On Sep 6, 2011, at 5:51 PM, Charles Oliver Nutter wrote: > On Tue, Sep 6, 2011 at 10:39 AM, Rémi Forax <fo...@univ-mlv.fr> wrote: >> Yes, but don't forget that PHP.reboot has no overflow check. > > Did we ever figure out if it's possible to trick Hotspot into doing a > JO instead of the raw bit-level operations? John/Christian/Tom: what > would it take to get HS to "know" that we're doing an integer > overflow-after-maths check and do the (faster?) JO?
We already talked a bit about that some while ago. I think matching that double-xor-trick (or whatever it's called) is too risky. A JDK method that does the check (and the math?) would be nice so we can intrinsify it. GWT would fit here. Btw. what means JO? -- Christian > > Rémi: For what it's worth, I did specialize +/- for 1 and 2 in the > indy-based call protocols to avoid a full overflow check. > > - Charlie > _______________________________________________ > mlvm-dev mailing list > mlvm-dev@openjdk.java.net > http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev _______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
