8064524: Compiler code generation improvements

Reviewed-by: jrose, acorn, vlivanov

src/share/vm/code/dependencies.cpp

 /*
- * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2014, 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
@@ -544,7 +544,7 @@ void Dependencies::print_dependency(DepType dept, int nargs, DepArgument args[],
       put_star = !Dependencies::is_concrete_klass((Klass*)arg.metadata_value());
     } else if (arg.is_method()) {
       what = "method ";
-      put_star = !Dependencies::is_concrete_method((Method*)arg.metadata_value());
+      put_star = !Dependencies::is_concrete_method((Method*)arg.metadata_value(), NULL);
     } else if (arg.is_klass()) {
       what = "class  ";
     } else {
@@ -826,8 +826,8 @@ class ClassHierarchyWalker {
         // Static methods don't override non-static so punt
         return true;
       }
-      if (   !Dependencies::is_concrete_method(lm)
-          && !Dependencies::is_concrete_method(m)
+      if (   !Dependencies::is_concrete_method(lm, k)
+          && !Dependencies::is_concrete_method(m, ctxk)
           && lm->method_holder()->is_subtype_of(m->method_holder()))
         // Method m is overridden by lm, but both are non-concrete.
         return true;
@@ -861,8 +861,17 @@ class ClassHierarchyWalker {
     if (doing_subtype_search()) {
       return Dependencies::is_concrete_klass(k);
     } else {
-      Method* m = InstanceKlass::cast(k)->find_method(_name, _signature);
-      if (m == NULL || !Dependencies::is_concrete_method(m))  return false;
+      // Search class hierarchy first.
+      Method* m = InstanceKlass::cast(k)->find_instance_method(_name, _signature);
+      if (!Dependencies::is_concrete_method(m, k)) {
+        // Check interface defaults also, if any exist.
+        Array<Method*>* default_methods = InstanceKlass::cast(k)->default_methods();
+        if (default_methods == NULL)
+            return false;
+        m = InstanceKlass::cast(k)->find_method(default_methods, _name, _signature);
+        if (!Dependencies::is_concrete_method(m, NULL))
+            return false;
+      }
       _found_methods[_num_participants] = m;
       // Note:  If add_participant(k) is called,
       // the method m will already be memoized for it.
@@ -1153,15 +1162,17 @@ bool Dependencies::is_concrete_klass(Klass* k) {
   return true;
 }
 
-bool Dependencies::is_concrete_method(Method* m) {
-  // Statics are irrelevant to virtual call sites.
-  if (m->is_static())  return false;
-
-  // We could also return false if m does not yet appear to be
-  // executed, if the VM version supports this distinction also.
-  // Default methods are considered "concrete" as well.
-  return !m->is_abstract() &&
-         !m->is_overpass(); // error functions aren't concrete
+bool Dependencies::is_concrete_method(Method* m, Klass * k) {
+  // NULL is not a concrete method,
+  // statics are irrelevant to virtual call sites,
+  // abstract methods are not concrete,
+  // overpass (error) methods are not concrete if k is abstract
+  //
+  // note "true" is conservative answer --
+  //     overpass clause is false if k == NULL, implies return true if
+  //     answer depends on overpass clause.
+  return ! ( m == NULL || m -> is_static() || m -> is_abstract() ||
+             m->is_overpass() && k != NULL && k -> is_abstract() );
 }
 
 
@@ -1186,16 +1197,6 @@ bool Dependencies::is_concrete_klass(ciInstanceKlass* k) {
   return true;
 }
 
-bool Dependencies::is_concrete_method(ciMethod* m) {
-  // Statics are irrelevant to virtual call sites.
-  if (m->is_static())  return false;
-
-  // We could also return false if m does not yet appear to be
-  // executed, if the VM version supports this distinction also.
-  return !m->is_abstract();
-}
-
-
 bool Dependencies::has_finalizable_subclass(ciInstanceKlass* k) {
   return k->has_finalizable_subclass();
 }
@@ -1409,7 +1410,7 @@ Method* Dependencies::find_unique_concrete_method(Klass* ctxk, Method* m) {
   Klass* wit = wf.find_witness_definer(ctxk);
   if (wit != NULL)  return NULL;  // Too many witnesses.
   Method* fm = wf.found_method(0);  // Will be NULL if num_parts == 0.
-  if (Dependencies::is_concrete_method(m)) {
+  if (Dependencies::is_concrete_method(m, ctxk)) {
     if (fm == NULL) {
       // It turns out that m was always the only implementation.
       fm = m;
@@ -1439,61 +1440,6 @@ Klass* Dependencies::check_exclusive_concrete_methods(Klass* ctxk,
   return wf.find_witness_definer(ctxk, changes);
 }
 
-// Find the set of all non-abstract methods under ctxk that match m[0].
-// (The method m[0] must be defined or inherited in ctxk.)
-// Include m itself in the set, unless it is abstract.
-// Fill the given array m[0..(mlen-1)] with this set, and return the length.
-// (The length may be zero if no concrete methods are found anywhere.)
-// If there are too many concrete methods to fit in marray, return -1.
-int Dependencies::find_exclusive_concrete_methods(Klass* ctxk,
-                                                  int mlen,
-                                                  Method* marray[]) {
-  Method* m0 = marray[0];
-  ClassHierarchyWalker wf(m0);
-  assert(wf.check_method_context(ctxk, m0), "proper context");
-  wf.record_witnesses(mlen);
-  bool participants_hide_witnesses = true;
-  Klass* wit = wf.find_witness_definer(ctxk);
-  if (wit != NULL)  return -1;  // Too many witnesses.
-  int num = wf.num_participants();
-  assert(num <= mlen, "oob");
-  // Keep track of whether m is also part of the result set.
-  int mfill = 0;
-  assert(marray[mfill] == m0, "sanity");
-  if (Dependencies::is_concrete_method(m0))
-    mfill++;  // keep m0 as marray[0], the first result
-  for (int i = 0; i < num; i++) {
-    Method* fm = wf.found_method(i);
-    if (fm == m0)  continue;  // Already put this guy in the list.
-    if (mfill == mlen) {
-      return -1;              // Oops.  Too many methods after all!
-    }
-    marray[mfill++] = fm;
-  }
-#ifndef PRODUCT
-  // Make sure the dependency mechanism will pass this discovery:
-  if (VerifyDependencies) {
-    // Turn off dependency tracing while actually testing deps.
-    FlagSetting fs(TraceDependencies, false);
-    switch (mfill) {
-    case 1:
-      guarantee(NULL == (void *)check_unique_concrete_method(ctxk, marray[0]),
-                "verify dep.");
-      break;
-    case 2:
-      guarantee(NULL == (void *)
-                check_exclusive_concrete_methods(ctxk, marray[0], marray[1]),
-                "verify dep.");
-      break;
-    default:
-      ShouldNotReachHere();  // mlen > 2 yet supported
-    }
-  }
-#endif //PRODUCT
-  return mfill;
-}
-
-
 Klass* Dependencies::check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepChange* changes) {
   Klass* search_at = ctxk;
   if (changes != NULL)
@@ -1501,7 +1447,6 @@ Klass* Dependencies::check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepCh
   return find_finalizable_subclass(search_at);
 }
 
-
 Klass* Dependencies::check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes) {
   assert(call_site    ->is_a(SystemDictionary::CallSite_klass()),     "sanity");
   assert(method_handle->is_a(SystemDictionary::MethodHandle_klass()), "sanity");

src/share/vm/code/dependencies.hpp

 /*
- * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2014, 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
@@ -287,7 +287,7 @@ class Dependencies: public ResourceObj {
   // In that case, there would be a middle ground between concrete
   // and abstract (as defined by the Java language and VM).
   static bool is_concrete_klass(Klass* k);    // k is instantiable
-  static bool is_concrete_method(Method* m);  // m is invocable
+  static bool is_concrete_method(Method* m, Klass* k);  // m is invocable
   static Klass* find_finalizable_subclass(Klass* k);
 
   // These versions of the concreteness queries work through the CI.
@@ -301,7 +301,6 @@ class Dependencies: public ResourceObj {
   // not go back into the VM to get their value; they must cache the
   // bit in the CI, either eagerly or lazily.)
   static bool is_concrete_klass(ciInstanceKlass* k); // k appears instantiable
-  static bool is_concrete_method(ciMethod* m);       // m appears invocable
   static bool has_finalizable_subclass(ciInstanceKlass* k);
 
   // As a general rule, it is OK to compile under the assumption that
@@ -348,7 +347,6 @@ class Dependencies: public ResourceObj {
   static Klass*    find_unique_concrete_subtype(Klass* ctxk);
   static Method*   find_unique_concrete_method(Klass* ctxk, Method* m);
   static int       find_exclusive_concrete_subtypes(Klass* ctxk, int klen, Klass* k[]);
-  static int       find_exclusive_concrete_methods(Klass* ctxk, int mlen, Method* m[]);
 
   // Create the encoding which will be stored in an nmethod.
   void encode_content_bytes();

src/share/vm/interpreter/linkResolver.cpp

@@ -320,7 +320,7 @@ int LinkResolver::vtable_index_of_interface_method(KlassHandle klass,
   // First check in default method array
   if (!resolved_method->is_abstract() &&
     (InstanceKlass::cast(klass())->default_methods() != NULL)) {
-    int index = InstanceKlass::find_method_index(InstanceKlass::cast(klass())->default_methods(), name, signature, false);
+    int index = InstanceKlass::find_method_index(InstanceKlass::cast(klass())->default_methods(), name, signature, false, false);
     if (index >= 0 ) {
       vtable_index = InstanceKlass::cast(klass())->default_vtable_indices()->at(index);
     }

src/share/vm/oops/instanceKlass.cpp

@@ -1435,32 +1435,41 @@ Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
 }
 
 Method* InstanceKlass::find_method_impl(Symbol* name, Symbol* signature, bool skipping_overpass) const {
-  return InstanceKlass::find_method_impl(methods(), name, signature, skipping_overpass);
+  return InstanceKlass::find_method_impl(methods(), name, signature, skipping_overpass, false);
 }
 
 // find_instance_method looks up the name/signature in the local methods array
 // and skips over static methods
 Method* InstanceKlass::find_instance_method(
     Array<Method*>* methods, Symbol* name, Symbol* signature) {
-  Method* meth = InstanceKlass::find_method(methods, name, signature);
-  if (meth != NULL && meth->is_static()) {
-      meth = NULL;
-  }
+  Method* meth = InstanceKlass::find_method_impl(methods, name, signature, false, true);
   return meth;
 }
 
+// find_instance_method looks up the name/signature in the local methods array
+// and skips over static methods
+Method* InstanceKlass::find_instance_method(Symbol* name, Symbol* signature) {
+    return InstanceKlass::find_instance_method(methods(), name, signature);
+}
+
 // find_method looks up the name/signature in the local methods array
 Method* InstanceKlass::find_method(
     Array<Method*>* methods, Symbol* name, Symbol* signature) {
-  return InstanceKlass::find_method_impl(methods, name, signature, false);
+  return InstanceKlass::find_method_impl(methods, name, signature, false, false);
 }
 
 Method* InstanceKlass::find_method_impl(
-    Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass) {
-  int hit = find_method_index(methods, name, signature, skipping_overpass);
+    Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass, bool skipping_static) {
+  int hit = find_method_index(methods, name, signature, skipping_overpass, skipping_static);
   return hit >= 0 ? methods->at(hit): NULL;
 }
 
+bool InstanceKlass::method_matches(Method* m, Symbol* signature, bool skipping_overpass, bool skipping_static) {
+    return (m->signature() == signature) &&
+            (!skipping_overpass || !m->is_overpass()) &&
+            (!skipping_static || !m->is_static());
+}
+
 // Used directly for default_methods to find the index into the
 // default_vtable_indices, and indirectly by find_method
 // find_method_index looks in the local methods array to return the index
@@ -1469,13 +1478,14 @@ Method* InstanceKlass::find_method_impl(
 // is important during method resolution to prefer a static method, for example,
 // over an overpass method.
 int InstanceKlass::find_method_index(
-    Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass) {
+    Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass, bool skipping_static) {
   int hit = binary_search(methods, name);
   if (hit != -1) {
     Method* m = methods->at(hit);
+
     // Do linear search to find matching signature.  First, quick check
     // for common case, ignoring overpasses if requested.
-    if ((m->signature() == signature) && (!skipping_overpass || !m->is_overpass())) return hit;
+    if (method_matches(m, signature, skipping_overpass, skipping_static)) return hit;
 
     // search downwards through overloaded methods
     int i;
@@ -1483,18 +1493,18 @@ int InstanceKlass::find_method_index(
         Method* m = methods->at(i);
         assert(m->is_method(), "must be method");
         if (m->name() != name) break;
-        if ((m->signature() == signature) && (!skipping_overpass || !m->is_overpass())) return i;
+        if (method_matches(m, signature, skipping_overpass, skipping_static)) return i;
     }
     // search upwards
     for (i = hit + 1; i < methods->length(); ++i) {
         Method* m = methods->at(i);
         assert(m->is_method(), "must be method");
         if (m->name() != name) break;
-        if ((m->signature() == signature) && (!skipping_overpass || !m->is_overpass())) return i;
+        if (method_matches(m, signature, skipping_overpass, skipping_static)) return i;
     }
     // not found
 #ifdef ASSERT
-    int index = skipping_overpass ? -1 : linear_search(methods, name, signature);
+    int index = skipping_overpass || skipping_static ? -1 : linear_search(methods, name, signature);
     assert(index == -1, err_msg("binary search should have found entry %d", index));
 #endif
   }

src/share/vm/oops/instanceKlass.hpp

@@ -515,10 +515,16 @@ class InstanceKlass: public Klass {
   // find a local method (returns NULL if not found)
   Method* find_method(Symbol* name, Symbol* signature) const;
   static Method* find_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
+
+  // find a local method, but skip static methods
+  Method* find_instance_method(Symbol* name, Symbol* signature);
   static Method* find_instance_method(Array<Method*>* methods, Symbol* name, Symbol* signature);
 
+  // true if method matches signature and conforms to skipping_X conditions.
+  static bool method_matches(Method* m, Symbol* signature, bool skipping_overpass, bool skipping_static);
+
   // find a local method index in default_methods (returns -1 if not found)
-  static int find_method_index(Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass);
+  static int find_method_index(Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass, bool skipping_static);
 
   // lookup operation (returns NULL if not found)
   Method* uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const;
@@ -1050,7 +1056,7 @@ private:
 
   // find a local method (returns NULL if not found)
   Method* find_method_impl(Symbol* name, Symbol* signature, bool skipping_overpass) const;
-  static Method* find_method_impl(Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass);
+  static Method* find_method_impl(Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass, bool skipping_static);
 
   // Free CHeap allocated fields.
   void release_C_heap_structures();