[Mono-dev] Big Arrays, Many Changes --- Request for Advice

Luis F. Ortiz LuisOrtiz at Verizon.Net
Thu Sep 6 07:15:34 EDT 2007

On Sep 5, 2007, at 1:12 AM, Jeroen Frijters wrote:
> Luis F. Ortiz wrote:
>> On Sep 4, 2007, at 6:51 AM, Marek Safar wrote:
>>> Hi Luis,
>>>> 1)  MCS assumed that the arguments to NEWARR were always U4 or I4,
>>>> which does not seem
>>>>      to be the case as far as ECMA-335v4.
>>>> ...
>>>> A)  Fix mcs/expression.cs to emit OpCodes.Conv_Ovf_U/I instead of
>>>> OpCodes.Conv_Ovf_U4/I4
>>>>      for array size arguments,
>>> Any mcs patches with self contained tests are welcome. However, I
>>> think I fix this issue 2-3 weeks ago. Please use SVN version  
>>> instead.
>> I see you did do serious surgery to the code in question in revision
>> 84357.
>> I have a question: ¿How literally should ECMA-335 be taken?
>> If one were to take section 4.20 (newarr - create a zero-based, one-
>> dimensional array)
>> literally:
>>      Valid array indexes are 0 <= index < numElems. ...
>>      Verifiability:  .numElems shall be of type native int or int32.
>> then I would be inclined to say some work might still be necessary.
>> The implication would be that unsigned arguments are not proper and
>> that a 32 bit implementation should be limited to 2^32 - 1 elements.
> No. The verifier doesn't care about signed vs. unsigned. So the  
> above quote really means "native [u]int or [u]int32". For details  
> see the section "Verification Types" in the ECMA CLI spec.

Thanks for taking the time to straighten me out, Jeroen.


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