6883468: C2 compiler enters infinite loop in PhaseIterGVN::transform
Summary: Avoid ideal transformation ping-pong between AddPNode::Ideal() and CastX2PNode::Ideal().
Reviewed-by: cfang
--- a/hotspot/src/share/vm/opto/connode.cpp Wed Sep 23 23:57:44 2009 -0700
+++ b/hotspot/src/share/vm/opto/connode.cpp Fri Sep 25 13:26:02 2009 -0700
@@ -1085,6 +1085,9 @@
switch (op) {
case Op_SubX:
x = in(1)->in(1);
+ // Avoid ideal transformations ping-pong between this and AddP for raw pointers.
+ if (phase->find_intptr_t_con(x, -1) == 0)
+ break;
y = in(1)->in(2);
if (fits_in_int(phase->type(y), true)) {
return addP_of_X2P(phase, x, y, true);