7004940: CTW: assert(!def_outside->member(r)) failed: Use of external LRG overlaps the same LRG

Reviewed-by: kvn, twisti

src/share/vm/opto/chaitin.cpp

@@ -1782,7 +1782,7 @@ void PhaseChaitin::dump() const {
   for(uint i2 = 1; i2 < _maxlrg; i2++ ) {
     tty->print("L%d: ",i2);
     if( i2 < _ifg->_maxlrg ) lrgs(i2).dump( );
-    else tty->print("new LRG");
+    else tty->print_cr("new LRG");
   }
   tty->print_cr("");
 
@@ -1993,7 +1993,7 @@ void PhaseChaitin::dump_bb( uint pre_order ) const {
 }
 
 //------------------------------dump_lrg---------------------------------------
-void PhaseChaitin::dump_lrg( uint lidx ) const {
+void PhaseChaitin::dump_lrg( uint lidx, bool defs_only ) const {
   tty->print_cr("---dump of L%d---",lidx);
 
   if( _ifg ) {
@@ -2002,9 +2002,11 @@ void PhaseChaitin::dump_lrg( uint lidx ) const {
       return;
     }
     tty->print("L%d: ",lidx);
-    lrgs(lidx).dump( );
+    if( lidx < _ifg->_maxlrg ) lrgs(lidx).dump( );
+    else tty->print_cr("new LRG");
   }
-  if( _ifg ) {    tty->print("Neighbors: %d - ", _ifg->neighbor_cnt(lidx));
+  if( _ifg && lidx < _ifg->_maxlrg) {
+    tty->print("Neighbors: %d - ", _ifg->neighbor_cnt(lidx));
     _ifg->neighbors(lidx)->dump();
     tty->cr();
   }
@@ -2024,16 +2026,18 @@ void PhaseChaitin::dump_lrg( uint lidx ) const {
         dump(n);
         continue;
       }
-      uint cnt = n->req();
-      for( uint k = 1; k < cnt; k++ ) {
-        Node *m = n->in(k);
-        if (!m)  continue;  // be robust in the dumper
-        if( Find_const(m) == lidx ) {
-          if( !dump_once++ ) {
-            tty->cr();
-            b->dump_head( &_cfg._bbs );
+      if (!defs_only) {
+        uint cnt = n->req();
+        for( uint k = 1; k < cnt; k++ ) {
+          Node *m = n->in(k);
+          if (!m)  continue;  // be robust in the dumper
+          if( Find_const(m) == lidx ) {
+            if( !dump_once++ ) {
+              tty->cr();
+              b->dump_head( &_cfg._bbs );
+            }
+            dump(n);
           }
-          dump(n);
         }
       }
     }

src/share/vm/opto/chaitin.hpp

@@ -512,7 +512,11 @@ private:
   void dump( const Block * b ) const;
   void dump_degree_lists() const;
   void dump_simplified() const;
-  void dump_lrg( uint lidx ) const;
+  void dump_lrg( uint lidx, bool defs_only) const;
+  void dump_lrg( uint lidx) const {
+    // dump defs and uses by default
+    dump_lrg(lidx, false);
+  }
   void dump_bb( uint pre_order ) const;
 
   // Verify that base pointers and derived pointers are still sane

src/share/vm/opto/reg_split.cpp

@@ -1239,6 +1239,7 @@ uint PhaseChaitin::Split( uint maxlrg ) {
   // Cycle through this block's predecessors, collecting Reaches
   // info for each spilled LRG and update edges.
   // Walk the phis list to patch inputs, split phis, and name phis
+  uint lrgs_before_phi_split = maxlrg;
   for( insidx = 0; insidx < phis->size(); insidx++ ) {
     Node *phi = phis->at(insidx);
     assert(phi->is_Phi(),"This list must only contain Phi Nodes");
@@ -1273,7 +1274,16 @@ uint PhaseChaitin::Split( uint maxlrg ) {
       assert( def, "must have reaching def" );
       // If input up/down sense and reg-pressure DISagree
       if( def->rematerialize() ) {
-        def = split_Rematerialize( def, pred, pred->end_idx(), maxlrg, splits, slidx, lrg2reach, Reachblock, false );
+        // Place the rematerialized node above any MSCs created during
+        // phi node splitting.  end_idx points at the insertion point
+        // so look at the node before it.
+        int insert = pred->end_idx();
+        while (insert >= 1 &&
+               pred->_nodes[insert - 1]->is_SpillCopy() &&
+               Find(pred->_nodes[insert - 1]) >= lrgs_before_phi_split) {
+          insert--;
+        }
+        def = split_Rematerialize( def, pred, insert, maxlrg, splits, slidx, lrg2reach, Reachblock, false );
         if( !def ) return 0;    // Bail out
       }
       // Update the Phi's input edge array