--- a/hotspot/src/share/vm/opto/loopnode.cpp Wed Dec 09 13:41:04 2015 +0100
+++ b/hotspot/src/share/vm/opto/loopnode.cpp Thu Dec 10 14:51:53 2015 +0300
@@ -1818,10 +1818,9 @@
}
void IdealLoopTree::remove_safepoints(PhaseIdealLoop* phase, bool keep_one) {
- // Look for a safepoint on the idom-path.
Node* keep = NULL;
if (keep_one) {
- // Keep one if possible
+ // Look for a safepoint on the idom-path.
for (Node* i = tail(); i != _head; i = phase->idom(i)) {
if (i->Opcode() == Op_SafePoint && phase->get_loop(i) == this) {
keep = i;
@@ -1830,9 +1829,14 @@
}
}
+ // Don't remove any safepoints if it is requested to keep a single safepoint and
+ // no safepoint was found on idom-path. It is not safe to remove any safepoint
+ // in this case since there's no safepoint dominating all paths in the loop body.
+ bool prune = !keep_one || keep != NULL;
+
// Delete other safepoints in this loop.
Node_List* sfpts = _safepts;
- if (sfpts != NULL) {
+ if (prune && sfpts != NULL) {
assert(keep == NULL || keep->Opcode() == Op_SafePoint, "not safepoint");
for (uint i = 0; i < sfpts->size(); i++) {
Node* n = sfpts->at(i);
@@ -1925,6 +1929,15 @@
if (cl->is_main_loop()) tty->print(" main");
if (cl->is_post_loop()) tty->print(" post");
}
+ if (_has_call) tty->print(" has_call");
+ if (_has_sfpt) tty->print(" has_sfpt");
+ if (_rce_candidate) tty->print(" rce");
+ if (_safepts != NULL && _safepts->size() > 0) {
+ tty->print(" sfpts={"); _safepts->dump_simple(); tty->print(" }");
+ }
+ if (_required_safept != NULL && _required_safept->size() > 0) {
+ tty->print(" req={"); _required_safept->dump_simple(); tty->print(" }");
+ }
tty->cr();
}