Request reviews (S): 6896352: CTW fails hotspot/src/share/vm/opto/escape.cpp:1155

[Tom Rodriguez]

I don't think adding volatile could have the effect you are hoping for  
and I also don't think it's needed even if it did.  get_alias_index  
has a side effect over in find_alias_type so it's impossible for it to  
be optimized away even if the return value isn't used.  Also if the  
new call in Ideal_common is doing it's job then do you really need the  
call in escape.cpp?  I don't see how splitting an AddP could create a  
new alias type if one already existed for that AddP.

tom

On Nov 4, 2009, at 10:51 AM, Vladimir Kozlov wrote:

>
> http://cr.openjdk.java.net/~kvn/6896352/webrev.00
>
> Fixed 6896352: CTW fails hotspot/src/share/vm/opto/escape.cpp:1155
>
> Problem:
> Alias type for LoadUS(ConP char[]) node from the test
> was not defined during Parse before EA since
> C->get_alias_index(phase->type(address)) was not called.
> But EA expects all alias types to be defined before it starts.
>
> Solution:
> Always call C->get_alias_index(phase->type(address)) in
> MemNode::Ideal_common() which is called by all memory nodes.
> I added "volatile" to expressions to avoid C++ removal
> since the result is not used.
>
> Reviewed by:
>
> Fix verified (y/n): y, test
>
> Other testing:
> JPRT, CTW
>