truffle: src/share/vm/oops/generateOopMap.cpp comparison

comparison src/share/vm/oops/generateOopMap.cpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	37f87013dfd8

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--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 1997-2005 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.
+*
+*/
+//
+//
+// Compute stack layouts for each instruction in method.
+//
+//  Problems:
+//  - What to do about jsr with different types of local vars?
+//  Need maps that are conditional on jsr path?
+//  - Jsr and exceptions should be done more efficiently (the retAddr stuff)
+//
+//  Alternative:
+//  - Could extend verifier to provide this information.
+//    For: one fewer abstract interpreter to maintain. Against: the verifier
+//    solves a bigger problem so slower (undesirable to force verification of
+//    everything?).
+//
+//  Algorithm:
+//    Partition bytecodes into basic blocks
+//    For each basic block: store entry state (vars, stack). For instructions
+//    inside basic blocks we do not store any state (instead we recompute it
+//    from state produced by previous instruction).
+//
+//    Perform abstract interpretation of bytecodes over this lattice:
+//
+//                _--'#'--_
+//               /  /  \   \
+//             /   /     \   \
+//            /    |     |     \
+//          'r'   'v'   'p'   ' '
+//           \     |     |     /
+//            \    \     /    /
+//              \   \   /    /
+//                -- '@' --
+//
+//    '#'  top, result of conflict merge
+//    'r'  reference type
+//    'v'  value type
+//    'p'  pc type for jsr/ret
+//    ' '  uninitialized; never occurs on operand stack in Java
+//    '@'  bottom/unexecuted; initial state each bytecode.
+//
+//    Basic block headers are the only merge points. We use this iteration to
+//    compute the information:
+//
+//    find basic blocks;
+//    initialize them with uninitialized state;
+//    initialize first BB according to method signature;
+//    mark first BB changed
+//    while (some BB is changed) do {
+//      perform abstract interpration of all bytecodes in BB;
+//      merge exit state of BB into entry state of all successor BBs,
+//      noting if any of these change;
+//    }
+//
+//  One additional complication is necessary. The jsr instruction pushes
+//  a return PC on the stack (a 'p' type in the abstract interpretation).
+//  To be able to process "ret" bytecodes, we keep track of these return
+//  PC's in a 'retAddrs' structure in abstract interpreter context (when
+//  processing a "ret" bytecodes, it is not sufficient to know that it gets
+//  an argument of the right type 'p'; we need to know which address it
+//  returns to).
+//
+// (Note this comment is borrowed form the original author of the algorithm)
+#include "incls/_precompiled.incl"
+#include "incls/_generateOopMap.cpp.incl"
+// ComputeCallStack
+//
+// Specialization of SignatureIterator - compute the effects of a call
+//
+class ComputeCallStack : public SignatureIterator {
+CellTypeState *_effect;
+int _idx;
+void setup();
+void set(CellTypeState state)         { _effect[_idx++] = state; }
+int  length()                         { return _idx; };
+virtual void do_bool  ()              { set(CellTypeState::value); };
+virtual void do_char  ()              { set(CellTypeState::value); };
+virtual void do_float ()              { set(CellTypeState::value); };
+virtual void do_byte  ()              { set(CellTypeState::value); };
+virtual void do_short ()              { set(CellTypeState::value); };
+virtual void do_int   ()              { set(CellTypeState::value); };
+virtual void do_void  ()              { set(CellTypeState::bottom);};
+virtual void do_object(int begin, int end)  { set(CellTypeState::ref); };
+virtual void do_array (int begin, int end)  { set(CellTypeState::ref); };
+void do_double()                      { set(CellTypeState::value);
+set(CellTypeState::value); }
+void do_long  ()                      { set(CellTypeState::value);
+set(CellTypeState::value); }
+public:
+ComputeCallStack(symbolOop signature) : SignatureIterator(signature) {};
+// Compute methods
+int compute_for_parameters(bool is_static, CellTypeState *effect) {
+_idx    = 0;
+_effect = effect;
+if (!is_static)
+effect[_idx++] = CellTypeState::ref;
+iterate_parameters();
+return length();
+};
+int compute_for_returntype(CellTypeState *effect) {
+_idx    = 0;
+_effect = effect;
+iterate_returntype();
+set(CellTypeState::bottom);  // Always terminate with a bottom state, so ppush works
+return length();
+}
+};
+//=========================================================================================
+// ComputeEntryStack
+//
+// Specialization of SignatureIterator - in order to set up first stack frame
+//
+class ComputeEntryStack : public SignatureIterator {
+CellTypeState *_effect;
+int _idx;
+void setup();
+void set(CellTypeState state)         { _effect[_idx++] = state; }
+int  length()                         { return _idx; };
+virtual void do_bool  ()              { set(CellTypeState::value); };
+virtual void do_char  ()              { set(CellTypeState::value); };
+virtual void do_float ()              { set(CellTypeState::value); };
+virtual void do_byte  ()              { set(CellTypeState::value); };
+virtual void do_short ()              { set(CellTypeState::value); };
+virtual void do_int   ()              { set(CellTypeState::value); };
+virtual void do_void  ()              { set(CellTypeState::bottom);};
+virtual void do_object(int begin, int end)  { set(CellTypeState::make_slot_ref(_idx)); }
+virtual void do_array (int begin, int end)  { set(CellTypeState::make_slot_ref(_idx)); }
+void do_double()                      { set(CellTypeState::value);
+set(CellTypeState::value); }
+void do_long  ()                      { set(CellTypeState::value);
+set(CellTypeState::value); }
+public:
+ComputeEntryStack(symbolOop signature) : SignatureIterator(signature) {};
+// Compute methods
+int compute_for_parameters(bool is_static, CellTypeState *effect) {
+_idx    = 0;
+_effect = effect;
+if (!is_static)
+effect[_idx++] = CellTypeState::make_slot_ref(0);
+iterate_parameters();
+return length();
+};
+int compute_for_returntype(CellTypeState *effect) {
+_idx    = 0;
+_effect = effect;
+iterate_returntype();
+set(CellTypeState::bottom);  // Always terminate with a bottom state, so ppush works
+return length();
+}
+};
+//=====================================================================================
+//
+// Implementation of RetTable/RetTableEntry
+//
+// Contains function to itereate through all bytecodes
+// and find all return entry points
+//
+int RetTable::_init_nof_entries = 10;
+int RetTableEntry::_init_nof_jsrs = 5;
+void RetTableEntry::add_delta(int bci, int delta) {
+if (_target_bci > bci) _target_bci += delta;
+for (int k = 0; k < _jsrs->length(); k++) {
+int jsr = _jsrs->at(k);
+if (jsr > bci) _jsrs->at_put(k, jsr+delta);
+}
+}
+void RetTable::compute_ret_table(methodHandle method) {
+BytecodeStream i(method);
+Bytecodes::Code bytecode;
+while( (bytecode = i.next()) >= 0) {
+switch (bytecode) {
+case Bytecodes::_jsr:
+add_jsr(i.next_bci(), i.dest());
+break;
+case Bytecodes::_jsr_w:
+add_jsr(i.next_bci(), i.dest_w());
+break;
+}
+}
+}
+void RetTable::add_jsr(int return_bci, int target_bci) {
+RetTableEntry* entry = _first;
+// Scan table for entry
+for (;entry && entry->target_bci() != target_bci; entry = entry->next());
+if (!entry) {
+// Allocate new entry and put in list
+entry = new RetTableEntry(target_bci, _first);
+_first = entry;
+}
+// Now "entry" is set.  Make sure that the entry is initialized
+// and has room for the new jsr.
+entry->add_jsr(return_bci);
+}
+RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
+RetTableEntry *cur = _first;
+while(cur) {
+assert(cur->target_bci() != -1, "sanity check");
+if (cur->target_bci() == targBci)  return cur;
+cur = cur->next();
+}
+ShouldNotReachHere();
+return NULL;
+}
+// The instruction at bci is changing size by "delta".  Update the return map.
+void RetTable::update_ret_table(int bci, int delta) {
+RetTableEntry *cur = _first;
+while(cur) {
+cur->add_delta(bci, delta);
+cur = cur->next();
+}
+}
+//
+// Celltype state
+//
+CellTypeState CellTypeState::bottom      = CellTypeState::make_bottom();
+CellTypeState CellTypeState::uninit      = CellTypeState::make_any(uninit_value);
+CellTypeState CellTypeState::ref         = CellTypeState::make_any(ref_conflict);
+CellTypeState CellTypeState::value       = CellTypeState::make_any(val_value);
+CellTypeState CellTypeState::refUninit   = CellTypeState::make_any(ref_conflict | uninit_value);
+CellTypeState CellTypeState::top         = CellTypeState::make_top();
+CellTypeState CellTypeState::addr        = CellTypeState::make_any(addr_conflict);
+// Commonly used constants
+static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
+static CellTypeState   refCTS   = CellTypeState::ref;
+static CellTypeState   valCTS   = CellTypeState::value;
+static CellTypeState    vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
+static CellTypeState    rCTS[2] = { CellTypeState::ref,   CellTypeState::bottom };
+static CellTypeState   rrCTS[3] = { CellTypeState::ref,   CellTypeState::ref,   CellTypeState::bottom };
+static CellTypeState   vrCTS[3] = { CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
+static CellTypeState   vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
+static CellTypeState  rvrCTS[4] = { CellTypeState::ref,   CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
+static CellTypeState  vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
+static CellTypeState  vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
+static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
+static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
+char CellTypeState::to_char() const {
+if (can_be_reference()) {
+if (can_be_value() || can_be_address())
+return '#';    // Conflict that needs to be rewritten
+else
+return 'r';
+} else if (can_be_value())
+return 'v';
+else if (can_be_address())
+return 'p';
+else if (can_be_uninit())
+return ' ';
+else
+return '@';
+}
+// Print a detailed CellTypeState.  Indicate all bits that are set.  If
+// the CellTypeState represents an address or a reference, print the
+// value of the additional information.
+void CellTypeState::print(outputStream *os) {
+if (can_be_address()) {
+os->print("(p");
+} else {
+os->print("( ");
+}
+if (can_be_reference()) {
+os->print("r");
+} else {
+os->print(" ");
+}
+if (can_be_value()) {
+os->print("v");
+} else {
+os->print(" ");
+}
+if (can_be_uninit()) {
+os->print("u|");
+} else {
+os->print(" |");
+}
+if (is_info_top()) {
+os->print("Top)");
+} else if (is_info_bottom()) {
+os->print("Bot)");
+} else {
+if (is_reference()) {
+int info = get_info();
+int data = info & ~(ref_not_lock_bit | ref_slot_bit);
+if (info & ref_not_lock_bit) {
+// Not a monitor lock reference.
+if (info & ref_slot_bit) {
+// slot
+os->print("slot%d)", data);
+} else {
+// line
+os->print("line%d)", data);
+}
+} else {
+// lock
+os->print("lock%d)", data);
+}
+} else {
+os->print("%d)", get_info());
+}
+}
+}
+//
+// Basicblock handling methods
+//
+void GenerateOopMap ::initialize_bb() {
+_gc_points = 0;
+_bb_count  = 0;
+int size = binsToHold(method()->code_size());
+_bb_hdr_bits = NEW_RESOURCE_ARRAY(uintptr_t,size);
+memset(_bb_hdr_bits, 0, size*sizeof(uintptr_t));
+}
+void GenerateOopMap ::set_bbmark_bit(int bci) {
+int idx  = bci >> LogBitsPerWord;
+uintptr_t bit = (uintptr_t)1 << (bci & (BitsPerWord-1));
+_bb_hdr_bits[idx] |= bit;
+}
+void GenerateOopMap ::clear_bbmark_bit(int bci) {
+int idx   = bci >> LogBitsPerWord;
+uintptr_t bit = (uintptr_t)1 << (bci & (BitsPerWord-1));
+_bb_hdr_bits[idx] &= (~bit);
+}
+void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
+assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
+if (c->is_bb_header(bci))
+return;
+if (TraceNewOopMapGeneration) {
+tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
+}
+c->set_bbmark_bit(bci);
+c->_bb_count++;
+}
+void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
+initialize_bb();
+bool fellThrough = false;  // False to get first BB marked.
+// First mark all exception handlers as start of a basic-block
+typeArrayOop excps = method()->exception_table();
+for(int i = 0; i < excps->length(); i += 4) {
+int handler_pc_idx = i+2;
+bb_mark_fct(this, excps->int_at(handler_pc_idx), NULL);
+}
+// Then iterate through the code
+BytecodeStream bcs(_method);
+Bytecodes::Code bytecode;
+while( (bytecode = bcs.next()) >= 0) {
+int bci = bcs.bci();
+if (!fellThrough)
+bb_mark_fct(this, bci, NULL);
+fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);
+/* We will also mark successors of jsr's as basic block headers. */
+switch (bytecode) {
+case Bytecodes::_jsr:
+assert(!fellThrough, "should not happen");
+bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
+break;
+case Bytecodes::_jsr_w:
+assert(!fellThrough, "should not happen");
+bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
+break;
+}
+if (possible_gc_point(&bcs))
+_gc_points++;
+}
+}
+void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
+assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
+BasicBlock* bb = c->get_basic_block_at(bci);
+if (bb->is_dead()) {
+bb->mark_as_alive();
+*data = 1; // Mark basicblock as changed
+}
+}
+void GenerateOopMap::mark_reachable_code() {
+int change = 1; // int to get function pointers to work
+// Mark entry basic block as alive and all exception handlers
+_basic_blocks[0].mark_as_alive();
+typeArrayOop excps = method()->exception_table();
+for(int i = 0; i < excps->length(); i += 4) {
+int handler_pc_idx = i+2;
+BasicBlock *bb = get_basic_block_at(excps->int_at(handler_pc_idx));
+// If block is not already alive (due to multiple exception handlers to same bb), then
+// make it alive
+if (bb->is_dead()) bb->mark_as_alive();
+}
+BytecodeStream bcs(_method);
+// Iterate through all basic blocks until we reach a fixpoint
+while (change) {
+change = 0;
+for (int i = 0; i < _bb_count; i++) {
+BasicBlock *bb = &_basic_blocks[i];
+if (bb->is_alive()) {
+// Position bytecodestream at last bytecode in basicblock
+bcs.set_start(bb->_end_bci);
+bcs.next();
+Bytecodes::Code bytecode = bcs.code();
+int bci = bcs.bci();
+assert(bci == bb->_end_bci, "wrong bci");
+bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
+// We will also mark successors of jsr's as alive.
+switch (bytecode) {
+case Bytecodes::_jsr:
+case Bytecodes::_jsr_w:
+assert(!fell_through, "should not happen");
+reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
+break;
+}
+if (fell_through) {
+// Mark successor as alive
+if (bb[1].is_dead()) {
+bb[1].mark_as_alive();
+change = 1;
+}
+}
+}
+}
+}
+}
+/* If the current instruction in "c" has no effect on control flow,
+returns "true".  Otherwise, calls "jmpFct" one or more times, with
+"c", an appropriate "pcDelta", and "data" as arguments, then
+returns "false".  There is one exception: if the current
+instruction is a "ret", returns "false" without calling "jmpFct".
+Arrangements for tracking the control flow of a "ret" must be made
+externally. */
+bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
+int bci = bcs->bci();
+switch (bcs->code()) {
+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:
+(*jmpFct)(this, bcs->dest(), data);
+(*jmpFct)(this, bci + 3, data);
+break;
+case Bytecodes::_goto:
+(*jmpFct)(this, bcs->dest(), data);
+break;
+case Bytecodes::_goto_w:
+(*jmpFct)(this, bcs->dest_w(), data);
+break;
+case Bytecodes::_tableswitch:
+{ Bytecode_tableswitch *tableswitch = Bytecode_tableswitch_at(bcs->bcp());
+int len = tableswitch->length();
+(*jmpFct)(this, bci + tableswitch->default_offset(), data); /* Default. jump address */
+while (--len >= 0) {
+(*jmpFct)(this, bci + tableswitch->dest_offset_at(len), data);
+}
+break;
+}
+case Bytecodes::_lookupswitch:
+{ Bytecode_lookupswitch *lookupswitch = Bytecode_lookupswitch_at(bcs->bcp());
+int npairs = lookupswitch->number_of_pairs();
+(*jmpFct)(this, bci + lookupswitch->default_offset(), data); /* Default. */
+while(--npairs >= 0) {
+LookupswitchPair *pair = lookupswitch->pair_at(npairs);
+(*jmpFct)(this, bci + pair->offset(), data);
+}
+break;
+}
+case Bytecodes::_jsr:
+assert(bcs->is_wide()==false, "sanity check");
+(*jmpFct)(this, bcs->dest(), data);
+break;
+case Bytecodes::_jsr_w:
+(*jmpFct)(this, bcs->dest_w(), data);
+break;
+case Bytecodes::_wide:
+ShouldNotReachHere();
+return true;
+break;
+case Bytecodes::_athrow:
+case Bytecodes::_ireturn:
+case Bytecodes::_lreturn:
+case Bytecodes::_freturn:
+case Bytecodes::_dreturn:
+case Bytecodes::_areturn:
+case Bytecodes::_return:
+case Bytecodes::_ret:
+break;
+default:
+return true;
+}
+return false;
+}
+/* Requires "pc" to be the head of a basic block; returns that basic
+block. */
+BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
+BasicBlock* bb = get_basic_block_containing(bci);
+assert(bb->_bci == bci, "should have found BB");
+return bb;
+}
+// Requires "pc" to be the start of an instruction; returns the basic
+//   block containing that instruction. */
+BasicBlock  *GenerateOopMap::get_basic_block_containing(int bci) const {
+BasicBlock *bbs = _basic_blocks;
+int lo = 0, hi = _bb_count - 1;
+while (lo <= hi) {
+int m = (lo + hi) / 2;
+int mbci = bbs[m]._bci;
+int nbci;
+if ( m == _bb_count-1) {
+assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
+return bbs+m;
+} else {
+nbci = bbs[m+1]._bci;
+}
+if ( mbci <= bci && bci < nbci) {
+return bbs+m;
+} else if (mbci < bci) {
+lo = m + 1;
+} else {
+assert(mbci > bci, "sanity check");
+hi = m - 1;
+}
+}
+fatal("should have found BB");
+return NULL;
+}
+void GenerateOopMap::restore_state(BasicBlock *bb)
+{
+memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
+_stack_top = bb->_stack_top;
+_monitor_top = bb->_monitor_top;
+}
+int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
+int bbNum = bb - _basic_blocks + 1;
+if (bbNum == _bb_count)
+return method()->code_size();
+return _basic_blocks[bbNum]._bci;
+}
+//
+// CellType handling methods
+//
+void GenerateOopMap::init_state() {
+_state_len     = _max_locals + _max_stack + _max_monitors;
+_state         = NEW_RESOURCE_ARRAY(CellTypeState, _state_len);
+memset(_state, 0, _state_len * sizeof(CellTypeState));
+_state_vec_buf = NEW_RESOURCE_ARRAY(char, MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */);
+}
+void GenerateOopMap::make_context_uninitialized() {
+CellTypeState* vs = vars();
+for (int i = 0; i < _max_locals; i++)
+vs[i] = CellTypeState::uninit;
+_stack_top = 0;
+_monitor_top = 0;
+}
+int GenerateOopMap::methodsig_to_effect(symbolOop signature, bool is_static, CellTypeState* effect) {
+ComputeEntryStack ces(signature);
+return ces.compute_for_parameters(is_static, effect);
+}
+// Return result of merging cts1 and cts2.
+CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
+CellTypeState result;
+assert(!is_bottom() && !cts.is_bottom(),
+"merge of bottom values is handled elsewhere");
+result._state = _state | cts._state;
+// If the top bit is set, we don't need to do any more work.
+if (!result.is_info_top()) {
+assert((result.can_be_address() || result.can_be_reference()),
+"only addresses and references have non-top info");
+if (!equal(cts)) {
+// The two values being merged are different.  Raise to top.
+if (result.is_reference()) {
+result = CellTypeState::make_slot_ref(slot);
+} else {
+result._state |= info_conflict;
+}
+}
+}
+assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
+return result;
+}
+// Merge the variable state for locals and stack from cts into bbts.
+bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
+CellTypeState* bbts) {
+int i;
+int len = _max_locals + _stack_top;
+bool change = false;
+for (i = len - 1; i >= 0; i--) {
+CellTypeState v = cts[i].merge(bbts[i], i);
+change = change || !v.equal(bbts[i]);
+bbts[i] = v;
+}
+return change;
+}
+// Merge the monitor stack state from cts into bbts.
+bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
+CellTypeState* bbts) {
+bool change = false;
+if (_max_monitors > 0 && _monitor_top != bad_monitors) {
+// If there are no monitors in the program, or there has been
+// a monitor matching error before this point in the program,
+// then we do not merge in the monitor state.
+int base = _max_locals + _max_stack;
+int len = base + _monitor_top;
+for (int i = len - 1; i >= base; i--) {
+CellTypeState v = cts[i].merge(bbts[i], i);
+// Can we prove that, when there has been a change, it will already
+// have been detected at this point?  That would make this equal
+// check here unnecessary.
+change = change || !v.equal(bbts[i]);
+bbts[i] = v;
+}
+}
+return change;
+}
+void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
+int len = _max_locals + _stack_top;
+for (int i = 0; i < len; i++) {
+if (src[i].is_nonlock_reference()) {
+dst[i] = CellTypeState::make_slot_ref(i);
+} else {
+dst[i] = src[i];
+}
+}
+if (_max_monitors > 0 && _monitor_top != bad_monitors) {
+int base = _max_locals + _max_stack;
+len = base + _monitor_top;
+for (int i = base; i < len; i++) {
+dst[i] = src[i];
+}
+}
+}
+// Merge the states for the current block and the next.  As long as a
+// block is reachable the locals and stack must be merged.  If the
+// stack heights don't match then this is a verification error and
+// it's impossible to interpret the code.  Simultaneously monitor
+// states are being check to see if they nest statically.  If monitor
+// depths match up then their states are merged.  Otherwise the
+// mismatch is simply recorded and interpretation continues since
+// monitor matching is purely informational and doesn't say anything
+// about the correctness of the code.
+void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
+assert(bb->is_alive(), "merging state into a dead basicblock");
+if (_stack_top == bb->_stack_top) {
+// always merge local state even if monitors don't match.
+if (merge_local_state_vectors(_state, bb->_state)) {
+bb->set_changed(true);
+}
+if (_monitor_top == bb->_monitor_top) {
+// monitors still match so continue merging monitor states.
+if (merge_monitor_state_vectors(_state, bb->_state)) {
+bb->set_changed(true);
+}
+} else {
+if (TraceMonitorMismatch) {
+report_monitor_mismatch("monitor stack height merge conflict");
+}
+// When the monitor stacks are not matched, we set _monitor_top to
+// bad_monitors.  This signals that, from here on, the monitor stack cannot
+// be trusted.  In particular, monitorexit bytecodes may throw
+// exceptions.  We mark this block as changed so that the change
+// propagates properly.
+bb->_monitor_top = bad_monitors;
+bb->set_changed(true);
+_monitor_safe = false;
+}
+} else if (!bb->is_reachable()) {
+// First time we look at this  BB
+copy_state(bb->_state, _state);
+bb->_stack_top = _stack_top;
+bb->_monitor_top = _monitor_top;
+bb->set_changed(true);
+} else {
+verify_error("stack height conflict: %d vs. %d",  _stack_top, bb->_stack_top);
+}
+}
+void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
+gom->merge_state_into_bb(gom->get_basic_block_at(bci));
+}
+void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
+assert(cts.is_reference() || cts.is_value() || cts.is_address(),
+"wrong celltypestate");
+if (localNo < 0 || localNo > _max_locals) {
+verify_error("variable write error: r%d", localNo);
+return;
+}
+vars()[localNo] = cts;
+}
+CellTypeState GenerateOopMap::get_var(int localNo) {
+assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error")
+if (localNo < 0 || localNo > _max_locals) {
+verify_error("variable read error: r%d", localNo);
+return valCTS; // just to pick something;
+}
+return vars()[localNo];
+}
+CellTypeState GenerateOopMap::pop() {
+if ( _stack_top <= 0) {
+verify_error("stack underflow");
+return valCTS; // just to pick something
+}
+return  stack()[--_stack_top];
+}
+void GenerateOopMap::push(CellTypeState cts) {
+if ( _stack_top >= _max_stack) {
+verify_error("stack overflow");
+return;
+}
+stack()[_stack_top++] = cts;
+}
+CellTypeState GenerateOopMap::monitor_pop() {
+assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
+if (_monitor_top == 0) {
+// We have detected a pop of an empty monitor stack.
+_monitor_safe = false;
+_monitor_top = bad_monitors;
+if (TraceMonitorMismatch) {
+report_monitor_mismatch("monitor stack underflow");
+}
+return CellTypeState::ref; // just to keep the analysis going.
+}
+return  monitors()[--_monitor_top];
+}
+void GenerateOopMap::monitor_push(CellTypeState cts) {
+assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
+if (_monitor_top >= _max_monitors) {
+// Some monitorenter is being executed more than once.
+// This means that the monitor stack cannot be simulated.
+_monitor_safe = false;
+_monitor_top = bad_monitors;
+if (TraceMonitorMismatch) {
+report_monitor_mismatch("monitor stack overflow");
+}
+return;
+}
+monitors()[_monitor_top++] = cts;
+}
+//
+// Interpretation handling methods
+//
+void GenerateOopMap::do_interpretation()
+{
+// "i" is just for debugging, so we can detect cases where this loop is
+// iterated more than once.
+int i = 0;
+do {
+#ifndef PRODUCT
+if (TraceNewOopMapGeneration) {
+tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
+method()->print_name(tty);
+tty->print("\n\n");
+}
+#endif
+_conflict = false;
+_monitor_safe = true;
+// init_state is now called from init_basic_blocks.  The length of a
+// state vector cannot be determined until we have made a pass through
+// the bytecodes counting the possible monitor entries.
+if (!_got_error) init_basic_blocks();
+if (!_got_error) setup_method_entry_state();
+if (!_got_error) interp_all();
+if (!_got_error) rewrite_refval_conflicts();
+i++;
+} while (_conflict && !_got_error);
+}
+void GenerateOopMap::init_basic_blocks() {
+// Note: Could consider reserving only the needed space for each BB's state
+// (entry stack may not be of maximal height for every basic block).
+// But cumbersome since we don't know the stack heights yet.  (Nor the
+// monitor stack heights...)
+_basic_blocks = NEW_RESOURCE_ARRAY(BasicBlock, _bb_count);
+// Make a pass through the bytecodes.  Count the number of monitorenters.
+// This can be used an upper bound on the monitor stack depth in programs
+// which obey stack discipline with their monitor usage.  Initialize the
+// known information about basic blocks.
+BytecodeStream j(_method);
+Bytecodes::Code bytecode;
+int bbNo = 0;
+int monitor_count = 0;
+int prev_bci = -1;
+while( (bytecode = j.next()) >= 0) {
+if (j.code() == Bytecodes::_monitorenter) {
+monitor_count++;
+}
+int bci = j.bci();
+if (is_bb_header(bci)) {
+// Initialize the basicblock structure
+BasicBlock *bb   = _basic_blocks + bbNo;
+bb->_bci         = bci;
+bb->_max_locals  = _max_locals;
+bb->_max_stack   = _max_stack;
+bb->set_changed(false);
+bb->_stack_top   = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
+bb->_monitor_top = bad_monitors;
+if (bbNo > 0) {
+_basic_blocks[bbNo - 1]._end_bci = prev_bci;
+}
+bbNo++;
+}
+// Remember prevous bci.
+prev_bci = bci;
+}
+// Set
+_basic_blocks[bbNo-1]._end_bci = prev_bci;
+_max_monitors = monitor_count;
+// Now that we have a bound on the depth of the monitor stack, we can
+// initialize the CellTypeState-related information.
+init_state();
+// We allocate space for all state-vectors for all basicblocks in one huge chuck.
+// Then in the next part of the code, we set a pointer in each _basic_block that
+// points to each piece.
+CellTypeState *basicBlockState = NEW_RESOURCE_ARRAY(CellTypeState, bbNo * _state_len);
+memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
+// Make a pass over the basicblocks and assign their state vectors.
+for (int blockNum=0; blockNum < bbNo; blockNum++) {
+BasicBlock *bb = _basic_blocks + blockNum;
+bb->_state = basicBlockState + blockNum * _state_len;
+#ifdef ASSERT
+if (blockNum + 1 < bbNo) {
+address bcp = _method->bcp_from(bb->_end_bci);
+int bc_len = Bytecodes::java_length_at(bcp);
+assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
+}
+#endif
+}
+#ifdef ASSERT
+{ BasicBlock *bb = &_basic_blocks[bbNo-1];
+address bcp = _method->bcp_from(bb->_end_bci);
+int bc_len = Bytecodes::java_length_at(bcp);
+assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
+}
+#endif
+// Check that the correct number of basicblocks was found
+if (bbNo !=_bb_count) {
+if (bbNo < _bb_count) {
+verify_error("jump into the middle of instruction?");
+return;
+} else {
+verify_error("extra basic blocks - should not happen?");
+return;
+}
+}
+// Mark all alive blocks
+mark_reachable_code();
+}
+void GenerateOopMap::setup_method_entry_state() {
+// Initialize all locals to 'uninit' and set stack-height to 0
+make_context_uninitialized();
+// Initialize CellState type of arguments
+methodsig_to_effect(method()->signature(), method()->is_static(), vars());
+// If some references must be pre-assigned to null, then set that up
+initialize_vars();
+// This is the start state
+merge_state_into_bb(&_basic_blocks[0]);
+assert(_basic_blocks[0].changed(), "we are not getting off the ground");
+}
+// The instruction at bci is changing size by "delta".  Update the basic blocks.
+void GenerateOopMap::update_basic_blocks(int bci, int delta,
+int new_method_size) {
+assert(new_method_size >= method()->code_size() + delta,
+"new method size is too small");
+int newWords = binsToHold(new_method_size);
+uintptr_t * new_bb_hdr_bits = NEW_RESOURCE_ARRAY(uintptr_t, newWords);
+BitMap bb_bits(new_bb_hdr_bits, new_method_size);
+bb_bits.clear();
+for(int k = 0; k < _bb_count; k++) {
+if (_basic_blocks[k]._bci > bci) {
+_basic_blocks[k]._bci     += delta;
+_basic_blocks[k]._end_bci += delta;
+}
+bb_bits.at_put(_basic_blocks[k]._bci, true);
+}
+_bb_hdr_bits = new_bb_hdr_bits ;
+}
+//
+// Initvars handling
+//
+void GenerateOopMap::initialize_vars() {
+for (int k = 0; k < _init_vars->length(); k++)
+_state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
+}
+void GenerateOopMap::add_to_ref_init_set(int localNo) {
+if (TraceNewOopMapGeneration)
+tty->print_cr("Added init vars: %d", localNo);
+// Is it already in the set?
+if (_init_vars->contains(localNo) )
+return;
+_init_vars->append(localNo);
+}
+//
+// Interpreration code
+//
+void GenerateOopMap::interp_all() {
+bool change = true;
+while (change && !_got_error) {
+change = false;
+for (int i = 0; i < _bb_count && !_got_error; i++) {
+BasicBlock *bb = &_basic_blocks[i];
+if (bb->changed()) {
+if (_got_error) return;
+change = true;
+bb->set_changed(false);
+interp_bb(bb);
+}
+}
+}
+}
+void GenerateOopMap::interp_bb(BasicBlock *bb) {
+// We do not want to do anything in case the basic-block has not been initialized. This
+// will happen in the case where there is dead-code hang around in a method.
+assert(bb->is_reachable(), "should be reachable or deadcode exist");
+restore_state(bb);
+BytecodeStream itr(_method);
+// Set iterator interval to be the current basicblock
+int lim_bci = next_bb_start_pc(bb);
+itr.set_interval(bb->_bci, lim_bci);
+assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
+itr.next(); // read first instruction
+// Iterates through all bytecodes except the last in a basic block.
+// We handle the last one special, since there is controlflow change.
+while(itr.next_bci() < lim_bci && !_got_error) {
+if (_has_exceptions || _monitor_top != 0) {
+// We do not need to interpret the results of exceptional
+// continuation from this instruction when the method has no
+// exception handlers and the monitor stack is currently
+// empty.
+do_exception_edge(&itr);
+}
+interp1(&itr);
+itr.next();
+}
+// Handle last instruction.
+if (!_got_error) {
+assert(itr.next_bci() == lim_bci, "must point to end");
+if (_has_exceptions || _monitor_top != 0) {
+do_exception_edge(&itr);
+}
+interp1(&itr);
+bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
+if (_got_error)  return;
+if (itr.code() == Bytecodes::_ret) {
+assert(!fall_through, "cannot be set if ret instruction");
+// Automatically handles 'wide' ret indicies
+ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
+} else if (fall_through) {
+// Hit end of BB, but the instr. was a fall-through instruction,
+// so perform transition as if the BB ended in a "jump".
+if (lim_bci != bb[1]._bci) {
+verify_error("bytecodes fell through last instruction");
+return;
+}
+merge_state_into_bb(bb + 1);
+}
+}
+}
+void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
+// Only check exception edge, if bytecode can trap
+if (!Bytecodes::can_trap(itr->code())) return;
+switch (itr->code()) {
+case Bytecodes::_aload_0:
+// These bytecodes can trap for rewriting.  We need to assume that
+// they do not throw exceptions to make the monitor analysis work.
+return;
+case Bytecodes::_ireturn:
+case Bytecodes::_lreturn:
+case Bytecodes::_freturn:
+case Bytecodes::_dreturn:
+case Bytecodes::_areturn:
+case Bytecodes::_return:
+// If the monitor stack height is not zero when we leave the method,
+// then we are either exiting with a non-empty stack or we have
+// found monitor trouble earlier in our analysis.  In either case,
+// assume an exception could be taken here.
+if (_monitor_top == 0) {
+return;
+}
+break;
+case Bytecodes::_monitorexit:
+// If the monitor stack height is bad_monitors, then we have detected a
+// monitor matching problem earlier in the analysis.  If the
+// monitor stack height is 0, we are about to pop a monitor
+// off of an empty stack.  In either case, the bytecode
+// could throw an exception.
+if (_monitor_top != bad_monitors && _monitor_top != 0) {
+return;
+}
+break;
+}
+if (_has_exceptions) {
+int bci = itr->bci();
+typeArrayOop exct  = method()->exception_table();
+for(int i = 0; i< exct->length(); i+=4) {
+int start_pc   = exct->int_at(i);
+int end_pc     = exct->int_at(i+1);
+int handler_pc = exct->int_at(i+2);
+int catch_type = exct->int_at(i+3);
+if (start_pc <= bci && bci < end_pc) {
+BasicBlock *excBB = get_basic_block_at(handler_pc);
+CellTypeState *excStk = excBB->stack();
+CellTypeState *cOpStck = stack();
+CellTypeState cOpStck_0 = cOpStck[0];
+int cOpStackTop = _stack_top;
+// Exception stacks are always the same.
+assert(method()->max_stack() > 0, "sanity check");
+// We remembered the size and first element of "cOpStck"
+// above; now we temporarily set them to the appropriate
+// values for an exception handler. */
+cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
+_stack_top = 1;
+merge_state_into_bb(excBB);
+// Now undo the temporary change.
+cOpStck[0] = cOpStck_0;
+_stack_top = cOpStackTop;
+// If this is a "catch all" handler, then we do not need to
+// consider any additional handlers.
+if (catch_type == 0) {
+return;
+}
+}
+}
+}
+// It is possible that none of the exception handlers would have caught
+// the exception.  In this case, we will exit the method.  We must
+// ensure that the monitor stack is empty in this case.
+if (_monitor_top == 0) {
+return;
+}
+// We pessimistically assume that this exception can escape the
+// method. (It is possible that it will always be caught, but
+// we don't care to analyse the types of the catch clauses.)
+// We don't set _monitor_top to bad_monitors because there are no successors
+// to this exceptional exit.
+if (TraceMonitorMismatch && _monitor_safe) {
+// We check _monitor_safe so that we only report the first mismatched
+// exceptional exit.
+report_monitor_mismatch("non-empty monitor stack at exceptional exit");
+}
+_monitor_safe = false;
+}
+void GenerateOopMap::report_monitor_mismatch(const char *msg) {
+#ifndef PRODUCT
+tty->print("    Monitor mismatch in method ");
+method()->print_short_name(tty);
+tty->print_cr(": %s", msg);
+#endif
+}
+void GenerateOopMap::print_states(outputStream *os,
+CellTypeState* vec, int num) {
+for (int i = 0; i < num; i++) {
+vec[i].print(tty);
+}
+}
+// Print the state values at the current bytecode.
+void GenerateOopMap::print_current_state(outputStream   *os,
+BytecodeStream *currentBC,
+bool            detailed) {
+if (detailed) {
+os->print("     %4d vars     = ", currentBC->bci());
+print_states(os, vars(), _max_locals);
+os->print("    %s", Bytecodes::name(currentBC->code()));
+switch(currentBC->code()) {
+case Bytecodes::_invokevirtual:
+case Bytecodes::_invokespecial:
+case Bytecodes::_invokestatic:
+case Bytecodes::_invokeinterface:
+int idx = currentBC->get_index_big();
+constantPoolOop cp    = method()->constants();
+int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
+int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
+symbolOop signature   = cp->symbol_at(signatureIdx);
+os->print("%s", signature->as_C_string());
+}
+os->cr();
+os->print("          stack    = ");
+print_states(os, stack(), _stack_top);
+os->cr();
+if (_monitor_top != bad_monitors) {
+os->print("          monitors = ");
+print_states(os, monitors(), _monitor_top);
+} else {
+os->print("          [bad monitor stack]");
+}
+os->cr();
+} else {
+os->print("    %4d  vars = '%s' ", currentBC->bci(),  state_vec_to_string(vars(), _max_locals));
+os->print("     stack = '%s' ", state_vec_to_string(stack(), _stack_top));
+if (_monitor_top != bad_monitors) {
+os->print("  monitors = '%s'  \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
+} else {
+os->print("  [bad monitor stack]");
+}
+switch(currentBC->code()) {
+case Bytecodes::_invokevirtual:
+case Bytecodes::_invokespecial:
+case Bytecodes::_invokestatic:
+case Bytecodes::_invokeinterface:
+int idx = currentBC->get_index_big();
+constantPoolOop cp    = method()->constants();
+int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
+int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
+symbolOop signature   = cp->symbol_at(signatureIdx);
+os->print("%s", signature->as_C_string());
+}
+os->cr();
+}
+}
+// Sets the current state to be the state after executing the
+// current instruction, starting in the current state.
+void GenerateOopMap::interp1(BytecodeStream *itr) {
+if (TraceNewOopMapGeneration) {
+print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
+}
+// Should we report the results? Result is reported *before* the instruction at the current bci is executed.
+// However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
+// they have been popped (in method ppl).
+if (_report_result == true) {
+switch(itr->code()) {
+case Bytecodes::_invokevirtual:
+case Bytecodes::_invokespecial:
+case Bytecodes::_invokestatic:
+case Bytecodes::_invokeinterface:
+_itr_send = itr;
+_report_result_for_send = true;
+break;
+default:
+fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
+break;
+}
+}
+// abstract interpretation of current opcode
+switch(itr->code()) {
+case Bytecodes::_nop:                                           break;
+case Bytecodes::_goto:                                          break;
+case Bytecodes::_goto_w:                                        break;
+case Bytecodes::_iinc:                                          break;
+case Bytecodes::_return:            do_return_monitor_check();
+break;
+case Bytecodes::_aconst_null:
+case Bytecodes::_new:               ppush1(CellTypeState::make_line_ref(itr->bci()));
+break;
+case Bytecodes::_iconst_m1:
+case Bytecodes::_iconst_0:
+case Bytecodes::_iconst_1:
+case Bytecodes::_iconst_2:
+case Bytecodes::_iconst_3:
+case Bytecodes::_iconst_4:
+case Bytecodes::_iconst_5:
+case Bytecodes::_fconst_0:
+case Bytecodes::_fconst_1:
+case Bytecodes::_fconst_2:
+case Bytecodes::_bipush:
+case Bytecodes::_sipush:            ppush1(valCTS);             break;
+case Bytecodes::_lconst_0:
+case Bytecodes::_lconst_1:
+case Bytecodes::_dconst_0:
+case Bytecodes::_dconst_1:          ppush(vvCTS);               break;
+case Bytecodes::_ldc2_w:            ppush(vvCTS);               break;
+case Bytecodes::_ldc:               do_ldc(itr->get_index(), itr->bci());    break;
+case Bytecodes::_ldc_w:             do_ldc(itr->get_index_big(), itr->bci());break;
+case Bytecodes::_iload:
+case Bytecodes::_fload:             ppload(vCTS, itr->get_index()); break;
+case Bytecodes::_lload:
+case Bytecodes::_dload:             ppload(vvCTS,itr->get_index()); break;
+case Bytecodes::_aload:             ppload(rCTS, itr->get_index()); break;
+case Bytecodes::_iload_0:
+case Bytecodes::_fload_0:           ppload(vCTS, 0);            break;
+case Bytecodes::_iload_1:
+case Bytecodes::_fload_1:           ppload(vCTS, 1);            break;
+case Bytecodes::_iload_2:
+case Bytecodes::_fload_2:           ppload(vCTS, 2);            break;
+case Bytecodes::_iload_3:
+case Bytecodes::_fload_3:           ppload(vCTS, 3);            break;
+case Bytecodes::_lload_0:
+case Bytecodes::_dload_0:           ppload(vvCTS, 0);           break;
+case Bytecodes::_lload_1:
+case Bytecodes::_dload_1:           ppload(vvCTS, 1);           break;
+case Bytecodes::_lload_2:
+case Bytecodes::_dload_2:           ppload(vvCTS, 2);           break;
+case Bytecodes::_lload_3:
+case Bytecodes::_dload_3:           ppload(vvCTS, 3);           break;
+case Bytecodes::_aload_0:           ppload(rCTS, 0);            break;
+case Bytecodes::_aload_1:           ppload(rCTS, 1);            break;
+case Bytecodes::_aload_2:           ppload(rCTS, 2);            break;
+case Bytecodes::_aload_3:           ppload(rCTS, 3);            break;
+case Bytecodes::_iaload:
+case Bytecodes::_faload:
+case Bytecodes::_baload:
+case Bytecodes::_caload:
+case Bytecodes::_saload:            pp(vrCTS, vCTS); break;
+case Bytecodes::_laload:            pp(vrCTS, vvCTS);  break;
+case Bytecodes::_daload:            pp(vrCTS, vvCTS); break;
+case Bytecodes::_aaload:            pp_new_ref(vrCTS, itr->bci()); break;
+case Bytecodes::_istore:
+case Bytecodes::_fstore:            ppstore(vCTS, itr->get_index()); break;
+case Bytecodes::_lstore:
+case Bytecodes::_dstore:            ppstore(vvCTS, itr->get_index()); break;
+case Bytecodes::_astore:            do_astore(itr->get_index());     break;
+case Bytecodes::_istore_0:
+case Bytecodes::_fstore_0:          ppstore(vCTS, 0);           break;
+case Bytecodes::_istore_1:
+case Bytecodes::_fstore_1:          ppstore(vCTS, 1);           break;
+case Bytecodes::_istore_2:
+case Bytecodes::_fstore_2:          ppstore(vCTS, 2);           break;
+case Bytecodes::_istore_3:
+case Bytecodes::_fstore_3:          ppstore(vCTS, 3);           break;
+case Bytecodes::_lstore_0:
+case Bytecodes::_dstore_0:          ppstore(vvCTS, 0);          break;
+case Bytecodes::_lstore_1:
+case Bytecodes::_dstore_1:          ppstore(vvCTS, 1);          break;
+case Bytecodes::_lstore_2:
+case Bytecodes::_dstore_2:          ppstore(vvCTS, 2);          break;
+case Bytecodes::_lstore_3:
+case Bytecodes::_dstore_3:          ppstore(vvCTS, 3);          break;
+case Bytecodes::_astore_0:          do_astore(0);               break;
+case Bytecodes::_astore_1:          do_astore(1);               break;
+case Bytecodes::_astore_2:          do_astore(2);               break;
+case Bytecodes::_astore_3:          do_astore(3);               break;
+case Bytecodes::_iastore:
+case Bytecodes::_fastore:
+case Bytecodes::_bastore:
+case Bytecodes::_castore:
+case Bytecodes::_sastore:           ppop(vvrCTS);               break;
+case Bytecodes::_lastore:
+case Bytecodes::_dastore:           ppop(vvvrCTS);              break;
+case Bytecodes::_aastore:           ppop(rvrCTS);               break;
+case Bytecodes::_pop:               ppop_any(1);                break;
+case Bytecodes::_pop2:              ppop_any(2);                break;
+case Bytecodes::_dup:               ppdupswap(1, "11");         break;
+case Bytecodes::_dup_x1:            ppdupswap(2, "121");        break;
+case Bytecodes::_dup_x2:            ppdupswap(3, "1321");       break;
+case Bytecodes::_dup2:              ppdupswap(2, "2121");       break;
+case Bytecodes::_dup2_x1:           ppdupswap(3, "21321");      break;
+case Bytecodes::_dup2_x2:           ppdupswap(4, "214321");     break;
+case Bytecodes::_swap:              ppdupswap(2, "12");         break;
+case Bytecodes::_iadd:
+case Bytecodes::_fadd:
+case Bytecodes::_isub:
+case Bytecodes::_fsub:
+case Bytecodes::_imul:
+case Bytecodes::_fmul:
+case Bytecodes::_idiv:
+case Bytecodes::_fdiv:
+case Bytecodes::_irem:
+case Bytecodes::_frem:
+case Bytecodes::_ishl:
+case Bytecodes::_ishr:
+case Bytecodes::_iushr:
+case Bytecodes::_iand:
+case Bytecodes::_ior:
+case Bytecodes::_ixor:
+case Bytecodes::_l2f:
+case Bytecodes::_l2i:
+case Bytecodes::_d2f:
+case Bytecodes::_d2i:
+case Bytecodes::_fcmpl:
+case Bytecodes::_fcmpg:             pp(vvCTS, vCTS); break;
+case Bytecodes::_ladd:
+case Bytecodes::_dadd:
+case Bytecodes::_lsub:
+case Bytecodes::_dsub:
+case Bytecodes::_lmul:
+case Bytecodes::_dmul:
+case Bytecodes::_ldiv:
+case Bytecodes::_ddiv:
+case Bytecodes::_lrem:
+case Bytecodes::_drem:
+case Bytecodes::_land:
+case Bytecodes::_lor:
+case Bytecodes::_lxor:              pp(vvvvCTS, vvCTS); break;
+case Bytecodes::_ineg:
+case Bytecodes::_fneg:
+case Bytecodes::_i2f:
+case Bytecodes::_f2i:
+case Bytecodes::_i2c:
+case Bytecodes::_i2s:
+case Bytecodes::_i2b:               pp(vCTS, vCTS); break;
+case Bytecodes::_lneg:
+case Bytecodes::_dneg:
+case Bytecodes::_l2d:
+case Bytecodes::_d2l:               pp(vvCTS, vvCTS); break;
+case Bytecodes::_lshl:
+case Bytecodes::_lshr:
+case Bytecodes::_lushr:             pp(vvvCTS, vvCTS); break;
+case Bytecodes::_i2l:
+case Bytecodes::_i2d:
+case Bytecodes::_f2l:
+case Bytecodes::_f2d:               pp(vCTS, vvCTS); break;
+case Bytecodes::_lcmp:              pp(vvvvCTS, vCTS); break;
+case Bytecodes::_dcmpl:
+case Bytecodes::_dcmpg:             pp(vvvvCTS, vCTS); break;
+case Bytecodes::_ifeq:
+case Bytecodes::_ifne:
+case Bytecodes::_iflt:
+case Bytecodes::_ifge:
+case Bytecodes::_ifgt:
+case Bytecodes::_ifle:
+case Bytecodes::_tableswitch:       ppop1(valCTS);
+break;
+case Bytecodes::_ireturn:
+case Bytecodes::_freturn:           do_return_monitor_check();
+ppop1(valCTS);
+break;
+case Bytecodes::_if_icmpeq:
+case Bytecodes::_if_icmpne:
+case Bytecodes::_if_icmplt:
+case Bytecodes::_if_icmpge:
+case Bytecodes::_if_icmpgt:
+case Bytecodes::_if_icmple:         ppop(vvCTS);
+break;
+case Bytecodes::_lreturn:           do_return_monitor_check();
+ppop(vvCTS);
+break;
+case Bytecodes::_dreturn:           do_return_monitor_check();
+ppop(vvCTS);
+break;
+case Bytecodes::_if_acmpeq:
+case Bytecodes::_if_acmpne:         ppop(rrCTS);                 break;
+case Bytecodes::_jsr:               do_jsr(itr->dest());         break;
+case Bytecodes::_jsr_w:             do_jsr(itr->dest_w());       break;
+case Bytecodes::_getstatic:         do_field(true,  true,
+itr->get_index_big(),
+itr->bci()); break;
+case Bytecodes::_putstatic:         do_field(false, true,  itr->get_index_big(), itr->bci()); break;
+case Bytecodes::_getfield:          do_field(true,  false, itr->get_index_big(), itr->bci()); break;
+case Bytecodes::_putfield:          do_field(false, false, itr->get_index_big(), itr->bci()); break;
+case Bytecodes::_invokevirtual:
+case Bytecodes::_invokespecial:     do_method(false, false, itr->get_index_big(), itr->bci()); break;
+case Bytecodes::_invokestatic:      do_method(true,  false, itr->get_index_big(), itr->bci()); break;
+case Bytecodes::_invokeinterface:   do_method(false, true,  itr->get_index_big(), itr->bci()); break;
+case Bytecodes::_newarray:
+case Bytecodes::_anewarray:         pp_new_ref(vCTS, itr->bci()); break;
+case Bytecodes::_checkcast:         do_checkcast(); break;
+case Bytecodes::_arraylength:
+case Bytecodes::_instanceof:        pp(rCTS, vCTS); break;
+case Bytecodes::_monitorenter:      do_monitorenter(itr->bci()); break;
+case Bytecodes::_monitorexit:       do_monitorexit(itr->bci()); break;
+case Bytecodes::_athrow:            // handled by do_exception_edge() BUT ...
+// vlh(apple): do_exception_edge() does not get
+// called if method has no exception handlers
+if ((!_has_exceptions) && (_monitor_top > 0)) {
+_monitor_safe = false;
+}
+break;
+case Bytecodes::_areturn:           do_return_monitor_check();
+ppop1(refCTS);
+break;
+case Bytecodes::_ifnull:
+case Bytecodes::_ifnonnull:         ppop1(refCTS); break;
+case Bytecodes::_multianewarray:    do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
+case Bytecodes::_wide:              fatal("Iterator should skip this bytecode"); break;
+case Bytecodes::_ret:                                           break;
+// Java opcodes
+case Bytecodes::_lookupswitch:      ppop1(valCTS);             break;
+default:
+tty->print("unexpected opcode: %d\n", itr->code());
+ShouldNotReachHere();
+break;
+}
+}
+void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
+if (!expected.equal_kind(actual)) {
+verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
+}
+}
+void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
+while(!(*in).is_bottom()) {
+CellTypeState expected =*in++;
+CellTypeState actual   = pop();
+check_type(expected, actual);
+assert(loc_no >= 0, "sanity check");
+set_var(loc_no++, actual);
+}
+}
+void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
+while(!(*out).is_bottom()) {
+CellTypeState out1 = *out++;
+CellTypeState vcts = get_var(loc_no);
+assert(out1.can_be_reference() || out1.can_be_value(),
+"can only load refs. and values.");
+if (out1.is_reference()) {
+assert(loc_no>=0, "sanity check");
+if (!vcts.is_reference()) {
+// We were asked to push a reference, but the type of the
+// variable can be something else
+_conflict = true;
+if (vcts.can_be_uninit()) {
+// It is a ref-uninit conflict (at least). If there are other
+// problems, we'll get them in the next round
+add_to_ref_init_set(loc_no);
+vcts = out1;
+} else {
+// It wasn't a ref-uninit conflict. So must be a
+// ref-val or ref-pc conflict. Split the variable.
+record_refval_conflict(loc_no);
+vcts = out1;
+}
+push(out1); // recover...
+} else {
+push(vcts); // preserve reference.
+}
+// Otherwise it is a conflict, but one that verification would
+// have caught if illegal. In particular, it can't be a topCTS
+// resulting from mergeing two difference pcCTS's since the verifier
+// would have rejected any use of such a merge.
+} else {
+push(out1); // handle val/init conflict
+}
+loc_no++;
+}
+}
+void GenerateOopMap::ppdupswap(int poplen, const char *out) {
+CellTypeState actual[5];
+assert(poplen < 5, "this must be less than length of actual vector");
+// pop all arguments
+for(int i = 0; i < poplen; i++) actual[i] = pop();
+// put them back
+char push_ch = *out++;
+while (push_ch != '\0') {
+int idx = push_ch - '1';
+assert(idx >= 0 && idx < poplen, "wrong arguments");
+push(actual[idx]);
+push_ch = *out++;
+}
+}
+void GenerateOopMap::ppop1(CellTypeState out) {
+CellTypeState actual = pop();
+check_type(out, actual);
+}
+void GenerateOopMap::ppop(CellTypeState *out) {
+while (!(*out).is_bottom()) {
+ppop1(*out++);
+}
+}
+void GenerateOopMap::ppush1(CellTypeState in) {
+assert(in.is_reference() | in.is_value(), "sanity check");
+push(in);
+}
+void GenerateOopMap::ppush(CellTypeState *in) {
+while (!(*in).is_bottom()) {
+ppush1(*in++);
+}
+}
+void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
+ppop(in);
+ppush(out);
+}
+void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
+ppop(in);
+ppush1(CellTypeState::make_line_ref(bci));
+}
+void GenerateOopMap::ppop_any(int poplen) {
+if (_stack_top >= poplen) {
+_stack_top -= poplen;
+} else {
+verify_error("stack underflow");
+}
+}
+// Replace all occurences of the state 'match' with the state 'replace'
+// in our current state vector.
+void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
+CellTypeState replace) {
+int i;
+int len = _max_locals + _stack_top;
+bool change = false;
+for (i = len - 1; i >= 0; i--) {
+if (match.equal(_state[i])) {
+_state[i] = replace;
+}
+}
+if (_monitor_top > 0) {
+int base = _max_locals + _max_stack;
+len = base + _monitor_top;
+for (i = len - 1; i >= base; i--) {
+if (match.equal(_state[i])) {
+_state[i] = replace;
+}
+}
+}
+}
+void GenerateOopMap::do_checkcast() {
+CellTypeState actual = pop();
+check_type(refCTS, actual);
+push(actual);
+}
+void GenerateOopMap::do_monitorenter(int bci) {
+CellTypeState actual = pop();
+if (_monitor_top == bad_monitors) {
+return;
+}
+// Bail out when we get repeated locks on an identical monitor.  This case
+// isn't too hard to handle and can be made to work if supporting nested
+// redundant synchronized statements becomes a priority.
+//
+// See also "Note" in do_monitorexit(), below.
+if (actual.is_lock_reference()) {
+_monitor_top = bad_monitors;
+_monitor_safe = false;
+if (TraceMonitorMismatch) {
+report_monitor_mismatch("nested redundant lock -- bailout...");
+}
+return;
+}
+CellTypeState lock = CellTypeState::make_lock_ref(bci);
+check_type(refCTS, actual);
+if (!actual.is_info_top()) {
+replace_all_CTS_matches(actual, lock);
+monitor_push(lock);
+}
+}
+void GenerateOopMap::do_monitorexit(int bci) {
+CellTypeState actual = pop();
+if (_monitor_top == bad_monitors) {
+return;
+}
+check_type(refCTS, actual);
+CellTypeState expected = monitor_pop();
+if (!actual.is_lock_reference() || !expected.equal(actual)) {
+// The monitor we are exiting is not verifiably the one
+// on the top of our monitor stack.  This causes a monitor
+// mismatch.
+_monitor_top = bad_monitors;
+_monitor_safe = false;
+// We need to mark this basic block as changed so that
+// this monitorexit will be visited again.  We need to
+// do this to ensure that we have accounted for the
+// possibility that this bytecode will throw an
+// exception.
+BasicBlock* bb = get_basic_block_containing(bci);
+bb->set_changed(true);
+bb->_monitor_top = bad_monitors;
+if (TraceMonitorMismatch) {
+report_monitor_mismatch("improper monitor pair");
+}
+} else {
+// This code is a fix for the case where we have repeated
+// locking of the same object in straightline code.  We clear
+// out the lock when it is popped from the monitor stack
+// and replace it with an unobtrusive reference value that can
+// be locked again.
+//
+// Note: when generateOopMap is fixed to properly handle repeated,
+//       nested, redundant locks on the same object, then this
+//       fix will need to be removed at that time.
+replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
+}
+}
+void GenerateOopMap::do_return_monitor_check() {
+if (_monitor_top > 0) {
+// The monitor stack must be empty when we leave the method
+// for the monitors to be properly matched.
+_monitor_safe = false;
+// Since there are no successors to the *return bytecode, it
+// isn't necessary to set _monitor_top to bad_monitors.
+if (TraceMonitorMismatch) {
+report_monitor_mismatch("non-empty monitor stack at return");
+}
+}
+}
+void GenerateOopMap::do_jsr(int targ_bci) {
+push(CellTypeState::make_addr(targ_bci));
+}
+void GenerateOopMap::do_ldc(int idx, int bci) {
+constantPoolOop cp = method()->constants();
+constantTag tag    = cp->tag_at(idx);
+CellTypeState cts = (tag.is_string() || tag.is_unresolved_string() ||
+tag.is_klass()  || tag.is_unresolved_klass())
+? CellTypeState::make_line_ref(bci) : valCTS;
+ppush1(cts);
+}
+void GenerateOopMap::do_multianewarray(int dims, int bci) {
+assert(dims >= 1, "sanity check");
+for(int i = dims -1; i >=0; i--) {
+ppop1(valCTS);
+}
+ppush1(CellTypeState::make_line_ref(bci));
+}
+void GenerateOopMap::do_astore(int idx) {
+CellTypeState r_or_p = pop();
+if (!r_or_p.is_address() && !r_or_p.is_reference()) {
+// We actually expected ref or pc, but we only report that we expected a ref. It does not
+// really matter (at least for now)
+verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
+return;
+}
+set_var(idx, r_or_p);
+}
+// Copies bottom/zero terminated CTS string from "src" into "dst".
+//   Does NOT terminate with a bottom. Returns the number of cells copied.
+int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
+int idx = 0;
+while (!src[idx].is_bottom()) {
+dst[idx] = src[idx];
+idx++;
+}
+return idx;
+}
+void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
+// Dig up signature for field in constant pool
+constantPoolOop cp     = method()->constants();
+int nameAndTypeIdx     = cp->name_and_type_ref_index_at(idx);
+int signatureIdx       = cp->signature_ref_index_at(nameAndTypeIdx);
+symbolOop signature    = cp->symbol_at(signatureIdx);
+// Parse signature (espcially simple for fields)
+assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
+// The signature is UFT8 encoded, but the first char is always ASCII for signatures.
+char sigch = (char)*(signature->base());
+CellTypeState temp[4];
+CellTypeState *eff  = sigchar_to_effect(sigch, bci, temp);
+CellTypeState in[4];
+CellTypeState *out;
+int i =  0;
+if (is_get) {
+out = eff;
+} else {
+out = epsilonCTS;
+i   = copy_cts(in, eff);
+}
+if (!is_static) in[i++] = CellTypeState::ref;
+in[i] = CellTypeState::bottom;
+assert(i<=3, "sanity check");
+pp(in, out);
+}
+void GenerateOopMap::do_method(int is_static, int is_interface, int idx, int bci) {
+// Dig up signature for field in constant pool
+constantPoolOop cp    = _method->constants();
+int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
+int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
+symbolOop signature   = cp->symbol_at(signatureIdx);
+// Parse method signature
+CellTypeState out[4];
+CellTypeState in[MAXARGSIZE+1];   // Includes result
+ComputeCallStack cse(signature);
+// Compute return type
+int res_length=  cse.compute_for_returntype(out);
+// Temporary hack.
+if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
+out[0] = CellTypeState::make_line_ref(bci);
+}
+assert(res_length<=4, "max value should be vv");
+// Compute arguments
+int arg_length = cse.compute_for_parameters(is_static != 0, in);
+assert(arg_length<=MAXARGSIZE, "too many locals");
+// Pop arguments
+for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
+// Report results
+if (_report_result_for_send == true) {
+fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
+_report_result_for_send = false;
+}
+// Push return address
+ppush(out);
+}
+// This is used to parse the signature for fields, since they are very simple...
+CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
+// Object and array
+if (sigch=='L' || sigch=='[') {
+out[0] = CellTypeState::make_line_ref(bci);
+out[1] = CellTypeState::bottom;
+return out;
+}
+if (sigch == 'J' || sigch == 'D' ) return vvCTS;  // Long and Double
+if (sigch == 'V' ) return epsilonCTS;             // Void
+return vCTS;                                      // Otherwise
+}
+long GenerateOopMap::_total_byte_count = 0;
+elapsedTimer GenerateOopMap::_total_oopmap_time;
+// This function assumes "bcs" is at a "ret" instruction and that the vars
+// state is valid for that instruction. Furthermore, the ret instruction
+// must be the last instruction in "bb" (we store information about the
+// "ret" in "bb").
+void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
+CellTypeState ra = vars()[varNo];
+if (!ra.is_good_address()) {
+verify_error("ret returns from two jsr subroutines?");
+return;
+}
+int target = ra.get_info();
+RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
+int bci = bcs->bci();
+for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
+int target_bci = rtEnt->jsrs(i);
+// Make sure a jrtRet does not set the changed bit for dead basicblock.
+BasicBlock* jsr_bb    = get_basic_block_containing(target_bci - 1);
+debug_only(BasicBlock* target_bb = &jsr_bb[1];)
+assert(target_bb  == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
+bool alive = jsr_bb->is_alive();
+if (TraceNewOopMapGeneration) {
+tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
+}
+if (alive) jmpFct(this, target_bci, data);
+}
+}
+//
+// Debug method
+//
+char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
+#ifdef ASSERT
+int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
+assert(len < checklen, "state_vec_buf overflow");
+#endif
+for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
+_state_vec_buf[len] = 0;
+return _state_vec_buf;
+}
+void GenerateOopMap::print_time() {
+tty->print_cr ("Accumulated oopmap times:");
+tty->print_cr ("---------------------------");
+tty->print_cr ("  Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
+tty->print_cr ("  (%3.0f bytecodes per sec) ",
+GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
+}
+//
+//  ============ Main Entry Point ===========
+//
+GenerateOopMap::GenerateOopMap(methodHandle method) {
+// We have to initialize all variables here, that can be queried direcly
+_method = method;
+_max_locals=0;
+_init_vars = NULL;
+#ifndef PRODUCT
+// If we are doing a detailed trace, include the regular trace information.
+if (TraceNewOopMapGenerationDetailed) {
+TraceNewOopMapGeneration = true;
+}
+#endif
+}
+void GenerateOopMap::compute_map(TRAPS) {
+#ifndef PRODUCT
+if (TimeOopMap2) {
+method()->print_short_name(tty);
+tty->print("  ");
+}
+if (TimeOopMap) {
+_total_byte_count += method()->code_size();
+}
+#endif
+TraceTime t_single("oopmap time", TimeOopMap2);
+TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
+// Initialize values
+_got_error      = false;
+_conflict       = false;
+_max_locals     = method()->max_locals();
+_max_stack      = method()->max_stack();
+_has_exceptions = (method()->exception_table()->length() > 0);
+_nof_refval_conflicts = 0;
+_init_vars      = new GrowableArray<intptr_t>(5);  // There are seldom more than 5 init_vars
+_report_result  = false;
+_report_result_for_send = false;
+_new_var_map    = NULL;
+_ret_adr_tos    = new GrowableArray<intptr_t>(5);  // 5 seems like a good number;
+_did_rewriting  = false;
+_did_relocation = false;
+if (TraceNewOopMapGeneration) {
+tty->print("Method name: %s\n", method()->name()->as_C_string());
+if (Verbose) {
+_method->print_codes();
+tty->print_cr("Exception table:");
+typeArrayOop excps = method()->exception_table();
+for(int i = 0; i < excps->length(); i += 4) {
+tty->print_cr("[%d - %d] -> %d", excps->int_at(i + 0), excps->int_at(i + 1), excps->int_at(i + 2));
+}
+}
+}
+// if no code - do nothing
+// compiler needs info
+if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
+fill_stackmap_prolog(0);
+fill_stackmap_epilog();
+return;
+}
+// Step 1: Compute all jump targets and their return value
+if (!_got_error)
+_rt.compute_ret_table(_method);
+// Step 2: Find all basic blocks and count GC points
+if (!_got_error)
+mark_bbheaders_and_count_gc_points();
+// Step 3: Calculate stack maps
+if (!_got_error)
+do_interpretation();
+// Step 4:Return results
+if (!_got_error && report_results())
+report_result();
+if (_got_error) {
+THROW_HANDLE(_exception);
+}
+}
+// Error handling methods
+// These methods create an exception for the current thread which is thrown
+// at the bottom of the call stack, when it returns to compute_map().  The
+// _got_error flag controls execution.  NOT TODO: The VM exception propagation
+// mechanism using TRAPS/CHECKs could be used here instead but it would need
+// to be added as a parameter to every function and checked for every call.
+// The tons of extra code it would generate didn't seem worth the change.
+//
+void GenerateOopMap::error_work(const char *format, va_list ap) {
+_got_error = true;
+char msg_buffer[512];
+vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
+// Append method name
+char msg_buffer2[512];
+jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
+_exception = Exceptions::new_exception(Thread::current(),
+vmSymbols::java_lang_LinkageError(), msg_buffer2);
+}
+void GenerateOopMap::report_error(const char *format, ...) {
+va_list ap;
+va_start(ap, format);
+error_work(format, ap);
+}
+void GenerateOopMap::verify_error(const char *format, ...) {
+// We do not distinguish between different types of errors for verification
+// errors.  Let the verifier give a better message.
+const char *msg = "Illegal class file encountered. Try running with -Xverify:all";
+error_work(msg, NULL);
+}
+//
+// Report result opcodes
+//
+void GenerateOopMap::report_result() {
+if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
+// We now want to report the result of the parse
+_report_result = true;
+// Prolog code
+fill_stackmap_prolog(_gc_points);
+// Mark everything changed, then do one interpretation pass.
+for (int i = 0; i<_bb_count; i++) {
+if (_basic_blocks[i].is_reachable()) {
+_basic_blocks[i].set_changed(true);
+interp_bb(&_basic_blocks[i]);
+}
+}
+// Note: Since we are skipping dead-code when we are reporting results, then
+// the no. of encountered gc-points might be fewer than the previously number
+// we have counted. (dead-code is a pain - it should be removed before we get here)
+fill_stackmap_epilog();
+// Report initvars
+fill_init_vars(_init_vars);
+_report_result = false;
+}
+void GenerateOopMap::result_for_basicblock(int bci) {
+if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
+// We now want to report the result of the parse
+_report_result = true;
+// Find basicblock and report results
+BasicBlock* bb = get_basic_block_containing(bci);
+assert(bb->is_reachable(), "getting result from unreachable basicblock");
+bb->set_changed(true);
+interp_bb(bb);
+}
+//
+// Conflict handling code
+//
+void GenerateOopMap::record_refval_conflict(int varNo) {
+assert(varNo>=0 && varNo< _max_locals, "index out of range");
+if (TraceOopMapRewrites) {
+tty->print("### Conflict detected (local no: %d)\n", varNo);
+}
+if (!_new_var_map) {
+_new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
+for (int k = 0; k < _max_locals; k++)  _new_var_map[k] = k;
+}
+if ( _new_var_map[varNo] == varNo) {
+// Check if max. number of locals has been reached
+if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
+report_error("Rewriting exceeded local variable limit");
+return;
+}
+_new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
+_nof_refval_conflicts++;
+}
+}
+void GenerateOopMap::rewrite_refval_conflicts()
+{
+// We can get here two ways: Either a rewrite conflict was detected, or
+// an uninitialize reference was detected. In the second case, we do not
+// do any rewriting, we just want to recompute the reference set with the
+// new information
+int nof_conflicts = 0;              // Used for debugging only
+if ( _nof_refval_conflicts == 0 )
+return;
+// Check if rewrites are allowed in this parse.
+if (!allow_rewrites() && !IgnoreRewrites) {
+fatal("Rewriting method not allowed at this stage");
+}
+// This following flag is to tempoary supress rewrites. The locals that might conflict will
+// all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
+// tested it is nice to have.
+if (IgnoreRewrites) {
+if (Verbose) {
+tty->print("rewrites suppressed for local no. ");
+for (int l = 0; l < _max_locals; l++) {
+if (_new_var_map[l] != l) {
+tty->print("%d ", l);
+vars()[l] = CellTypeState::value;
+}
+}
+tty->cr();
+}
+// That was that...
+_new_var_map = NULL;
+_nof_refval_conflicts = 0;
+_conflict = false;
+return;
+}
+// Tracing flag
+_did_rewriting = true;
+if (TraceOopMapRewrites) {
+tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
+method()->print();
+method()->print_codes();
+}
+assert(_new_var_map!=NULL, "nothing to rewrite");
+assert(_conflict==true, "We should not be here");
+compute_ret_adr_at_TOS();
+if (!_got_error) {
+for (int k = 0; k < _max_locals && !_got_error; k++) {
+if (_new_var_map[k] != k) {
+if (TraceOopMapRewrites) {
+tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
+}
+rewrite_refval_conflict(k, _new_var_map[k]);
+if (_got_error) return;
+nof_conflicts++;
+}
+}
+}
+assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
+// Adjust the number of locals
+method()->set_max_locals(_max_locals+_nof_refval_conflicts);
+_max_locals += _nof_refval_conflicts;
+// That was that...
+_new_var_map = NULL;
+_nof_refval_conflicts = 0;
+}
+void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
+bool startOver;
+do {
+// Make sure that the BytecodeStream is constructed in the loop, since
+// during rewriting a new method oop is going to be used, and the next time
+// around we want to use that.
+BytecodeStream bcs(_method);
+startOver = false;
+while( bcs.next() >=0 && !startOver && !_got_error) {
+startOver = rewrite_refval_conflict_inst(&bcs, from, to);
+}
+} while (startOver && !_got_error);
+}
+/* If the current instruction is one that uses local variable "from"
+in a ref way, change it to use "to". There's a subtle reason why we
+renumber the ref uses and not the non-ref uses: non-ref uses may be
+2 slots wide (double, long) which would necessitate keeping track of
+whether we should add one or two variables to the method. If the change
+affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
+Another reason for moving ref's value is for solving (addr, ref) conflicts, which
+both uses aload/astore methods.
+*/
+bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
+Bytecodes::Code bc = itr->code();
+int index;
+int bci = itr->bci();
+if (is_aload(itr, &index) && index == from) {
+if (TraceOopMapRewrites) {
+tty->print_cr("Rewriting aload at bci: %d", bci);
+}
+return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
+}
+if (is_astore(itr, &index) && index == from) {
+if (!stack_top_holds_ret_addr(bci)) {
+if (TraceOopMapRewrites) {
+tty->print_cr("Rewriting astore at bci: %d", bci);
+}
+return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
+} else {
+if (TraceOopMapRewrites) {
+tty->print_cr("Supress rewriting of astore at bci: %d", bci);
+}
+}
+}
+return false;
+}
+// The argument to this method is:
+// bc : Current bytecode
+// bcN : either _aload or _astore
+// bc0 : either _aload_0 or _astore_0
+bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
+assert(bcN == Bytecodes::_astore   || bcN == Bytecodes::_aload,   "wrong argument (bcN)");
+assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
+int ilen = Bytecodes::length_at(bcs->bcp());
+int newIlen;
+if (ilen == 4) {
+// Original instruction was wide; keep it wide for simplicity
+newIlen = 4;
+} else if (varNo < 4)
+newIlen = 1;
+else if (varNo >= 256)
+newIlen = 4;
+else
+newIlen = 2;
+// If we need to relocate in order to patch the byte, we
+// do the patching in a temp. buffer, that is passed to the reloc.
+// The patching of the bytecode stream is then done by the Relocator.
+// This is neccesary, since relocating the instruction at a certain bci, might
+// also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
+// Hence, we do not know which bci to patch after relocation.
+assert(newIlen <= 4, "sanity check");
+u_char inst_buffer[4]; // Max. instruction size is 4.
+address bcp;
+if (newIlen != ilen) {
+// Relocation needed do patching in temp. buffer
+bcp = (address)inst_buffer;
+} else {
+bcp = _method->bcp_from(bcs->bci());
+}
+// Patch either directly in methodOop or in temp. buffer
+if (newIlen == 1) {
+assert(varNo < 4, "varNo too large");
+*bcp = bc0 + varNo;
+} else if (newIlen == 2) {
+assert(varNo < 256, "2-byte index needed!");
+*(bcp + 0) = bcN;
+*(bcp + 1) = varNo;
+} else {
+assert(newIlen == 4, "Wrong instruction length");
+*(bcp + 0) = Bytecodes::_wide;
+*(bcp + 1) = bcN;
+Bytes::put_Java_u2(bcp+2, varNo);
+}
+if (newIlen != ilen) {
+expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
+}
+return (newIlen != ilen);
+}
+class RelocCallback : public RelocatorListener {
+private:
+GenerateOopMap* _gom;
+public:
+RelocCallback(GenerateOopMap* gom) { _gom = gom; };
+// Callback method
+virtual void relocated(int bci, int delta, int new_code_length) {
+_gom->update_basic_blocks  (bci, delta, new_code_length);
+_gom->update_ret_adr_at_TOS(bci, delta);
+_gom->_rt.update_ret_table (bci, delta);
+}
+};
+// Returns true if expanding was succesful. Otherwise, reports an error and
+// returns false.
+void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
+Thread *THREAD = Thread::current();  // Could really have TRAPS argument.
+RelocCallback rcb(this);
+Relocator rc(_method, &rcb);
+methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
+if (m.is_null() || HAS_PENDING_EXCEPTION) {
+report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
+return;
+}
+// Relocator returns a new method oop.
+_did_relocation = true;
+_method = m;
+}
+bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
+Bytecodes::Code bc = itr->code();
+switch(bc) {
+case Bytecodes::_astore_0:
+case Bytecodes::_astore_1:
+case Bytecodes::_astore_2:
+case Bytecodes::_astore_3:
+*index = bc - Bytecodes::_astore_0;
+return true;
+case Bytecodes::_astore:
+*index = itr->get_index();
+return true;
+}
+return false;
+}
+bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
+Bytecodes::Code bc = itr->code();
+switch(bc) {
+case Bytecodes::_aload_0:
+case Bytecodes::_aload_1:
+case Bytecodes::_aload_2:
+case Bytecodes::_aload_3:
+*index = bc - Bytecodes::_aload_0;
+return true;
+case Bytecodes::_aload:
+*index = itr->get_index();
+return true;
+}
+return false;
+}
+// Return true iff the top of the operand stack holds a return address at
+// the current instruction
+bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
+for(int i = 0; i < _ret_adr_tos->length(); i++) {
+if (_ret_adr_tos->at(i) == bci)
+return true;
+}
+return false;
+}
+void GenerateOopMap::compute_ret_adr_at_TOS() {
+assert(_ret_adr_tos != NULL, "must be initialized");
+_ret_adr_tos->clear();
+for (int i = 0; i < bb_count(); i++) {
+BasicBlock* bb = &_basic_blocks[i];
+// Make sure to only check basicblocks that are reachable
+if (bb->is_reachable()) {
+// For each Basic block we check all instructions
+BytecodeStream bcs(_method);
+bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
+restore_state(bb);
+while (bcs.next()>=0 && !_got_error) {
+// TDT: should this be is_good_address() ?
+if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
+_ret_adr_tos->append(bcs.bci());
+if (TraceNewOopMapGeneration) {
+tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
+}
+}
+interp1(&bcs);
+}
+}
+}
+}
+void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
+for(int i = 0; i < _ret_adr_tos->length(); i++) {
+int v = _ret_adr_tos->at(i);
+if (v > bci)  _ret_adr_tos->at_put(i, v + delta);
+}
+}
+// ===================================================================
+#ifndef PRODUCT
+int ResolveOopMapConflicts::_nof_invocations  = 0;
+int ResolveOopMapConflicts::_nof_rewrites     = 0;
+int ResolveOopMapConflicts::_nof_relocations  = 0;
+#endif
+methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
+compute_map(CHECK_(methodHandle()));
+#ifndef PRODUCT
+// Tracking and statistics
+if (PrintRewrites) {
+_nof_invocations++;
+if (did_rewriting()) {
+_nof_rewrites++;
+if (did_relocation()) _nof_relocations++;
+tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
+method()->print_value(); tty->cr();
+tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
+_nof_invocations,
+_nof_rewrites,    (_nof_rewrites    * 100) / _nof_invocations,
+_nof_relocations, (_nof_relocations * 100) / _nof_invocations);
+}
+}
+#endif
+return methodHandle(THREAD, method());
+}

Mercurial > hg > truffle

comparison src/share/vm/oops/generateOopMap.cpp @ 0:a61af66fc99e jdk7-b24