1 /*
   2  * Copyright (c) 1998, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "code/codeBlob.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "code/nmethod.hpp"
  29 #include "code/scopeDesc.hpp"
  30 #include "compiler/oopMap.hpp"
  31 #include "gc/shared/collectedHeap.hpp"
  32 #include "memory/allocation.inline.hpp"
  33 #include "memory/iterator.hpp"
  34 #include "memory/resourceArea.hpp"
  35 #include "oops/valueKlass.hpp"
  36 #include "runtime/frame.inline.hpp"
  37 #include "runtime/handles.inline.hpp"
  38 #include "runtime/signature.hpp"
  39 #include "utilities/align.hpp"
  40 #ifdef COMPILER1
  41 #include "c1/c1_Defs.hpp"
  42 #endif
  43 #ifdef COMPILER2
  44 #include "opto/optoreg.hpp"
  45 #endif
  46 
  47 // OopMapStream
  48 
  49 OopMapStream::OopMapStream(OopMap* oop_map, int oop_types_mask) {
  50   _stream = new CompressedReadStream(oop_map->write_stream()->buffer());
  51   _mask = oop_types_mask;
  52   _size = oop_map->omv_count();
  53   _position = 0;
  54   _valid_omv = false;
  55 }
  56 
  57 OopMapStream::OopMapStream(const ImmutableOopMap* oop_map, int oop_types_mask) {
  58   _stream = new CompressedReadStream(oop_map->data_addr());
  59   _mask = oop_types_mask;
  60   _size = oop_map->count();
  61   _position = 0;
  62   _valid_omv = false;
  63 }
  64 
  65 void OopMapStream::find_next() {
  66   while(_position++ < _size) {
  67     _omv.read_from(_stream);
  68     if(((int)_omv.type() & _mask) > 0) {
  69       _valid_omv = true;
  70       return;
  71     }
  72   }
  73   _valid_omv = false;
  74 }
  75 
  76 
  77 // OopMap
  78 
  79 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
  80 // slots to hold 4-byte values like ints and floats in the LP64 build.
  81 OopMap::OopMap(int frame_size, int arg_count) {
  82   // OopMaps are usually quite so small, so pick a small initial size
  83   set_write_stream(new CompressedWriteStream(32));
  84   set_omv_count(0);
  85 
  86 #ifdef ASSERT
  87   _locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count;
  88   _locs_used   = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
  89   for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
  90 #endif
  91 }
  92 
  93 
  94 OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) {
  95   // This constructor does a deep copy
  96   // of the source OopMap.
  97   set_write_stream(new CompressedWriteStream(source->omv_count() * 2));
  98   set_omv_count(0);
  99   set_offset(source->offset());
 100 
 101 #ifdef ASSERT
 102   _locs_length = source->_locs_length;
 103   _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
 104   for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
 105 #endif
 106 
 107   // We need to copy the entries too.
 108   for (OopMapStream oms(source); !oms.is_done(); oms.next()) {
 109     OopMapValue omv = oms.current();
 110     omv.write_on(write_stream());
 111     increment_count();
 112   }
 113 }
 114 
 115 
 116 OopMap* OopMap::deep_copy() {
 117   return new OopMap(_deep_copy_token, this);
 118 }
 119 
 120 void OopMap::copy_data_to(address addr) const {
 121   memcpy(addr, write_stream()->buffer(), write_stream()->position());
 122 }
 123 
 124 int OopMap::heap_size() const {
 125   int size = sizeof(OopMap);
 126   int align = sizeof(void *) - 1;
 127   size += write_stream()->position();
 128   // Align to a reasonable ending point
 129   size = ((size+align) & ~align);
 130   return size;
 131 }
 132 
 133 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
 134 // slots to hold 4-byte values like ints and floats in the LP64 build.
 135 void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {
 136 
 137   assert(reg->value() < _locs_length, "too big reg value for stack size");
 138   assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );
 139   debug_only( _locs_used[reg->value()] = x; )
 140 
 141   OopMapValue o(reg, x);
 142 
 143   if(x == OopMapValue::callee_saved_value) {
 144     // This can never be a stack location, so we don't need to transform it.
 145     assert(optional->is_reg(), "Trying to callee save a stack location");
 146     o.set_content_reg(optional);
 147   } else if(x == OopMapValue::derived_oop_value) {
 148     o.set_content_reg(optional);
 149   }
 150 
 151   o.write_on(write_stream());
 152   increment_count();
 153 }
 154 
 155 
 156 void OopMap::set_oop(VMReg reg) {
 157   set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad());
 158 }
 159 
 160 
 161 void OopMap::set_value(VMReg reg) {
 162   // At this time, we don't need value entries in our OopMap.
 163 }
 164 
 165 
 166 void OopMap::set_narrowoop(VMReg reg) {
 167   set_xxx(reg, OopMapValue::narrowoop_value, VMRegImpl::Bad());
 168 }
 169 
 170 
 171 void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) {
 172   set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register);
 173 }
 174 
 175 
 176 void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) {
 177   if( reg == derived_from_local_register ) {
 178     // Actually an oop, derived shares storage with base,
 179     set_oop(reg);
 180   } else {
 181     set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register);
 182   }
 183 }
 184 
 185 // OopMapSet
 186 
 187 OopMapSet::OopMapSet() {
 188   set_om_size(MinOopMapAllocation);
 189   set_om_count(0);
 190   OopMap** temp = NEW_RESOURCE_ARRAY(OopMap*, om_size());
 191   set_om_data(temp);
 192 }
 193 
 194 
 195 void OopMapSet::grow_om_data() {
 196   int new_size = om_size() * 2;
 197   OopMap** new_data = NEW_RESOURCE_ARRAY(OopMap*, new_size);
 198   memcpy(new_data,om_data(),om_size() * sizeof(OopMap*));
 199   set_om_size(new_size);
 200   set_om_data(new_data);
 201 }
 202 
 203 void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) {
 204   assert(om_size() != -1,"Cannot grow a fixed OopMapSet");
 205 
 206   if(om_count() >= om_size()) {
 207     grow_om_data();
 208   }
 209   map->set_offset(pc_offset);
 210 
 211 #ifdef ASSERT
 212   if(om_count() > 0) {
 213     OopMap* last = at(om_count()-1);
 214     if (last->offset() == map->offset() ) {
 215       fatal("OopMap inserted twice");
 216     }
 217     if(last->offset() > map->offset()) {
 218       tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d",
 219                       om_count(),last->offset(),om_count()+1,map->offset());
 220     }
 221   }
 222 #endif // ASSERT
 223 
 224   set(om_count(),map);
 225   increment_count();
 226 }
 227 
 228 
 229 int OopMapSet::heap_size() const {
 230   // The space we use
 231   int size = sizeof(OopMap);
 232   int align = sizeof(void *) - 1;
 233   size = ((size+align) & ~align);
 234   size += om_count() * sizeof(OopMap*);
 235 
 236   // Now add in the space needed for the indivdiual OopMaps
 237   for(int i=0; i < om_count(); i++) {
 238     size += at(i)->heap_size();
 239   }
 240   // We don't need to align this, it will be naturally pointer aligned
 241   return size;
 242 }
 243 
 244 
 245 OopMap* OopMapSet::singular_oop_map() {
 246   guarantee(om_count() == 1, "Make sure we only have a single gc point");
 247   return at(0);
 248 }
 249 
 250 
 251 OopMap* OopMapSet::find_map_at_offset(int pc_offset) const {
 252   int i, len = om_count();
 253   assert( len > 0, "must have pointer maps" );
 254 
 255   // Scan through oopmaps. Stop when current offset is either equal or greater
 256   // than the one we are looking for.
 257   for( i = 0; i < len; i++) {
 258     if( at(i)->offset() >= pc_offset )
 259       break;
 260   }
 261 
 262   assert( i < len, "oopmap not found" );
 263 
 264   OopMap* m = at(i);
 265   assert( m->offset() == pc_offset, "oopmap not found" );
 266   return m;
 267 }
 268 
 269 static void add_derived_oop(oop* base, oop* derived) {
 270 #if !defined(TIERED) && !INCLUDE_JVMCI
 271   COMPILER1_PRESENT(ShouldNotReachHere();)
 272 #endif // !defined(TIERED) && !INCLUDE_JVMCI
 273 #if COMPILER2_OR_JVMCI
 274   DerivedPointerTable::add(derived, base);
 275 #endif // COMPILER2_OR_JVMCI
 276 }
 277 
 278 
 279 #ifndef PRODUCT
 280 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) {
 281   // Print oopmap and regmap
 282   tty->print_cr("------ ");
 283   CodeBlob* cb = fr->cb();
 284   const ImmutableOopMapSet* maps = cb->oop_maps();
 285   const ImmutableOopMap* map = cb->oop_map_for_return_address(fr->pc());
 286   map->print();
 287   if( cb->is_nmethod() ) {
 288     nmethod* nm = (nmethod*)cb;
 289     // native wrappers have no scope data, it is implied
 290     if (nm->is_native_method()) {
 291       tty->print("bci: 0 (native)");
 292     } else {
 293       ScopeDesc* scope  = nm->scope_desc_at(fr->pc());
 294       tty->print("bci: %d ",scope->bci());
 295     }
 296   }
 297   tty->cr();
 298   fr->print_on(tty);
 299   tty->print("     ");
 300   cb->print_value_on(tty);  tty->cr();
 301   reg_map->print();
 302   tty->print_cr("------ ");
 303 
 304 }
 305 #endif // PRODUCT
 306 
 307 void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) {
 308   // add derived oops to a table
 309   all_do(fr, reg_map, f, add_derived_oop, &do_nothing_cl);
 310 }
 311 
 312 
 313 void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
 314                        OopClosure* oop_fn, void derived_oop_fn(oop*, oop*),
 315                        OopClosure* value_fn) {
 316   CodeBlob* cb = fr->cb();
 317   assert(cb != NULL, "no codeblob");
 318 
 319   NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);)
 320 
 321   const ImmutableOopMapSet* maps = cb->oop_maps();
 322   const ImmutableOopMap* map = cb->oop_map_for_return_address(fr->pc());
 323   assert(map != NULL, "no ptr map found");
 324 
 325   // handle derived pointers first (otherwise base pointer may be
 326   // changed before derived pointer offset has been collected)
 327   OopMapValue omv;
 328   {
 329     OopMapStream oms(map,OopMapValue::derived_oop_value);
 330     if (!oms.is_done()) {
 331 #ifndef TIERED
 332       COMPILER1_PRESENT(ShouldNotReachHere();)
 333 #if INCLUDE_JVMCI
 334       if (UseJVMCICompiler) {
 335         ShouldNotReachHere();
 336       }
 337 #endif
 338 #endif // !TIERED
 339       // Protect the operation on the derived pointers.  This
 340       // protects the addition of derived pointers to the shared
 341       // derived pointer table in DerivedPointerTable::add().
 342       MutexLockerEx x(DerivedPointerTableGC_lock, Mutex::_no_safepoint_check_flag);
 343       do {
 344         omv = oms.current();
 345         oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
 346         guarantee(loc != NULL, "missing saved register");
 347         oop *derived_loc = loc;
 348         oop *base_loc    = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
 349         // Ignore NULL oops and decoded NULL narrow oops which
 350         // equal to Universe::narrow_oop_base when a narrow oop
 351         // implicit null check is used in compiled code.
 352         // The narrow_oop_base could be NULL or be the address
 353         // of the page below heap depending on compressed oops mode.
 354         if (base_loc != NULL && *base_loc != (oop)NULL && !Universe::is_narrow_oop_base(*base_loc)) {
 355           derived_oop_fn(base_loc, derived_loc);
 356         }
 357         oms.next();
 358       }  while (!oms.is_done());
 359     }
 360   }
 361 
 362   // We want coop and oop oop_types
 363   int mask = OopMapValue::oop_value | OopMapValue::narrowoop_value;
 364   BufferedValuesDealiaser* dealiaser = NULL;
 365   {
 366     for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) {
 367       omv = oms.current();
 368       oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
 369       // It should be an error if no location can be found for a
 370       // register mentioned as contained an oop of some kind.  Maybe
 371       // this was allowed previously because value_value items might
 372       // be missing?
 373       guarantee(loc != NULL, "missing saved register");
 374       if ( omv.type() == OopMapValue::oop_value ) {
 375         oop val = *loc;
 376         if (val == (oop)NULL || Universe::is_narrow_oop_base(val)) {
 377           // Ignore NULL oops and decoded NULL narrow oops which
 378           // equal to Universe::narrow_oop_base when a narrow oop
 379           // implicit null check is used in compiled code.
 380           // The narrow_oop_base could be NULL or be the address
 381           // of the page below heap depending on compressed oops mode.
 382           continue;
 383         }
 384 #ifdef ASSERT
 385         // We can not verify the oop here if we are using ZGC, the oop
 386         // will be bad in case we had a safepoint between a load and a
 387         // load barrier.
 388         if (!UseZGC &&
 389             ((((uintptr_t)loc & (sizeof(*loc)-1)) != 0) ||
 390              (!Universe::heap()->is_in_or_null(*loc) && !VTBuffer::is_in_vt_buffer(*loc)))) {
 391           tty->print_cr("# Found non oop pointer.  Dumping state at failure");
 392           // try to dump out some helpful debugging information
 393           trace_codeblob_maps(fr, reg_map);
 394           omv.print();
 395           tty->print_cr("register r");
 396           omv.reg()->print();
 397           tty->print_cr("loc = %p *loc = %p\n", loc, (address)*loc);
 398           // do the real assert.
 399           assert(Universe::heap()->is_in_or_null(*loc) || VTBuffer::is_in_vt_buffer(*loc),
 400                  "found non oop pointer");
 401         }
 402 #endif // ASSERT
 403         if (!VTBuffer::is_in_vt_buffer(*loc)) {
 404           oop_fn->do_oop(loc);
 405         } else {
 406           assert((*loc)->is_value(), "Sanity check");
 407           if (dealiaser == NULL) {
 408             dealiaser = Thread::current()->buffered_values_dealiaser();
 409           }
 410           dealiaser->oops_do(oop_fn, *loc);
 411         }
 412       } else if ( omv.type() == OopMapValue::narrowoop_value ) {
 413         narrowOop *nl = (narrowOop*)loc;
 414 #ifndef VM_LITTLE_ENDIAN
 415         VMReg vmReg = omv.reg();
 416         // Don't do this on SPARC float registers as they can be individually addressed
 417         if (!vmReg->is_stack() SPARC_ONLY(&& !vmReg->is_FloatRegister())) {
 418           // compressed oops in registers only take up 4 bytes of an
 419           // 8 byte register but they are in the wrong part of the
 420           // word so adjust loc to point at the right place.
 421           nl = (narrowOop*)((address)nl + 4);
 422         }
 423 #endif
 424         oop_fn->do_oop(nl);
 425       }
 426     }
 427   }
 428 }
 429 
 430 
 431 // Update callee-saved register info for the following frame
 432 void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
 433   ResourceMark rm;
 434   CodeBlob* cb = fr->cb();
 435   assert(cb != NULL, "no codeblob");
 436 
 437   // Any reg might be saved by a safepoint handler (see generate_handler_blob).
 438   assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id),
 439          "already updated this map; do not 'update' it twice!" );
 440   debug_only(reg_map->_update_for_id = fr->id());
 441 
 442   // Check if caller must update oop argument
 443   assert((reg_map->include_argument_oops() ||
 444           !cb->caller_must_gc_arguments(reg_map->thread())),
 445          "include_argument_oops should already be set");
 446 
 447   // Scan through oopmap and find location of all callee-saved registers
 448   // (we do not do update in place, since info could be overwritten)
 449 
 450   address pc = fr->pc();
 451   const ImmutableOopMap* map  = cb->oop_map_for_return_address(pc);
 452   assert(map != NULL, "no ptr map found");
 453   DEBUG_ONLY(int nof_callee = 0;)
 454 
 455   for (OopMapStream oms(map, OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) {
 456     OopMapValue omv = oms.current();
 457     VMReg reg = omv.content_reg();
 458     oop* loc = fr->oopmapreg_to_location(omv.reg(), reg_map);
 459     reg_map->set_location(reg, (address) loc);
 460     DEBUG_ONLY(nof_callee++;)
 461   }
 462 
 463   // Check that runtime stubs save all callee-saved registers
 464 #ifdef COMPILER2
 465   assert(cb->is_compiled_by_c1() || cb->is_compiled_by_jvmci() || !cb->is_runtime_stub() ||
 466          (nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),
 467          "must save all");
 468 #endif // COMPILER2
 469 }
 470 
 471 //=============================================================================
 472 // Non-Product code
 473 
 474 #ifndef PRODUCT
 475 
 476 bool ImmutableOopMap::has_derived_pointer() const {
 477 #if !defined(TIERED) && !INCLUDE_JVMCI
 478   COMPILER1_PRESENT(return false);
 479 #endif // !TIERED
 480 #if COMPILER2_OR_JVMCI
 481   OopMapStream oms(this,OopMapValue::derived_oop_value);
 482   return oms.is_done();
 483 #else
 484   return false;
 485 #endif // COMPILER2_OR_JVMCI
 486 }
 487 
 488 #endif //PRODUCT
 489 
 490 // Printing code is present in product build for -XX:+PrintAssembly.
 491 
 492 static
 493 void print_register_type(OopMapValue::oop_types x, VMReg optional,
 494                          outputStream* st) {
 495   switch( x ) {
 496   case OopMapValue::oop_value:
 497     st->print("Oop");
 498     break;
 499   case OopMapValue::narrowoop_value:
 500     st->print("NarrowOop");
 501     break;
 502   case OopMapValue::callee_saved_value:
 503     st->print("Callers_");
 504     optional->print_on(st);
 505     break;
 506   case OopMapValue::derived_oop_value:
 507     st->print("Derived_oop_");
 508     optional->print_on(st);
 509     break;
 510   default:
 511     ShouldNotReachHere();
 512   }
 513 }
 514 
 515 void OopMapValue::print_on(outputStream* st) const {
 516   reg()->print_on(st);
 517   st->print("=");
 518   print_register_type(type(),content_reg(),st);
 519   st->print(" ");
 520 }
 521 
 522 void ImmutableOopMap::print_on(outputStream* st) const {
 523   OopMapValue omv;
 524   st->print("ImmutableOopMap{");
 525   for(OopMapStream oms(this); !oms.is_done(); oms.next()) {
 526     omv = oms.current();
 527     omv.print_on(st);
 528   }
 529   st->print("}");
 530 }
 531 
 532 void OopMap::print_on(outputStream* st) const {
 533   OopMapValue omv;
 534   st->print("OopMap{");
 535   for(OopMapStream oms((OopMap*)this); !oms.is_done(); oms.next()) {
 536     omv = oms.current();
 537     omv.print_on(st);
 538   }
 539   st->print("off=%d}", (int) offset());
 540 }
 541 
 542 void ImmutableOopMapSet::print_on(outputStream* st) const {
 543   const ImmutableOopMap* last = NULL;
 544   for (int i = 0; i < _count; ++i) {
 545     const ImmutableOopMapPair* pair = pair_at(i);
 546     const ImmutableOopMap* map = pair->get_from(this);
 547     if (map != last) {
 548       st->cr();
 549       map->print_on(st);
 550       st->print("pc offsets: ");
 551     }
 552     last = map;
 553     st->print("%d ", pair->pc_offset());
 554   }
 555 }
 556 
 557 void OopMapSet::print_on(outputStream* st) const {
 558   int i, len = om_count();
 559 
 560   st->print_cr("OopMapSet contains %d OopMaps\n",len);
 561 
 562   for( i = 0; i < len; i++) {
 563     OopMap* m = at(i);
 564     st->print_cr("#%d ",i);
 565     m->print_on(st);
 566     st->cr();
 567   }
 568 }
 569 
 570 bool OopMap::equals(const OopMap* other) const {
 571   if (other->_omv_count != _omv_count) {
 572     return false;
 573   }
 574   if (other->write_stream()->position() != write_stream()->position()) {
 575     return false;
 576   }
 577   if (memcmp(other->write_stream()->buffer(), write_stream()->buffer(), write_stream()->position()) != 0) {
 578     return false;
 579   }
 580   return true;
 581 }
 582 
 583 const ImmutableOopMap* ImmutableOopMapSet::find_map_at_offset(int pc_offset) const {
 584   ImmutableOopMapPair* pairs = get_pairs();
 585 
 586   int i;
 587   for (i = 0; i < _count; ++i) {
 588     if (pairs[i].pc_offset() >= pc_offset) {
 589       break;
 590     }
 591   }
 592   ImmutableOopMapPair* last = &pairs[i];
 593 
 594   assert(last->pc_offset() == pc_offset, "oopmap not found");
 595   return last->get_from(this);
 596 }
 597 
 598 const ImmutableOopMap* ImmutableOopMapPair::get_from(const ImmutableOopMapSet* set) const {
 599   return set->oopmap_at_offset(_oopmap_offset);
 600 }
 601 
 602 ImmutableOopMap::ImmutableOopMap(const OopMap* oopmap) : _count(oopmap->count()) {
 603   address addr = data_addr();
 604   oopmap->copy_data_to(addr);
 605 }
 606 
 607 #ifdef ASSERT
 608 int ImmutableOopMap::nr_of_bytes() const {
 609   OopMapStream oms(this);
 610 
 611   while (!oms.is_done()) {
 612     oms.next();
 613   }
 614   return sizeof(ImmutableOopMap) + oms.stream_position();
 615 }
 616 #endif
 617 
 618 ImmutableOopMapBuilder::ImmutableOopMapBuilder(const OopMapSet* set) : _set(set), _empty(NULL), _last(NULL), _empty_offset(-1), _last_offset(-1), _offset(0), _required(-1), _new_set(NULL) {
 619   _mapping = NEW_RESOURCE_ARRAY(Mapping, _set->size());
 620 }
 621 
 622 int ImmutableOopMapBuilder::size_for(const OopMap* map) const {
 623   return align_up((int)sizeof(ImmutableOopMap) + map->data_size(), 8);
 624 }
 625 
 626 int ImmutableOopMapBuilder::heap_size() {
 627   int base = sizeof(ImmutableOopMapSet);
 628   base = align_up(base, 8);
 629 
 630   // all of ours pc / offset pairs
 631   int pairs = _set->size() * sizeof(ImmutableOopMapPair);
 632   pairs = align_up(pairs, 8);
 633 
 634   for (int i = 0; i < _set->size(); ++i) {
 635     int size = 0;
 636     OopMap* map = _set->at(i);
 637 
 638     if (is_empty(map)) {
 639       /* only keep a single empty map in the set */
 640       if (has_empty()) {
 641         _mapping[i].set(Mapping::OOPMAP_EMPTY, _empty_offset, 0, map, _empty);
 642       } else {
 643         _empty_offset = _offset;
 644         _empty = map;
 645         size = size_for(map);
 646         _mapping[i].set(Mapping::OOPMAP_NEW, _offset, size, map);
 647       }
 648     } else if (is_last_duplicate(map)) {
 649       /* if this entry is identical to the previous one, just point it there */
 650       _mapping[i].set(Mapping::OOPMAP_DUPLICATE, _last_offset, 0, map, _last);
 651     } else {
 652       /* not empty, not an identical copy of the previous entry */
 653       size = size_for(map);
 654       _mapping[i].set(Mapping::OOPMAP_NEW, _offset, size, map);
 655       _last_offset = _offset;
 656       _last = map;
 657     }
 658 
 659     assert(_mapping[i]._map == map, "check");
 660     _offset += size;
 661   }
 662 
 663   int total = base + pairs + _offset;
 664   DEBUG_ONLY(total += 8);
 665   _required = total;
 666   return total;
 667 }
 668 
 669 void ImmutableOopMapBuilder::fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set) {
 670   assert(offset < set->nr_of_bytes(), "check");
 671   new ((address) pair) ImmutableOopMapPair(map->offset(), offset);
 672 }
 673 
 674 int ImmutableOopMapBuilder::fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set) {
 675   fill_pair(pair, map, offset, set);
 676   address addr = (address) pair->get_from(_new_set); // location of the ImmutableOopMap
 677 
 678   new (addr) ImmutableOopMap(map);
 679   return size_for(map);
 680 }
 681 
 682 void ImmutableOopMapBuilder::fill(ImmutableOopMapSet* set, int sz) {
 683   ImmutableOopMapPair* pairs = set->get_pairs();
 684 
 685   for (int i = 0; i < set->count(); ++i) {
 686     const OopMap* map = _mapping[i]._map;
 687     ImmutableOopMapPair* pair = NULL;
 688     int size = 0;
 689 
 690     if (_mapping[i]._kind == Mapping::OOPMAP_NEW) {
 691       size = fill_map(&pairs[i], map, _mapping[i]._offset, set);
 692     } else if (_mapping[i]._kind == Mapping::OOPMAP_DUPLICATE || _mapping[i]._kind == Mapping::OOPMAP_EMPTY) {
 693       fill_pair(&pairs[i], map, _mapping[i]._offset, set);
 694     }
 695 
 696     const ImmutableOopMap* nv = set->find_map_at_offset(map->offset());
 697     assert(memcmp(map->data(), nv->data_addr(), map->data_size()) == 0, "check identity");
 698   }
 699 }
 700 
 701 #ifdef ASSERT
 702 void ImmutableOopMapBuilder::verify(address buffer, int size, const ImmutableOopMapSet* set) {
 703   for (int i = 0; i < 8; ++i) {
 704     assert(buffer[size - 8 + i] == (unsigned char) 0xff, "overwritten memory check");
 705   }
 706 
 707   for (int i = 0; i < set->count(); ++i) {
 708     const ImmutableOopMapPair* pair = set->pair_at(i);
 709     assert(pair->oopmap_offset() < set->nr_of_bytes(), "check size");
 710     const ImmutableOopMap* map = pair->get_from(set);
 711     int nr_of_bytes = map->nr_of_bytes();
 712     assert(pair->oopmap_offset() + nr_of_bytes <= set->nr_of_bytes(), "check size + size");
 713   }
 714 }
 715 #endif
 716 
 717 ImmutableOopMapSet* ImmutableOopMapBuilder::generate_into(address buffer) {
 718   DEBUG_ONLY(memset(&buffer[_required-8], 0xff, 8));
 719 
 720   _new_set = new (buffer) ImmutableOopMapSet(_set, _required);
 721   fill(_new_set, _required);
 722 
 723   DEBUG_ONLY(verify(buffer, _required, _new_set));
 724 
 725   return _new_set;
 726 }
 727 
 728 ImmutableOopMapSet* ImmutableOopMapBuilder::build() {
 729   _required = heap_size();
 730 
 731   // We need to allocate a chunk big enough to hold the ImmutableOopMapSet and all of its ImmutableOopMaps
 732   address buffer = (address) NEW_C_HEAP_ARRAY(unsigned char, _required, mtCode);
 733   return generate_into(buffer);
 734 }
 735 
 736 ImmutableOopMapSet* ImmutableOopMapSet::build_from(const OopMapSet* oopmap_set) {
 737   ResourceMark mark;
 738   ImmutableOopMapBuilder builder(oopmap_set);
 739   return builder.build();
 740 }
 741 
 742 
 743 //------------------------------DerivedPointerTable---------------------------
 744 
 745 #if COMPILER2_OR_JVMCI
 746 
 747 class DerivedPointerEntry : public CHeapObj<mtCompiler> {
 748  private:
 749   oop*     _location; // Location of derived pointer (also pointing to the base)
 750   intptr_t _offset;   // Offset from base pointer
 751  public:
 752   DerivedPointerEntry(oop* location, intptr_t offset) { _location = location; _offset = offset; }
 753   oop* location()    { return _location; }
 754   intptr_t  offset() { return _offset; }
 755 };
 756 
 757 
 758 GrowableArray<DerivedPointerEntry*>* DerivedPointerTable::_list = NULL;
 759 bool DerivedPointerTable::_active = false;
 760 
 761 
 762 void DerivedPointerTable::clear() {
 763   // The first time, we create the list.  Otherwise it should be
 764   // empty.  If not, then we have probably forgotton to call
 765   // update_pointers after last GC/Scavenge.
 766   assert (!_active, "should not be active");
 767   assert(_list == NULL || _list->length() == 0, "table not empty");
 768   if (_list == NULL) {
 769     _list = new (ResourceObj::C_HEAP, mtCompiler) GrowableArray<DerivedPointerEntry*>(10, true); // Allocated on C heap
 770   }
 771   _active = true;
 772 }
 773 
 774 
 775 // Returns value of location as an int
 776 intptr_t value_of_loc(oop *pointer) { return cast_from_oop<intptr_t>((*pointer)); }
 777 
 778 
 779 void DerivedPointerTable::add(oop *derived_loc, oop *base_loc) {
 780   assert(Universe::heap()->is_in_or_null(*base_loc), "not an oop");
 781   assert(derived_loc != base_loc, "Base and derived in same location");
 782   if (_active) {
 783     assert(*derived_loc != (oop)base_loc, "location already added");
 784     assert(_list != NULL, "list must exist");
 785     intptr_t offset = value_of_loc(derived_loc) - value_of_loc(base_loc);
 786     // This assert is invalid because derived pointers can be
 787     // arbitrarily far away from their base.
 788     // assert(offset >= -1000000, "wrong derived pointer info");
 789 
 790     if (TraceDerivedPointers) {
 791       tty->print_cr(
 792         "Add derived pointer@" INTPTR_FORMAT
 793         " - Derived: " INTPTR_FORMAT
 794         " Base: " INTPTR_FORMAT " (@" INTPTR_FORMAT ") (Offset: " INTX_FORMAT ")",
 795         p2i(derived_loc), p2i((address)*derived_loc), p2i((address)*base_loc), p2i(base_loc), offset
 796       );
 797     }
 798     // Set derived oop location to point to base.
 799     *derived_loc = (oop)base_loc;
 800     assert_lock_strong(DerivedPointerTableGC_lock);
 801     DerivedPointerEntry *entry = new DerivedPointerEntry(derived_loc, offset);
 802     _list->append(entry);
 803   }
 804 }
 805 
 806 
 807 void DerivedPointerTable::update_pointers() {
 808   assert(_list != NULL, "list must exist");
 809   for(int i = 0; i < _list->length(); i++) {
 810     DerivedPointerEntry* entry = _list->at(i);
 811     oop* derived_loc = entry->location();
 812     intptr_t offset  = entry->offset();
 813     // The derived oop was setup to point to location of base
 814     oop  base        = **(oop**)derived_loc;
 815     assert(Universe::heap()->is_in_or_null(base), "must be an oop");
 816 
 817     *derived_loc = (oop)(((address)base) + offset);
 818     assert(value_of_loc(derived_loc) - value_of_loc(&base) == offset, "sanity check");
 819 
 820     if (TraceDerivedPointers) {
 821       tty->print_cr("Updating derived pointer@" INTPTR_FORMAT
 822                     " - Derived: " INTPTR_FORMAT "  Base: " INTPTR_FORMAT " (Offset: " INTX_FORMAT ")",
 823           p2i(derived_loc), p2i((address)*derived_loc), p2i((address)base), offset);
 824     }
 825 
 826     // Delete entry
 827     delete entry;
 828     _list->at_put(i, NULL);
 829   }
 830   // Clear list, so it is ready for next traversal (this is an invariant)
 831   if (TraceDerivedPointers && !_list->is_empty()) {
 832     tty->print_cr("--------------------------");
 833   }
 834   _list->clear();
 835   _active = false;
 836 }
 837 
 838 #endif // COMPILER2_OR_JVMCI