8238691: C2: turn subtype check into macro node

Reviewed-by: vlivanov, thartmann

src/hotspot/share/opto/c2_globals.hpp

@@ -746,6 +746,9 @@
           range(0, max_juint)                                               \
                                                                             \
   product(bool, UseProfiledLoopPredicate, true,                             \
-          "move predicates out of loops based on profiling data")           \
+          "Move predicates out of loops based on profiling data")           \
+                                                                            \
+  diagnostic(bool, ExpandSubTypeCheckAtParseTime, false,                    \
+          "Do not use subtype check macro node")                            \
 
 #endif // SHARE_OPTO_C2_GLOBALS_HPP

src/hotspot/share/opto/classes.cpp

@@ -46,6 +46,7 @@
 #include "opto/opaquenode.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/subnode.hpp"
+#include "opto/subtypenode.hpp"
 #include "opto/vectornode.hpp"
 #include "utilities/macros.hpp"
 #if INCLUDE_SHENANDOAHGC

src/hotspot/share/opto/classes.hpp

@@ -250,6 +250,7 @@ macro(OverflowMulL)
 macro(PCTable)
 macro(Parm)
 macro(PartialSubtypeCheck)
+macro(SubTypeCheck)
 macro(Phi)
 macro(PopCountI)
 macro(PopCountL)

src/hotspot/share/opto/compile.cpp

@@ -4239,6 +4239,9 @@ int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
         // Add a dependency if there is a chance of a later subclass.
         dependencies()->assert_leaf_type(ik);
       }
+      if (ik->is_abstract()) {
+        return SSC_always_false;
+      }
       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
     }
   } else {

src/hotspot/share/opto/escape.cpp

@@ -3199,6 +3199,7 @@ void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist,
               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
               op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
               op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
+              op == Op_SubTypeCheck ||
               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
           n->dump();
           use->dump();

src/hotspot/share/opto/graphKit.cpp

@@ -41,6 +41,7 @@
 #include "opto/parse.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/runtime.hpp"
+#include "opto/subtypenode.hpp"
 #include "runtime/deoptimization.hpp"
 #include "runtime/sharedRuntime.hpp"
 #include "utilities/bitMap.inline.hpp"
@@ -2623,21 +2624,94 @@ void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool sep
   set_control(norm);
 }
 
-static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
+static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN& gvn, BasicType bt) {
   Node* cmp = NULL;
   switch(bt) {
   case T_INT: cmp = new CmpINode(in1, in2); break;
   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
   default: fatal("unexpected comparison type %s", type2name(bt));
   }
-  gvn->transform(cmp);
+  gvn.transform(cmp);
-  Node* bol = gvn->transform(new BoolNode(cmp, test));
+  Node* bol = gvn.transform(new BoolNode(cmp, test));
   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
-  gvn->transform(iff);
+  gvn.transform(iff);
-  if (!bol->is_Con()) gvn->record_for_igvn(iff);
+  if (!bol->is_Con()) gvn.record_for_igvn(iff);
   return iff;
 }
 
+// Find the memory state for the secondary super type cache load when
+// a subtype check is expanded at macro expansion time. That field is
+// mutable so should not use immutable memory but
+// PartialSubtypeCheckNode that might modify it doesn't produce a new
+// memory state so bottom memory is the most accurate memory state to
+// hook the load with. This follows the implementation used when the
+// subtype check is expanded at parse time.
+static Node* find_bottom_mem(Node* ctrl, Compile* C) {
+  const TypePtr* adr_type = TypeKlassPtr::make(TypePtr::NotNull, C->env()->Object_klass(), Type::OffsetBot);
+  Node_Stack stack(0);
+  VectorSet seen(Thread::current()->resource_area());
+
+  Node* c = ctrl;
+  Node* mem = NULL;
+  uint iter = 0;
+  do {
+    iter++;
+    assert(iter < C->live_nodes(), "infinite loop");
+    if (c->is_Region()) {
+      for (DUIterator_Fast imax, i = c->fast_outs(imax); i < imax && mem == NULL; i++) {
+        Node* u = c->fast_out(i);
+        if (u->is_Phi() && u->bottom_type() == Type::MEMORY &&
+            (u->adr_type() == TypePtr::BOTTOM || u->adr_type() == adr_type)) {
+          mem = u;
+        }
+      }
+      if (mem == NULL) {
+        if (!seen.test_set(c->_idx)) {
+          stack.push(c, 2);
+          c = c->in(1);
+        } else {
+          Node* phi = NULL;
+          uint idx = 0;
+          for (;;) {
+            phi = stack.node();
+            idx = stack.index();
+            if (idx < phi->req()) {
+              break;
+            }
+            stack.pop();
+          }
+          c = phi->in(idx);
+          stack.set_index(idx+1);
+        }
+      }
+    } else if (c->is_Proj() && c->in(0)->adr_type() == TypePtr::BOTTOM) {
+      for (DUIterator_Fast imax, i = c->in(0)->fast_outs(imax); i < imax; i++) {
+        Node* u = c->in(0)->fast_out(i);
+        if (u->bottom_type() == Type::MEMORY && u->as_Proj()->_is_io_use == c->as_Proj()->_is_io_use) {
+          assert(mem == NULL, "");
+          mem = u;
+        }
+      }
+    } else if (c->is_CatchProj() && c->in(0)->in(0)->in(0)->adr_type() == TypePtr::BOTTOM) {
+      Node* call = c->in(0)->in(0)->in(0);
+      assert(call->is_Call(), "CatchProj with no call?");
+      CallProjections projs;
+      call->as_Call()->extract_projections(&projs, false, false);
+      if (projs.catchall_memproj == NULL) {
+        mem = projs.fallthrough_memproj;
+      } else if (c == projs.fallthrough_catchproj) {
+        mem = projs.fallthrough_memproj;
+      } else {
+        assert(c == projs.catchall_catchproj, "strange control");
+        mem = projs.catchall_memproj;
+      }
+    } else {
+      assert(!c->is_Start(), "should stop before start");
+      c = c->in(0);
+    }
+  } while (mem == NULL);
+  return mem;
+}
 
 //-------------------------------gen_subtype_check-----------------------------
 // Generate a subtyping check.  Takes as input the subtype and supertype.
@@ -2647,9 +2721,8 @@ static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolT
 // but that's not exposed to the optimizer.  This call also doesn't take in an
 // Object; if you wish to check an Object you need to load the Object's class
 // prior to coming here.
-Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
+Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Node* mem, PhaseGVN& gvn) {
-  Compile* C = gvn->C;
+  Compile* C = gvn.C;
-
   if ((*ctrl)->is_top()) {
     return C->top();
   }
@@ -2660,9 +2733,9 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
   if (subklass == superklass)
     return C->top();             // false path is dead; no test needed.
 
-  if (gvn->type(superklass)->singleton()) {
+  if (gvn.type(superklass)->singleton()) {
-    ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
+    ciKlass* superk = gvn.type(superklass)->is_klassptr()->klass();
-    ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
+    ciKlass* subk   = gvn.type(subklass)->is_klassptr()->klass();
 
     // In the common case of an exact superklass, try to fold up the
     // test before generating code.  You may ask, why not just generate
@@ -2677,7 +2750,7 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
     case Compile::SSC_always_false:
       {
         Node* always_fail = *ctrl;
-        *ctrl = gvn->C->top();
+        *ctrl = gvn.C->top();
         return always_fail;
       }
     case Compile::SSC_always_true:
@@ -2686,8 +2759,8 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
       {
         // Just do a direct pointer compare and be done.
         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
-        *ctrl = gvn->transform(new IfTrueNode(iff));
+        *ctrl = gvn.transform(new IfTrueNode(iff));
-        return gvn->transform(new IfFalseNode(iff));
+        return gvn.transform(new IfFalseNode(iff));
       }
     case Compile::SSC_full_test:
       break;
@@ -2701,11 +2774,11 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
   // will always succeed.  We could leave a dependency behind to ensure this.
 
   // First load the super-klass's check-offset
-  Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
+  Node *p1 = gvn.transform(new AddPNode(superklass, superklass, gvn.MakeConX(in_bytes(Klass::super_check_offset_offset()))));
-  Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
+  Node* m = C->immutable_memory();
-  Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
+  Node *chk_off = gvn.transform(new LoadINode(NULL, m, p1, gvn.type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
-  bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
+  bool might_be_cache = (gvn.find_int_con(chk_off, cacheoff_con) == cacheoff_con);
 
   // Load from the sub-klass's super-class display list, or a 1-word cache of
   // the secondary superclass list, or a failing value with a sentinel offset
@@ -2715,15 +2788,22 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
   // klass loads can never produce a NULL).
   Node *chk_off_X = chk_off;
 #ifdef _LP64
-  chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
+  chk_off_X = gvn.transform(new ConvI2LNode(chk_off_X));
 #endif
-  Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
+  Node *p2 = gvn.transform(new AddPNode(subklass,subklass,chk_off_X));
   // For some types like interfaces the following loadKlass is from a 1-word
   // cache which is mutable so can't use immutable memory.  Other
   // types load from the super-class display table which is immutable.
-  m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
+  Node *kmem = C->immutable_memory();
-  Node *kmem = might_be_cache ? m : C->immutable_memory();
+  if (might_be_cache) {
-  Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
+    assert((C->get_alias_index(TypeKlassPtr::make(TypePtr::NotNull, C->env()->Object_klass(), Type::OffsetBot)) ==
+            C->get_alias_index(gvn.type(p2)->is_ptr())), "");
+    if (mem == NULL) {
+      mem = find_bottom_mem(*ctrl, C);
+    }
+    kmem = mem->is_MergeMem() ? mem->as_MergeMem()->memory_at(C->get_alias_index(gvn.type(p2)->is_ptr())) : mem;
+  }
+  Node *nkls = gvn.transform(LoadKlassNode::make(gvn, NULL, kmem, p2, gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
 
   // Compile speed common case: ARE a subtype and we canNOT fail
   if( superklass == nkls )
@@ -2733,8 +2813,8 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
   // time.  Test to see if the value loaded just previously from the subklass
   // is exactly the superklass.
   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
-  Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
+  Node *iftrue1 = gvn.transform( new IfTrueNode (iff1));
-  *ctrl = gvn->transform(new IfFalseNode(iff1));
+  *ctrl = gvn.transform(new IfFalseNode(iff1));
 
   // Compile speed common case: Check for being deterministic right now.  If
   // chk_off is a constant and not equal to cacheoff then we are NOT a
@@ -2748,9 +2828,9 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
 
   // Gather the various success & failures here
   RegionNode *r_ok_subtype = new RegionNode(4);
-  gvn->record_for_igvn(r_ok_subtype);
+  gvn.record_for_igvn(r_ok_subtype);
   RegionNode *r_not_subtype = new RegionNode(3);
-  gvn->record_for_igvn(r_not_subtype);
+  gvn.record_for_igvn(r_not_subtype);
 
   r_ok_subtype->init_req(1, iftrue1);
 
@@ -2759,17 +2839,17 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
   // check-offset points into the subklass display list or the 1-element
   // cache.  If it points to the display (and NOT the cache) and the display
   // missed then it's not a subtype.
-  Node *cacheoff = gvn->intcon(cacheoff_con);
+  Node *cacheoff = gvn.intcon(cacheoff_con);
   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
-  r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
+  r_not_subtype->init_req(1, gvn.transform(new IfTrueNode (iff2)));
-  *ctrl = gvn->transform(new IfFalseNode(iff2));
+  *ctrl = gvn.transform(new IfFalseNode(iff2));
 
   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
   // No performance impact (too rare) but allows sharing of secondary arrays
   // which has some footprint reduction.
   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
-  r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
+  r_ok_subtype->init_req(2, gvn.transform(new IfTrueNode(iff3)));
-  *ctrl = gvn->transform(new IfFalseNode(iff3));
+  *ctrl = gvn.transform(new IfFalseNode(iff3));
 
   // -- Roads not taken here: --
   // We could also have chosen to perform the self-check at the beginning
@@ -2792,16 +2872,38 @@ Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Me
   // out of line, and it can only improve I-cache density.
   // The decision to inline or out-of-line this final check is platform
   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
-  Node* psc = gvn->transform(
+  Node* psc = gvn.transform(
     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
 
-  IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
+  IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn.zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
-  r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
+  r_not_subtype->init_req(2, gvn.transform(new IfTrueNode (iff4)));
-  r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
+  r_ok_subtype ->init_req(3, gvn.transform(new IfFalseNode(iff4)));
 
   // Return false path; set default control to true path.
-  *ctrl = gvn->transform(r_ok_subtype);
+  *ctrl = gvn.transform(r_ok_subtype);
-  return gvn->transform(r_not_subtype);
+  return gvn.transform(r_not_subtype);
+}
+
+Node* GraphKit::gen_subtype_check(Node* obj_or_subklass, Node* superklass) {
+  if (ExpandSubTypeCheckAtParseTime) {
+    MergeMemNode* mem = merged_memory();
+    Node* ctrl = control();
+    Node* subklass = obj_or_subklass;
+    if (!_gvn.type(obj_or_subklass)->isa_klassptr()) {
+      subklass = load_object_klass(obj_or_subklass);
+    }
+
+    Node* n = Phase::gen_subtype_check(subklass, superklass, &ctrl, mem, _gvn);
+    set_control(ctrl);
+    return n;
+  }
+
+  const TypePtr* adr_type = TypeKlassPtr::make(TypePtr::NotNull, C->env()->Object_klass(), Type::OffsetBot);
+  Node* check = _gvn.transform(new SubTypeCheckNode(C, obj_or_subklass, superklass));
+  Node* bol = _gvn.transform(new BoolNode(check, BoolTest::eq));
+  IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
+  set_control(_gvn.transform(new IfTrueNode(iff)));
+  return _gvn.transform(new IfFalseNode(iff));
 }
 
 // Profile-driven exact type check:
@@ -2833,10 +2935,9 @@ Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
 Node* GraphKit::subtype_check_receiver(Node* receiver, ciKlass* klass,
                                        Node** casted_receiver) {
   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
-  Node* recv_klass = load_object_klass(receiver);
   Node* want_klass = makecon(tklass);
 
-  Node* slow_ctl = gen_subtype_check(recv_klass, want_klass);
+  Node* slow_ctl = gen_subtype_check(receiver, want_klass);
 
   // Cast receiver after successful check
   const TypeOopPtr* recv_type = tklass->cast_to_exactness(false)->is_klassptr()->as_instance_type();
@@ -3101,11 +3202,8 @@ Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replac
     }
   }
 
-  // Load the object's klass
-  Node* obj_klass = load_object_klass(not_null_obj);
-
   // Generate the subtype check
-  Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
+  Node* not_subtype_ctrl = gen_subtype_check(not_null_obj, superklass);
 
   // Plug in the success path to the general merge in slot 1.
   region->init_req(_obj_path, control());
@@ -3228,11 +3326,8 @@ Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
   }
 
   if (cast_obj == NULL) {
-    // Load the object's klass
-    Node* obj_klass = load_object_klass(not_null_obj);
-
     // Generate the subtype check
-    Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
+    Node* not_subtype_ctrl = gen_subtype_check(not_null_obj, superklass );
 
     // Plug in success path into the merge
     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
@@ -3241,7 +3336,7 @@ Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
       if (not_subtype_ctrl != top()) { // If failure is possible
         PreserveJVMState pjvms(this);
         set_control(not_subtype_ctrl);
-        builtin_throw(Deoptimization::Reason_class_check, obj_klass);
+        builtin_throw(Deoptimization::Reason_class_check, load_object_klass(not_null_obj));
       }
     } else {
       (*failure_control) = not_subtype_ctrl;

src/hotspot/share/opto/graphKit.hpp

@@ -825,13 +825,7 @@ class GraphKit : public Phase {
   Node* gen_checkcast( Node *subobj, Node* superkls,
                        Node* *failure_control = NULL );
 
-  Node* gen_subtype_check(Node* subklass, Node* superklass) {
+  Node* gen_subtype_check(Node* obj, Node* superklass);
-    MergeMemNode* mem = merged_memory();
-    Node* ctrl = control();
-    Node* n = Phase::gen_subtype_check(subklass, superklass, &ctrl, mem, &_gvn);
-    set_control(ctrl);
-    return n;
-  }
 
   // Exact type check used for predicted calls and casts.
   // Rewrites (*casted_receiver) to be casted to the stronger type.

src/hotspot/share/opto/library_call.cpp

@@ -3699,8 +3699,7 @@ bool LibraryCallKit::inline_array_copyOf(bool is_copyOfRange) {
       // Reason_class_check rather than Reason_intrinsic because we
       // want to intrinsify even if this traps.
       if (!too_many_traps(Deoptimization::Reason_class_check)) {
-        Node* not_subtype_ctrl = gen_subtype_check(load_object_klass(original),
+        Node* not_subtype_ctrl = gen_subtype_check(original, klass_node);
-                                                   klass_node);
 
         if (not_subtype_ctrl != top()) {
           PreserveJVMState pjvms(this);
@@ -4766,9 +4765,9 @@ bool LibraryCallKit::inline_arraycopy() {
     }
 
     // (9) each element of an oop array must be assignable
-    Node* src_klass  = load_object_klass(src);
     Node* dest_klass = load_object_klass(dest);
-    Node* not_subtype_ctrl = gen_subtype_check(src_klass, dest_klass);
+    if (src != dest) {
+      Node* not_subtype_ctrl = gen_subtype_check(src, dest_klass);
 
       if (not_subtype_ctrl != top()) {
         PreserveJVMState pjvms(this);
@@ -4777,6 +4776,7 @@ bool LibraryCallKit::inline_arraycopy() {
                       Deoptimization::Action_make_not_entrant);
         assert(stopped(), "Should be stopped");
       }
+    }
     {
       PreserveJVMState pjvms(this);
       set_control(_gvn.transform(slow_region));

src/hotspot/share/opto/loopnode.cpp

@@ -4089,7 +4089,7 @@ Node *PhaseIdealLoop::get_late_ctrl( Node *n, Node *early ) {
           }
         } else {
           Node *sctrl = has_ctrl(s) ? get_ctrl(s) : s->in(0);
-          assert(sctrl != NULL || s->outcnt() == 0, "must have control");
+          assert(sctrl != NULL || !s->is_reachable_from_root(), "must have control");
           if (sctrl != NULL && !sctrl->is_top() && C->can_alias(s->adr_type(), load_alias_idx) && is_dominator(early, sctrl)) {
             LCA = dom_lca_for_get_late_ctrl(LCA, sctrl, n);
           }

src/hotspot/share/opto/loopopts.cpp

@@ -40,6 +40,7 @@
 #include "opto/opaquenode.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/subnode.hpp"
+#include "opto/subtypenode.hpp"
 #include "utilities/macros.hpp"
 
 //=============================================================================
@@ -656,6 +657,9 @@ Node *PhaseIdealLoop::conditional_move( Node *region ) {
   }
   assert(bol->Opcode() == Op_Bool, "Unexpected node");
   int cmp_op = bol->in(1)->Opcode();
+  if (cmp_op == Op_SubTypeCheck) { // SubTypeCheck expansion expects an IfNode
+    return NULL;
+  }
   // It is expensive to generate flags from a float compare.
   // Avoid duplicated float compare.
   if (phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL;

src/hotspot/share/opto/macro.cpp

@@ -35,6 +35,7 @@
 #include "opto/compile.hpp"
 #include "opto/convertnode.hpp"
 #include "opto/graphKit.hpp"
+#include "opto/intrinsicnode.hpp"
 #include "opto/locknode.hpp"
 #include "opto/loopnode.hpp"
 #include "opto/macro.hpp"
@@ -46,6 +47,7 @@
 #include "opto/rootnode.hpp"
 #include "opto/runtime.hpp"
 #include "opto/subnode.hpp"
+#include "opto/subtypenode.hpp"
 #include "opto/type.hpp"
 #include "runtime/sharedRuntime.hpp"
 #include "utilities/macros.hpp"
@@ -2533,6 +2535,43 @@ void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
   _igvn.replace_node(_memproj_fallthrough, mem_phi);
 }
 
+void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) {
+  assert(check->in(SubTypeCheckNode::Control) == NULL, "should be pinned");
+  Node* bol = check->unique_out();
+  Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass);
+  Node* superklass = check->in(SubTypeCheckNode::SuperKlass);
+  assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node");
+
+  for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) {
+    Node* iff = bol->last_out(i);
+    assert(iff->is_If(), "where's the if?");
+
+    if (iff->in(0)->is_top()) {
+      _igvn.replace_input_of(iff, 1, C->top());
+      continue;
+    }
+
+    Node* iftrue = iff->as_If()->proj_out(1);
+    Node* iffalse = iff->as_If()->proj_out(0);
+    Node* ctrl = iff->in(0);
+
+    Node* subklass = NULL;
+    if (_igvn.type(obj_or_subklass)->isa_klassptr()) {
+      subklass = obj_or_subklass;
+    } else {
+      Node* k_adr = basic_plus_adr(obj_or_subklass, oopDesc::klass_offset_in_bytes());
+      subklass = _igvn.transform(LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), k_adr, TypeInstPtr::KLASS));
+    }
+
+    Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, NULL, _igvn);
+
+    _igvn.replace_input_of(iff, 0, C->top());
+    _igvn.replace_node(iftrue, not_subtype_ctrl);
+    _igvn.replace_node(iffalse, ctrl);
+  }
+  _igvn.replace_node(check, C->top());
+}
+
 //---------------------------eliminate_macro_nodes----------------------
 // Eliminate scalar replaced allocations and associated locks.
 void PhaseMacroExpand::eliminate_macro_nodes() {
@@ -2589,6 +2628,8 @@ void PhaseMacroExpand::eliminate_macro_nodes() {
         break;
       case Node::Class_OuterStripMinedLoop:
         break;
+      case Node::Class_SubTypeCheck:
+        break;
       default:
         assert(n->Opcode() == Op_LoopLimit ||
                n->Opcode() == Op_Opaque1   ||
@@ -2695,6 +2736,10 @@ bool PhaseMacroExpand::expand_macro_nodes() {
       expand_arraycopy_node(n->as_ArrayCopy());
       assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
       break;
+    case Node::Class_SubTypeCheck:
+      expand_subtypecheck_node(n->as_SubTypeCheck());
+      assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
+      break;
     }
     if (C->failing())  return true;
   }

src/hotspot/share/opto/macro.hpp

@@ -30,6 +30,7 @@
 class  AllocateNode;
 class  AllocateArrayNode;
 class  CallNode;
+class  SubTypeCheckNode;
 class  Node;
 class  PhaseIterGVN;
 
@@ -183,6 +184,8 @@ private:
 
   void expand_arraycopy_node(ArrayCopyNode *ac);
 
+  void expand_subtypecheck_node(SubTypeCheckNode *check);
+
   int replace_input(Node *use, Node *oldref, Node *newref);
   void migrate_outs(Node *old, Node *target);
   void copy_call_debug_info(CallNode *oldcall, CallNode * newcall);

src/hotspot/share/opto/macroArrayCopy.cpp

@@ -524,7 +524,7 @@ Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode*
       // Test S[] against D[], not S against D, because (probably)
       // the secondary supertype cache is less busy for S[] than S.
       // This usually only matters when D is an interface.
-      Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, &_igvn);
+      Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, _igvn);
       // Plug failing path into checked_oop_disjoint_arraycopy
       if (not_subtype_ctrl != top()) {
         Node* local_ctrl = not_subtype_ctrl;

src/hotspot/share/opto/node.hpp

@@ -146,6 +146,7 @@ class StartNode;
 class State;
 class StoreNode;
 class SubNode;
+class SubTypeCheckNode;
 class Type;
 class TypeNode;
 class UnlockNode;
@@ -706,6 +707,7 @@ public:
       DEFINE_CLASS_ID(Cmp,   Sub, 0)
         DEFINE_CLASS_ID(FastLock,   Cmp, 0)
         DEFINE_CLASS_ID(FastUnlock, Cmp, 1)
+        DEFINE_CLASS_ID(SubTypeCheck,Cmp, 2)
 
     DEFINE_CLASS_ID(MergeMem, Node, 7)
     DEFINE_CLASS_ID(Bool,     Node, 8)
@@ -875,6 +877,7 @@ public:
   DEFINE_CLASS_QUERY(Start)
   DEFINE_CLASS_QUERY(Store)
   DEFINE_CLASS_QUERY(Sub)
+  DEFINE_CLASS_QUERY(SubTypeCheck)
   DEFINE_CLASS_QUERY(Type)
   DEFINE_CLASS_QUERY(Vector)
   DEFINE_CLASS_QUERY(LoadVector)

src/hotspot/share/opto/phase.hpp

@@ -132,7 +132,7 @@ protected:
   // Object; if you wish to check an Object you need to load the Object's
   // class prior to coming here.
   // Used in GraphKit and PhaseMacroExpand
-  static Node* gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn);
+  static Node* gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, Node* mem, PhaseGVN& gvn);
 
 public:
   Compile * C;

src/hotspot/share/opto/subnode.cpp

@@ -1352,7 +1352,7 @@ Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   Node *cmp = in(1);
   if( !cmp->is_Sub() ) return NULL;
   int cop = cmp->Opcode();
-  if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL;
+  if( cop == Op_FastLock || cop == Op_FastUnlock || cmp->is_SubTypeCheck()) return NULL;
   Node *cmp1 = cmp->in(1);
   Node *cmp2 = cmp->in(2);
   if( !cmp1 ) return NULL;

src/hotspot/share/opto/subtypenode.cpp

@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2020, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "opto/addnode.hpp"
+#include "opto/connode.hpp"
+#include "opto/convertnode.hpp"
+#include "opto/phaseX.hpp"
+#include "opto/subnode.hpp"
+#include "opto/subtypenode.hpp"
+
+const Type* SubTypeCheckNode::sub(const Type* sub_t, const Type* super_t) const {
+  ciKlass* superk = super_t->is_klassptr()->klass();
+  ciKlass* subk   = sub_t->isa_klassptr() ? sub_t->is_klassptr()->klass() : sub_t->is_oopptr()->klass();
+
+  bool xsuperk = super_t->is_klassptr()->klass_is_exact();
+  bool xsubk = sub_t->isa_klassptr() ? sub_t->is_klassptr()->klass_is_exact() : sub_t->is_oopptr()->klass_is_exact();
+
+  // Similar to logic in CmpPNode::sub()
+  if (superk && subk &&
+      superk->is_loaded() && !superk->is_interface() &&
+      subk->is_loaded() && !subk->is_interface() &&
+      (!superk->is_obj_array_klass() ||
+       !superk->as_obj_array_klass()->base_element_klass()->is_interface()) &&
+      (!subk->is_obj_array_klass() ||
+       !subk->as_obj_array_klass()->base_element_klass()->is_interface() ||
+       xsubk)) {
+    bool unrelated_classes = false;
+    if (superk->equals(subk)) {
+      // skip
+    } else if (superk->is_subtype_of(subk)) {
+      unrelated_classes = xsubk;
+    } else if (subk->is_subtype_of(superk)) {
+      // skip
+    } else {
+      unrelated_classes = true;
+    }
+    if (unrelated_classes) {
+      TypePtr::PTR jp = sub_t->is_ptr()->join_ptr(super_t->is_ptr()->_ptr);
+      if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
+        return TypeInt::CC_GT;
+      }
+    }
+  }
+
+  if (super_t->singleton()) {
+    if (subk != NULL) {
+      switch (Compile::current()->static_subtype_check(superk, subk)) {
+      case Compile::SSC_always_false:
+        return TypeInt::CC_GT;
+      case Compile::SSC_always_true:
+        return TypeInt::CC_EQ;
+      case Compile::SSC_easy_test:
+      case Compile::SSC_full_test:
+        break;
+      default:
+        ShouldNotReachHere();
+      }
+    }
+  }
+
+  return bottom_type();
+}
+
+Node *SubTypeCheckNode::Ideal(PhaseGVN *phase, bool can_reshape) {
+  // Verify that optimizing the subtype check to a simple code pattern
+  // when possible would not constant fold better
+#ifdef ASSERT
+  Node* obj_or_subklass = in(ObjOrSubKlass);
+  Node* superklass = in(SuperKlass);
+
+  if (obj_or_subklass == NULL ||
+      superklass == NULL) {
+    return NULL;
+  }
+
+  const Type* sub_t = phase->type(obj_or_subklass);
+  const Type* super_t = phase->type(superklass);
+
+  if (!super_t->isa_klassptr() ||
+      (!sub_t->isa_klassptr() && !sub_t->isa_oopptr())) {
+    return NULL;
+  }
+
+
+  ciKlass* superk = super_t->is_klassptr()->klass();
+  ciKlass* subk   = sub_t->isa_klassptr() ? sub_t->is_klassptr()->klass() : sub_t->is_oopptr()->klass();
+
+  if (super_t->singleton() && subk != NULL && phase->C->static_subtype_check(superk, subk) == Compile::SSC_easy_test) {
+    Node* subklass = NULL;
+    if (sub_t->isa_oopptr()) {
+      Node* adr = phase->transform(new AddPNode(obj_or_subklass, obj_or_subklass, phase->MakeConX(oopDesc::klass_offset_in_bytes())));
+      subklass = phase->transform(LoadKlassNode::make(*phase, NULL, phase->C->immutable_memory(), adr, TypeInstPtr::KLASS));
+    } else {
+      subklass = obj_or_subklass;
+    }
+    Node* res = new CmpPNode(subklass, superklass);
+    const Type* t = phase->type(phase->transform(res));
+    assert((Value(phase) == t) || (t != TypeInt::CC_GT && t != TypeInt::CC_EQ), "missing Value() optimization");
+    if (phase->is_IterGVN()) {
+      phase->is_IterGVN()->_worklist.push(res);
+    }
+    return NULL;
+  }
+
+  if (super_t->singleton() && subk != NULL && phase->C->static_subtype_check(superk, subk) == Compile::SSC_full_test) {
+    Node* subklass = NULL;
+    if (sub_t->isa_oopptr()) {
+      Node* adr = phase->transform(new AddPNode(obj_or_subklass, obj_or_subklass, phase->MakeConX(oopDesc::klass_offset_in_bytes())));
+      subklass = phase->transform(LoadKlassNode::make(*phase, NULL, phase->C->immutable_memory(), adr, TypeInstPtr::KLASS));
+    } else {
+      subklass = obj_or_subklass;
+    }
+
+    Node *p1 = phase->transform(new AddPNode(superklass, superklass, phase->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
+    Node* m = phase->C->immutable_memory();
+    Node *chk_off = phase->transform(new LoadINode(NULL, m, p1, phase->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
+    int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
+    bool might_be_cache = (phase->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
+
+    if (might_be_cache) {
+      return NULL;
+    }
+
+    Node *chk_off_X = chk_off;
+#ifdef _LP64
+    chk_off_X = phase->transform(new ConvI2LNode(chk_off_X));
+#endif
+    Node *p2 = phase->transform(new AddPNode(subklass,subklass,chk_off_X));
+    Node *kmem = phase->C->immutable_memory();
+    Node *nkls = phase->transform(LoadKlassNode::make(*phase, NULL, kmem, p2, phase->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
+
+    Node* res = new CmpPNode(superklass, nkls);
+    const Type* t = phase->type(phase->transform(res));
+    assert((Value(phase) == t) || (t != TypeInt::CC_GT && t != TypeInt::CC_EQ), "missing Value() optimization");
+    if (phase->is_IterGVN()) {
+      phase->is_IterGVN()->_worklist.push(res);
+    }
+    return NULL;
+  }
+#endif
+
+  return NULL;
+}

src/hotspot/share/opto/subtypenode.hpp

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2020, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_OPTO_SUBTYPENODE_HPP
+#define SHARE_OPTO_SUBTYPENODE_HPP
+
+#include "opto/node.hpp"
+
+class SubTypeCheckNode : public CmpNode {
+public:
+  enum {
+    Control,
+    ObjOrSubKlass,
+    SuperKlass
+  };
+
+  SubTypeCheckNode(Compile* C, Node* obj_or_subklass, Node* superklass)
+    : CmpNode(obj_or_subklass, superklass) {
+    init_class_id(Class_SubTypeCheck);
+    init_flags(Flag_is_macro);
+    C->add_macro_node(this);
+  }
+
+  Node* Ideal(PhaseGVN *phase, bool can_reshape);
+  virtual const Type* sub(const Type*, const Type*) const;
+  Node* Identity(PhaseGVN* phase) { return this; }
+
+  virtual int Opcode() const;
+  const Type* bottom_type() const { return TypeInt::CC; }
+  bool depends_only_on_test() const { return false; };
+};
+
+#endif // SHARE_OPTO_SUBTYPENODE_HPP