review (S) for 6926979: should simplify catch_inline_exception
Christian.Thalinger at Sun.COM
Tue Feb 23 01:19:59 PST 2010
On 02/19/10 10:10 PM, Tom Rodriguez wrote:
> 6926979: should simplify catch_inline_exception
> 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.
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?
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