review (S) for 7004940: CTW: assert(!def_outside->member(r)) failed: Use of external LRG overlaps the same LRG

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/7004940

7004940: CTW: assert(!def_outside->member(r)) failed: Use of external LRG overlaps the same LRG
Reviewed-by:

When splitting an LRG involving a phi the processing of the phi is
delayed to the end and it is split by inserting copies in each of the
predecessor blocks and then merging the new splits with the phi into a
single LRG.  The merging is done blindly after all the phis have been
split.  Usually this is fine because all MSCs are inserted at the end
of the predecessor and they are disjoint LRGs by definition.  The
problem comes when rematerialization is done because this adds an
extra use mixed in with the MSCs and that use might be the same LRG as
one of the phis that was just split.  If the rematerialize is done
first then it all works out because of insertion order but if it's
done afterwards then you can get the failure we're seeing.  The fix is
insert the rematerialized nodes above the MSCs that were inserted
during the phi node splitting process.  I also added/fixed some of the
printing code in PhaseChaitin.  Tested with full ctw on sparc 32 and
64 bit.