duke@435: /*
trims@1907:  * Copyright (c) 2000, 2009, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: # include "incls/_precompiled.incl"
duke@435: # include "incls/_methodComparator.cpp.incl"
duke@435: 
duke@435: BytecodeStream *MethodComparator::_s_old;
duke@435: BytecodeStream *MethodComparator::_s_new;
duke@435: constantPoolOop MethodComparator::_old_cp;
duke@435: constantPoolOop MethodComparator::_new_cp;
duke@435: BciMap *MethodComparator::_bci_map;
duke@435: bool MethodComparator::_switchable_test;
duke@435: GrowableArray<int> *MethodComparator::_fwd_jmps;
duke@435: 
duke@435: bool MethodComparator::methods_EMCP(methodOop old_method, methodOop new_method) {
duke@435:   if (old_method->code_size() != new_method->code_size())
duke@435:     return false;
duke@435:   if (check_stack_and_locals_size(old_method, new_method) != 0) {
duke@435:     // RC_TRACE macro has an embedded ResourceMark
duke@435:     RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",
duke@435:       old_method->name()->as_C_string(),
duke@435:       check_stack_and_locals_size(old_method, new_method)));
duke@435:     return false;
duke@435:   }
duke@435: 
duke@435:   _old_cp = old_method->constants();
duke@435:   _new_cp = new_method->constants();
duke@435:   BytecodeStream s_old(old_method);
duke@435:   BytecodeStream s_new(new_method);
duke@435:   _s_old = &s_old;
duke@435:   _s_new = &s_new;
duke@435:   _switchable_test = false;
duke@435:   Bytecodes::Code c_old, c_new;
duke@435: 
duke@435:   while ((c_old = s_old.next()) >= 0) {
duke@435:     if ((c_new = s_new.next()) < 0 || c_old != c_new)
duke@435:       return false;
duke@435: 
duke@435:     if (! args_same(c_old, c_new))
duke@435:       return false;
duke@435:   }
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: 
duke@435: bool MethodComparator::methods_switchable(methodOop old_method, methodOop new_method,
duke@435:                                           BciMap &bci_map) {
duke@435:   if (old_method->code_size() > new_method->code_size())
duke@435:     // Something has definitely been deleted in the new method, compared to the old one.
duke@435:     return false;
duke@435: 
duke@435:   if (! check_stack_and_locals_size(old_method, new_method))
duke@435:     return false;
duke@435: 
duke@435:   _old_cp = old_method->constants();
duke@435:   _new_cp = new_method->constants();
duke@435:   BytecodeStream s_old(old_method);
duke@435:   BytecodeStream s_new(new_method);
duke@435:   _s_old = &s_old;
duke@435:   _s_new = &s_new;
duke@435:   _bci_map = &bci_map;
duke@435:   _switchable_test = true;
duke@435:   GrowableArray<int> fwd_jmps(16);
duke@435:   _fwd_jmps = &fwd_jmps;
duke@435:   Bytecodes::Code c_old, c_new;
duke@435: 
duke@435:   while ((c_old = s_old.next()) >= 0) {
duke@435:     if ((c_new = s_new.next()) < 0)
duke@435:       return false;
duke@435:     if (! (c_old == c_new && args_same(c_old, c_new))) {
duke@435:       int old_bci = s_old.bci();
duke@435:       int new_st_bci = s_new.bci();
duke@435:       bool found_match = false;
duke@435:       do {
duke@435:         c_new = s_new.next();
duke@435:         if (c_new == c_old && args_same(c_old, c_new)) {
duke@435:           found_match = true;
duke@435:           break;
duke@435:         }
duke@435:       } while (c_new >= 0);
duke@435:       if (! found_match)
duke@435:         return false;
duke@435:       int new_end_bci = s_new.bci();
duke@435:       bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Now we can test all forward jumps
duke@435:   for (int i = 0; i < fwd_jmps.length() / 2; i++) {
duke@435:     if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
duke@435:       RC_TRACE(0x00800000,
duke@435:         ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
duke@435:         fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
duke@435:         fwd_jmps.at(i*2+1)));
duke@435:       return false;
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: 
duke@435: bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
duke@435:   // BytecodeStream returns the correct standard Java bytecodes for various "fast"
duke@435:   // bytecode versions, so we don't have to bother about them here..
duke@435:   switch (c_old) {
duke@435:   case Bytecodes::_new            : // fall through
duke@435:   case Bytecodes::_anewarray      : // fall through
duke@435:   case Bytecodes::_multianewarray : // fall through
duke@435:   case Bytecodes::_checkcast      : // fall through
duke@435:   case Bytecodes::_instanceof     : {
duke@435:     u2 cpi_old = _s_old->get_index_big();
duke@435:     u2 cpi_new = _s_new->get_index_big();
duke@435:     if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))
duke@435:         return false;
duke@435:     if (c_old == Bytecodes::_multianewarray &&
duke@435:         *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))
duke@435:       return false;
duke@435:     break;
duke@435:   }
duke@435: 
duke@435:   case Bytecodes::_getstatic       : // fall through
duke@435:   case Bytecodes::_putstatic       : // fall through
duke@435:   case Bytecodes::_getfield        : // fall through
duke@435:   case Bytecodes::_putfield        : // fall through
duke@435:   case Bytecodes::_invokevirtual   : // fall through
duke@435:   case Bytecodes::_invokespecial   : // fall through
duke@435:   case Bytecodes::_invokestatic    : // fall through
duke@435:   case Bytecodes::_invokeinterface : {
jrose@1161:     u2 cpci_old = _s_old->get_index_int();
jrose@1161:     u2 cpci_new = _s_new->get_index_int();
duke@435:     // Check if the names of classes, field/method names and signatures at these indexes
duke@435:     // are the same. Indices which are really into constantpool cache (rather than constant
duke@435:     // pool itself) are accepted by the constantpool query routines below.
duke@435:     if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||
duke@435:         (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
duke@435:         (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
duke@435:       return false;
duke@435:     break;
duke@435:   }
duke@435: 
duke@435:   case Bytecodes::_ldc   : // fall through
duke@435:   case Bytecodes::_ldc_w : {
duke@435:     u2 cpi_old, cpi_new;
duke@435:     if (c_old == Bytecodes::_ldc) {
duke@435:       cpi_old = _s_old->bcp()[1];
duke@435:       cpi_new = _s_new->bcp()[1];
duke@435:     } else {
duke@435:       cpi_old = _s_old->get_index_big();
duke@435:       cpi_new = _s_new->get_index_big();
duke@435:     }
duke@435:     constantTag tag_old = _old_cp->tag_at(cpi_old);
duke@435:     constantTag tag_new = _new_cp->tag_at(cpi_new);
duke@435:     if (tag_old.is_int() || tag_old.is_float()) {
duke@435:       if (tag_old.value() != tag_new.value())
duke@435:         return false;
duke@435:       if (tag_old.is_int()) {
duke@435:         if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))
duke@435:           return false;
duke@435:       } else {
duke@435:         if (_old_cp->float_at(cpi_old) != _new_cp->float_at(cpi_new))
duke@435:           return false;
duke@435:       }
duke@435:     } else if (tag_old.is_string() || tag_old.is_unresolved_string()) {
duke@435:       if (! (tag_new.is_unresolved_string() || tag_new.is_string()))
duke@435:         return false;
duke@435:       if (strcmp(_old_cp->string_at_noresolve(cpi_old),
duke@435:                  _new_cp->string_at_noresolve(cpi_new)) != 0)
duke@435:         return false;
duke@435:     } else { // tag_old should be klass - 4881222
duke@435:       if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))
duke@435:         return false;
duke@435:       if (_old_cp->klass_at_noresolve(cpi_old) !=
duke@435:           _new_cp->klass_at_noresolve(cpi_new))
duke@435:         return false;
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435: 
duke@435:   case Bytecodes::_ldc2_w : {
duke@435:     u2 cpi_old = _s_old->get_index_big();
duke@435:     u2 cpi_new = _s_new->get_index_big();
duke@435:     constantTag tag_old = _old_cp->tag_at(cpi_old);
duke@435:     constantTag tag_new = _new_cp->tag_at(cpi_new);
duke@435:     if (tag_old.value() != tag_new.value())
duke@435:       return false;
duke@435:     if (tag_old.is_long()) {
duke@435:       if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))
duke@435:         return false;
duke@435:     } else {
duke@435:       if (_old_cp->double_at(cpi_old) != _new_cp->double_at(cpi_new))
duke@435:         return false;
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435: 
duke@435:   case Bytecodes::_bipush :
duke@435:     if (_s_old->bcp()[1] != _s_new->bcp()[1])
duke@435:       return false;
duke@435:     break;
duke@435: 
duke@435:   case Bytecodes::_sipush    :
duke@435:     if (_s_old->get_index_big() != _s_new->get_index_big())
duke@435:       return false;
duke@435:     break;
duke@435: 
duke@435:   case Bytecodes::_aload  : // fall through
duke@435:   case Bytecodes::_astore : // fall through
duke@435:   case Bytecodes::_dload  : // fall through
duke@435:   case Bytecodes::_dstore : // fall through
duke@435:   case Bytecodes::_fload  : // fall through
duke@435:   case Bytecodes::_fstore : // fall through
duke@435:   case Bytecodes::_iload  : // fall through
duke@435:   case Bytecodes::_istore : // fall through
duke@435:   case Bytecodes::_lload  : // fall through
duke@435:   case Bytecodes::_lstore : // fall through
duke@435:   case Bytecodes::_ret    :
duke@435:     if (_s_old->is_wide() != _s_new->is_wide())
duke@435:       return false;
duke@435:     if (_s_old->get_index() != _s_new->get_index())
duke@435:       return false;
duke@435:     break;
duke@435: 
duke@435:   case Bytecodes::_goto      : // fall through
duke@435:   case Bytecodes::_if_acmpeq : // fall through
duke@435:   case Bytecodes::_if_acmpne : // fall through
duke@435:   case Bytecodes::_if_icmpeq : // fall through
duke@435:   case Bytecodes::_if_icmpne : // fall through
duke@435:   case Bytecodes::_if_icmplt : // fall through
duke@435:   case Bytecodes::_if_icmpge : // fall through
duke@435:   case Bytecodes::_if_icmpgt : // fall through
duke@435:   case Bytecodes::_if_icmple : // fall through
duke@435:   case Bytecodes::_ifeq      : // fall through
duke@435:   case Bytecodes::_ifne      : // fall through
duke@435:   case Bytecodes::_iflt      : // fall through
duke@435:   case Bytecodes::_ifge      : // fall through
duke@435:   case Bytecodes::_ifgt      : // fall through
duke@435:   case Bytecodes::_ifle      : // fall through
duke@435:   case Bytecodes::_ifnonnull : // fall through
duke@435:   case Bytecodes::_ifnull    : // fall through
duke@435:   case Bytecodes::_jsr       : {
duke@435:     short old_ofs = (short) _s_old->get_index_big();
duke@435:     short new_ofs = (short) _s_new->get_index_big();
duke@435:     if (_switchable_test) {
duke@435:       int old_dest = _s_old->bci() + old_ofs;
duke@435:       int new_dest = _s_new->bci() + new_ofs;
duke@435:       if (old_ofs < 0 && new_ofs < 0) {
duke@435:         if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
duke@435:           return false;
duke@435:       } else if (old_ofs > 0 && new_ofs > 0) {
duke@435:         _fwd_jmps->append(old_dest);
duke@435:         _fwd_jmps->append(new_dest);
duke@435:       } else {
duke@435:         return false;
duke@435:       }
duke@435:     } else {
duke@435:       if (old_ofs != new_ofs)
duke@435:         return false;
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435: 
duke@435:   case Bytecodes::_iinc :
duke@435:     if (_s_old->is_wide() != _s_new->is_wide())
duke@435:       return false;
duke@435:     if (! _s_old->is_wide()) {
duke@435:       if (_s_old->get_index_big() != _s_new->get_index_big())
duke@435:         return false;
duke@435:     } else {
duke@435:       if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))
duke@435:         return false;
duke@435:     }
duke@435:     break;
duke@435: 
duke@435:   case Bytecodes::_goto_w : // fall through
duke@435:   case Bytecodes::_jsr_w  : {
duke@435:     int old_ofs = (int) Bytes::get_Java_u4(_s_old->bcp() + 1);
duke@435:     int new_ofs = (int) Bytes::get_Java_u4(_s_new->bcp() + 1);
duke@435:     if (_switchable_test) {
duke@435:       int old_dest = _s_old->bci() + old_ofs;
duke@435:       int new_dest = _s_new->bci() + new_ofs;
duke@435:       if (old_ofs < 0 && new_ofs < 0) {
duke@435:         if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
duke@435:           return false;
duke@435:       } else if (old_ofs > 0 && new_ofs > 0) {
duke@435:         _fwd_jmps->append(old_dest);
duke@435:         _fwd_jmps->append(new_dest);
duke@435:       } else {
duke@435:         return false;
duke@435:       }
duke@435:     } else {
duke@435:       if (old_ofs != new_ofs)
duke@435:         return false;
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435: 
duke@435:   case Bytecodes::_lookupswitch : // fall through
duke@435:   case Bytecodes::_tableswitch  : {
duke@435:     if (_switchable_test) {
duke@435:       address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
duke@435:       address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
duke@435:       int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
duke@435:       int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
duke@435:       _fwd_jmps->append(_s_old->bci() + default_old);
duke@435:       _fwd_jmps->append(_s_new->bci() + default_new);
duke@435:       if (c_old == Bytecodes::_lookupswitch) {
duke@435:         int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
duke@435:         int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
duke@435:         if (npairs_old != npairs_new)
duke@435:           return false;
duke@435:         for (int i = 0; i < npairs_old; i++) {
duke@435:           int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
duke@435:           int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
duke@435:           if (match_old != match_new)
duke@435:             return false;
duke@435:           int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
duke@435:           int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
duke@435:           _fwd_jmps->append(_s_old->bci() + ofs_old);
duke@435:           _fwd_jmps->append(_s_new->bci() + ofs_new);
duke@435:         }
duke@435:       } else if (c_old == Bytecodes::_tableswitch) {
duke@435:         int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
duke@435:         int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
duke@435:         if (lo_old != lo_new)
duke@435:           return false;
duke@435:         int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
duke@435:         int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
duke@435:         if (hi_old != hi_new)
duke@435:           return false;
duke@435:         for (int i = 0; i < hi_old - lo_old + 1; i++) {
duke@435:           int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
duke@435:           int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
duke@435:           _fwd_jmps->append(_s_old->bci() + ofs_old);
duke@435:           _fwd_jmps->append(_s_new->bci() + ofs_new);
duke@435:         }
duke@435:       }
duke@435:     } else { // !_switchable_test, can use fast rough compare
duke@435:       int len_old = _s_old->next_bcp() - _s_old->bcp();
duke@435:       int len_new = _s_new->next_bcp() - _s_new->bcp();
duke@435:       if (len_old != len_new)
duke@435:         return false;
duke@435:       if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
duke@435:         return false;
duke@435:     }
duke@435:     break;
duke@435:   }
duke@435:   }
duke@435: 
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: 
duke@435: int MethodComparator::check_stack_and_locals_size(methodOop old_method, methodOop new_method) {
duke@435:   if (old_method->max_stack() != new_method->max_stack()) {
duke@435:     return 1;
duke@435:   } else if (old_method->max_locals() != new_method->max_locals()) {
duke@435:     return 2;
duke@435:   } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {
duke@435:     return 3;
duke@435:   } else return 0;
duke@435: }