review (S) for 6926979: should simplify catch_inline_exception

[Tom Rodriguez]

I've updated the webrev to delete that too.

tom

On Feb 23, 2010, at 1:19 AM, Christian Thalinger wrote:

> On 02/19/10 10:10 PM, Tom Rodriguez wrote:
>> http://cr.openjdk.java.net/~never/6926979
>> 
>> 6926979: should simplify catch_inline_exception
>> Reviewed-by:
>> 
>> This is the follow on fix to 6877221 that I'm proposing for hs18.
>> That fix patched over some uncommon trap conditions that could result
>> in unneeded uncommon traps during exception dispatch.  This fix
>> rewrites the exception paths to take advantage of the fast subtype
>> checks to handle more cases inline and removes the use of the uncommon
>> trap that used Reason_unhandled/Action_none to deal with unloaded
>> classes or classes with subtypes.  Instead we emit full subtype checks
>> for catch classes with subclass and allow catch_call_exceptions to
>> emit a Reason_unloaded exception handler for unloaded catch classes.
>> This way we won't uncommon trap unless we really need to and in that
>> case we'll throw out the code and recompile.
>> 
>> src/share/vm/opto/doCall.cpp
>> src/share/vm/opto/parse.hpp
>> src/share/vm/opto/parse1.cpp
> 
> I think this looks good.  What about the removed comment that says:
> 
> !     // %%% Now that subclass checking is very fast, we need to rewrite
> !     // this section and remove the option "DeutschShiffmanExceptions".
> 
> Do we still need this option?
> 
> -- Christian