jdk8-mips64-public/hotspot: src/share/vm/ci/ciMethodBlocks.cpp@6ca61c728c2d (annotated)

src/share/vm/ci/ciMethodBlocks.cpp@6ca61c728c2d (annotated)

src/share/vm/ci/ciMethodBlocks.cpp

Fri, 25 Jul 2008 11:32:56 -0700

author: never
date: Fri, 25 Jul 2008 11:32:56 -0700
changeset 685: 6ca61c728c2d
parent 631: d1605aabd0a1
child 802: 194b8e3a2fc4
permissions: -rw-r--r--

6712835: Server compiler fails with assertion (loop_count < K,"infinite loop in PhaseIterGVN::transform")
Reviewed-by: kvn

 /*
  * Copyright 2006-2008 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/_ciMethodBlocks.cpp.incl"
 // ciMethodBlocks
 ciBlock *ciMethodBlocks::block_containing(int bci) {
   ciBlock *blk = _bci_to_block[bci];
   return blk;
 }
 bool ciMethodBlocks::is_block_start(int bci) {
   assert(bci >=0 && bci < _code_size, "valid bytecode range");
   ciBlock *b = _bci_to_block[bci];
   assert(b != NULL, "must have block for bytecode");
   return b->start_bci() == bci;
 }
 // ------------------------------------------------------------------
 // ciMethodBlocks::split_block_at
 //
 // Split the block spanning bci into two separate ranges.  The former
 // block becomes the second half and a new range is created for the
 // first half.  Returns the range beginning at bci.
 ciBlock *ciMethodBlocks::split_block_at(int bci) {
   ciBlock *former_block = block_containing(bci);
   ciBlock *new_block = new(_arena) ciBlock(_method, _num_blocks++, this, former_block->start_bci());
   _blocks->append(new_block);
   assert(former_block != NULL, "must not be NULL");
   new_block->set_limit_bci(bci);
   former_block->set_start_bci(bci);
   for (int pos=bci-1; pos >= 0; pos--) {
     ciBlock *current_block = block_containing(pos);
     if (current_block == former_block) {
       // Replace it.
       _bci_to_block[pos] = new_block;
     } else if (current_block == NULL) {
       // Non-bytecode start.  Skip.
       continue;
     } else {
       // We are done with our backwards walk
       break;
     }
   }
   // Move an exception handler information if needed.
   if (former_block->is_handler()) {
     int ex_start = former_block->ex_start_bci();
     int ex_end = former_block->ex_limit_bci();
     new_block->set_exception_range(ex_start, ex_end);
     // Clear information in former_block.
     former_block->clear_exception_handler();
   }
   return former_block;
 }
 ciBlock *ciMethodBlocks::make_block_at(int bci) {
   ciBlock *cb = block_containing(bci);
   if (cb == NULL ) {
     // This is our first time visiting this bytecode.  Create
     // a fresh block and assign it this starting point.
     ciBlock *nb = new(_arena) ciBlock(_method, _num_blocks++, this, bci);
     _blocks->append(nb);
      _bci_to_block[bci] = nb;
     return nb;
   } else if (cb->start_bci() == bci) {
     // The block begins at bci.  Simply return it.
     return cb;
   } else {
     // We have already created a block containing bci but
     // not starting at bci.  This existing block needs to
     // be split into two.
     return split_block_at(bci);
   }
 }
 void ciMethodBlocks::do_analysis() {
   ciBytecodeStream s(_method);
   ciBlock *cur_block = block_containing(0);
   int limit_bci = _method->code_size();
   while (s.next() != ciBytecodeStream::EOBC()) {
     int bci = s.cur_bci();
     // Determine if a new block has been made at the current bci.  If
     // this block differs from our current range, switch to the new
     // one and end the old one.
     assert(cur_block != NULL, "must always have a current block");
     ciBlock *new_block = block_containing(bci);
     if (new_block == NULL || new_block == cur_block) {
       // We have not marked this bci as the start of a new block.
       // Keep interpreting the current_range.
       _bci_to_block[bci] = cur_block;
     } else {
       cur_block->set_limit_bci(bci);
       cur_block = new_block;
     }
     switch (s.cur_bc()) {
       case Bytecodes::_ifeq        :
       case Bytecodes::_ifne        :
       case Bytecodes::_iflt        :
       case Bytecodes::_ifge        :
       case Bytecodes::_ifgt        :
       case Bytecodes::_ifle        :
       case Bytecodes::_if_icmpeq   :
       case Bytecodes::_if_icmpne   :
       case Bytecodes::_if_icmplt   :
       case Bytecodes::_if_icmpge   :
       case Bytecodes::_if_icmpgt   :
       case Bytecodes::_if_icmple   :
       case Bytecodes::_if_acmpeq   :
       case Bytecodes::_if_acmpne   :
       case Bytecodes::_ifnull      :
       case Bytecodes::_ifnonnull   :
       {
         cur_block->set_control_bci(bci);
         ciBlock *fall_through = make_block_at(s.next_bci());
         int dest_bci = s.get_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
       }
       case Bytecodes::_goto        :
       {
         cur_block->set_control_bci(bci);
         if (s.next_bci() < limit_bci) {
           (void) make_block_at(s.next_bci());
         }
         int dest_bci = s.get_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
       }
       case Bytecodes::_jsr         :
       {
         cur_block->set_control_bci(bci);
         ciBlock *ret = make_block_at(s.next_bci());
         int dest_bci = s.get_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
       }
       case Bytecodes::_tableswitch :
         {
           cur_block->set_control_bci(bci);
           Bytecode_tableswitch* switch_ = Bytecode_tableswitch_at(s.cur_bcp());
           int len = switch_->length();
           ciBlock *dest;
           int dest_bci;
           for (int i = 0; i < len; i++) {
             dest_bci = s.cur_bci() + switch_->dest_offset_at(i);
             dest = make_block_at(dest_bci);
           }
           dest_bci = s.cur_bci() + switch_->default_offset();
           make_block_at(dest_bci);
           if (s.next_bci() < limit_bci) {
             dest = make_block_at(s.next_bci());
           }
         }
         break;
       case Bytecodes::_lookupswitch:
         {
           cur_block->set_control_bci(bci);
           Bytecode_lookupswitch* switch_ = Bytecode_lookupswitch_at(s.cur_bcp());
           int len = switch_->number_of_pairs();
           ciBlock *dest;
           int dest_bci;
           for (int i = 0; i < len; i++) {
             dest_bci = s.cur_bci() + switch_->pair_at(i)->offset();
             dest = make_block_at(dest_bci);
           }
           dest_bci = s.cur_bci() + switch_->default_offset();
           dest = make_block_at(dest_bci);
           if (s.next_bci() < limit_bci) {
             dest = make_block_at(s.next_bci());
           }
         }
         break;
       case Bytecodes::_goto_w      :
       {
         cur_block->set_control_bci(bci);
         if (s.next_bci() < limit_bci) {
           (void) make_block_at(s.next_bci());
         }
         int dest_bci = s.get_far_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
       }
       case Bytecodes::_jsr_w       :
       {
         cur_block->set_control_bci(bci);
         ciBlock *ret = make_block_at(s.next_bci());
         int dest_bci = s.get_far_dest();
         ciBlock *dest = make_block_at(dest_bci);
         break;
       }
       case Bytecodes::_athrow      :
         cur_block->set_may_throw();
         // fall-through
       case Bytecodes::_ret         :
       case Bytecodes::_ireturn     :
       case Bytecodes::_lreturn     :
       case Bytecodes::_freturn     :
       case Bytecodes::_dreturn     :
       case Bytecodes::_areturn     :
       case Bytecodes::_return      :
         cur_block->set_control_bci(bci);
         if (s.next_bci() < limit_bci) {
           (void) make_block_at(s.next_bci());
         }
         break;
     }
   }
   //  End the last block
   cur_block->set_limit_bci(limit_bci);
 }
 ciMethodBlocks::ciMethodBlocks(Arena *arena, ciMethod *meth): _method(meth),
                           _arena(arena), _num_blocks(0), _code_size(meth->code_size()) {
   int block_estimate = _code_size / 8;
   _blocks =  new(_arena) GrowableArray<ciBlock *>(block_estimate);
   int b2bsize = _code_size * sizeof(ciBlock **);
   _bci_to_block = (ciBlock **) arena->Amalloc(b2bsize);
   Copy::zero_to_words((HeapWord*) _bci_to_block, b2bsize / sizeof(HeapWord));
   // create initial block covering the entire method
   ciBlock *b = new(arena) ciBlock(_method, _num_blocks++, this, 0);
   _blocks->append(b);
   _bci_to_block[0] = b;
   // create blocks for exception handlers
   if (meth->has_exception_handlers()) {
     for(ciExceptionHandlerStream str(meth); !str.is_done(); str.next()) {
       ciExceptionHandler* handler = str.handler();
       ciBlock *eb = make_block_at(handler->handler_bci());
       //
       // Several exception handlers can have the same handler_bci:
       //
       //  try {
       //    if (a.foo(b) < 0) {
       //      return a.error();
       //    }
       //    return CoderResult.UNDERFLOW;
       //  } finally {
       //      a.position(b);
       //  }
       //
       //  The try block above is divided into 2 exception blocks
       //  separated by 'areturn' bci.
       //
       int ex_start = handler->start();
       int ex_end = handler->limit();
       if (eb->is_handler()) {
         // Extend old handler exception range to cover additional range.
         int old_ex_start = eb->ex_start_bci();
         int old_ex_end   = eb->ex_limit_bci();
         if (ex_start > old_ex_start)
           ex_start = old_ex_start;
         if (ex_end < old_ex_end)
           ex_end = old_ex_end;
         eb->clear_exception_handler(); // Reset exception information
       }
       eb->set_exception_range(ex_start, ex_end);
       // ensure a block at the start of exception range and start of following code
       (void) make_block_at(ex_start);
       if (ex_end < _code_size)
         (void) make_block_at(ex_end);
     }
   }
   // scan the bytecodes and identify blocks
   do_analysis();
   // mark blocks that have exception handlers
   if (meth->has_exception_handlers()) {
     for(ciExceptionHandlerStream str(meth); !str.is_done(); str.next()) {
       ciExceptionHandler* handler = str.handler();
       int ex_start = handler->start();
       int ex_end = handler->limit();
       int bci = ex_start;
       while (bci < ex_end) {
         ciBlock *b = block_containing(bci);
         b->set_has_handler();
         bci = b->limit_bci();
       }
     }
   }
 }
 void ciMethodBlocks::clear_processed() {
   for (int i = 0; i < _blocks->length(); i++)
     _blocks->at(i)->clear_processed();
 }
 #ifndef PRODUCT
 void ciMethodBlocks::dump() {
   tty->print("---- blocks for method: ");
   _method->print();
   tty->cr();
   for (int i = 0; i < _blocks->length(); i++) {
     tty->print("  B%d: ", i); _blocks->at(i)->dump();
   }
 }
 #endif
 ciBlock::ciBlock(ciMethod *method, int index, ciMethodBlocks *mb, int start_bci) :
 #ifndef PRODUCT
                          _method(method),
 #endif
                          _idx(index), _flags(0), _start_bci(start_bci), _limit_bci(-1), _control_bci(fall_through_bci),
                          _ex_start_bci(-1), _ex_limit_bci(-1) {
 }
 void ciBlock::set_exception_range(int start_bci, int limit_bci)  {
    assert(limit_bci >= start_bci, "valid range");
    assert(!is_handler() && _ex_start_bci == -1 && _ex_limit_bci == -1, "must not be handler");
    _ex_start_bci = start_bci;
    _ex_limit_bci = limit_bci;
    set_handler();
 }
 #ifndef PRODUCT
 static const char *flagnames[] = {
   "Processed",
   "Handler",
   "MayThrow",
   "Jsr",
   "Ret",
   "RetTarget",
   "HasHandler",
 };
 void ciBlock::dump() {
   tty->print(" [%d .. %d), {", _start_bci, _limit_bci);
   for (int i = 0; i < 8; i++) {
     if ((_flags & (1 << i)) != 0) {
       tty->print(" %s", flagnames[i]);
     }
   }
   tty->print(" ]");
   if (is_handler())
     tty->print(" handles(%d..%d)", _ex_start_bci, _ex_limit_bci);
   tty->cr();
 }
 // ------------------------------------------------------------------
 // ciBlock::print_on
 void ciBlock::print_on(outputStream* st) const {
   st->print_cr("--------------------------------------------------------");
   st->print   ("ciBlock [%d - %d) control : ", start_bci(), limit_bci());
   if (control_bci() == fall_through_bci) {
     st->print_cr("%d:fall through", limit_bci());
   } else {
     st->print_cr("%d:%s", control_bci(),
         Bytecodes::name(method()->java_code_at_bci(control_bci())));
   }
   if (Verbose || WizardMode) {
     method()->print_codes_on(start_bci(), limit_bci(), st);
   }
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/ci/ciMethodBlocks.cpp@6ca61c728c2d (annotated)

src/share/vm/ci/ciMethodBlocks.cpp