Request for Review (S) 6852078: HSX 14/16 in jdk 5.0: api/javax_management api/org_omg jck tests crashes or make tnameserv crash

[Vladimir Kozlov]

OK.

Vladimir

Changpeng Fang wrote:
> On 10/29/09 17:18, Vladimir Kozlov wrote:
>> I don't think having assert there is correct
>> since there is nothing wrong with ideal graph.
>>
> 1924   //unsafe reference could not be aligned appropriately without 
> runtime checking
> 1925   if (base == NULL || base->bottom_type() == Type::TOP) {
> 1926     assert(!valid(), "unsafe access");
> 1927     return;
> 1928   }
> 
> 
> The assert is nothing related to ideal graph. It just makes sure that 
> the SWPointer returned from
> here is not useable. You may see many places that use SWPointer::valid() 
> checking before  doing
> actual thing (alignment, for example).
> 
> Thanks,
> 
> Changpeng
> 
> 
>> Vladimir
>>
>> Changpeng Fang wrote:
>>> Was sent  to the gc mailing list. Resend to the correct compiler 
>>> list. Thanks,
>>>
>>>> http://cr.openjdk.java.net/~cfang/6852078/webrev.00/
>>>>
>>>> Note that I am requesting for change to the current jdk source (For 
>>>> the SubCR)
>>>>
>>>> 6852078: HSX 14/16 in jdk 5.0: api/javax_management api/org_omg jck 
>>>> tests crashes or make tnameserv crash
>>>>
>>>> Problem: Current implementation of superword optimization does not 
>>>> check for unsafe memory accesses. Since
>>>> unsafe memory accesses could not be aligned appropriately without 
>>>> runtime checking, a un-aligned superword
>>>> read/write could cause runtime failure.
>>>>
>>>> Solution: Simply disable superword for unsafe memory access whose 
>>>> base is top.
>>>>
>>>> Tests: Test case in 6852078
>>>>
>>>> Thanks,
>>>>
>>>> Changpeng
>>>>
>>>>
>>>
>