1 /*
   2  * Copyright 1997-2010 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_compiledIC.cpp.incl"
  27 
  28 
  29 // Every time a compiled IC is changed or its type is being accessed,
  30 // either the CompiledIC_lock must be set or we must be at a safe point.
  31 
  32 //-----------------------------------------------------------------------------
  33 // Low-level access to an inline cache. Private, since they might not be
  34 // MT-safe to use.
  35 
  36 void CompiledIC::set_cached_oop(oop cache) {
  37   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
  38   assert (!is_optimized(), "an optimized virtual call does not have a cached oop");
  39   assert (cache == NULL || cache != badOop, "invalid oop");
  40 
  41   if (TraceCompiledIC) {
  42     tty->print("  ");
  43     print_compiled_ic();
  44     tty->print_cr(" changing oop to " INTPTR_FORMAT, (address)cache);
  45   }
  46 
  47   if (cache == NULL)  cache = (oop)Universe::non_oop_word();
  48 
  49   *_oop_addr = cache;
  50   // fix up the relocations
  51   RelocIterator iter = _oops;
  52   while (iter.next()) {
  53     if (iter.type() == relocInfo::oop_type) {
  54       oop_Relocation* r = iter.oop_reloc();
  55       if (r->oop_addr() == _oop_addr)
  56         r->fix_oop_relocation();
  57     }
  58   }
  59   return;
  60 }
  61 
  62 
  63 oop CompiledIC::cached_oop() const {
  64   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
  65   assert (!is_optimized(), "an optimized virtual call does not have a cached oop");
  66 
  67   if (!is_in_transition_state()) {
  68     oop data = *_oop_addr;
  69     // If we let the oop value here be initialized to zero...
  70     assert(data != NULL || Universe::non_oop_word() == NULL,
  71            "no raw nulls in CompiledIC oops, because of patching races");
  72     return (data == (oop)Universe::non_oop_word()) ? (oop)NULL : data;
  73   } else {
  74     return InlineCacheBuffer::cached_oop_for((CompiledIC *)this);
  75   }
  76 }
  77 
  78 
  79 void CompiledIC::set_ic_destination(address entry_point) {
  80   assert(entry_point != NULL, "must set legal entry point");
  81   assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
  82   if (TraceCompiledIC) {
  83     tty->print("  ");
  84     print_compiled_ic();
  85     tty->print_cr(" changing destination to " INTPTR_FORMAT, entry_point);
  86   }
  87   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
  88 #ifdef ASSERT
  89   CodeBlob* cb = CodeCache::find_blob_unsafe(_ic_call);
  90   assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
  91 #endif
  92   _ic_call->set_destination_mt_safe(entry_point);
  93 }
  94 
  95 
  96 address CompiledIC::ic_destination() const {
  97  assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
  98  if (!is_in_transition_state()) {
  99    return _ic_call->destination();
 100  } else {
 101    return InlineCacheBuffer::ic_destination_for((CompiledIC *)this);
 102  }
 103 }
 104 
 105 
 106 bool CompiledIC::is_in_transition_state() const {
 107   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 108   return InlineCacheBuffer::contains(_ic_call->destination());
 109 }
 110 
 111 
 112 // Returns native address of 'call' instruction in inline-cache. Used by
 113 // the InlineCacheBuffer when it needs to find the stub.
 114 address CompiledIC::stub_address() const {
 115   assert(is_in_transition_state(), "should only be called when we are in a transition state");
 116   return _ic_call->destination();
 117 }
 118 
 119 
 120 //-----------------------------------------------------------------------------
 121 // High-level access to an inline cache. Guaranteed to be MT-safe.
 122 
 123 
 124 void CompiledIC::set_to_megamorphic(CallInfo* call_info, Bytecodes::Code bytecode, TRAPS) {
 125   methodHandle method = call_info->selected_method();
 126   bool is_invoke_interface = (bytecode == Bytecodes::_invokeinterface && !call_info->has_vtable_index());
 127   assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 128   assert(method->is_oop(), "cannot be NULL and must be oop");
 129   assert(!is_optimized(), "cannot set an optimized virtual call to megamorphic");
 130   assert(is_call_to_compiled() || is_call_to_interpreted(), "going directly to megamorphic?");
 131 
 132   address entry;
 133   if (is_invoke_interface) {
 134     int index = klassItable::compute_itable_index(call_info->resolved_method()());
 135     entry = VtableStubs::create_stub(false, index, method());
 136     assert(entry != NULL, "entry not computed");
 137     klassOop k = call_info->resolved_method()->method_holder();
 138     assert(Klass::cast(k)->is_interface(), "sanity check");
 139     InlineCacheBuffer::create_transition_stub(this, k, entry);
 140   } else {
 141     // Can be different than method->vtable_index(), due to package-private etc.
 142     int vtable_index = call_info->vtable_index();
 143     entry = VtableStubs::create_stub(true, vtable_index, method());
 144     InlineCacheBuffer::create_transition_stub(this, method(), entry);
 145   }
 146 
 147   if (TraceICs) {
 148     ResourceMark rm;
 149     tty->print_cr ("IC@" INTPTR_FORMAT ": to megamorphic %s entry: " INTPTR_FORMAT,
 150                    instruction_address(), method->print_value_string(), entry);
 151   }
 152 
 153   Events::log("compiledIC " INTPTR_FORMAT " --> megamorphic " INTPTR_FORMAT, this, (address)method());
 154   // We can't check this anymore. With lazy deopt we could have already
 155   // cleaned this IC entry before we even return. This is possible if
 156   // we ran out of space in the inline cache buffer trying to do the
 157   // set_next and we safepointed to free up space. This is a benign
 158   // race because the IC entry was complete when we safepointed so
 159   // cleaning it immediately is harmless.
 160   // assert(is_megamorphic(), "sanity check");
 161 }
 162 
 163 
 164 // true if destination is megamorphic stub
 165 bool CompiledIC::is_megamorphic() const {
 166   assert(CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 167   assert(!is_optimized(), "an optimized call cannot be megamorphic");
 168 
 169   // Cannot rely on cached_oop. It is either an interface or a method.
 170   return VtableStubs::is_entry_point(ic_destination());
 171 }
 172 
 173 bool CompiledIC::is_call_to_compiled() const {
 174   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 175 
 176   // Use unsafe, since an inline cache might point to a zombie method. However, the zombie
 177   // method is guaranteed to still exist, since we only remove methods after all inline caches
 178   // has been cleaned up
 179   CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
 180   bool is_monomorphic = (cb != NULL && cb->is_nmethod());
 181   // Check that the cached_oop is a klass for non-optimized monomorphic calls
 182   // This assertion is invalid for compiler1: a call that does not look optimized (no static stub) can be used
 183   // for calling directly to vep without using the inline cache (i.e., cached_oop == NULL)
 184 #ifdef ASSERT
 185 #ifdef TIERED
 186   CodeBlob* caller = CodeCache::find_blob_unsafe(instruction_address());
 187   bool is_c1_method = caller->is_compiled_by_c1();
 188 #else
 189 #ifdef COMPILER1
 190   bool is_c1_method = true;
 191 #else
 192   bool is_c1_method = false;
 193 #endif // COMPILER1
 194 #endif // TIERED
 195   assert( is_c1_method ||
 196          !is_monomorphic ||
 197          is_optimized() ||
 198          (cached_oop() != NULL && cached_oop()->is_klass()), "sanity check");
 199 #endif // ASSERT
 200   return is_monomorphic;
 201 }
 202 
 203 
 204 bool CompiledIC::is_call_to_interpreted() const {
 205   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 206   // Call to interpreter if destination is either calling to a stub (if it
 207   // is optimized), or calling to an I2C blob
 208   bool is_call_to_interpreted = false;
 209   if (!is_optimized()) {
 210     // must use unsafe because the destination can be a zombie (and we're cleaning)
 211     // and the print_compiled_ic code wants to know if site (in the non-zombie)
 212     // is to the interpreter.
 213     CodeBlob* cb = CodeCache::find_blob_unsafe(ic_destination());
 214     is_call_to_interpreted = (cb != NULL && cb->is_adapter_blob());
 215     assert(!is_call_to_interpreted ||  (cached_oop() != NULL && cached_oop()->is_compiledICHolder()), "sanity check");
 216   } else {
 217     // Check if we are calling into our own codeblob (i.e., to a stub)
 218     CodeBlob* cb = CodeCache::find_blob(_ic_call->instruction_address());
 219     address dest = ic_destination();
 220 #ifdef ASSERT
 221     {
 222       CodeBlob* db = CodeCache::find_blob_unsafe(dest);
 223       assert(!db->is_adapter_blob(), "must use stub!");
 224     }
 225 #endif /* ASSERT */
 226     is_call_to_interpreted = cb->contains(dest);
 227   }
 228   return is_call_to_interpreted;
 229 }
 230 
 231 
 232 void CompiledIC::set_to_clean() {
 233   assert(SafepointSynchronize::is_at_safepoint() || CompiledIC_lock->is_locked() , "MT-unsafe call");
 234   if (TraceInlineCacheClearing || TraceICs) {
 235     tty->print_cr("IC@" INTPTR_FORMAT ": set to clean", instruction_address());
 236     print();
 237   }
 238 
 239   address entry;
 240   if (is_optimized()) {
 241     entry = SharedRuntime::get_resolve_opt_virtual_call_stub();
 242   } else {
 243     entry = SharedRuntime::get_resolve_virtual_call_stub();
 244   }
 245 
 246   // A zombie transition will always be safe, since the oop has already been set to NULL, so
 247   // we only need to patch the destination
 248   bool safe_transition = is_optimized() || SafepointSynchronize::is_at_safepoint();
 249 
 250   if (safe_transition) {
 251     if (!is_optimized()) set_cached_oop(NULL);
 252     // Kill any leftover stub we might have too
 253     if (is_in_transition_state()) {
 254       ICStub* old_stub = ICStub_from_destination_address(stub_address());
 255       old_stub->clear();
 256     }
 257     set_ic_destination(entry);
 258   } else {
 259     // Unsafe transition - create stub.
 260     InlineCacheBuffer::create_transition_stub(this, NULL, entry);
 261   }
 262   // We can't check this anymore. With lazy deopt we could have already
 263   // cleaned this IC entry before we even return. This is possible if
 264   // we ran out of space in the inline cache buffer trying to do the
 265   // set_next and we safepointed to free up space. This is a benign
 266   // race because the IC entry was complete when we safepointed so
 267   // cleaning it immediately is harmless.
 268   // assert(is_clean(), "sanity check");
 269 }
 270 
 271 
 272 bool CompiledIC::is_clean() const {
 273   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 274   bool is_clean = false;
 275   address dest = ic_destination();
 276   is_clean = dest == SharedRuntime::get_resolve_opt_virtual_call_stub() ||
 277              dest == SharedRuntime::get_resolve_virtual_call_stub();
 278   assert(!is_clean || is_optimized() || cached_oop() == NULL, "sanity check");
 279   return is_clean;
 280 }
 281 
 282 
 283 void CompiledIC::set_to_monomorphic(const CompiledICInfo& info) {
 284   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "");
 285   // Updating a cache to the wrong entry can cause bugs that are very hard
 286   // to track down - if cache entry gets invalid - we just clean it. In
 287   // this way it is always the same code path that is responsible for
 288   // updating and resolving an inline cache
 289   //
 290   // The above is no longer true. SharedRuntime::fixup_callers_callsite will change optimized
 291   // callsites. In addition ic_miss code will update a site to monomorphic if it determines
 292   // that an monomorphic call to the interpreter can now be monomorphic to compiled code.
 293   //
 294   // In both of these cases the only thing being modifed is the jump/call target and these
 295   // transitions are mt_safe
 296 
 297   Thread *thread = Thread::current();
 298   if (info._to_interpreter) {
 299     // Call to interpreter
 300     if (info.is_optimized() && is_optimized()) {
 301        assert(is_clean(), "unsafe IC path");
 302        MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 303       // the call analysis (callee structure) specifies that the call is optimized
 304       // (either because of CHA or the static target is final)
 305       // At code generation time, this call has been emitted as static call
 306       // Call via stub
 307       assert(info.cached_oop().not_null() && info.cached_oop()->is_method(), "sanity check");
 308       CompiledStaticCall* csc = compiledStaticCall_at(instruction_address());
 309       methodHandle method (thread, (methodOop)info.cached_oop()());
 310       csc->set_to_interpreted(method, info.entry());
 311       if (TraceICs) {
 312          ResourceMark rm(thread);
 313          tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter: %s",
 314            instruction_address(),
 315            method->print_value_string());
 316       }
 317     } else {
 318       // Call via method-klass-holder
 319       assert(info.cached_oop().not_null(), "must be set");
 320       InlineCacheBuffer::create_transition_stub(this, info.cached_oop()(), info.entry());
 321 
 322       if (TraceICs) {
 323          ResourceMark rm(thread);
 324          tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to interpreter via mkh", instruction_address());
 325       }
 326     }
 327   } else {
 328     // Call to compiled code
 329     bool static_bound = info.is_optimized() || (info.cached_oop().is_null());
 330 #ifdef ASSERT
 331     CodeBlob* cb = CodeCache::find_blob_unsafe(info.entry());
 332     assert (cb->is_nmethod(), "must be compiled!");
 333 #endif /* ASSERT */
 334 
 335     // This is MT safe if we come from a clean-cache and go through a
 336     // non-verified entry point
 337     bool safe = SafepointSynchronize::is_at_safepoint() ||
 338                 (!is_in_transition_state() && (info.is_optimized() || static_bound || is_clean()));
 339 
 340     if (!safe) {
 341       InlineCacheBuffer::create_transition_stub(this, info.cached_oop()(), info.entry());
 342     } else {
 343       set_ic_destination(info.entry());
 344       if (!is_optimized()) set_cached_oop(info.cached_oop()());
 345     }
 346 
 347     if (TraceICs) {
 348       ResourceMark rm(thread);
 349       assert(info.cached_oop() == NULL || info.cached_oop()()->is_klass(), "must be");
 350       tty->print_cr ("IC@" INTPTR_FORMAT ": monomorphic to compiled (rcvr klass) %s: %s",
 351         instruction_address(),
 352         ((klassOop)info.cached_oop()())->print_value_string(),
 353         (safe) ? "" : "via stub");
 354     }
 355   }
 356   // We can't check this anymore. With lazy deopt we could have already
 357   // cleaned this IC entry before we even return. This is possible if
 358   // we ran out of space in the inline cache buffer trying to do the
 359   // set_next and we safepointed to free up space. This is a benign
 360   // race because the IC entry was complete when we safepointed so
 361   // cleaning it immediately is harmless.
 362   // assert(is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
 363 }
 364 
 365 
 366 // is_optimized: Compiler has generated an optimized call (i.e., no inline
 367 // cache) static_bound: The call can be static bound (i.e, no need to use
 368 // inline cache)
 369 void CompiledIC::compute_monomorphic_entry(methodHandle method,
 370                                            KlassHandle receiver_klass,
 371                                            bool is_optimized,
 372                                            bool static_bound,
 373                                            CompiledICInfo& info,
 374                                            TRAPS) {
 375   info._is_optimized = is_optimized;
 376 
 377   nmethod* method_code = method->code();
 378   address entry = NULL;
 379   if (method_code != NULL) {
 380     // Call to compiled code
 381     if (static_bound || is_optimized) {
 382       entry      = method_code->verified_entry_point();
 383     } else {
 384       entry      = method_code->entry_point();
 385     }
 386   }
 387   if (entry != NULL) {
 388     // Call to compiled code
 389     info._entry      = entry;
 390     if (static_bound || is_optimized) {
 391       info._cached_oop = Handle(THREAD, (oop)NULL);
 392     } else {
 393       info._cached_oop = receiver_klass;
 394     }
 395     info._to_interpreter = false;
 396   } else {
 397     // Note: the following problem exists with Compiler1:
 398     //   - at compile time we may or may not know if the destination is final
 399     //   - if we know that the destination is final, we will emit an optimized
 400     //     virtual call (no inline cache), and need a methodOop to make a call
 401     //     to the interpreter
 402     //   - if we do not know if the destination is final, we emit a standard
 403     //     virtual call, and use CompiledICHolder to call interpreted code
 404     //     (no static call stub has been generated)
 405     //     However in that case we will now notice it is static_bound
 406     //     and convert the call into what looks to be an optimized
 407     //     virtual call. This causes problems in verifying the IC because
 408     //     it look vanilla but is optimized. Code in is_call_to_interpreted
 409     //     is aware of this and weakens its asserts.
 410 
 411     info._to_interpreter = true;
 412     // static_bound should imply is_optimized -- otherwise we have a
 413     // performance bug (statically-bindable method is called via
 414     // dynamically-dispatched call note: the reverse implication isn't
 415     // necessarily true -- the call may have been optimized based on compiler
 416     // analysis (static_bound is only based on "final" etc.)
 417 #ifdef COMPILER2
 418 #ifdef TIERED
 419 #if defined(ASSERT)
 420     // can't check the assert because we don't have the CompiledIC with which to
 421     // find the address if the call instruction.
 422     //
 423     // CodeBlob* cb = find_blob_unsafe(instruction_address());
 424     // assert(cb->is_compiled_by_c1() || !static_bound || is_optimized, "static_bound should imply is_optimized");
 425 #endif // ASSERT
 426 #else
 427     assert(!static_bound || is_optimized, "static_bound should imply is_optimized");
 428 #endif // TIERED
 429 #endif // COMPILER2
 430     if (is_optimized) {
 431       // Use stub entry
 432       info._entry      = method()->get_c2i_entry();
 433       info._cached_oop = method;
 434     } else {
 435       // Use mkh entry
 436       oop holder = oopFactory::new_compiledICHolder(method, receiver_klass, CHECK);
 437       info._cached_oop = Handle(THREAD, holder);
 438       info._entry      = method()->get_c2i_unverified_entry();
 439     }
 440   }
 441 }
 442 
 443 
 444 inline static RelocIterator parse_ic(nmethod* nm, address ic_call, oop* &_oop_addr, bool *is_optimized) {
 445    address  first_oop = NULL;
 446    // Mergers please note: Sun SC5.x CC insists on an lvalue for a reference parameter.
 447    nmethod* tmp_nm = nm;
 448    return virtual_call_Relocation::parse_ic(tmp_nm, ic_call, first_oop, _oop_addr, is_optimized);
 449 }
 450 
 451 CompiledIC::CompiledIC(NativeCall* ic_call)
 452   : _ic_call(ic_call),
 453     _oops(parse_ic(NULL, ic_call->instruction_address(), _oop_addr, &_is_optimized))
 454 {
 455 }
 456 
 457 
 458 CompiledIC::CompiledIC(Relocation* ic_reloc)
 459   : _ic_call(nativeCall_at(ic_reloc->addr())),
 460     _oops(parse_ic(ic_reloc->code(), ic_reloc->addr(), _oop_addr, &_is_optimized))
 461 {
 462   assert(ic_reloc->type() == relocInfo::virtual_call_type ||
 463          ic_reloc->type() == relocInfo::opt_virtual_call_type, "wrong reloc. info");
 464 }
 465 
 466 
 467 // ----------------------------------------------------------------------------
 468 
 469 void CompiledStaticCall::set_to_clean() {
 470   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
 471   // Reset call site
 472   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 473 #ifdef ASSERT
 474   CodeBlob* cb = CodeCache::find_blob_unsafe(this);
 475   assert(cb != NULL && cb->is_nmethod(), "must be nmethod");
 476 #endif
 477   set_destination_mt_safe(SharedRuntime::get_resolve_static_call_stub());
 478 
 479   // Do not reset stub here:  It is too expensive to call find_stub.
 480   // Instead, rely on caller (nmethod::clear_inline_caches) to clear
 481   // both the call and its stub.
 482 }
 483 
 484 
 485 bool CompiledStaticCall::is_clean() const {
 486   return destination() == SharedRuntime::get_resolve_static_call_stub();
 487 }
 488 
 489 bool CompiledStaticCall::is_call_to_compiled() const {
 490   return CodeCache::contains(destination());
 491 }
 492 
 493 
 494 bool CompiledStaticCall::is_call_to_interpreted() const {
 495   // It is a call to interpreted, if it calls to a stub. Hence, the destination
 496   // must be in the stub part of the nmethod that contains the call
 497   nmethod* nm = CodeCache::find_nmethod(instruction_address());
 498   return nm->stub_contains(destination());
 499 }
 500 
 501 
 502 void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
 503   address stub=find_stub();
 504   assert(stub!=NULL, "stub not found");
 505 
 506   if (TraceICs) {
 507     ResourceMark rm;
 508     tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
 509                   instruction_address(),
 510                   callee->name_and_sig_as_C_string());
 511   }
 512 
 513   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);   // creation also verifies the object
 514   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 515 
 516   assert(method_holder->data()    == 0           || method_holder->data()    == (intptr_t)callee(), "a) MT-unsafe modification of inline cache");
 517   assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry, "b) MT-unsafe modification of inline cache");
 518 
 519   // Update stub
 520   method_holder->set_data((intptr_t)callee());
 521   jump->set_jump_destination(entry);
 522 
 523   // Update jump to call
 524   set_destination_mt_safe(stub);
 525 }
 526 
 527 
 528 void CompiledStaticCall::set(const StaticCallInfo& info) {
 529   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
 530   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
 531   // Updating a cache to the wrong entry can cause bugs that are very hard
 532   // to track down - if cache entry gets invalid - we just clean it. In
 533   // this way it is always the same code path that is responsible for
 534   // updating and resolving an inline cache
 535   assert(is_clean(), "do not update a call entry - use clean");
 536 
 537   if (info._to_interpreter) {
 538     // Call to interpreted code
 539     set_to_interpreted(info.callee(), info.entry());
 540   } else {
 541     if (TraceICs) {
 542       ResourceMark rm;
 543       tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_compiled " INTPTR_FORMAT,
 544                     instruction_address(),
 545                     info.entry());
 546     }
 547     // Call to compiled code
 548     assert (CodeCache::contains(info.entry()), "wrong entry point");
 549     set_destination_mt_safe(info.entry());
 550   }
 551 }
 552 
 553 
 554 // Compute settings for a CompiledStaticCall. Since we might have to set
 555 // the stub when calling to the interpreter, we need to return arguments.
 556 void CompiledStaticCall::compute_entry(methodHandle m, StaticCallInfo& info) {
 557   nmethod* m_code = m->code();
 558   info._callee = m;
 559   if (m_code != NULL) {
 560     info._to_interpreter = false;
 561     info._entry  = m_code->verified_entry_point();
 562   } else {
 563     // Callee is interpreted code.  In any case entering the interpreter
 564     // puts a converter-frame on the stack to save arguments.
 565     info._to_interpreter = true;
 566     info._entry      = m()->get_c2i_entry();
 567   }
 568 }
 569 
 570 
 571 void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
 572   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
 573   // Reset stub
 574   address stub = static_stub->addr();
 575   assert(stub!=NULL, "stub not found");
 576   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);   // creation also verifies the object
 577   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 578   method_holder->set_data(0);
 579   jump->set_jump_destination((address)-1);
 580 }
 581 
 582 
 583 address CompiledStaticCall::find_stub() {
 584   // Find reloc. information containing this call-site
 585   RelocIterator iter((nmethod*)NULL, instruction_address());
 586   while (iter.next()) {
 587     if (iter.addr() == instruction_address()) {
 588       switch(iter.type()) {
 589         case relocInfo::static_call_type:
 590           return iter.static_call_reloc()->static_stub();
 591         // We check here for opt_virtual_call_type, since we reuse the code
 592         // from the CompiledIC implementation
 593         case relocInfo::opt_virtual_call_type:
 594           return iter.opt_virtual_call_reloc()->static_stub();
 595         case relocInfo::poll_type:
 596         case relocInfo::poll_return_type: // A safepoint can't overlap a call.
 597         default:
 598           ShouldNotReachHere();
 599       }
 600     }
 601   }
 602   return NULL;
 603 }
 604 
 605 
 606 //-----------------------------------------------------------------------------
 607 // Non-product mode code
 608 #ifndef PRODUCT
 609 
 610 void CompiledIC::verify() {
 611   // make sure code pattern is actually a call imm32 instruction
 612   _ic_call->verify();
 613   if (os::is_MP()) {
 614     _ic_call->verify_alignment();
 615   }
 616   assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted()
 617           || is_optimized() || is_megamorphic(), "sanity check");
 618 }
 619 
 620 
 621 void CompiledIC::print() {
 622   print_compiled_ic();
 623   tty->cr();
 624 }
 625 
 626 
 627 void CompiledIC::print_compiled_ic() {
 628   tty->print("Inline cache at " INTPTR_FORMAT ", calling %s " INTPTR_FORMAT,
 629              instruction_address(), is_call_to_interpreted() ? "interpreted " : "", ic_destination());
 630 }
 631 
 632 
 633 void CompiledStaticCall::print() {
 634   tty->print("static call at " INTPTR_FORMAT " -> ", instruction_address());
 635   if (is_clean()) {
 636     tty->print("clean");
 637   } else if (is_call_to_compiled()) {
 638     tty->print("compiled");
 639   } else if (is_call_to_interpreted()) {
 640     tty->print("interpreted");
 641   }
 642   tty->cr();
 643 }
 644 
 645 void CompiledStaticCall::verify() {
 646   // Verify call
 647   NativeCall::verify();
 648   if (os::is_MP()) {
 649     verify_alignment();
 650   }
 651 
 652   // Verify stub
 653   address stub = find_stub();
 654   assert(stub != NULL, "no stub found for static call");
 655   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);   // creation also verifies the object
 656   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 657 
 658   // Verify state
 659   assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
 660 }
 661 
 662 #endif