1.1 --- a/src/share/vm/opto/compile.cpp Thu Jul 02 16:51:57 2020 -0400
1.2 +++ b/src/share/vm/opto/compile.cpp Mon Mar 09 17:41:30 2020 +0100
1.3 @@ -2075,6 +2075,23 @@
1.4 }
1.5
1.6
1.7 +// Remove edges from "root" to each SafePoint at a backward branch.
1.8 +// They were inserted during parsing (see add_safepoint()) to make
1.9 +// infinite loops without calls or exceptions visible to root, i.e.,
1.10 +// useful.
1.11 +void Compile::remove_root_to_sfpts_edges() {
1.12 + Node *r = root();
1.13 + if (r != NULL) {
1.14 + for (uint i = r->req(); i < r->len(); ++i) {
1.15 + Node *n = r->in(i);
1.16 + if (n != NULL && n->is_SafePoint()) {
1.17 + r->rm_prec(i);
1.18 + --i;
1.19 + }
1.20 + }
1.21 + }
1.22 +}
1.23 +
1.24 //------------------------------Optimize---------------------------------------
1.25 // Given a graph, optimize it.
1.26 void Compile::Optimize() {
1.27 @@ -2130,6 +2147,10 @@
1.28 if (failing()) return;
1.29 }
1.30
1.31 + // Now that all inlining is over, cut edge from root to loop
1.32 + // safepoints
1.33 + remove_root_to_sfpts_edges();
1.34 +
1.35 // Remove the speculative part of types and clean up the graph from
1.36 // the extra CastPP nodes whose only purpose is to carry them. Do
1.37 // that early so that optimizations are not disrupted by the extra
1.38 @@ -3012,8 +3033,10 @@
1.39 break;
1.40 }
1.41 }
1.42 - assert(proj != NULL, "must be found");
1.43 - p->subsume_by(proj, this);
1.44 + assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
1.45 + if (proj != NULL) {
1.46 + p->subsume_by(proj, this);
1.47 + }
1.48 }
1.49 }
1.50 break;
