jdk8-mips64-public/hotspot: src/share/vm/interpreter/rewriter.cpp@11d5942ef9c7 (annotated)

src/share/vm/interpreter/rewriter.cpp@11d5942ef9c7 (annotated)

src/share/vm/interpreter/rewriter.cpp

Tue, 12 Mar 2013 18:22:40 -0700

author: lana
date: Tue, 12 Mar 2013 18:22:40 -0700
changeset 4706: 11d5942ef9c7
parent 4643: f16e75e0cf11
child 4712: 3efdfd6ddbf2
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1998, 2013, 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 "interpreter/bytecodes.hpp"
 #include "interpreter/interpreter.hpp"
 #include "interpreter/rewriter.hpp"
 #include "memory/gcLocker.hpp"
 #include "memory/resourceArea.hpp"
 #include "oops/generateOopMap.hpp"
 #include "prims/methodHandles.hpp"
 // Computes a CPC map (new_index -> original_index) for constant pool entries
 // that are referred to by the interpreter at runtime via the constant pool cache.
 // Also computes a CP map (original_index -> new_index).
 // Marks entries in CP which require additional processing.
 void Rewriter::compute_index_maps() {
   const int length  = _pool->length();
   init_maps(length);
   bool saw_mh_symbol = false;
   for (int i = 0; i < length; i++) {
     int tag = _pool->tag_at(i).value();
     switch (tag) {
       case JVM_CONSTANT_InterfaceMethodref:
       case JVM_CONSTANT_Fieldref          : // fall through
       case JVM_CONSTANT_Methodref         : // fall through
         add_cp_cache_entry(i);
         break;
       case JVM_CONSTANT_String:
       case JVM_CONSTANT_MethodHandle      : // fall through
       case JVM_CONSTANT_MethodType        : // fall through
         add_resolved_references_entry(i);
         break;
       case JVM_CONSTANT_Utf8:
         if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle())
           saw_mh_symbol = true;
         break;
     }
   }
   // Record limits of resolved reference map for constant pool cache indices
   record_map_limits();
   guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1),
             "all cp cache indexes fit in a u2");
   if (saw_mh_symbol)
     _method_handle_invokers.initialize(length, (int)0);
 }
 // Unrewrite the bytecodes if an error occurs.
 void Rewriter::restore_bytecodes() {
   int len = _methods->length();
   for (int i = len-1; i >= 0; i--) {
     Method* method = _methods->at(i);
     scan_method(method, true);
   }
 }
 // Creates a constant pool cache given a CPC map
 void Rewriter::make_constant_pool_cache(TRAPS) {
   const int length = _cp_cache_map.length();
   ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data();
   ConstantPoolCache* cache =
       ConstantPoolCache::allocate(loader_data, length, CHECK);
   // initialize object cache in constant pool
   _pool->initialize_resolved_references(loader_data, _resolved_references_map,
                                         _resolved_reference_limit,
                                         CHECK);
   No_Safepoint_Verifier nsv;
   cache->initialize(_cp_cache_map, _invokedynamic_references_map);
   _pool->set_cache(cache);
   cache->set_constant_pool(_pool());
 }
 // The new finalization semantics says that registration of
 // finalizable objects must be performed on successful return from the
 // Object.<init> constructor.  We could implement this trivially if
 // <init> were never rewritten but since JVMTI allows this to occur, a
 // more complicated solution is required.  A special return bytecode
 // is used only by Object.<init> to signal the finalization
 // registration point.  Additionally local 0 must be preserved so it's
 // available to pass to the registration function.  For simplicty we
 // require that local 0 is never overwritten so it's available as an
 // argument for registration.
 void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) {
   RawBytecodeStream bcs(method);
   while (!bcs.is_last_bytecode()) {
     Bytecodes::Code opcode = bcs.raw_next();
     switch (opcode) {
       case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break;
       case Bytecodes::_istore:
       case Bytecodes::_lstore:
       case Bytecodes::_fstore:
       case Bytecodes::_dstore:
       case Bytecodes::_astore:
         if (bcs.get_index() != 0) continue;
         // fall through
       case Bytecodes::_istore_0:
       case Bytecodes::_lstore_0:
       case Bytecodes::_fstore_0:
       case Bytecodes::_dstore_0:
       case Bytecodes::_astore_0:
         THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(),
                   "can't overwrite local 0 in Object.<init>");
         break;
     }
   }
 }
 // Rewrite a classfile-order CP index into a native-order CPC index.
 void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) {
   address p = bcp + offset;
   if (!reverse) {
     int  cp_index    = Bytes::get_Java_u2(p);
     int  cache_index = cp_entry_to_cp_cache(cp_index);
     Bytes::put_native_u2(p, cache_index);
     if (!_method_handle_invokers.is_empty())
       maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse);
   } else {
     int cache_index = Bytes::get_native_u2(p);
     int pool_index = cp_cache_entry_pool_index(cache_index);
     Bytes::put_Java_u2(p, pool_index);
     if (!_method_handle_invokers.is_empty())
       maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse);
   }
 }
 // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.)
 void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) {
   if (!reverse) {
     if ((*opc) == (u1)Bytecodes::_invokevirtual ||
         // allow invokespecial as an alias, although it would be very odd:
         (*opc) == (u1)Bytecodes::_invokespecial) {
       assert(_pool->tag_at(cp_index).is_method(), "wrong index");
       // Determine whether this is a signature-polymorphic method.
       if (cp_index >= _method_handle_invokers.length())  return;
       int status = _method_handle_invokers[cp_index];
       assert(status >= -1 && status <= 1, "oob tri-state");
       if (status == 0) {
         if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() &&
             MethodHandles::is_signature_polymorphic_name(SystemDictionary::MethodHandle_klass(),
                                                          _pool->name_ref_at(cp_index))) {
           // we may need a resolved_refs entry for the appendix
           add_invokedynamic_resolved_references_entries(cp_index, cache_index);
           status = +1;
         } else {
           status = -1;
         }
         _method_handle_invokers[cp_index] = status;
       }
       // We use a special internal bytecode for such methods (if non-static).
       // The basic reason for this is that such methods need an extra "appendix" argument
       // to transmit the call site's intended call type.
       if (status > 0) {
         (*opc) = (u1)Bytecodes::_invokehandle;
       }
     }
   } else {
     // Do not need to look at cp_index.
     if ((*opc) == (u1)Bytecodes::_invokehandle) {
       (*opc) = (u1)Bytecodes::_invokevirtual;
       // Ignore corner case of original _invokespecial instruction.
       // This is safe because (a) the signature polymorphic method was final, and
       // (b) the implementation of MethodHandle will not call invokespecial on it.
     }
   }
 }
 void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {
   address p = bcp + offset;
   assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
   if (!reverse) {
     int cp_index = Bytes::get_Java_u2(p);
     int cache_index = add_invokedynamic_cp_cache_entry(cp_index);
     add_invokedynamic_resolved_references_entries(cp_index, cache_index);
     // Replace the trailing four bytes with a CPC index for the dynamic
     // call site.  Unlike other CPC entries, there is one per bytecode,
     // not just one per distinct CP entry.  In other words, the
     // CPC-to-CP relation is many-to-one for invokedynamic entries.
     // This means we must use a larger index size than u2 to address
     // all these entries.  That is the main reason invokedynamic
     // must have a five-byte instruction format.  (Of course, other JVM
     // implementations can use the bytes for other purposes.)
     Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index));
     // Note: We use native_u4 format exclusively for 4-byte indexes.
   } else {
     // callsite index
     int cache_index = ConstantPool::decode_invokedynamic_index(
                         Bytes::get_native_u4(p));
     int cp_index = cp_cache_entry_pool_index(cache_index);
     assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index");
     // zero out 4 bytes
     Bytes::put_Java_u4(p, 0);
     Bytes::put_Java_u2(p, cp_index);
   }
 }
 // Rewrite some ldc bytecodes to _fast_aldc
 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide,
                                  bool reverse) {
   if (!reverse) {
     assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode");
     address p = bcp + offset;
     int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p);
     constantTag tag = _pool->tag_at(cp_index).value();
     if (tag.is_method_handle() || tag.is_method_type() || tag.is_string()) {
       int ref_index = cp_entry_to_resolved_references(cp_index);
       if (is_wide) {
         (*bcp) = Bytecodes::_fast_aldc_w;
         assert(ref_index == (u2)ref_index, "index overflow");
         Bytes::put_native_u2(p, ref_index);
       } else {
         (*bcp) = Bytecodes::_fast_aldc;
         assert(ref_index == (u1)ref_index, "index overflow");
         (*p) = (u1)ref_index;
       }
     }
   } else {
     Bytecodes::Code rewritten_bc =
               (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc);
     if ((*bcp) == rewritten_bc) {
       address p = bcp + offset;
       int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p);
       int pool_index = resolved_references_entry_to_pool_index(ref_index);
       if (is_wide) {
         (*bcp) = Bytecodes::_ldc_w;
         assert(pool_index == (u2)pool_index, "index overflow");
         Bytes::put_Java_u2(p, pool_index);
       } else {
         (*bcp) = Bytecodes::_ldc;
         assert(pool_index == (u1)pool_index, "index overflow");
         (*p) = (u1)pool_index;
       }
     }
   }
 }
 // Rewrites a method given the index_map information
 void Rewriter::scan_method(Method* method, bool reverse) {
   int nof_jsrs = 0;
   bool has_monitor_bytecodes = false;
   {
     // We cannot tolerate a GC in this block, because we've
     // cached the bytecodes in 'code_base'. If the Method*
     // moves, the bytecodes will also move.
     No_Safepoint_Verifier nsv;
     Bytecodes::Code c;
     // Bytecodes and their length
     const address code_base = method->code_base();
     const int code_length = method->code_size();
     int bc_length;
     for (int bci = 0; bci < code_length; bci += bc_length) {
       address bcp = code_base + bci;
       int prefix_length = 0;
       c = (Bytecodes::Code)(*bcp);
       // Since we have the code, see if we can get the length
       // directly. Some more complicated bytecodes will report
       // a length of zero, meaning we need to make another method
       // call to calculate the length.
       bc_length = Bytecodes::length_for(c);
       if (bc_length == 0) {
         bc_length = Bytecodes::length_at(method, bcp);
         // length_at will put us at the bytecode after the one modified
         // by 'wide'. We don't currently examine any of the bytecodes
         // modified by wide, but in case we do in the future...
         if (c == Bytecodes::_wide) {
           prefix_length = 1;
           c = (Bytecodes::Code)bcp[1];
         }
       }
       assert(bc_length != 0, "impossible bytecode length");
       switch (c) {
         case Bytecodes::_lookupswitch   : {
 #ifndef CC_INTERP
           Bytecode_lookupswitch bc(method, bcp);
           (*bcp) = (
             bc.number_of_pairs() < BinarySwitchThreshold
             ? Bytecodes::_fast_linearswitch
             : Bytecodes::_fast_binaryswitch
           );
 #endif
           break;
         }
         case Bytecodes::_fast_linearswitch:
         case Bytecodes::_fast_binaryswitch: {
 #ifndef CC_INTERP
           (*bcp) = Bytecodes::_lookupswitch;
 #endif
           break;
         }
         case Bytecodes::_getstatic      : // fall through
         case Bytecodes::_putstatic      : // fall through
         case Bytecodes::_getfield       : // fall through
         case Bytecodes::_putfield       : // fall through
         case Bytecodes::_invokevirtual  : // fall through
         case Bytecodes::_invokespecial  : // fall through
         case Bytecodes::_invokestatic   :
         case Bytecodes::_invokeinterface:
         case Bytecodes::_invokehandle   : // if reverse=true
           rewrite_member_reference(bcp, prefix_length+1, reverse);
           break;
         case Bytecodes::_invokedynamic:
           rewrite_invokedynamic(bcp, prefix_length+1, reverse);
           break;
         case Bytecodes::_ldc:
         case Bytecodes::_fast_aldc:  // if reverse=true
           maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse);
           break;
         case Bytecodes::_ldc_w:
         case Bytecodes::_fast_aldc_w:  // if reverse=true
           maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse);
           break;
         case Bytecodes::_jsr            : // fall through
         case Bytecodes::_jsr_w          : nof_jsrs++;                   break;
         case Bytecodes::_monitorenter   : // fall through
         case Bytecodes::_monitorexit    : has_monitor_bytecodes = true; break;
       }
     }
   }
   // Update access flags
   if (has_monitor_bytecodes) {
     method->set_has_monitor_bytecodes();
   }
   // The present of a jsr bytecode implies that the method might potentially
   // have to be rewritten, so we run the oopMapGenerator on the method
   if (nof_jsrs > 0) {
     method->set_has_jsrs();
     // Second pass will revisit this method.
     assert(method->has_jsrs(), "didn't we just set this?");
   }
 }
 // After constant pool is created, revisit methods containing jsrs.
 methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) {
   ResourceMark rm(THREAD);
   ResolveOopMapConflicts romc(method);
   methodHandle original_method = method;
   method = romc.do_potential_rewrite(CHECK_(methodHandle()));
   // Update monitor matching info.
   if (romc.monitor_safe()) {
     method->set_guaranteed_monitor_matching();
   }
   return method;
 }
 void Rewriter::rewrite(instanceKlassHandle klass, TRAPS) {
   ResourceMark rm(THREAD);
   Rewriter     rw(klass, klass->constants(), klass->methods(), CHECK);
   // (That's all, folks.)
 }
 Rewriter::Rewriter(instanceKlassHandle klass, constantPoolHandle cpool, Array<Method*>* methods, TRAPS)
   : _klass(klass),
     _pool(cpool),
     _methods(methods)
 {
   assert(_pool->cache() == NULL, "constant pool cache must not be set yet");
   // determine index maps for Method* rewriting
   compute_index_maps();
   if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
     bool did_rewrite = false;
     int i = _methods->length();
     while (i-- > 0) {
       Method* method = _methods->at(i);
       if (method->intrinsic_id() == vmIntrinsics::_Object_init) {
         // rewrite the return bytecodes of Object.<init> to register the
         // object for finalization if needed.
         methodHandle m(THREAD, method);
         rewrite_Object_init(m, CHECK);
         did_rewrite = true;
         break;
       }
     }
     assert(did_rewrite, "must find Object::<init> to rewrite it");
   }
   // rewrite methods, in two passes
   int len = _methods->length();
   for (int i = len-1; i >= 0; i--) {
     Method* method = _methods->at(i);
     scan_method(method);
   }
   // allocate constant pool cache, now that we've seen all the bytecodes
   make_constant_pool_cache(THREAD);
   // Restore bytecodes to their unrewritten state if there are exceptions
   // rewriting bytecodes or allocating the cpCache
   if (HAS_PENDING_EXCEPTION) {
     restore_bytecodes();
     return;
   }
   // Relocate after everything, but still do this under the is_rewritten flag,
   // so methods with jsrs in custom class lists in aren't attempted to be
   // rewritten in the RO section of the shared archive.
   // Relocated bytecodes don't have to be restored, only the cp cache entries
   for (int i = len-1; i >= 0; i--) {
     methodHandle m(THREAD, _methods->at(i));
     if (m->has_jsrs()) {
       m = rewrite_jsrs(m, THREAD);
       // Restore bytecodes to their unrewritten state if there are exceptions
       // relocating bytecodes.  If some are relocated, that is ok because that
       // doesn't affect constant pool to cpCache rewriting.
       if (HAS_PENDING_EXCEPTION) {
         restore_bytecodes();
         return;
       }
       // Method might have gotten rewritten.
       methods->at_put(i, m());
     }
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/interpreter/rewriter.cpp@11d5942ef9c7 (annotated)

src/share/vm/interpreter/rewriter.cpp