Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 2000-2010 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 # include "incls/_precompiled.incl"

 # include "incls/_methodComparator.cpp.incl"

 BytecodeStream *MethodComparator::_s_old;

 BytecodeStream *MethodComparator::_s_new;

 constantPoolOop MethodComparator::_old_cp;

 constantPoolOop MethodComparator::_new_cp;

 BciMap *MethodComparator::_bci_map;

 bool MethodComparator::_switchable_test;

 GrowableArray<int> *MethodComparator::_fwd_jmps;

 bool MethodComparator::methods_EMCP(methodOop old_method, methodOop new_method) {

   if (old_method->code_size() != new_method->code_size())

     return false;

   if (check_stack_and_locals_size(old_method, new_method) != 0) {

     // RC_TRACE macro has an embedded ResourceMark

     RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",

       old_method->name()->as_C_string(),

       check_stack_and_locals_size(old_method, new_method)));

     return false;

   }

   _old_cp = old_method->constants();

   _new_cp = new_method->constants();

   BytecodeStream s_old(old_method);

   BytecodeStream s_new(new_method);

   _s_old = &s_old;

   _s_new = &s_new;

   _switchable_test = false;

   Bytecodes::Code c_old, c_new;

   while ((c_old = s_old.next()) >= 0) {

     if ((c_new = s_new.next()) < 0 || c_old != c_new)

       return false;

     if (! args_same(c_old, c_new))

       return false;

   }

   return true;

 }

 bool MethodComparator::methods_switchable(methodOop old_method, methodOop new_method,

                                           BciMap &bci_map) {

   if (old_method->code_size() > new_method->code_size())

     // Something has definitely been deleted in the new method, compared to the old one.

     return false;

   if (! check_stack_and_locals_size(old_method, new_method))

     return false;

   _old_cp = old_method->constants();

   _new_cp = new_method->constants();

   BytecodeStream s_old(old_method);

   BytecodeStream s_new(new_method);

   _s_old = &s_old;

   _s_new = &s_new;

   _bci_map = &bci_map;

   _switchable_test = true;

   GrowableArray<int> fwd_jmps(16);

   _fwd_jmps = &fwd_jmps;

   Bytecodes::Code c_old, c_new;

   while ((c_old = s_old.next()) >= 0) {

     if ((c_new = s_new.next()) < 0)

       return false;

     if (! (c_old == c_new && args_same(c_old, c_new))) {

       int old_bci = s_old.bci();

       int new_st_bci = s_new.bci();

       bool found_match = false;

       do {

         c_new = s_new.next();

         if (c_new == c_old && args_same(c_old, c_new)) {

           found_match = true;

           break;

         }

       } while (c_new >= 0);

       if (! found_match)

         return false;

       int new_end_bci = s_new.bci();

       bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);

     }

   }

   // Now we can test all forward jumps

   for (int i = 0; i < fwd_jmps.length() / 2; i++) {

     if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {

       RC_TRACE(0x00800000,

         ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",

         fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),

         fwd_jmps.at(i*2+1)));

       return false;

     }

   }

   return true;

 }

 bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {

   // BytecodeStream returns the correct standard Java bytecodes for various "fast"

   // bytecode versions, so we don't have to bother about them here..

   switch (c_old) {

   case Bytecodes::_new            : // fall through

   case Bytecodes::_anewarray      : // fall through

   case Bytecodes::_multianewarray : // fall through

   case Bytecodes::_checkcast      : // fall through

   case Bytecodes::_instanceof     : {

     u2 cpi_old = _s_old->get_index_u2();

     u2 cpi_new = _s_new->get_index_u2();

     if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))

         return false;

     if (c_old == Bytecodes::_multianewarray &&

         *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))

       return false;

     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    : // fall through

   case Bytecodes::_invokedynamic   : // fall through

   case Bytecodes::_invokeinterface : {

     int cpci_old = _s_old->has_index_u4() ? _s_old->get_index_u4() : _s_old->get_index_u2_cpcache();

     int cpci_new = _s_new->has_index_u4() ? _s_new->get_index_u4() : _s_new->get_index_u2_cpcache();

     // Check if the names of classes, field/method names and signatures at these indexes

     // are the same. Indices which are really into constantpool cache (rather than constant

     // pool itself) are accepted by the constantpool query routines below.

     if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||

         (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||

         (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))

       return false;

     break;

   }

   case Bytecodes::_ldc   : // fall through

   case Bytecodes::_ldc_w : {

     Bytecode_loadconstant* ldc_old = Bytecode_loadconstant_at(_s_old->method()(), _s_old->bcp());

     Bytecode_loadconstant* ldc_new = Bytecode_loadconstant_at(_s_new->method()(), _s_new->bcp());

     int cpi_old = ldc_old->index();

     int cpi_new = ldc_new->index();

     constantTag tag_old = _old_cp->tag_at(cpi_old);

     constantTag tag_new = _new_cp->tag_at(cpi_new);

     if (tag_old.is_int() || tag_old.is_float()) {

       if (tag_old.value() != tag_new.value())

         return false;

       if (tag_old.is_int()) {

         if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))

           return false;

       } else {

         // Use jint_cast to compare the bits rather than numerical values.

         // This makes a difference for NaN constants.

         if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new)))

           return false;

       }

     } else if (tag_old.is_string() || tag_old.is_unresolved_string()) {

       if (! (tag_new.is_unresolved_string() || tag_new.is_string()))

         return false;

       if (strcmp(_old_cp->string_at_noresolve(cpi_old),

                  _new_cp->string_at_noresolve(cpi_new)) != 0)

         return false;

     } else { // tag_old should be klass - 4881222

       if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))

         return false;

       if (_old_cp->klass_at_noresolve(cpi_old) !=

           _new_cp->klass_at_noresolve(cpi_new))

         return false;

     }

     break;

   }

   case Bytecodes::_ldc2_w : {

     u2 cpi_old = _s_old->get_index_u2();

     u2 cpi_new = _s_new->get_index_u2();

     constantTag tag_old = _old_cp->tag_at(cpi_old);

     constantTag tag_new = _new_cp->tag_at(cpi_new);

     if (tag_old.value() != tag_new.value())

       return false;

     if (tag_old.is_long()) {

       if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))

         return false;

     } else {

       // Use jlong_cast to compare the bits rather than numerical values.

       // This makes a difference for NaN constants.

       if (jlong_cast(_old_cp->double_at(cpi_old)) != jlong_cast(_new_cp->double_at(cpi_new)))

         return false;

     }

     break;

   }

   case Bytecodes::_bipush :

     if (_s_old->bcp()[1] != _s_new->bcp()[1])

       return false;

     break;

   case Bytecodes::_sipush    :

     if (_s_old->get_index_u2() != _s_new->get_index_u2())

       return false;

     break;

   case Bytecodes::_aload  : // fall through

   case Bytecodes::_astore : // fall through

   case Bytecodes::_dload  : // fall through

   case Bytecodes::_dstore : // fall through

   case Bytecodes::_fload  : // fall through

   case Bytecodes::_fstore : // fall through

   case Bytecodes::_iload  : // fall through

   case Bytecodes::_istore : // fall through

   case Bytecodes::_lload  : // fall through

   case Bytecodes::_lstore : // fall through

   case Bytecodes::_ret    :

     if (_s_old->is_wide() != _s_new->is_wide())

       return false;

     if (_s_old->get_index() != _s_new->get_index())

       return false;

     break;

   case Bytecodes::_goto      : // fall through

   case Bytecodes::_if_acmpeq : // fall through

   case Bytecodes::_if_acmpne : // fall through

   case Bytecodes::_if_icmpeq : // fall through

   case Bytecodes::_if_icmpne : // fall through

   case Bytecodes::_if_icmplt : // fall through

   case Bytecodes::_if_icmpge : // fall through

   case Bytecodes::_if_icmpgt : // fall through

   case Bytecodes::_if_icmple : // fall through

   case Bytecodes::_ifeq      : // fall through

   case Bytecodes::_ifne      : // fall through

   case Bytecodes::_iflt      : // fall through

   case Bytecodes::_ifge      : // fall through

   case Bytecodes::_ifgt      : // fall through

   case Bytecodes::_ifle      : // fall through

   case Bytecodes::_ifnonnull : // fall through

   case Bytecodes::_ifnull    : // fall through

   case Bytecodes::_jsr       : {

     int old_ofs = _s_old->bytecode()->get_offset_s2(c_old);

     int new_ofs = _s_new->bytecode()->get_offset_s2(c_new);

     if (_switchable_test) {

       int old_dest = _s_old->bci() + old_ofs;

       int new_dest = _s_new->bci() + new_ofs;

       if (old_ofs < 0 && new_ofs < 0) {

         if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))

           return false;

       } else if (old_ofs > 0 && new_ofs > 0) {

         _fwd_jmps->append(old_dest);

         _fwd_jmps->append(new_dest);

       } else {

         return false;

       }

     } else {

       if (old_ofs != new_ofs)

         return false;

     }

     break;

   }

   case Bytecodes::_iinc :

     if (_s_old->is_wide() != _s_new->is_wide())

       return false;

     if (! _s_old->is_wide()) {

       // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once:

       if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1))

         return false;

     } else {

       // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once:

       if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))

         return false;

     }

     break;

   case Bytecodes::_goto_w : // fall through

   case Bytecodes::_jsr_w  : {

     int old_ofs = _s_old->bytecode()->get_offset_s4(c_old);

     int new_ofs = _s_new->bytecode()->get_offset_s4(c_new);

     if (_switchable_test) {

       int old_dest = _s_old->bci() + old_ofs;

       int new_dest = _s_new->bci() + new_ofs;

       if (old_ofs < 0 && new_ofs < 0) {

         if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))

           return false;

       } else if (old_ofs > 0 && new_ofs > 0) {

         _fwd_jmps->append(old_dest);

         _fwd_jmps->append(new_dest);

       } else {

         return false;

       }

     } else {

       if (old_ofs != new_ofs)

         return false;

     }

     break;

   }

   case Bytecodes::_lookupswitch : // fall through

   case Bytecodes::_tableswitch  : {

     if (_switchable_test) {

       address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);

       address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);

       int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);

       int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);

       _fwd_jmps->append(_s_old->bci() + default_old);

       _fwd_jmps->append(_s_new->bci() + default_new);

       if (c_old == Bytecodes::_lookupswitch) {

         int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);

         int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);

         if (npairs_old != npairs_new)

           return false;

         for (int i = 0; i < npairs_old; i++) {

           int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);

           int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);

           if (match_old != match_new)

             return false;

           int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);

           int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);

           _fwd_jmps->append(_s_old->bci() + ofs_old);

           _fwd_jmps->append(_s_new->bci() + ofs_new);

         }

       } else if (c_old == Bytecodes::_tableswitch) {

         int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);

         int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);

         if (lo_old != lo_new)

           return false;

         int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);

         int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);

         if (hi_old != hi_new)

           return false;

         for (int i = 0; i < hi_old - lo_old + 1; i++) {

           int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);

           int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);

           _fwd_jmps->append(_s_old->bci() + ofs_old);

           _fwd_jmps->append(_s_new->bci() + ofs_new);

         }

       }

     } else { // !_switchable_test, can use fast rough compare

       int len_old = _s_old->instruction_size();

       int len_new = _s_new->instruction_size();

       if (len_old != len_new)

         return false;

       if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)

         return false;

     }

     break;

   }

   }

   return true;

 }

 int MethodComparator::check_stack_and_locals_size(methodOop old_method, methodOop new_method) {

   if (old_method->max_stack() != new_method->max_stack()) {

     return 1;

   } else if (old_method->max_locals() != new_method->max_locals()) {

     return 2;

   } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {

     return 3;

   } else return 0;

 }