diff options
| -rw-r--r-- | src/share/vm/opto/c2_globals.hpp | 3 | ||||
| -rw-r--r-- | src/share/vm/opto/memnode.cpp | 15 | ||||
| -rw-r--r-- | src/share/vm/opto/node.cpp | 20 |
3 files changed, 23 insertions, 15 deletions
diff --git a/src/share/vm/opto/c2_globals.hpp b/src/share/vm/opto/c2_globals.hpp index bdf07f63f..691914e2b 100644 --- a/src/share/vm/opto/c2_globals.hpp +++ b/src/share/vm/opto/c2_globals.hpp @@ -390,5 +390,8 @@ \ product(intx, MaxLabelRootDepth, 1100, \ "Maximum times call Label_Root to prevent stack overflow") \ + \ + diagnostic(intx, DominatorSearchLimit, 1000, \ + "Iterations limit in Node::dominates") \ C2_FLAGS(DECLARE_DEVELOPER_FLAG, DECLARE_PD_DEVELOPER_FLAG, DECLARE_PRODUCT_FLAG, DECLARE_PD_PRODUCT_FLAG, DECLARE_DIAGNOSTIC_FLAG, DECLARE_NOTPRODUCT_FLAG) diff --git a/src/share/vm/opto/memnode.cpp b/src/share/vm/opto/memnode.cpp index b28c37b78..4785ccb86 100644 --- a/src/share/vm/opto/memnode.cpp +++ b/src/share/vm/opto/memnode.cpp @@ -256,7 +256,7 @@ bool MemNode::all_controls_dominate(Node* dom, Node* sub) { if (dom == NULL || dom->is_top()) return false; // Conservative answer for dead code - if (dom->is_Start() || dom->is_Root() || dom == sub) + if (dom->is_Con() || dom->is_Start() || dom->is_Root() || dom == sub) return true; // 'dom' dominates 'sub' if its control edge and control edges @@ -298,7 +298,7 @@ bool MemNode::all_controls_dominate(Node* dom, Node* sub) { return false; // Conservative answer for dead code assert(n->is_CFG(), "expecting control"); } - if (n->is_Start() || n->is_Root()) { + if (n->is_Con() || n->is_Start() || n->is_Root()) { only_dominating_controls = true; } else if (n->is_CFG()) { if (n->dominates(sub, nlist)) @@ -308,12 +308,11 @@ bool MemNode::all_controls_dominate(Node* dom, Node* sub) { } else { // First, own control edge. Node* m = n->find_exact_control(n->in(0)); - if (m == NULL) - continue; - if (m->is_top()) - return false; // Conservative answer for dead code - dom_list.push(m); - + if (m != NULL) { + if (m->is_top()) + return false; // Conservative answer for dead code + dom_list.push(m); + } // Now, the rest of edges. uint cnt = n->req(); for (uint i = 1; i < cnt; i++) { diff --git a/src/share/vm/opto/node.cpp b/src/share/vm/opto/node.cpp index d3c2c65f8..52aa1b17c 100644 --- a/src/share/vm/opto/node.cpp +++ b/src/share/vm/opto/node.cpp @@ -1043,6 +1043,9 @@ bool Node::dominates(Node* sub, Node_List &nlist) { assert(this->is_CFG(), "expecting control"); assert(sub != NULL && sub->is_CFG(), "expecting control"); + // detect dead cycle without regions + int iterations_without_region_limit = DominatorSearchLimit; + Node* orig_sub = sub; nlist.clear(); bool this_dominates = false; @@ -1057,6 +1060,7 @@ bool Node::dominates(Node* sub, Node_List &nlist) { // Region nodes were visited. Continue walk up to Start or Root // to make sure that it did not walk in a cycle. this_dominates = true; // first time meet + iterations_without_region_limit = DominatorSearchLimit; // Reset } else { return false; // already met before: walk in a cycle } @@ -1069,19 +1073,20 @@ bool Node::dominates(Node* sub, Node_List &nlist) { return false; // Conservative answer for dead code if (sub == up && sub->is_Loop()) { - up = sub->in(0); // in(LoopNode::EntryControl); - } else if (sub == up && sub->is_Region()) { + up = sub->in(1); // in(LoopNode::EntryControl); + } else if (sub == up && sub->is_Region() && sub->req() == 3) { + iterations_without_region_limit = DominatorSearchLimit; // Reset uint i = 1; - if (nlist.size() == 0) { + uint size = nlist.size(); + if (size == 0) { // No Region nodes (except Loops) were visited before. // Take first valid path on the way up to 'this'. - } else if (nlist.at(nlist.size() - 1) == sub) { + } else if (nlist.at(size - 1) == sub) { // This Region node was just visited. Take other path. i = region_input + 1; nlist.pop(); } else { // Was this Region node visited before? - uint size = nlist.size(); for (uint j = 0; j < size; j++) { if (nlist.at(j) == sub) { return false; // The Region node was visited before. Give up. @@ -1104,8 +1109,9 @@ bool Node::dominates(Node* sub, Node_List &nlist) { } if (sub == up) return false; // some kind of tight cycle - if (orig_sub == up) - return false; // walk in a cycle + + if (--iterations_without_region_limit < 0) + return false; // dead cycle sub = up; } |