--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/interpreter/rewriter.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,217 @@
+/*
+ * 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
+ * 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_VM_INTERPRETER_REWRITER_HPP
+#define SHARE_VM_INTERPRETER_REWRITER_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/handles.inline.hpp"
+#include "utilities/growableArray.hpp"
+
+// The Rewriter adds caches to the constant pool and rewrites bytecode indices
+// pointing into the constant pool for better interpreter performance.
+
+class Rewriter: public StackObj {
+ private:
+ InstanceKlass* _klass;
+ constantPoolHandle _pool;
+ Array<Method*>* _methods;
+ GrowableArray<int> _cp_map;
+ GrowableArray<int> _cp_cache_map; // for Methodref, Fieldref,
+ // InterfaceMethodref and InvokeDynamic
+ GrowableArray<int> _reference_map; // maps from cp index to resolved_refs index (or -1)
+ GrowableArray<int> _resolved_references_map; // for strings, methodHandle, methodType
+ GrowableArray<int> _invokedynamic_references_map; // for invokedynamic resolved refs
+ GrowableArray<int> _method_handle_invokers;
+ int _resolved_reference_limit;
+
+ // For mapping invokedynamic bytecodes, which are discovered during method
+ // scanning. The invokedynamic entries are added at the end of the cpCache.
+ // If there are any invokespecial/InterfaceMethodref special case bytecodes,
+ // these entries are added before invokedynamic entries so that the
+ // invokespecial bytecode 16 bit index doesn't overflow.
+ GrowableArray<int> _invokedynamic_cp_cache_map;
+
+ // For patching.
+ GrowableArray<address>* _patch_invokedynamic_bcps;
+ GrowableArray<int>* _patch_invokedynamic_refs;
+
+ void init_maps(int length) {
+ _cp_map.trunc_to(0);
+ _cp_map.at_grow(length, -1);
+
+ _cp_cache_map.trunc_to(0);
+ // Also cache resolved objects, in another different cache.
+ _reference_map.trunc_to(0);
+ _reference_map.at_grow(length, -1);
+
+ _method_handle_invokers.trunc_to(0);
+ _resolved_references_map.trunc_to(0);
+ _invokedynamic_references_map.trunc_to(0);
+ _resolved_reference_limit = -1;
+ _first_iteration_cp_cache_limit = -1;
+
+ // invokedynamic specific fields
+ _invokedynamic_cp_cache_map.trunc_to(0);
+ _patch_invokedynamic_bcps = new GrowableArray<address>(length / 4);
+ _patch_invokedynamic_refs = new GrowableArray<int>(length / 4);
+ }
+
+ int _first_iteration_cp_cache_limit;
+ void record_map_limits() {
+ // Record initial size of the two arrays generated for the CP cache
+ // relative to walking the constant pool.
+ _first_iteration_cp_cache_limit = _cp_cache_map.length();
+ _resolved_reference_limit = _resolved_references_map.length();
+ }
+
+ int cp_cache_delta() {
+ // How many cp cache entries were added since recording map limits after
+ // cp cache initialization?
+ assert(_first_iteration_cp_cache_limit != -1, "only valid after first iteration");
+ return _cp_cache_map.length() - _first_iteration_cp_cache_limit;
+ }
+
+ int cp_entry_to_cp_cache(int i) { assert(has_cp_cache(i), "oob"); return _cp_map.at(i); }
+ bool has_cp_cache(int i) { return (uint) i < (uint) _cp_map.length() && _cp_map.at(i) >= 0; }
+
+ int add_map_entry(int cp_index, GrowableArray<int>* cp_map, GrowableArray<int>* cp_cache_map) {
+ assert(cp_map->at(cp_index) == -1, "not twice on same cp_index");
+ int cache_index = cp_cache_map->append(cp_index);
+ cp_map->at_put(cp_index, cache_index);
+ return cache_index;
+ }
+
+ int add_cp_cache_entry(int cp_index) {
+ assert(_pool->tag_at(cp_index).value() != JVM_CONSTANT_InvokeDynamic, "use indy version");
+ assert(_first_iteration_cp_cache_limit == -1, "do not add cache entries after first iteration");
+ int cache_index = add_map_entry(cp_index, &_cp_map, &_cp_cache_map);
+ assert(cp_entry_to_cp_cache(cp_index) == cache_index, "");
+ assert(cp_cache_entry_pool_index(cache_index) == cp_index, "");
+ return cache_index;
+ }
+
+ int add_invokedynamic_cp_cache_entry(int cp_index) {
+ assert(_pool->tag_at(cp_index).value() == JVM_CONSTANT_InvokeDynamic, "use non-indy version");
+ assert(_first_iteration_cp_cache_limit >= 0, "add indy cache entries after first iteration");
+ // add to the invokedynamic index map.
+ int cache_index = _invokedynamic_cp_cache_map.append(cp_index);
+ // do not update _cp_map, since the mapping is one-to-many
+ assert(invokedynamic_cp_cache_entry_pool_index(cache_index) == cp_index, "");
+ // this index starts at one but in the bytecode it's appended to the end.
+ return cache_index + _first_iteration_cp_cache_limit;
+ }
+
+ int invokedynamic_cp_cache_entry_pool_index(int cache_index) {
+ int cp_index = _invokedynamic_cp_cache_map.at(cache_index);
+ return cp_index;
+ }
+
+ // add a new CP cache entry beyond the normal cache for the special case of
+ // invokespecial with InterfaceMethodref as cpool operand.
+ int add_invokespecial_cp_cache_entry(int cp_index) {
+ assert(_first_iteration_cp_cache_limit >= 0, "add these special cache entries after first iteration");
+ // Don't add InterfaceMethodref if it already exists at the end.
+ for (int i = _first_iteration_cp_cache_limit; i < _cp_cache_map.length(); i++) {
+ if (cp_cache_entry_pool_index(i) == cp_index) {
+ return i;
+ }
+ }
+ int cache_index = _cp_cache_map.append(cp_index);
+ assert(cache_index >= _first_iteration_cp_cache_limit, "");
+ // do not update _cp_map, since the mapping is one-to-many
+ assert(cp_cache_entry_pool_index(cache_index) == cp_index, "");
+ return cache_index;
+ }
+
+ int cp_entry_to_resolved_references(int cp_index) const {
+ assert(has_entry_in_resolved_references(cp_index), "oob");
+ return _reference_map.at(cp_index);
+ }
+ bool has_entry_in_resolved_references(int cp_index) const {
+ return (uint) cp_index < (uint) _reference_map.length() && _reference_map.at(cp_index) >= 0;
+ }
+
+ // add a new entry to the resolved_references map
+ int add_resolved_references_entry(int cp_index) {
+ int ref_index = add_map_entry(cp_index, &_reference_map, &_resolved_references_map);
+ assert(cp_entry_to_resolved_references(cp_index) == ref_index, "");
+ return ref_index;
+ }
+
+ // add a new entries to the resolved_references map (for invokedynamic and invokehandle only)
+ int add_invokedynamic_resolved_references_entries(int cp_index, int cache_index) {
+ assert(_resolved_reference_limit >= 0, "must add indy refs after first iteration");
+ int ref_index = -1;
+ for (int entry = 0; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
+ const int index = _resolved_references_map.append(cp_index); // many-to-one
+ assert(index >= _resolved_reference_limit, "");
+ if (entry == 0) {
+ ref_index = index;
+ }
+ assert((index - entry) == ref_index, "entries must be consecutive");
+ _invokedynamic_references_map.at_put_grow(index, cache_index, -1);
+ }
+ return ref_index;
+ }
+
+ int resolved_references_entry_to_pool_index(int ref_index) {
+ int cp_index = _resolved_references_map.at(ref_index);
+ return cp_index;
+ }
+
+ // Access the contents of _cp_cache_map to determine CP cache layout.
+ int cp_cache_entry_pool_index(int cache_index) {
+ int cp_index = _cp_cache_map.at(cache_index);
+ return cp_index;
+ }
+
+ // All the work goes in here:
+ Rewriter(InstanceKlass* klass, const constantPoolHandle& cpool, Array<Method*>* methods, TRAPS);
+
+ void compute_index_maps();
+ void make_constant_pool_cache(TRAPS);
+ void scan_method(Method* m, bool reverse, bool* invokespecial_error);
+ void rewrite_Object_init(const methodHandle& m, TRAPS);
+ void rewrite_member_reference(address bcp, int offset, bool reverse);
+ void maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse);
+ void rewrite_invokedynamic(address bcp, int offset, bool reverse);
+ void maybe_rewrite_ldc(address bcp, int offset, bool is_wide, bool reverse);
+ void rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error);
+
+ void patch_invokedynamic_bytecodes();
+
+ // Do all the work.
+ void rewrite_bytecodes(TRAPS);
+
+ // Revert bytecodes in case of an exception.
+ void restore_bytecodes();
+
+ static methodHandle rewrite_jsrs(const methodHandle& m, TRAPS);
+ public:
+ // Driver routine:
+ static void rewrite(InstanceKlass* klass, TRAPS);
+};
+
+#endif // SHARE_VM_INTERPRETER_REWRITER_HPP