8148786: xml.tranform fails on x86-64

Summary: CCP computes wrong type for CountedLoop iv Phi
Reviewed-by: kvn

src/share/vm/opto/loopnode.hpp

 /*
- * Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -257,19 +257,29 @@ public:
   Node *incr() const                { Node *tmp = cmp_node(); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; }
   Node *limit() const               { Node *tmp = cmp_node(); return (tmp && tmp->req()==3) ? tmp->in(2) : NULL; }
   Node *stride() const              { Node *tmp = incr    (); return (tmp && tmp->req()==3) ? tmp->in(2) : NULL; }
-  Node *phi() const                 { Node *tmp = incr    (); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; }
   Node *init_trip() const           { Node *tmp = phi     (); return (tmp && tmp->req()==3) ? tmp->in(1) : NULL; }
   int stride_con() const;
   bool stride_is_con() const        { Node *tmp = stride  (); return (tmp != NULL && tmp->is_Con()); }
   BoolTest::mask test_trip() const  { return in(TestValue)->as_Bool()->_test._test; }
+  PhiNode *phi() const {
+    Node *tmp = incr();
+    if (tmp && tmp->req() == 3) {
+      Node* phi = tmp->in(1);
+      if (phi->is_Phi()) {
+        return phi->as_Phi();
+      }
+    }
+    return NULL;
+  }
   CountedLoopNode *loopnode() const {
     // The CountedLoopNode that goes with this CountedLoopEndNode may
     // have been optimized out by the IGVN so be cautious with the
     // pattern matching on the graph
-    if (phi() == NULL) {
+    PhiNode* iv_phi = phi();
+    if (iv_phi == NULL) {
       return NULL;
     }
-    Node *ln = phi()->in(0);
+    Node *ln = iv_phi->in(0);
     if (ln->is_CountedLoop() && ln->as_CountedLoop()->loopexit() == this) {
       return (CountedLoopNode*)ln;
     }

src/share/vm/opto/phaseX.cpp

 /*
- * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1416,6 +1416,27 @@ void PhaseIterGVN::add_users_to_worklist0( Node *n ) {
   }
 }
 
+// Return counted loop Phi if as a counted loop exit condition, cmp
+// compares the the induction variable with n
+static PhiNode* countedloop_phi_from_cmp(CmpINode* cmp, Node* n) {
+  for (DUIterator_Fast imax, i = cmp->fast_outs(imax); i < imax; i++) {
+    Node* bol = cmp->fast_out(i);
+    for (DUIterator_Fast i2max, i2 = bol->fast_outs(i2max); i2 < i2max; i2++) {
+      Node* iff = bol->fast_out(i2);
+      if (iff->is_CountedLoopEnd()) {
+        CountedLoopEndNode* cle = iff->as_CountedLoopEnd();
+        if (cle->limit() == n) {
+          PhiNode* phi = cle->phi();
+          if (phi != NULL) {
+            return phi;
+          }
+        }
+      }
+    }
+  }
+  return NULL;
+}
+
 void PhaseIterGVN::add_users_to_worklist( Node *n ) {
   add_users_to_worklist0(n);
 
@@ -1445,18 +1466,7 @@ void PhaseIterGVN::add_users_to_worklist( Node *n ) {
         Node* bol = use->raw_out(0);
         if (bol->outcnt() > 0) {
           Node* iff = bol->raw_out(0);
-          if (use_op == Op_CmpI &&
-              iff->is_CountedLoopEnd()) {
-            CountedLoopEndNode* cle = iff->as_CountedLoopEnd();
-            if (cle->limit() == n && cle->phi() != NULL) {
-              // If an opaque node feeds into the limit condition of a
-              // CountedLoop, we need to process the Phi node for the
-              // induction variable when the opaque node is removed:
-              // the range of values taken by the Phi is now known and
-              // so its type is also known.
-              _worklist.push(cle->phi());
-            }
-          } else if (iff->outcnt() == 2) {
+          if (iff->outcnt() == 2) {
             // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the
             // phi merging either 0 or 1 onto the worklist
             Node* ifproj0 = iff->raw_out(0);
@@ -1471,6 +1481,15 @@ void PhaseIterGVN::add_users_to_worklist( Node *n ) {
         }
       }
       if (use_op == Op_CmpI) {
+        Node* phi = countedloop_phi_from_cmp((CmpINode*)use, n);
+        if (phi != NULL) {
+          // If an opaque node feeds into the limit condition of a
+          // CountedLoop, we need to process the Phi node for the
+          // induction variable when the opaque node is removed:
+          // the range of values taken by the Phi is now known and
+          // so its type is also known.
+          _worklist.push(phi);
+        }
         Node* in1 = use->in(1);
         for (uint i = 0; i < in1->outcnt(); i++) {
           if (in1->raw_out(i)->Opcode() == Op_CastII) {
@@ -1659,6 +1678,15 @@ void PhaseCCP::analyze() {
             }
           }
         }
+        // If n is used in a counted loop exit condition then the type
+        // of the counted loop's Phi depends on the type of n. See
+        // PhiNode::Value().
+        if (m_op == Op_CmpI) {
+          PhiNode* phi = countedloop_phi_from_cmp((CmpINode*)m, n);
+          if (phi != NULL) {
+            worklist.push(phi);
+          }
+        }
       }
     }
   }

src/share/vm/opto/phaseX.hpp

 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -417,7 +417,7 @@ public:
 // Phase for iteratively performing local, pessimistic GVN-style optimizations.
 // and ideal transformations on the graph.
 class PhaseIterGVN : public PhaseGVN {
- private:
+private:
   bool _delay_transform;  // When true simply register the node when calling transform
                           // instead of actually optimizing it