src/share/vm/opto/loopnode.cpp

@@ -35,10 +35,14 @@
 #include "opto/loopnode.hpp"
 #include "opto/mulnode.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/superword.hpp"
 
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/shenandoah/c2/shenandoahSupport.hpp"
+#endif
+
 //=============================================================================
 //------------------------------is_loop_iv-------------------------------------
 // Determine if a node is Counted loop induction variable.
 // The method is declared in node.hpp.
 const Node* Node::is_loop_iv() const {

@@ -2353,10 +2357,16 @@
     // restore major progress flag
     for (int i = 0; i < old_progress; i++) {
       C->set_major_progress();
     }
 
+#if INCLUDE_ALL_GCS
+    if (UseShenandoahGC && !C->major_progress()) {
+      ShenandoahBarrierC2Support::pin_and_expand(this);
+    }
+#endif
+
     // Cleanup any modified bits
     _igvn.optimize();
 
     if (C->log() != NULL) {
       log_loop_tree(_ltree_root, _ltree_root, C->log());

@@ -3344,11 +3354,14 @@
       Node* s = mem->fast_out(i);
       worklist.push(s);
     }
     while(worklist.size() != 0 && LCA != early) {
       Node* s = worklist.pop();
-      if (s->is_Load()) {
+      if (s->is_Load() ||
+          (UseShenandoahGC &&
+           (s->is_ShenandoahBarrier() || s->Opcode() == Op_SafePoint ||
+            (s->is_CallStaticJava() && s->as_CallStaticJava()->uncommon_trap_request() != 0)))) {
         continue;
       } else if (s->is_MergeMem()) {
         for (DUIterator_Fast imax, i = s->fast_outs(imax); i < imax; i++) {
           Node* s1 = s->fast_out(i);
           worklist.push(s1);

@@ -3576,10 +3589,13 @@
     case Op_StrEquals:
     case Op_StrIndexOf:
     case Op_AryEq:
       pinned = false;
     }
+    if (UseShenandoahGC && n->is_CMove()) {
+      pinned = false;
+    }
     if( pinned ) {
       IdealLoopTree *chosen_loop = get_loop(n->is_CFG() ? n : get_ctrl(n));
       if( !chosen_loop->_child )       // Inner loop?
         chosen_loop->_body.push(n); // Collect inner loops
       return;

@@ -3630,12 +3646,39 @@
 
   // Try not to place code on a loop entry projection
   // which can inhibit range check elimination.
   if (least != early) {
     Node* ctrl_out = least->unique_ctrl_out();
-    if (ctrl_out && ctrl_out->is_CountedLoop() &&
+    if (UseShenandoahGC && ctrl_out && ctrl_out->is_Loop() &&
         least == ctrl_out->in(LoopNode::EntryControl)) {
+      // Move the node above predicates as far up as possible so a
+      // following pass of loop predication doesn't hoist a predicate
+      // that depends on it above that node.
+      Node* new_ctrl = least;
+      for (;;) {
+        if (!new_ctrl->is_Proj()) {
+          break;
+        }
+        CallStaticJavaNode* call = new_ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none);
+        if (call == NULL) {
+          break;
+        }
+        int req = call->uncommon_trap_request();
+        Deoptimization::DeoptReason trap_reason = Deoptimization::trap_request_reason(req);
+        if (trap_reason != Deoptimization::Reason_loop_limit_check &&
+            trap_reason != Deoptimization::Reason_predicate) {
+          break;
+        }
+        Node* c = new_ctrl->in(0)->in(0);
+        if (is_dominator(c, early) && c != early) {
+          break;
+        }
+        new_ctrl = c;
+      }
+      least = new_ctrl;
+    } else if (ctrl_out && ctrl_out->is_CountedLoop() &&
+               least == ctrl_out->in(LoopNode::EntryControl)) {
       Node* least_dom = idom(least);
       if (get_loop(least_dom)->is_member(get_loop(least))) {
         least = least_dom;
       }
     }

@@ -3817,10 +3860,11 @@
         }
       }
     }
   }
 }
+#endif
 
 // Collect a R-P-O for the whole CFG.
 // Result list is in post-order (scan backwards for RPO)
 void PhaseIdealLoop::rpo( Node *start, Node_Stack &stk, VectorSet &visited, Node_List &rpo_list ) const {
   stk.push(start, 0);

@@ -3839,11 +3883,10 @@
       rpo_list.push(m);
       stk.pop();
     }
   }
 }
-#endif
 
 
 //=============================================================================
 //------------------------------LoopTreeIterator-----------------------------------