8341444: Unnecessary check for JSRs in CDS

Reviewed-by: dholmes, coleenp

Author: Matias Saavedra Silva

src/hotspot/share/oops/instanceKlass.cpp

@@ -2452,11 +2452,11 @@ void InstanceKlass::metaspace_pointers_do(MetaspaceClosure* it) {
 #endif
 #if INCLUDE_CDS
   // For "old" classes with methods containing the jsr bytecode, the _methods array will
-  // be rewritten during runtime (see Rewriter::rewrite_jsrs()). So setting the _methods to
-  // be writable. The length check on the _methods is necessary because classes which
-  // don't have any methods share the Universe::_the_empty_method_array which is in the RO region.
-  if (_methods != nullptr && _methods->length() > 0 &&
-      !can_be_verified_at_dumptime() && methods_contain_jsr_bytecode()) {
+  // be rewritten during runtime (see Rewriter::rewrite_jsrs()) but they cannot be safely
+  // checked here with ByteCodeStream. All methods that can't be verified are made writable.
+  // The length check on the _methods is necessary because classes which don't have any
+  // methods share the Universe::_the_empty_method_array which is in the RO region.
+  if (_methods != nullptr && _methods->length() > 0 && !can_be_verified_at_dumptime()) {
     // To handle jsr bytecode, new Method* maybe stored into _methods
     it->push(&_methods, MetaspaceClosure::_writable);
   } else {
@@ -2697,21 +2697,6 @@ bool InstanceKlass::can_be_verified_at_dumptime() const {
   }
   return true;
 }
-
-bool InstanceKlass::methods_contain_jsr_bytecode() const {
-  Thread* thread = Thread::current();
-  for (int i = 0; i < _methods->length(); i++) {
-    methodHandle m(thread, _methods->at(i));
-    BytecodeStream bcs(m);
-    while (!bcs.is_last_bytecode()) {
-      Bytecodes::Code opcode = bcs.next();
-      if (opcode == Bytecodes::_jsr || opcode == Bytecodes::_jsr_w) {
-        return true;
-      }
-    }
-  }
-  return false;
-}
 #endif // INCLUDE_CDS
 
 #if INCLUDE_JVMTI

src/hotspot/share/oops/instanceKlass.hpp

@@ -1116,7 +1116,6 @@ class InstanceKlass: public Klass {
   void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, PackageEntry* pkg_entry, TRAPS);
   void init_shared_package_entry();
   bool can_be_verified_at_dumptime() const;
-  bool methods_contain_jsr_bytecode() const;
   void compute_has_loops_flag_for_methods();
 #endif