Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "interpreter/interpreter.hpp"

 #include "memory/resourceArea.hpp"

 #include "oops/markOop.hpp"

 #include "oops/method.hpp"

 #include "oops/oop.inline.hpp"

 #include "prims/methodHandles.hpp"

 #include "runtime/frame.inline.hpp"

 #include "runtime/handles.inline.hpp"

 #include "runtime/javaCalls.hpp"

 #include "runtime/monitorChunk.hpp"

 #include "runtime/signature.hpp"

 #include "runtime/stubCodeGenerator.hpp"

 #include "runtime/stubRoutines.hpp"

 #include "vmreg_sparc.inline.hpp"

 #ifdef COMPILER1

 #include "c1/c1_Runtime1.hpp"

 #include "runtime/vframeArray.hpp"

 #endif

 void RegisterMap::pd_clear() {

   if (_thread->has_last_Java_frame()) {

     frame fr = _thread->last_frame();

     _window = fr.sp();

   } else {

     _window = NULL;

   }

   _younger_window = NULL;

 }

 // Unified register numbering scheme: each 32-bits counts as a register

 // number, so all the V9 registers take 2 slots.

 const static int R_L_nums[] = {0+040,2+040,4+040,6+040,8+040,10+040,12+040,14+040};

 const static int R_I_nums[] = {0+060,2+060,4+060,6+060,8+060,10+060,12+060,14+060};

 const static int R_O_nums[] = {0+020,2+020,4+020,6+020,8+020,10+020,12+020,14+020};

 const static int R_G_nums[] = {0+000,2+000,4+000,6+000,8+000,10+000,12+000,14+000};

 static RegisterMap::LocationValidType bad_mask = 0;

 static RegisterMap::LocationValidType R_LIO_mask = 0;

 static bool register_map_inited = false;

 static void register_map_init() {

   if (!register_map_inited) {

     register_map_inited = true;

     int i;

     for (i = 0; i < 8; i++) {

       assert(R_L_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");

       assert(R_I_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");

       assert(R_O_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");

       assert(R_G_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");

     }

     bad_mask |= (1LL << R_O_nums[6]); // SP

     bad_mask |= (1LL << R_O_nums[7]); // cPC

     bad_mask |= (1LL << R_I_nums[6]); // FP

     bad_mask |= (1LL << R_I_nums[7]); // rPC

     bad_mask |= (1LL << R_G_nums[2]); // TLS

     bad_mask |= (1LL << R_G_nums[7]); // reserved by libthread

     for (i = 0; i < 8; i++) {

       R_LIO_mask |= (1LL << R_L_nums[i]);

       R_LIO_mask |= (1LL << R_I_nums[i]);

       R_LIO_mask |= (1LL << R_O_nums[i]);

     }

   }

 }

 address RegisterMap::pd_location(VMReg regname) const {

   register_map_init();

   assert(regname->is_reg(), "sanity check");

   // Only the GPRs get handled this way

   if( !regname->is_Register())

     return NULL;

   // don't talk about bad registers

   if ((bad_mask & ((LocationValidType)1 << regname->value())) != 0) {

     return NULL;

   }

   // Convert to a GPR

   Register reg;

   int second_word = 0;

   // 32-bit registers for in, out and local

   if (!regname->is_concrete()) {

     // HMM ought to return NULL for any non-concrete (odd) vmreg

     // this all tied up in the fact we put out double oopMaps for

     // register locations. When that is fixed we'd will return NULL

     // (or assert here).

     reg = regname->prev()->as_Register();

 #ifdef _LP64

     second_word = sizeof(jint);

 #else

     return NULL;

 #endif // _LP64

   } else {

     reg = regname->as_Register();

   }

   if (reg->is_out()) {

     assert(_younger_window != NULL, "Younger window should be available");

     return second_word + (address)&_younger_window[reg->after_save()->sp_offset_in_saved_window()];

   }

   if (reg->is_local() || reg->is_in()) {

     assert(_window != NULL, "Window should be available");

     return second_word + (address)&_window[reg->sp_offset_in_saved_window()];

   }

   // Only the window'd GPRs get handled this way; not the globals.

   return NULL;

 }

 #ifdef ASSERT

 void RegisterMap::check_location_valid() {

   register_map_init();

   assert((_location_valid[0] & bad_mask) == 0, "cannot have special locations for SP,FP,TLS,etc.");

 }

 #endif

 // We are shifting windows.  That means we are moving all %i to %o,

 // getting rid of all current %l, and keeping all %g.  This is only

 // complicated if any of the location pointers for these are valid.

 // The normal case is that everything is in its standard register window

 // home, and _location_valid[0] is zero.  In that case, this routine

 // does exactly nothing.

 void RegisterMap::shift_individual_registers() {

   if (!update_map())  return;  // this only applies to maps with locations

   register_map_init();

   check_location_valid();

   LocationValidType lv = _location_valid[0];

   LocationValidType lv0 = lv;

   lv &= ~R_LIO_mask;  // clear %l, %o, %i regs

   // if we cleared some non-%g locations, we may have to do some shifting

   if (lv != lv0) {

     // copy %i0-%i5 to %o0-%o5, if they have special locations

     // This can happen in within stubs which spill argument registers

     // around a dynamic link operation, such as resolve_opt_virtual_call.

     for (int i = 0; i < 8; i++) {

       if (lv0 & (1LL << R_I_nums[i])) {

         _location[R_O_nums[i]] = _location[R_I_nums[i]];

         lv |=  (1LL << R_O_nums[i]);

       }

     }

   }

   _location_valid[0] = lv;

   check_location_valid();

 }

 bool frame::safe_for_sender(JavaThread *thread) {

   address _SP = (address) sp();

   address _FP = (address) fp();

   address _UNEXTENDED_SP = (address) unextended_sp();

   // sp must be within the stack

   bool sp_safe = (_SP <= thread->stack_base()) &&

                  (_SP >= thread->stack_base() - thread->stack_size());

   if (!sp_safe) {

     return false;

   }

   // unextended sp must be within the stack and above or equal sp

   bool unextended_sp_safe = (_UNEXTENDED_SP <= thread->stack_base()) &&

                             (_UNEXTENDED_SP >= _SP);

   if (!unextended_sp_safe) return false;

   // an fp must be within the stack and above (but not equal) sp

   bool fp_safe = (_FP <= thread->stack_base()) &&

                  (_FP > _SP);

   // We know sp/unextended_sp are safe only fp is questionable here

   // If the current frame is known to the code cache then we can attempt to

   // to construct the sender and do some validation of it. This goes a long way

   // toward eliminating issues when we get in frame construction code

   if (_cb != NULL ) {

     // First check if frame is complete and tester is reliable

     // Unfortunately we can only check frame complete for runtime stubs and nmethod

     // other generic buffer blobs are more problematic so we just assume they are

     // ok. adapter blobs never have a frame complete and are never ok.

     if (!_cb->is_frame_complete_at(_pc)) {

       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {

         return false;

       }

     }

     // Could just be some random pointer within the codeBlob

     if (!_cb->code_contains(_pc)) {

       return false;

     }

     // Entry frame checks

     if (is_entry_frame()) {

       // an entry frame must have a valid fp.

       if (!fp_safe) {

         return false;

       }

       // Validate the JavaCallWrapper an entry frame must have

       address jcw = (address)entry_frame_call_wrapper();

       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > _FP);

       return jcw_safe;

     }

     intptr_t* younger_sp = sp();

     intptr_t* _SENDER_SP = sender_sp(); // sender is actually just _FP

     bool adjusted_stack = is_interpreted_frame();

     address   sender_pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;

     // We must always be able to find a recognizable pc

     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);

     if (sender_pc == NULL ||  sender_blob == NULL) {

       return false;

     }

     // Could be a zombie method

     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {

       return false;

     }

     // It should be safe to construct the sender though it might not be valid

     frame sender(_SENDER_SP, younger_sp, adjusted_stack);

     // Do we have a valid fp?

     address sender_fp = (address) sender.fp();

     // an fp must be within the stack and above (but not equal) current frame's _FP

     bool sender_fp_safe = (sender_fp <= thread->stack_base()) &&

                    (sender_fp > _FP);

     if (!sender_fp_safe) {

       return false;

     }

     // If the potential sender is the interpreter then we can do some more checking

     if (Interpreter::contains(sender_pc)) {

       return sender.is_interpreted_frame_valid(thread);

     }

     // Could just be some random pointer within the codeBlob

     if (!sender.cb()->code_contains(sender_pc)) {

       return false;

     }

     // We should never be able to see an adapter if the current frame is something from code cache

     if (sender_blob->is_adapter_blob()) {

       return false;

     }

     if( sender.is_entry_frame()) {

       // Validate the JavaCallWrapper an entry frame must have

       address jcw = (address)sender.entry_frame_call_wrapper();

       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > sender_fp);

       return jcw_safe;

     }

     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size

     // because you must allocate window space

     if (sender_blob->frame_size() <= 0) {

       assert(!sender_blob->is_nmethod(), "should count return address at least");

       return false;

     }

     // The sender should positively be an nmethod or call_stub. On sparc we might in fact see something else.

     // The cause of this is because at a save instruction the O7 we get is a leftover from an earlier

     // window use. So if a runtime stub creates two frames (common in fastdebug/debug) then we see the

     // stale pc. So if the sender blob is not something we'd expect we have little choice but to declare

     // the stack unwalkable. pd_get_top_frame_for_signal_handler tries to recover from this by unwinding

     // that initial frame and retrying.

     if (!sender_blob->is_nmethod()) {

       return false;

     }

     // Could put some more validation for the potential non-interpreted sender

     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...

     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb

     // We've validated the potential sender that would be created

     return true;

   }

   // Must be native-compiled frame. Since sender will try and use fp to find

   // linkages it must be safe

   if (!fp_safe) return false;

   // could try and do some more potential verification of native frame if we could think of some...

   return true;

 }

 // constructors

 // Construct an unpatchable, deficient frame

 frame::frame(intptr_t* sp, unpatchable_t, address pc, CodeBlob* cb) {

 #ifdef _LP64

   assert( (((intptr_t)sp & (wordSize-1)) == 0), "frame constructor passed an invalid sp");

 #endif

   _sp = sp;

   _younger_sp = NULL;

   _pc = pc;

   _cb = cb;

   _sp_adjustment_by_callee = 0;

   assert(pc == NULL && cb == NULL || pc != NULL, "can't have a cb and no pc!");

   if (_cb == NULL && _pc != NULL ) {

     _cb = CodeCache::find_blob(_pc);

   }

   _deopt_state = unknown;

 #ifdef ASSERT

   if ( _cb != NULL && _cb->is_nmethod()) {

     // Without a valid unextended_sp() we can't convert the pc to "original"

     assert(!((nmethod*)_cb)->is_deopt_pc(_pc), "invariant broken");

   }

 #endif // ASSERT

 }

 frame::frame(intptr_t* sp, intptr_t* younger_sp, bool younger_frame_is_interpreted) :

   _sp(sp),

   _younger_sp(younger_sp),

   _deopt_state(unknown),

   _sp_adjustment_by_callee(0) {

   if (younger_sp == NULL) {

     // make a deficient frame which doesn't know where its PC is

     _pc = NULL;

     _cb = NULL;

   } else {

     _pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;

     assert( (intptr_t*)younger_sp[FP->sp_offset_in_saved_window()] == (intptr_t*)((intptr_t)sp - STACK_BIAS), "younger_sp must be valid");

     // Any frame we ever build should always "safe" therefore we should not have to call

     // find_blob_unsafe

     // In case of native stubs, the pc retrieved here might be

     // wrong.  (the _last_native_pc will have the right value)

     // So do not put add any asserts on the _pc here.

   }

   if (_pc != NULL)

     _cb = CodeCache::find_blob(_pc);

   // Check for MethodHandle call sites.

   if (_cb != NULL) {

     nmethod* nm = _cb->as_nmethod_or_null();

     if (nm != NULL) {

       if (nm->is_deopt_mh_entry(_pc) || nm->is_method_handle_return(_pc)) {

         _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) sp[L7_mh_SP_save->sp_offset_in_saved_window()] + STACK_BIAS) - sp;

         // The SP is already adjusted by this MH call site, don't

         // overwrite this value with the wrong interpreter value.

         younger_frame_is_interpreted = false;

       }

     }

   }

   if (younger_frame_is_interpreted) {

     // compute adjustment to this frame's SP made by its interpreted callee

     _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) younger_sp[I5_savedSP->sp_offset_in_saved_window()] + STACK_BIAS) - sp;

   }

   // It is important that the frame is fully constructed when we do

   // this lookup as get_deopt_original_pc() needs a correct value for

   // unextended_sp() which uses _sp_adjustment_by_callee.

   if (_pc != NULL) {

     address original_pc = nmethod::get_deopt_original_pc(this);

     if (original_pc != NULL) {

       _pc = original_pc;

       _deopt_state = is_deoptimized;

     } else {

       _deopt_state = not_deoptimized;

     }

   }

 }

 bool frame::is_interpreted_frame() const  {

   return Interpreter::contains(pc());

 }

 // sender_sp

 intptr_t* frame::interpreter_frame_sender_sp() const {

   assert(is_interpreted_frame(), "interpreted frame expected");

   return fp();

 }

 #ifndef CC_INTERP

 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {

   assert(is_interpreted_frame(), "interpreted frame expected");

   Unimplemented();

 }

 #endif // CC_INTERP

 #ifdef ASSERT

 // Debugging aid

 static frame nth_sender(int n) {

   frame f = JavaThread::current()->last_frame();

   for(int i = 0; i < n; ++i)

     f = f.sender((RegisterMap*)NULL);

   printf("first frame %d\n",          f.is_first_frame()       ? 1 : 0);

   printf("interpreted frame %d\n",    f.is_interpreted_frame() ? 1 : 0);

   printf("java frame %d\n",           f.is_java_frame()        ? 1 : 0);

   printf("entry frame %d\n",          f.is_entry_frame()       ? 1 : 0);

   printf("native frame %d\n",         f.is_native_frame()      ? 1 : 0);

   if (f.is_compiled_frame()) {

     if (f.is_deoptimized_frame())

       printf("deoptimized frame 1\n");

     else

       printf("compiled frame 1\n");

   }

   return f;

 }

 #endif

 frame frame::sender_for_entry_frame(RegisterMap *map) const {

   assert(map != NULL, "map must be set");

   // Java frame called from C; skip all C frames and return top C

   // frame of that chunk as the sender

   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();

   assert(!entry_frame_is_first(), "next Java fp must be non zero");

   assert(jfa->last_Java_sp() > _sp, "must be above this frame on stack");

   intptr_t* last_Java_sp = jfa->last_Java_sp();

   // Since we are walking the stack now this nested anchor is obviously walkable

   // even if it wasn't when it was stacked.

   if (!jfa->walkable()) {

     // Capture _last_Java_pc (if needed) and mark anchor walkable.

     jfa->capture_last_Java_pc(_sp);

   }

   assert(jfa->last_Java_pc() != NULL, "No captured pc!");

   map->clear();

   map->make_integer_regs_unsaved();

   map->shift_window(last_Java_sp, NULL);

   assert(map->include_argument_oops(), "should be set by clear");

   return frame(last_Java_sp, frame::unpatchable, jfa->last_Java_pc());

 }

 frame frame::sender_for_interpreter_frame(RegisterMap *map) const {

   ShouldNotCallThis();

   return sender(map);

 }

 frame frame::sender_for_compiled_frame(RegisterMap *map) const {

   ShouldNotCallThis();

   return sender(map);

 }

 frame frame::sender(RegisterMap* map) const {

   assert(map != NULL, "map must be set");

   assert(CodeCache::find_blob_unsafe(_pc) == _cb, "inconsistent");

   // Default is not to follow arguments; update it accordingly below

   map->set_include_argument_oops(false);

   if (is_entry_frame()) return sender_for_entry_frame(map);

   intptr_t* younger_sp = sp();

   intptr_t* sp         = sender_sp();

   // Note:  The version of this operation on any platform with callee-save

   //        registers must update the register map (if not null).

   //        In order to do this correctly, the various subtypes of

   //        of frame (interpreted, compiled, glue, native),

   //        must be distinguished.  There is no need on SPARC for

   //        such distinctions, because all callee-save registers are

   //        preserved for all frames via SPARC-specific mechanisms.

   //

   //        *** HOWEVER, *** if and when we make any floating-point

   //        registers callee-saved, then we will have to copy over

   //        the RegisterMap update logic from the Intel code.

   // The constructor of the sender must know whether this frame is interpreted so it can set the

   // sender's _sp_adjustment_by_callee field.  An osr adapter frame was originally

   // interpreted but its pc is in the code cache (for c1 -> osr_frame_return_id stub), so it must be

   // explicitly recognized.

   bool frame_is_interpreted = is_interpreted_frame();

   if (frame_is_interpreted) {

     map->make_integer_regs_unsaved();

     map->shift_window(sp, younger_sp);

   } else if (_cb != NULL) {

     // Update the locations of implicitly saved registers to be their

     // addresses in the register save area.

     // For %o registers, the addresses of %i registers in the next younger

     // frame are used.

     map->shift_window(sp, younger_sp);

     if (map->update_map()) {

       // Tell GC to use argument oopmaps for some runtime stubs that need it.

       // For C1, the runtime stub might not have oop maps, so set this flag

       // outside of update_register_map.

       map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));

       if (_cb->oop_maps() != NULL) {

         OopMapSet::update_register_map(this, map);

       }

     }

   }

   return frame(sp, younger_sp, frame_is_interpreted);

 }

 void frame::patch_pc(Thread* thread, address pc) {

   if(thread == Thread::current()) {

    StubRoutines::Sparc::flush_callers_register_windows_func()();

   }

   if (TracePcPatching) {

     // QQQ this assert is invalid (or too strong anyway) sice _pc could

     // be original pc and frame could have the deopt pc.

     // assert(_pc == *O7_addr() + pc_return_offset, "frame has wrong pc");

     tty->print_cr("patch_pc at address  0x%x [0x%x -> 0x%x] ", O7_addr(), _pc, pc);

   }

   _cb = CodeCache::find_blob(pc);

   *O7_addr() = pc - pc_return_offset;

   _cb = CodeCache::find_blob(_pc);

   address original_pc = nmethod::get_deopt_original_pc(this);

   if (original_pc != NULL) {

     assert(original_pc == _pc, "expected original to be stored before patching");

     _deopt_state = is_deoptimized;

   } else {

     _deopt_state = not_deoptimized;

   }

 }

 static bool sp_is_valid(intptr_t* old_sp, intptr_t* young_sp, intptr_t* sp) {

   return (((intptr_t)sp & (2*wordSize-1)) == 0 &&

           sp <= old_sp &&

           sp >= young_sp);

 }

 /*

   Find the (biased) sp that is just younger than old_sp starting at sp.

   If not found return NULL. Register windows are assumed to be flushed.

 */

 intptr_t* frame::next_younger_sp_or_null(intptr_t* old_sp, intptr_t* sp) {

   intptr_t* previous_sp = NULL;

   intptr_t* orig_sp = sp;

   int max_frames = (old_sp - sp) / 16; // Minimum frame size is 16

   int max_frame2 = max_frames;

   while(sp != old_sp && sp_is_valid(old_sp, orig_sp, sp)) {

     if (max_frames-- <= 0)

       // too many frames have gone by; invalid parameters given to this function

       break;

     previous_sp = sp;

     sp = (intptr_t*)sp[FP->sp_offset_in_saved_window()];

     sp = (intptr_t*)((intptr_t)sp + STACK_BIAS);

   }

   return (sp == old_sp ? previous_sp : NULL);

 }

 /*

   Determine if "sp" is a valid stack pointer. "sp" is assumed to be younger than

   "valid_sp". So if "sp" is valid itself then it should be possible to walk frames

   from "sp" to "valid_sp". The assumption is that the registers windows for the

   thread stack in question are flushed.

 */

 bool frame::is_valid_stack_pointer(intptr_t* valid_sp, intptr_t* sp) {

   return next_younger_sp_or_null(valid_sp, sp) != NULL;

 }

 bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {

   assert(is_interpreted_frame(), "must be interpreter frame");

   return this->fp() == fp;

 }

 void frame::pd_gc_epilog() {

   if (is_interpreted_frame()) {

     // set constant pool cache entry for interpreter

     Method* m = interpreter_frame_method();

     *interpreter_frame_cpoolcache_addr() = m->constants()->cache();

   }

 }

 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {

 #ifdef CC_INTERP

   // Is there anything to do?

 #else

   assert(is_interpreted_frame(), "Not an interpreted frame");

   // These are reasonable sanity checks

   if (fp() == 0 || (intptr_t(fp()) & (2*wordSize-1)) != 0) {

     return false;

   }

   if (sp() == 0 || (intptr_t(sp()) & (2*wordSize-1)) != 0) {

     return false;

   }

   const intptr_t interpreter_frame_initial_sp_offset = interpreter_frame_vm_local_words;

   if (fp() + interpreter_frame_initial_sp_offset < sp()) {

     return false;

   }

   // These are hacks to keep us out of trouble.

   // The problem with these is that they mask other problems

   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above

     return false;

   }

   // do some validation of frame elements

   // first the method

   Method* m = *interpreter_frame_method_addr();

   // validate the method we'd find in this potential sender

   if (!m->is_valid_method()) return false;

   // stack frames shouldn't be much larger than max_stack elements

   if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {

     return false;

   }

   // validate bci/bcx

   intptr_t  bcx    = interpreter_frame_bcx();

   if (m->validate_bci_from_bcx(bcx) < 0) {

     return false;

   }

   // validate ConstantPoolCache*

   ConstantPoolCache* cp = *interpreter_frame_cache_addr();

   if (cp == NULL || !cp->is_metaspace_object()) return false;

   // validate locals

   address locals =  (address) *interpreter_frame_locals_addr();

   if (locals > thread->stack_base() || locals < (address) fp()) return false;

   // We'd have to be pretty unlucky to be mislead at this point

 #endif /* CC_INTERP */

   return true;

 }

 // Windows have been flushed on entry (but not marked). Capture the pc that

 // is the return address to the frame that contains "sp" as its stack pointer.

 // This pc resides in the called of the frame corresponding to "sp".

 // As a side effect we mark this JavaFrameAnchor as having flushed the windows.

 // This side effect lets us mark stacked JavaFrameAnchors (stacked in the

 // call_helper) as flushed when we have flushed the windows for the most

 // recent (i.e. current) JavaFrameAnchor. This saves useless flushing calls

 // and lets us find the pc just once rather than multiple times as it did

 // in the bad old _post_Java_state days.

 //

 void JavaFrameAnchor::capture_last_Java_pc(intptr_t* sp) {

   if (last_Java_sp() != NULL && last_Java_pc() == NULL) {

     // try and find the sp just younger than _last_Java_sp

     intptr_t* _post_Java_sp = frame::next_younger_sp_or_null(last_Java_sp(), sp);

     // Really this should never fail otherwise VM call must have non-standard

     // frame linkage (bad) or stack is not properly flushed (worse).

     guarantee(_post_Java_sp != NULL, "bad stack!");

     _last_Java_pc = (address) _post_Java_sp[ I7->sp_offset_in_saved_window()] + frame::pc_return_offset;

   }

   set_window_flushed();

 }

 void JavaFrameAnchor::make_walkable(JavaThread* thread) {

   if (walkable()) return;

   // Eventually make an assert

   guarantee(Thread::current() == (Thread*)thread, "only current thread can flush its registers");

   // We always flush in case the profiler wants it but we won't mark

   // the windows as flushed unless we have a last_Java_frame

   intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();

   if (last_Java_sp() != NULL ) {

     capture_last_Java_pc(sp);

   }

 }

 intptr_t* frame::entry_frame_argument_at(int offset) const {

   // convert offset to index to deal with tsi

   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);

   intptr_t* LSP = (intptr_t*) sp()[Lentry_args->sp_offset_in_saved_window()];

   return &LSP[index+1];

 }

 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {

   assert(is_interpreted_frame(), "interpreted frame expected");

   Method* method = interpreter_frame_method();

   BasicType type = method->result_type();

   if (method->is_native()) {

     // Prior to notifying the runtime of the method_exit the possible result

     // value is saved to l_scratch and d_scratch.

 #ifdef CC_INTERP

     interpreterState istate = get_interpreterState();

     intptr_t* l_scratch = (intptr_t*) &istate->_native_lresult;

     intptr_t* d_scratch = (intptr_t*) &istate->_native_fresult;

 #else /* CC_INTERP */

     intptr_t* l_scratch = fp() + interpreter_frame_l_scratch_fp_offset;

     intptr_t* d_scratch = fp() + interpreter_frame_d_scratch_fp_offset;

 #endif /* CC_INTERP */

     address l_addr = (address)l_scratch;

 #ifdef _LP64

     // On 64-bit the result for 1/8/16/32-bit result types is in the other

     // word half

     l_addr += wordSize/2;

 #endif

     switch (type) {

       case T_OBJECT:

       case T_ARRAY: {

 #ifdef CC_INTERP

         *oop_result = istate->_oop_temp;

 #else

         oop obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));

         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");

         *oop_result = obj;

 #endif // CC_INTERP

         break;

       }

       case T_BOOLEAN : { jint* p = (jint*)l_addr; value_result->z = (jboolean)((*p) & 0x1); break; }

       case T_BYTE    : { jint* p = (jint*)l_addr; value_result->b = (jbyte)((*p) & 0xff); break; }

       case T_CHAR    : { jint* p = (jint*)l_addr; value_result->c = (jchar)((*p) & 0xffff); break; }

       case T_SHORT   : { jint* p = (jint*)l_addr; value_result->s = (jshort)((*p) & 0xffff); break; }

       case T_INT     : value_result->i = *(jint*)l_addr; break;

       case T_LONG    : value_result->j = *(jlong*)l_scratch; break;

       case T_FLOAT   : value_result->f = *(jfloat*)d_scratch; break;

       case T_DOUBLE  : value_result->d = *(jdouble*)d_scratch; break;

       case T_VOID    : /* Nothing to do */ break;

       default        : ShouldNotReachHere();

     }

   } else {

     intptr_t* tos_addr = interpreter_frame_tos_address();

     switch(type) {

       case T_OBJECT:

       case T_ARRAY: {

         oop obj = cast_to_oop(*tos_addr);

         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");

         *oop_result = obj;

         break;

       }

       case T_BOOLEAN : { jint* p = (jint*)tos_addr; value_result->z = (jboolean)((*p) & 0x1); break; }

       case T_BYTE    : { jint* p = (jint*)tos_addr; value_result->b = (jbyte)((*p) & 0xff); break; }

       case T_CHAR    : { jint* p = (jint*)tos_addr; value_result->c = (jchar)((*p) & 0xffff); break; }

       case T_SHORT   : { jint* p = (jint*)tos_addr; value_result->s = (jshort)((*p) & 0xffff); break; }

       case T_INT     : value_result->i = *(jint*)tos_addr; break;

       case T_LONG    : value_result->j = *(jlong*)tos_addr; break;

       case T_FLOAT   : value_result->f = *(jfloat*)tos_addr; break;

       case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;

       case T_VOID    : /* Nothing to do */ break;

       default        : ShouldNotReachHere();

     }

   };

   return type;

 }

 // Lesp pointer is one word lower than the top item on the stack.

 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {

   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize) - 1;

   return &interpreter_frame_tos_address()[index];

 }

 #ifndef PRODUCT

 #define DESCRIBE_FP_OFFSET(name) \

   values.describe(frame_no, fp() + frame::name##_offset, #name)

 void frame::describe_pd(FrameValues& values, int frame_no) {

   for (int w = 0; w < frame::register_save_words; w++) {

     values.describe(frame_no, sp() + w, err_msg("register save area word %d", w), 1);

   }

   if (is_interpreted_frame()) {

     DESCRIBE_FP_OFFSET(interpreter_frame_d_scratch_fp);

     DESCRIBE_FP_OFFSET(interpreter_frame_l_scratch_fp);

     DESCRIBE_FP_OFFSET(interpreter_frame_padding);

     DESCRIBE_FP_OFFSET(interpreter_frame_oop_temp);

     // esp, according to Lesp (e.g. not depending on bci), if seems valid

     intptr_t* esp = *interpreter_frame_esp_addr();

     if ((esp >= sp()) && (esp < fp())) {

       values.describe(-1, esp, "*Lesp");

     }

   }

   if (!is_compiled_frame()) {

     if (frame::callee_aggregate_return_pointer_words != 0) {

       values.describe(frame_no, sp() + frame::callee_aggregate_return_pointer_sp_offset, "callee_aggregate_return_pointer_word");

     }

     for (int w = 0; w < frame::callee_register_argument_save_area_words; w++) {

       values.describe(frame_no, sp() + frame::callee_register_argument_save_area_sp_offset + w,

                       err_msg("callee_register_argument_save_area_words %d", w));

     }

   }

 }

 #endif

 intptr_t *frame::initial_deoptimization_info() {

   // unused... but returns fp() to minimize changes introduced by 7087445

   return fp();

 }