    assert(result->length() == length, "inconsistent debug information");
> +    return result;
>   }
> -  assert(result->length() == length, "inconsistent debug information");
> -  return result;
> +#endif
> +  return NULL;
> }
> 
> 
> 
> 
> 
> 
> 
>> Tom Rodriguez wrote:
>>> By the way, does anyone know why the objects for EA are decoded 
>>> eagerly instead of being decoded lazily like all the other debug 
>>> info?  That seems like unneeded overhead for most uses of ScopeDesc 
>>> for stack walking.
>>
>> Do you mean the call to decode_object_values()?
>> It is done only for top frame.
>> But you are right that we may need to call it only when we
>> need to decode narrow oop. I will look on it.
>>
>> Vladimir
>>
>>>
>>> tom
>>>
>