jdk8-mips64-public/hotspot: src/share/vm/interpreter/rewriter.cpp@136b78722a08 (annotated)

src/share/vm/interpreter/rewriter.cpp@136b78722a08 (annotated)

src/share/vm/interpreter/rewriter.cpp

Wed, 09 Jun 2010 18:50:45 -0700

author: jrose
date: Wed, 09 Jun 2010 18:50:45 -0700
changeset 1957: 136b78722a08
parent 1934: e9ff18c4ace7
child 2015: 083fde3b838e
permissions: -rw-r--r--

6939203: JSR 292 needs method handle constants
Summary: Add new CP types CONSTANT_MethodHandle, CONSTANT_MethodType; extend 'ldc' bytecode.
Reviewed-by: twisti, never

 /*
  * Copyright (c) 1998, 2010, 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 "incls/_precompiled.incl"
 # include "incls/_rewriter.cpp.incl"
 // 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_cp_map(length);
   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
       case JVM_CONSTANT_MethodHandle      : // fall through
       case JVM_CONSTANT_MethodType        : // fall through
         add_cp_cache_entry(i);
         break;
     }
   }
   guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1),
             "all cp cache indexes fit in a u2");
 }
 // Creates a constant pool cache given a CPC map
 // This creates the constant pool cache initially in a state
 // that is unsafe for concurrent GC processing but sets it to
 // a safe mode before the constant pool cache is returned.
 void Rewriter::make_constant_pool_cache(TRAPS) {
   const int length = _cp_cache_map.length();
   constantPoolCacheOop cache =
       oopFactory::new_constantPoolCache(length, methodOopDesc::IsUnsafeConc, CHECK);
   cache->initialize(_cp_cache_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) {
   address p = bcp + offset;
   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);
 }
 void Rewriter::rewrite_invokedynamic(address bcp, int offset) {
   address p = bcp + offset;
   assert(p[-1] == Bytecodes::_invokedynamic, "");
   int cp_index = Bytes::get_Java_u2(p);
   int cpc  = maybe_add_cp_cache_entry(cp_index);  // add lazily
   int cpc2 = add_secondary_cp_cache_entry(cpc);
   // 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, constantPoolCacheOopDesc::encode_secondary_index(cpc2));
   // Note: We use native_u4 format exclusively for 4-byte indexes.
 }
 // Rewrite some ldc bytecodes to _fast_aldc
 void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide) {
   assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "");
   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()) {
     int cache_index = cp_entry_to_cp_cache(cp_index);
     if (is_wide) {
       (*bcp) = Bytecodes::_fast_aldc_w;
       assert(cache_index == (u2)cache_index, "");
       Bytes::put_native_u2(p, cache_index);
     } else {
       (*bcp) = Bytecodes::_fast_aldc;
       assert(cache_index == (u1)cache_index, "");
       (*p) = (u1)cache_index;
     }
   }
 }
 // Rewrites a method given the index_map information
 void Rewriter::scan_method(methodOop method) {
   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 methodOop
     // 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(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 = Bytecode_lookupswitch_at(bcp);
           (*bcp) = (
             bc->number_of_pairs() < BinarySwitchThreshold
             ? Bytecodes::_fast_linearswitch
             : Bytecodes::_fast_binaryswitch
           );
 #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:
           rewrite_member_reference(bcp, prefix_length+1);
           break;
         case Bytecodes::_invokedynamic:
           rewrite_invokedynamic(bcp, prefix_length+1);
           break;
         case Bytecodes::_ldc:
           maybe_rewrite_ldc(bcp, prefix_length+1, false);
           break;
         case Bytecodes::_ldc_w:
           maybe_rewrite_ldc(bcp, prefix_length+1, true);
           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(), "");
   }
 }
 // After constant pool is created, revisit methods containing jsrs.
 methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) {
   ResolveOopMapConflicts romc(method);
   methodHandle original_method = method;
   method = romc.do_potential_rewrite(CHECK_(methodHandle()));
   if (method() != original_method()) {
     // Insert invalid bytecode into original methodOop and set
     // interpreter entrypoint, so that a executing this method
     // will manifest itself in an easy recognizable form.
     address bcp = original_method->bcp_from(0);
     *bcp = (u1)Bytecodes::_shouldnotreachhere;
     int kind = Interpreter::method_kind(original_method);
     original_method->set_interpreter_kind(kind);
   }
   // 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.)
 }
 void Rewriter::rewrite(instanceKlassHandle klass, constantPoolHandle cpool, objArrayHandle methods, TRAPS) {
   ResourceMark rm(THREAD);
   Rewriter     rw(klass, cpool, methods, CHECK);
   // (That's all, folks.)
 }
 Rewriter::Rewriter(instanceKlassHandle klass, constantPoolHandle cpool, objArrayHandle methods, TRAPS)
   : _klass(klass),
     _pool(cpool),
     _methods(methods)
 {
   assert(_pool->cache() == NULL, "constant pool cache must not be set yet");
   // determine index maps for methodOop rewriting
   compute_index_maps();
   if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) {
     bool did_rewrite = false;
     int i = _methods->length();
     while (i-- > 0) {
       methodOop method = (methodOop)_methods->obj_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 i, len = _methods->length();
   for (i = len; --i >= 0; ) {
     methodOop method = (methodOop)_methods->obj_at(i);
     scan_method(method);
   }
   // allocate constant pool cache, now that we've seen all the bytecodes
   make_constant_pool_cache(CHECK);
   for (i = len; --i >= 0; ) {
     methodHandle m(THREAD, (methodOop)_methods->obj_at(i));
     if (m->has_jsrs()) {
       m = rewrite_jsrs(m, CHECK);
       // Method might have gotten rewritten.
       _methods->obj_at_put(i, m());
     }
     // Set up method entry points for compiler and interpreter.
     m->link_method(m, CHECK);
 #ifdef ASSERT
     if (StressMethodComparator) {
       static int nmc = 0;
       for (int j = i; j >= 0 && j >= i-4; j--) {
         if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
         bool z = MethodComparator::methods_EMCP(m(), (methodOop)_methods->obj_at(j));
         if (j == i && !z) {
           tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
           assert(z, "method must compare equal to itself");
         }
       }
     }
 #endif //ASSERT
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/interpreter/rewriter.cpp@136b78722a08 (annotated)

src/share/vm/interpreter/rewriter.cpp