1 /*
   2  * Copyright (c) 1997, 2014, 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 "interpreter/interpreter.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "oops/markOop.hpp"
  29 #include "oops/method.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "prims/methodHandles.hpp"
  32 #include "runtime/frame.inline.hpp"
  33 #include "runtime/handles.inline.hpp"
  34 #include "runtime/javaCalls.hpp"
  35 #include "runtime/monitorChunk.hpp"
  36 #include "runtime/os.hpp"
  37 #include "runtime/signature.hpp"
  38 #include "runtime/stubCodeGenerator.hpp"
  39 #include "runtime/stubRoutines.hpp"
  40 #include "vmreg_x86.inline.hpp"
  41 #ifdef COMPILER1
  42 #include "c1/c1_Runtime1.hpp"
  43 #include "runtime/vframeArray.hpp"
  44 #endif
  45 
  46 #ifdef ASSERT
  47 void RegisterMap::check_location_valid() {
  48 }
  49 #endif
  50 
  51 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  52 
  53 // Profiling/safepoint support
  54 
  55 bool frame::safe_for_sender(JavaThread *thread) {
  56   address   sp = (address)_sp;
  57   address   fp = (address)_fp;
  58   address   unextended_sp = (address)_unextended_sp;
  59 
  60   // consider stack guards when trying to determine "safe" stack pointers
  61   static size_t stack_guard_size = os::uses_stack_guard_pages() ? (StackYellowPages + StackRedPages) * os::vm_page_size() : 0;
  62   size_t usable_stack_size = thread->stack_size() - stack_guard_size;
  63 
  64   // sp must be within the usable part of the stack (not in guards)
  65   bool sp_safe = (sp < thread->stack_base()) &&
  66                  (sp >= thread->stack_base() - usable_stack_size);
  67 
  68 
  69   if (!sp_safe) {
  70     return false;
  71   }
  72 
  73   // unextended sp must be within the stack and above or equal sp
  74   bool unextended_sp_safe = (unextended_sp < thread->stack_base()) &&
  75                             (unextended_sp >= sp);
  76 
  77   if (!unextended_sp_safe) {
  78     return false;
  79   }
  80 
  81   // an fp must be within the stack and above (but not equal) sp
  82   // second evaluation on fp+ is added to handle situation where fp is -1
  83   bool fp_safe = (fp < thread->stack_base() && (fp > sp) && (((fp + (return_addr_offset * sizeof(void*))) < thread->stack_base())));
  84 
  85   // We know sp/unextended_sp are safe only fp is questionable here
  86 
  87   // If the current frame is known to the code cache then we can attempt to
  88   // to construct the sender and do some validation of it. This goes a long way
  89   // toward eliminating issues when we get in frame construction code
  90 
  91   if (_cb != NULL ) {
  92 
  93     // First check if frame is complete and tester is reliable
  94     // Unfortunately we can only check frame complete for runtime stubs and nmethod
  95     // other generic buffer blobs are more problematic so we just assume they are
  96     // ok. adapter blobs never have a frame complete and are never ok.
  97 
  98     if (!_cb->is_frame_complete_at(_pc)) {
  99       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
 100         return false;
 101       }
 102     }
 103 
 104     // Could just be some random pointer within the codeBlob
 105     if (!_cb->code_contains(_pc)) {
 106       return false;
 107     }
 108 
 109     // Entry frame checks
 110     if (is_entry_frame()) {
 111       // an entry frame must have a valid fp.
 112 
 113       if (!fp_safe) return false;
 114 
 115       // Validate the JavaCallWrapper an entry frame must have
 116 
 117       address jcw = (address)entry_frame_call_wrapper();
 118 
 119       bool jcw_safe = (jcw < thread->stack_base()) && ( jcw > fp);
 120 
 121       return jcw_safe;
 122 
 123     }
 124 
 125     intptr_t* sender_sp = NULL;
 126     address   sender_pc = NULL;
 127 
 128     if (is_interpreted_frame()) {
 129       // fp must be safe
 130       if (!fp_safe) {
 131         return false;
 132       }
 133 
 134       sender_pc = (address) this->fp()[return_addr_offset];
 135       sender_sp = (intptr_t*) addr_at(sender_sp_offset);
 136 
 137     } else {
 138       // must be some sort of compiled/runtime frame
 139       // fp does not have to be safe (although it could be check for c1?)
 140 
 141       // check for a valid frame_size, otherwise we are unlikely to get a valid sender_pc
 142       if (_cb->frame_size() <= 0) {
 143         return false;
 144       }
 145 
 146       sender_sp = _unextended_sp + _cb->frame_size();
 147       // On Intel the return_address is always the word on the stack
 148       sender_pc = (address) *(sender_sp-1);
 149     }
 150 
 151 
 152     // If the potential sender is the interpreter then we can do some more checking
 153     if (Interpreter::contains(sender_pc)) {
 154 
 155       // ebp is always saved in a recognizable place in any code we generate. However
 156       // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved ebp
 157       // is really a frame pointer.
 158 
 159       intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);
 160       bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
 161 
 162       if (!saved_fp_safe) {
 163         return false;
 164       }
 165 
 166       // construct the potential sender
 167 
 168       frame sender(sender_sp, saved_fp, sender_pc);
 169 
 170       return sender.is_interpreted_frame_valid(thread);
 171 
 172     }
 173 
 174     // We must always be able to find a recognizable pc
 175     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
 176     if (sender_pc == NULL ||  sender_blob == NULL) {
 177       return false;
 178     }
 179 
 180     // Could be a zombie method
 181     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
 182       return false;
 183     }
 184 
 185     // Could just be some random pointer within the codeBlob
 186     if (!sender_blob->code_contains(sender_pc)) {
 187       return false;
 188     }
 189 
 190     // We should never be able to see an adapter if the current frame is something from code cache
 191     if (sender_blob->is_adapter_blob()) {
 192       return false;
 193     }
 194 
 195     // Could be the call_stub
 196     if (StubRoutines::returns_to_call_stub(sender_pc)) {
 197       intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset);
 198       bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
 199 
 200       if (!saved_fp_safe) {
 201         return false;
 202       }
 203 
 204       // construct the potential sender
 205 
 206       frame sender(sender_sp, saved_fp, sender_pc);
 207 
 208       // Validate the JavaCallWrapper an entry frame must have
 209       address jcw = (address)sender.entry_frame_call_wrapper();
 210 
 211       bool jcw_safe = (jcw < thread->stack_base()) && ( jcw > (address)sender.fp());
 212 
 213       return jcw_safe;
 214     }
 215 
 216     if (sender_blob->is_nmethod()) {
 217         nmethod* nm = sender_blob->as_nmethod_or_null();
 218         if (nm != NULL) {
 219             if (nm->is_deopt_mh_entry(sender_pc) || nm->is_deopt_entry(sender_pc)) {
 220                 return false;
 221             }
 222         }
 223     }
 224 
 225     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
 226     // because the return address counts against the callee's frame.
 227 
 228     if (sender_blob->frame_size() <= 0) {
 229       assert(!sender_blob->is_nmethod(), "should count return address at least");
 230       return false;
 231     }
 232 
 233     // We should never be able to see anything here except an nmethod. If something in the
 234     // code cache (current frame) is called by an entity within the code cache that entity
 235     // should not be anything but the call stub (already covered), the interpreter (already covered)
 236     // or an nmethod.
 237 
 238     if (!sender_blob->is_nmethod()) {
 239         return false;
 240     }
 241 
 242     // Could put some more validation for the potential non-interpreted sender
 243     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
 244 
 245     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
 246 
 247     // We've validated the potential sender that would be created
 248     return true;
 249   }
 250 
 251   // Must be native-compiled frame. Since sender will try and use fp to find
 252   // linkages it must be safe
 253 
 254   if (!fp_safe) {
 255     return false;
 256   }
 257 
 258   // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
 259 
 260   if ( (address) this->fp()[return_addr_offset] == NULL) return false;
 261 
 262 
 263   // could try and do some more potential verification of native frame if we could think of some...
 264 
 265   return true;
 266 
 267 }
 268 
 269 
 270 void frame::patch_pc(Thread* thread, address pc) {
 271   address* pc_addr = &(((address*) sp())[-1]);
 272   if (TracePcPatching) {
 273     tty->print_cr("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
 274                   pc_addr, *pc_addr, pc);
 275   }
 276   // Either the return address is the original one or we are going to
 277   // patch in the same address that's already there.
 278   assert(_pc == *pc_addr || pc == *pc_addr, "must be");
 279   *pc_addr = pc;
 280   _cb = CodeCache::find_blob(pc);
 281   address original_pc = nmethod::get_deopt_original_pc(this);
 282   if (original_pc != NULL) {
 283     assert(original_pc == _pc, "expected original PC to be stored before patching");
 284     _deopt_state = is_deoptimized;
 285     // leave _pc as is
 286   } else {
 287     _deopt_state = not_deoptimized;
 288     _pc = pc;
 289   }
 290 }
 291 
 292 bool frame::is_interpreted_frame() const  {
 293   return Interpreter::contains(pc());
 294 }
 295 
 296 int frame::frame_size(RegisterMap* map) const {
 297   frame sender = this->sender(map);
 298   return sender.sp() - sp();
 299 }
 300 
 301 intptr_t* frame::entry_frame_argument_at(int offset) const {
 302   // convert offset to index to deal with tsi
 303   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 304   // Entry frame's arguments are always in relation to unextended_sp()
 305   return &unextended_sp()[index];
 306 }
 307 
 308 // sender_sp
 309 #ifdef CC_INTERP
 310 intptr_t* frame::interpreter_frame_sender_sp() const {
 311   assert(is_interpreted_frame(), "interpreted frame expected");
 312   // QQQ why does this specialize method exist if frame::sender_sp() does same thing?
 313   // seems odd and if we always know interpreted vs. non then sender_sp() is really
 314   // doing too much work.
 315   return get_interpreterState()->sender_sp();
 316 }
 317 
 318 // monitor elements
 319 
 320 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
 321   return get_interpreterState()->monitor_base();
 322 }
 323 
 324 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
 325   return (BasicObjectLock*) get_interpreterState()->stack_base();
 326 }
 327 
 328 #else // CC_INTERP
 329 
 330 intptr_t* frame::interpreter_frame_sender_sp() const {
 331   assert(is_interpreted_frame(), "interpreted frame expected");
 332   return (intptr_t*) at(interpreter_frame_sender_sp_offset);
 333 }
 334 
 335 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
 336   assert(is_interpreted_frame(), "interpreted frame expected");
 337   ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
 338 }
 339 
 340 
 341 // monitor elements
 342 
 343 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
 344   return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
 345 }
 346 
 347 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
 348   BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
 349   // make sure the pointer points inside the frame
 350   assert(sp() <= (intptr_t*) result, "monitor end should be above the stack pointer");
 351   assert((intptr_t*) result < fp(),  "monitor end should be strictly below the frame pointer");
 352   return result;
 353 }
 354 
 355 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
 356   *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
 357 }
 358 
 359 // Used by template based interpreter deoptimization
 360 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
 361     *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
 362 }
 363 #endif // CC_INTERP
 364 
 365 frame frame::sender_for_entry_frame(RegisterMap* map) const {
 366   assert(map != NULL, "map must be set");
 367   // Java frame called from C; skip all C frames and return top C
 368   // frame of that chunk as the sender
 369   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
 370   assert(!entry_frame_is_first(), "next Java fp must be non zero");
 371   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
 372   map->clear();
 373   assert(map->include_argument_oops(), "should be set by clear");
 374   if (jfa->last_Java_pc() != NULL ) {
 375     frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
 376     return fr;
 377   }
 378   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
 379   return fr;
 380 }
 381 
 382 //------------------------------------------------------------------------------
 383 // frame::verify_deopt_original_pc
 384 //
 385 // Verifies the calculated original PC of a deoptimization PC for the
 386 // given unextended SP.  The unextended SP might also be the saved SP
 387 // for MethodHandle call sites.
 388 #ifdef ASSERT
 389 void frame::verify_deopt_original_pc(nmethod* nm, intptr_t* unextended_sp, bool is_method_handle_return) {
 390   frame fr;
 391 
 392   // This is ugly but it's better than to change {get,set}_original_pc
 393   // to take an SP value as argument.  And it's only a debugging
 394   // method anyway.
 395   fr._unextended_sp = unextended_sp;
 396 
 397   address original_pc = nm->get_original_pc(&fr);
 398   assert(nm->insts_contains(original_pc), "original PC must be in nmethod");
 399   assert(nm->is_method_handle_return(original_pc) == is_method_handle_return, "must be");
 400 }
 401 #endif
 402 
 403 //------------------------------------------------------------------------------
 404 // frame::adjust_unextended_sp
 405 void frame::adjust_unextended_sp() {
 406   // If we are returning to a compiled MethodHandle call site, the
 407   // saved_fp will in fact be a saved value of the unextended SP.  The
 408   // simplest way to tell whether we are returning to such a call site
 409   // is as follows:
 410 
 411   nmethod* sender_nm = (_cb == NULL) ? NULL : _cb->as_nmethod_or_null();
 412   if (sender_nm != NULL) {
 413     // If the sender PC is a deoptimization point, get the original
 414     // PC.  For MethodHandle call site the unextended_sp is stored in
 415     // saved_fp.
 416     if (sender_nm->is_deopt_mh_entry(_pc)) {
 417       DEBUG_ONLY(verify_deopt_mh_original_pc(sender_nm, _fp));
 418       _unextended_sp = _fp;
 419     }
 420     else if (sender_nm->is_deopt_entry(_pc)) {
 421       DEBUG_ONLY(verify_deopt_original_pc(sender_nm, _unextended_sp));
 422     }
 423     else if (sender_nm->is_method_handle_return(_pc)) {
 424       _unextended_sp = _fp;
 425     }
 426   }
 427 }
 428 
 429 //------------------------------------------------------------------------------
 430 // frame::update_map_with_saved_link
 431 void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
 432   // The interpreter and compiler(s) always save EBP/RBP in a known
 433   // location on entry. We must record where that location is
 434   // so this if EBP/RBP was live on callout from c2 we can find
 435   // the saved copy no matter what it called.
 436 
 437   // Since the interpreter always saves EBP/RBP if we record where it is then
 438   // we don't have to always save EBP/RBP on entry and exit to c2 compiled
 439   // code, on entry will be enough.
 440   map->set_location(rbp->as_VMReg(), (address) link_addr);
 441 #ifdef AMD64
 442   // this is weird "H" ought to be at a higher address however the
 443   // oopMaps seems to have the "H" regs at the same address and the
 444   // vanilla register.
 445   // XXXX make this go away
 446   if (true) {
 447     map->set_location(rbp->as_VMReg()->next(), (address) link_addr);
 448   }
 449 #endif // AMD64
 450 }
 451 
 452 
 453 //------------------------------------------------------------------------------
 454 // frame::sender_for_interpreter_frame
 455 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
 456   // SP is the raw SP from the sender after adapter or interpreter
 457   // extension.
 458   intptr_t* sender_sp = this->sender_sp();
 459 
 460   // This is the sp before any possible extension (adapter/locals).
 461   intptr_t* unextended_sp = interpreter_frame_sender_sp();
 462 
 463 #ifdef COMPILER2
 464   if (map->update_map()) {
 465     update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
 466   }
 467 #endif // COMPILER2
 468 
 469   return frame(sender_sp, unextended_sp, link(), sender_pc());
 470 }
 471 
 472 
 473 //------------------------------------------------------------------------------
 474 // frame::sender_for_compiled_frame
 475 frame frame::sender_for_compiled_frame(RegisterMap* map) const {
 476   assert(map != NULL, "map must be set");
 477 
 478   // frame owned by optimizing compiler
 479   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
 480   intptr_t* sender_sp = unextended_sp() + _cb->frame_size();
 481   intptr_t* unextended_sp = sender_sp;
 482 
 483   // On Intel the return_address is always the word on the stack
 484   address sender_pc = (address) *(sender_sp-1);
 485 
 486   // This is the saved value of EBP which may or may not really be an FP.
 487   // It is only an FP if the sender is an interpreter frame (or C1?).
 488   intptr_t** saved_fp_addr = (intptr_t**) (sender_sp - frame::sender_sp_offset);
 489 
 490   if (map->update_map()) {
 491     // Tell GC to use argument oopmaps for some runtime stubs that need it.
 492     // For C1, the runtime stub might not have oop maps, so set this flag
 493     // outside of update_register_map.
 494     map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 495     if (_cb->oop_maps() != NULL) {
 496       OopMapSet::update_register_map(this, map);
 497     }
 498 
 499     // Since the prolog does the save and restore of EBP there is no oopmap
 500     // for it so we must fill in its location as if there was an oopmap entry
 501     // since if our caller was compiled code there could be live jvm state in it.
 502     update_map_with_saved_link(map, saved_fp_addr);
 503   }
 504 
 505   assert(sender_sp != sp(), "must have changed");
 506   return frame(sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
 507 }
 508 
 509 
 510 //------------------------------------------------------------------------------
 511 // frame::sender
 512 frame frame::sender(RegisterMap* map) const {
 513   // Default is we done have to follow them. The sender_for_xxx will
 514   // update it accordingly
 515   map->set_include_argument_oops(false);
 516 
 517   if (is_entry_frame())       return sender_for_entry_frame(map);
 518   if (is_interpreted_frame()) return sender_for_interpreter_frame(map);
 519   assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
 520 
 521   if (_cb != NULL) {
 522     return sender_for_compiled_frame(map);
 523   }
 524   // Must be native-compiled frame, i.e. the marshaling code for native
 525   // methods that exists in the core system.
 526   return frame(sender_sp(), link(), sender_pc());
 527 }
 528 
 529 
 530 bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {
 531   assert(is_interpreted_frame(), "must be interpreter frame");
 532   Method* method = interpreter_frame_method();
 533   // When unpacking an optimized frame the frame pointer is
 534   // adjusted with:
 535   int diff = (method->max_locals() - method->size_of_parameters()) *
 536              Interpreter::stackElementWords;
 537   return _fp == (fp - diff);
 538 }
 539 
 540 void frame::pd_gc_epilog() {
 541   // nothing done here now
 542 }
 543 
 544 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
 545 // QQQ
 546 #ifdef CC_INTERP
 547 #else
 548   assert(is_interpreted_frame(), "Not an interpreted frame");
 549   // These are reasonable sanity checks
 550   if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
 551     return false;
 552   }
 553   if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
 554     return false;
 555   }
 556   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
 557     return false;
 558   }
 559   // These are hacks to keep us out of trouble.
 560   // The problem with these is that they mask other problems
 561   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
 562     return false;
 563   }
 564 
 565   // do some validation of frame elements
 566 
 567   // first the method
 568 
 569   Method* m = *interpreter_frame_method_addr();
 570 
 571   // validate the method we'd find in this potential sender
 572   if (!m->is_valid_method()) return false;
 573 
 574   // stack frames shouldn't be much larger than max_stack elements
 575 
 576   if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
 577     return false;
 578   }
 579 
 580   // validate bci/bcx
 581 
 582   intptr_t  bcx    = interpreter_frame_bcx();
 583   if (m->validate_bci_from_bcx(bcx) < 0) {
 584     return false;
 585   }
 586 
 587   // validate ConstantPoolCache*
 588   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
 589   if (cp == NULL || !cp->is_metaspace_object()) return false;
 590 
 591   // validate locals
 592 
 593   address locals =  (address) *interpreter_frame_locals_addr();
 594 
 595   if (locals > thread->stack_base() || locals < (address) fp()) return false;
 596 
 597   // We'd have to be pretty unlucky to be mislead at this point
 598 
 599 #endif // CC_INTERP
 600   return true;
 601 }
 602 
 603 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
 604 #ifdef CC_INTERP
 605   // Needed for JVMTI. The result should always be in the
 606   // interpreterState object
 607   interpreterState istate = get_interpreterState();
 608 #endif // CC_INTERP
 609   assert(is_interpreted_frame(), "interpreted frame expected");
 610   Method* method = interpreter_frame_method();
 611   BasicType type = method->result_type();
 612 
 613   intptr_t* tos_addr;
 614   if (method->is_native()) {
 615     // Prior to calling into the runtime to report the method_exit the possible
 616     // return value is pushed to the native stack. If the result is a jfloat/jdouble
 617     // then ST0 is saved before EAX/EDX. See the note in generate_native_result
 618     tos_addr = (intptr_t*)sp();
 619     if (type == T_FLOAT || type == T_DOUBLE) {
 620     // QQQ seems like this code is equivalent on the two platforms
 621 #ifdef AMD64
 622       // This is times two because we do a push(ltos) after pushing XMM0
 623       // and that takes two interpreter stack slots.
 624       tos_addr += 2 * Interpreter::stackElementWords;
 625 #else
 626       tos_addr += 2;
 627 #endif // AMD64
 628     }
 629   } else {
 630     tos_addr = (intptr_t*)interpreter_frame_tos_address();
 631   }
 632 
 633   switch (type) {
 634     case T_OBJECT  :
 635     case T_ARRAY   : {
 636       oop obj;
 637       if (method->is_native()) {
 638 #ifdef CC_INTERP
 639         obj = istate->_oop_temp;
 640 #else
 641         obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
 642 #endif // CC_INTERP
 643       } else {
 644         oop* obj_p = (oop*)tos_addr;
 645         obj = (obj_p == NULL) ? (oop)NULL : *obj_p;
 646       }
 647       assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 648       *oop_result = obj;
 649       break;
 650     }
 651     case T_BOOLEAN : value_result->z = *(jboolean*)tos_addr; break;
 652     case T_BYTE    : value_result->b = *(jbyte*)tos_addr; break;
 653     case T_CHAR    : value_result->c = *(jchar*)tos_addr; break;
 654     case T_SHORT   : value_result->s = *(jshort*)tos_addr; break;
 655     case T_INT     : value_result->i = *(jint*)tos_addr; break;
 656     case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
 657     case T_FLOAT   : {
 658 #ifdef AMD64
 659         value_result->f = *(jfloat*)tos_addr;
 660 #else
 661       if (method->is_native()) {
 662         jdouble d = *(jdouble*)tos_addr;  // Result was in ST0 so need to convert to jfloat
 663         value_result->f = (jfloat)d;
 664       } else {
 665         value_result->f = *(jfloat*)tos_addr;
 666       }
 667 #endif // AMD64
 668       break;
 669     }
 670     case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
 671     case T_VOID    : /* Nothing to do */ break;
 672     default        : ShouldNotReachHere();
 673   }
 674 
 675   return type;
 676 }
 677 
 678 
 679 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
 680   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 681   return &interpreter_frame_tos_address()[index];
 682 }
 683 
 684 #ifndef PRODUCT
 685 
 686 #define DESCRIBE_FP_OFFSET(name) \
 687   values.describe(frame_no, fp() + frame::name##_offset, #name)
 688 
 689 void frame::describe_pd(FrameValues& values, int frame_no) {
 690   if (is_interpreted_frame()) {
 691     DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
 692     DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
 693     DESCRIBE_FP_OFFSET(interpreter_frame_method);
 694     DESCRIBE_FP_OFFSET(interpreter_frame_mdx);
 695     DESCRIBE_FP_OFFSET(interpreter_frame_cache);
 696     DESCRIBE_FP_OFFSET(interpreter_frame_locals);
 697     DESCRIBE_FP_OFFSET(interpreter_frame_bcx);
 698     DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
 699   }
 700 }
 701 #endif
 702 
 703 intptr_t *frame::initial_deoptimization_info() {
 704   // used to reset the saved FP
 705   return fp();
 706 }
 707 
 708 intptr_t* frame::real_fp() const {
 709   if (_cb != NULL) {
 710     // use the frame size if valid
 711     int size = _cb->frame_size();
 712     if (size > 0) {
 713       return unextended_sp() + size;
 714     }
 715   }
 716   // else rely on fp()
 717   assert(! is_compiled_frame(), "unknown compiled frame size");
 718   return fp();
 719 }
 720 
 721 #ifndef PRODUCT
 722 // This is a generic constructor which is only used by pns() in debug.cpp.
 723 frame::frame(void* sp, void* fp, void* pc) {
 724   init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
 725 }
 726 #endif