1 /*
   2  * Copyright (c) 1999, 2022, 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 "asm/codeBuffer.hpp"
  27 #include "c1/c1_CodeStubs.hpp"
  28 #include "c1/c1_Defs.hpp"
  29 #include "c1/c1_FrameMap.hpp"
  30 #include "c1/c1_LIRAssembler.hpp"
  31 #include "c1/c1_MacroAssembler.hpp"
  32 #include "c1/c1_Runtime1.hpp"
  33 #include "classfile/javaClasses.inline.hpp"
  34 #include "classfile/vmClasses.hpp"
  35 #include "classfile/vmSymbols.hpp"
  36 #include "code/codeBlob.hpp"
  37 #include "code/compiledIC.hpp"
  38 #include "code/pcDesc.hpp"
  39 #include "code/scopeDesc.hpp"
  40 #include "code/vtableStubs.hpp"
  41 #include "compiler/compilationPolicy.hpp"
  42 #include "compiler/disassembler.hpp"
  43 #include "compiler/oopMap.hpp"
  44 #include "gc/shared/barrierSet.hpp"
  45 #include "gc/shared/c1/barrierSetC1.hpp"
  46 #include "gc/shared/collectedHeap.hpp"
  47 #include "interpreter/bytecode.hpp"
  48 #include "interpreter/interpreter.hpp"
  49 #include "jfr/support/jfrIntrinsics.hpp"
  50 #include "logging/log.hpp"
  51 #include "memory/allocation.inline.hpp"
  52 #include "memory/oopFactory.hpp"
  53 #include "memory/resourceArea.hpp"
  54 #include "memory/universe.hpp"
  55 #include "oops/access.inline.hpp"
  56 #include "oops/klass.inline.hpp"
  57 #include "oops/objArrayOop.inline.hpp"
  58 #include "oops/objArrayKlass.hpp"
  59 #include "oops/oop.inline.hpp"
  60 #include "prims/jvmtiExport.hpp"
  61 #include "runtime/atomic.hpp"
  62 #include "runtime/fieldDescriptor.inline.hpp"
  63 #include "runtime/frame.inline.hpp"
  64 #include "runtime/handles.inline.hpp"
  65 #include "runtime/interfaceSupport.inline.hpp"
  66 #include "runtime/javaCalls.hpp"
  67 #include "runtime/sharedRuntime.hpp"
  68 #include "runtime/stackWatermarkSet.hpp"
  69 #include "runtime/stubRoutines.hpp"
  70 #include "runtime/threadCritical.hpp"
  71 #include "runtime/vframe.inline.hpp"
  72 #include "runtime/vframeArray.hpp"
  73 #include "runtime/vm_version.hpp"
  74 #include "utilities/copy.hpp"
  75 #include "utilities/events.hpp"
  76 
  77 
  78 // Implementation of StubAssembler
  79 
  80 StubAssembler::StubAssembler(CodeBuffer* code, const char * name, int stub_id) : C1_MacroAssembler(code) {
  81   _name = name;
  82   _must_gc_arguments = false;
  83   _frame_size = no_frame_size;
  84   _num_rt_args = 0;
  85   _stub_id = stub_id;
  86 }
  87 
  88 
  89 void StubAssembler::set_info(const char* name, bool must_gc_arguments) {
  90   _name = name;
  91   _must_gc_arguments = must_gc_arguments;
  92 }
  93 
  94 
  95 void StubAssembler::set_frame_size(int size) {
  96   if (_frame_size == no_frame_size) {
  97     _frame_size = size;
  98   }
  99   assert(_frame_size == size, "can't change the frame size");
 100 }
 101 
 102 
 103 void StubAssembler::set_num_rt_args(int args) {
 104   if (_num_rt_args == 0) {
 105     _num_rt_args = args;
 106   }
 107   assert(_num_rt_args == args, "can't change the number of args");
 108 }
 109 
 110 // Implementation of Runtime1
 111 
 112 CodeBlob* Runtime1::_blobs[Runtime1::number_of_ids];
 113 const char *Runtime1::_blob_names[] = {
 114   RUNTIME1_STUBS(STUB_NAME, LAST_STUB_NAME)
 115 };
 116 
 117 #ifndef PRODUCT
 118 // statistics
 119 int Runtime1::_generic_arraycopystub_cnt = 0;
 120 int Runtime1::_arraycopy_slowcase_cnt = 0;
 121 int Runtime1::_arraycopy_checkcast_cnt = 0;
 122 int Runtime1::_arraycopy_checkcast_attempt_cnt = 0;
 123 int Runtime1::_new_type_array_slowcase_cnt = 0;
 124 int Runtime1::_new_object_array_slowcase_cnt = 0;
 125 int Runtime1::_new_instance_slowcase_cnt = 0;
 126 int Runtime1::_new_multi_array_slowcase_cnt = 0;
 127 int Runtime1::_monitorenter_slowcase_cnt = 0;
 128 int Runtime1::_monitorexit_slowcase_cnt = 0;
 129 int Runtime1::_patch_code_slowcase_cnt = 0;
 130 int Runtime1::_throw_range_check_exception_count = 0;
 131 int Runtime1::_throw_index_exception_count = 0;
 132 int Runtime1::_throw_div0_exception_count = 0;
 133 int Runtime1::_throw_null_pointer_exception_count = 0;
 134 int Runtime1::_throw_class_cast_exception_count = 0;
 135 int Runtime1::_throw_incompatible_class_change_error_count = 0;
 136 int Runtime1::_throw_count = 0;
 137 
 138 static int _byte_arraycopy_stub_cnt = 0;
 139 static int _short_arraycopy_stub_cnt = 0;
 140 static int _int_arraycopy_stub_cnt = 0;
 141 static int _long_arraycopy_stub_cnt = 0;
 142 static int _oop_arraycopy_stub_cnt = 0;
 143 
 144 address Runtime1::arraycopy_count_address(BasicType type) {
 145   switch (type) {
 146   case T_BOOLEAN:
 147   case T_BYTE:   return (address)&_byte_arraycopy_stub_cnt;
 148   case T_CHAR:
 149   case T_SHORT:  return (address)&_short_arraycopy_stub_cnt;
 150   case T_FLOAT:
 151   case T_INT:    return (address)&_int_arraycopy_stub_cnt;
 152   case T_DOUBLE:
 153   case T_LONG:   return (address)&_long_arraycopy_stub_cnt;
 154   case T_ARRAY:
 155   case T_OBJECT: return (address)&_oop_arraycopy_stub_cnt;
 156   default:
 157     ShouldNotReachHere();
 158     return NULL;
 159   }
 160 }
 161 
 162 
 163 #endif
 164 
 165 // Simple helper to see if the caller of a runtime stub which
 166 // entered the VM has been deoptimized
 167 
 168 static bool caller_is_deopted(JavaThread* current) {
 169   RegisterMap reg_map(current, false);
 170   frame runtime_frame = current->last_frame();
 171   frame caller_frame = runtime_frame.sender(&reg_map);
 172   assert(caller_frame.is_compiled_frame(), "must be compiled");
 173   return caller_frame.is_deoptimized_frame();
 174 }
 175 
 176 // Stress deoptimization
 177 static void deopt_caller(JavaThread* current) {
 178   if (!caller_is_deopted(current)) {
 179     RegisterMap reg_map(current, false);
 180     frame runtime_frame = current->last_frame();
 181     frame caller_frame = runtime_frame.sender(&reg_map);
 182     Deoptimization::deoptimize_frame(current, caller_frame.id());
 183     assert(caller_is_deopted(current), "Must be deoptimized");
 184   }
 185 }
 186 
 187 class StubIDStubAssemblerCodeGenClosure: public StubAssemblerCodeGenClosure {
 188  private:
 189   Runtime1::StubID _id;
 190  public:
 191   StubIDStubAssemblerCodeGenClosure(Runtime1::StubID id) : _id(id) {}
 192   virtual OopMapSet* generate_code(StubAssembler* sasm) {
 193     return Runtime1::generate_code_for(_id, sasm);
 194   }
 195 };
 196 
 197 CodeBlob* Runtime1::generate_blob(BufferBlob* buffer_blob, int stub_id, const char* name, bool expect_oop_map, StubAssemblerCodeGenClosure* cl) {
 198   ResourceMark rm;
 199   // create code buffer for code storage
 200   CodeBuffer code(buffer_blob);
 201 
 202   OopMapSet* oop_maps;
 203   int frame_size;
 204   bool must_gc_arguments;
 205 
 206   Compilation::setup_code_buffer(&code, 0);
 207 
 208   // create assembler for code generation
 209   StubAssembler* sasm = new StubAssembler(&code, name, stub_id);
 210   // generate code for runtime stub
 211   oop_maps = cl->generate_code(sasm);
 212   assert(oop_maps == NULL || sasm->frame_size() != no_frame_size,
 213          "if stub has an oop map it must have a valid frame size");
 214   assert(!expect_oop_map || oop_maps != NULL, "must have an oopmap");
 215 
 216   // align so printing shows nop's instead of random code at the end (SimpleStubs are aligned)
 217   sasm->align(BytesPerWord);
 218   // make sure all code is in code buffer
 219   sasm->flush();
 220 
 221   frame_size = sasm->frame_size();
 222   must_gc_arguments = sasm->must_gc_arguments();
 223   // create blob - distinguish a few special cases
 224   CodeBlob* blob = RuntimeStub::new_runtime_stub(name,
 225                                                  &code,
 226                                                  CodeOffsets::frame_never_safe,
 227                                                  frame_size,
 228                                                  oop_maps,
 229                                                  must_gc_arguments);
 230   assert(blob != NULL, "blob must exist");
 231   return blob;
 232 }
 233 
 234 void Runtime1::generate_blob_for(BufferBlob* buffer_blob, StubID id) {
 235   assert(0 <= id && id < number_of_ids, "illegal stub id");
 236   bool expect_oop_map = true;
 237 #ifdef ASSERT
 238   // Make sure that stubs that need oopmaps have them
 239   switch (id) {
 240     // These stubs don't need to have an oopmap
 241   case load_klass_id:
 242   case dtrace_object_alloc_id:
 243   case slow_subtype_check_id:
 244   case fpu2long_stub_id:
 245   case unwind_exception_id:
 246   case counter_overflow_id:
 247     expect_oop_map = false;
 248     break;
 249   default:
 250     break;
 251   }
 252 #endif
 253   StubIDStubAssemblerCodeGenClosure cl(id);
 254   CodeBlob* blob = generate_blob(buffer_blob, id, name_for(id), expect_oop_map, &cl);
 255   // install blob
 256   _blobs[id] = blob;
 257 }
 258 
 259 void Runtime1::initialize(BufferBlob* blob) {
 260   // platform-dependent initialization
 261   initialize_pd();
 262   // generate stubs
 263   for (int id = 0; id < number_of_ids; id++) generate_blob_for(blob, (StubID)id);
 264   // printing
 265 #ifndef PRODUCT
 266   if (PrintSimpleStubs) {
 267     ResourceMark rm;
 268     for (int id = 0; id < number_of_ids; id++) {
 269       _blobs[id]->print();
 270       if (_blobs[id]->oop_maps() != NULL) {
 271         _blobs[id]->oop_maps()->print();
 272       }
 273     }
 274   }
 275 #endif
 276   BarrierSetC1* bs = BarrierSet::barrier_set()->barrier_set_c1();
 277   bs->generate_c1_runtime_stubs(blob);
 278 }
 279 
 280 CodeBlob* Runtime1::blob_for(StubID id) {
 281   assert(0 <= id && id < number_of_ids, "illegal stub id");
 282   return _blobs[id];
 283 }
 284 
 285 
 286 const char* Runtime1::name_for(StubID id) {
 287   assert(0 <= id && id < number_of_ids, "illegal stub id");
 288   return _blob_names[id];
 289 }
 290 
 291 const char* Runtime1::name_for_address(address entry) {
 292   for (int id = 0; id < number_of_ids; id++) {
 293     if (entry == entry_for((StubID)id)) return name_for((StubID)id);
 294   }
 295 
 296 #define FUNCTION_CASE(a, f) \
 297   if ((intptr_t)a == CAST_FROM_FN_PTR(intptr_t, f))  return #f
 298 
 299   FUNCTION_CASE(entry, os::javaTimeMillis);
 300   FUNCTION_CASE(entry, os::javaTimeNanos);
 301   FUNCTION_CASE(entry, SharedRuntime::OSR_migration_end);
 302   FUNCTION_CASE(entry, SharedRuntime::d2f);
 303   FUNCTION_CASE(entry, SharedRuntime::d2i);
 304   FUNCTION_CASE(entry, SharedRuntime::d2l);
 305   FUNCTION_CASE(entry, SharedRuntime::dcos);
 306   FUNCTION_CASE(entry, SharedRuntime::dexp);
 307   FUNCTION_CASE(entry, SharedRuntime::dlog);
 308   FUNCTION_CASE(entry, SharedRuntime::dlog10);
 309   FUNCTION_CASE(entry, SharedRuntime::dpow);
 310   FUNCTION_CASE(entry, SharedRuntime::drem);
 311   FUNCTION_CASE(entry, SharedRuntime::dsin);
 312   FUNCTION_CASE(entry, SharedRuntime::dtan);
 313   FUNCTION_CASE(entry, SharedRuntime::f2i);
 314   FUNCTION_CASE(entry, SharedRuntime::f2l);
 315   FUNCTION_CASE(entry, SharedRuntime::frem);
 316   FUNCTION_CASE(entry, SharedRuntime::l2d);
 317   FUNCTION_CASE(entry, SharedRuntime::l2f);
 318   FUNCTION_CASE(entry, SharedRuntime::ldiv);
 319   FUNCTION_CASE(entry, SharedRuntime::lmul);
 320   FUNCTION_CASE(entry, SharedRuntime::lrem);
 321   FUNCTION_CASE(entry, SharedRuntime::lrem);
 322   FUNCTION_CASE(entry, SharedRuntime::dtrace_method_entry);
 323   FUNCTION_CASE(entry, SharedRuntime::dtrace_method_exit);
 324   FUNCTION_CASE(entry, is_instance_of);
 325   FUNCTION_CASE(entry, trace_block_entry);
 326 #ifdef JFR_HAVE_INTRINSICS
 327   FUNCTION_CASE(entry, JFR_TIME_FUNCTION);
 328 #endif
 329   FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32());
 330   FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32C());
 331   FUNCTION_CASE(entry, StubRoutines::vectorizedMismatch());
 332   FUNCTION_CASE(entry, StubRoutines::dexp());
 333   FUNCTION_CASE(entry, StubRoutines::dlog());
 334   FUNCTION_CASE(entry, StubRoutines::dlog10());
 335   FUNCTION_CASE(entry, StubRoutines::dpow());
 336   FUNCTION_CASE(entry, StubRoutines::dsin());
 337   FUNCTION_CASE(entry, StubRoutines::dcos());
 338   FUNCTION_CASE(entry, StubRoutines::dtan());
 339 
 340 #undef FUNCTION_CASE
 341 
 342   // Soft float adds more runtime names.
 343   return pd_name_for_address(entry);
 344 }
 345 
 346 
 347 JRT_ENTRY(void, Runtime1::new_instance(JavaThread* current, Klass* klass))
 348 #ifndef PRODUCT
 349   if (PrintC1Statistics) {
 350     _new_instance_slowcase_cnt++;
 351   }
 352 #endif
 353   assert(klass->is_klass(), "not a class");
 354   Handle holder(current, klass->klass_holder()); // keep the klass alive
 355   InstanceKlass* h = InstanceKlass::cast(klass);
 356   h->check_valid_for_instantiation(true, CHECK);
 357   // make sure klass is initialized
 358   h->initialize(CHECK);
 359   // allocate instance and return via TLS
 360   oop obj = h->allocate_instance(CHECK);
 361   current->set_vm_result(obj);
 362 JRT_END
 363 
 364 
 365 JRT_ENTRY(void, Runtime1::new_type_array(JavaThread* current, Klass* klass, jint length))
 366 #ifndef PRODUCT
 367   if (PrintC1Statistics) {
 368     _new_type_array_slowcase_cnt++;
 369   }
 370 #endif
 371   // Note: no handle for klass needed since they are not used
 372   //       anymore after new_typeArray() and no GC can happen before.
 373   //       (This may have to change if this code changes!)
 374   assert(klass->is_klass(), "not a class");
 375   BasicType elt_type = TypeArrayKlass::cast(klass)->element_type();
 376   oop obj = oopFactory::new_typeArray(elt_type, length, CHECK);
 377   current->set_vm_result(obj);
 378   // This is pretty rare but this runtime patch is stressful to deoptimization
 379   // if we deoptimize here so force a deopt to stress the path.
 380   if (DeoptimizeALot) {
 381     deopt_caller(current);
 382   }
 383 
 384 JRT_END
 385 
 386 
 387 JRT_ENTRY(void, Runtime1::new_object_array(JavaThread* current, Klass* array_klass, jint length))
 388 #ifndef PRODUCT
 389   if (PrintC1Statistics) {
 390     _new_object_array_slowcase_cnt++;
 391   }
 392 #endif
 393   // Note: no handle for klass needed since they are not used
 394   //       anymore after new_objArray() and no GC can happen before.
 395   //       (This may have to change if this code changes!)
 396   assert(array_klass->is_klass(), "not a class");
 397   Handle holder(current, array_klass->klass_holder()); // keep the klass alive
 398   Klass* elem_klass = ObjArrayKlass::cast(array_klass)->element_klass();
 399   objArrayOop obj = oopFactory::new_objArray(elem_klass, length, CHECK);
 400   current->set_vm_result(obj);
 401   // This is pretty rare but this runtime patch is stressful to deoptimization
 402   // if we deoptimize here so force a deopt to stress the path.
 403   if (DeoptimizeALot) {
 404     deopt_caller(current);
 405   }
 406 JRT_END
 407 
 408 
 409 JRT_ENTRY(void, Runtime1::new_multi_array(JavaThread* current, Klass* klass, int rank, jint* dims))
 410 #ifndef PRODUCT
 411   if (PrintC1Statistics) {
 412     _new_multi_array_slowcase_cnt++;
 413   }
 414 #endif
 415   assert(klass->is_klass(), "not a class");
 416   assert(rank >= 1, "rank must be nonzero");
 417   Handle holder(current, klass->klass_holder()); // keep the klass alive
 418   oop obj = ArrayKlass::cast(klass)->multi_allocate(rank, dims, CHECK);
 419   current->set_vm_result(obj);
 420 JRT_END
 421 
 422 
 423 JRT_ENTRY(void, Runtime1::unimplemented_entry(JavaThread* current, StubID id))
 424   tty->print_cr("Runtime1::entry_for(%d) returned unimplemented entry point", id);
 425 JRT_END
 426 
 427 
 428 JRT_ENTRY(void, Runtime1::throw_array_store_exception(JavaThread* current, oopDesc* obj))
 429   ResourceMark rm(current);
 430   const char* klass_name = obj->klass()->external_name();
 431   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayStoreException(), klass_name);
 432 JRT_END
 433 
 434 
 435 // counter_overflow() is called from within C1-compiled methods. The enclosing method is the method
 436 // associated with the top activation record. The inlinee (that is possibly included in the enclosing
 437 // method) method is passed as an argument. In order to do that it is embedded in the code as
 438 // a constant.
 439 static nmethod* counter_overflow_helper(JavaThread* current, int branch_bci, Method* m) {
 440   nmethod* osr_nm = NULL;
 441   methodHandle method(current, m);
 442 
 443   RegisterMap map(current, false);
 444   frame fr =  current->last_frame().sender(&map);
 445   nmethod* nm = (nmethod*) fr.cb();
 446   assert(nm!= NULL && nm->is_nmethod(), "Sanity check");
 447   methodHandle enclosing_method(current, nm->method());
 448 
 449   CompLevel level = (CompLevel)nm->comp_level();
 450   int bci = InvocationEntryBci;
 451   if (branch_bci != InvocationEntryBci) {
 452     // Compute destination bci
 453     address pc = method()->code_base() + branch_bci;
 454     Bytecodes::Code branch = Bytecodes::code_at(method(), pc);
 455     int offset = 0;
 456     switch (branch) {
 457       case Bytecodes::_if_icmplt: case Bytecodes::_iflt:
 458       case Bytecodes::_if_icmpgt: case Bytecodes::_ifgt:
 459       case Bytecodes::_if_icmple: case Bytecodes::_ifle:
 460       case Bytecodes::_if_icmpge: case Bytecodes::_ifge:
 461       case Bytecodes::_if_icmpeq: case Bytecodes::_if_acmpeq: case Bytecodes::_ifeq:
 462       case Bytecodes::_if_icmpne: case Bytecodes::_if_acmpne: case Bytecodes::_ifne:
 463       case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: case Bytecodes::_goto:
 464         offset = (int16_t)Bytes::get_Java_u2(pc + 1);
 465         break;
 466       case Bytecodes::_goto_w:
 467         offset = Bytes::get_Java_u4(pc + 1);
 468         break;
 469       default: ;
 470     }
 471     bci = branch_bci + offset;
 472   }
 473   osr_nm = CompilationPolicy::event(enclosing_method, method, branch_bci, bci, level, nm, current);
 474   return osr_nm;
 475 }
 476 
 477 JRT_BLOCK_ENTRY(address, Runtime1::counter_overflow(JavaThread* current, int bci, Method* method))
 478   nmethod* osr_nm;
 479   JRT_BLOCK
 480     osr_nm = counter_overflow_helper(current, bci, method);
 481     if (osr_nm != NULL) {
 482       RegisterMap map(current, false);
 483       frame fr =  current->last_frame().sender(&map);
 484       Deoptimization::deoptimize_frame(current, fr.id());
 485     }
 486   JRT_BLOCK_END
 487   return NULL;
 488 JRT_END
 489 
 490 extern void vm_exit(int code);
 491 
 492 // Enter this method from compiled code handler below. This is where we transition
 493 // to VM mode. This is done as a helper routine so that the method called directly
 494 // from compiled code does not have to transition to VM. This allows the entry
 495 // method to see if the nmethod that we have just looked up a handler for has
 496 // been deoptimized while we were in the vm. This simplifies the assembly code
 497 // cpu directories.
 498 //
 499 // We are entering here from exception stub (via the entry method below)
 500 // If there is a compiled exception handler in this method, we will continue there;
 501 // otherwise we will unwind the stack and continue at the caller of top frame method
 502 // Note: we enter in Java using a special JRT wrapper. This wrapper allows us to
 503 // control the area where we can allow a safepoint. After we exit the safepoint area we can
 504 // check to see if the handler we are going to return is now in a nmethod that has
 505 // been deoptimized. If that is the case we return the deopt blob
 506 // unpack_with_exception entry instead. This makes life for the exception blob easier
 507 // because making that same check and diverting is painful from assembly language.
 508 JRT_ENTRY_NO_ASYNC(static address, exception_handler_for_pc_helper(JavaThread* current, oopDesc* ex, address pc, nmethod*& nm))
 509   // Reset method handle flag.
 510   current->set_is_method_handle_return(false);
 511 
 512   Handle exception(current, ex);
 513 
 514   // This function is called when we are about to throw an exception. Therefore,
 515   // we have to poll the stack watermark barrier to make sure that not yet safe
 516   // stack frames are made safe before returning into them.
 517   if (current->last_frame().cb() == Runtime1::blob_for(Runtime1::handle_exception_from_callee_id)) {
 518     // The Runtime1::handle_exception_from_callee_id handler is invoked after the
 519     // frame has been unwound. It instead builds its own stub frame, to call the
 520     // runtime. But the throwing frame has already been unwound here.
 521     StackWatermarkSet::after_unwind(current);
 522   }
 523 
 524   nm = CodeCache::find_nmethod(pc);
 525   assert(nm != NULL, "this is not an nmethod");
 526   // Adjust the pc as needed/
 527   if (nm->is_deopt_pc(pc)) {
 528     RegisterMap map(current, false);
 529     frame exception_frame = current->last_frame().sender(&map);
 530     // if the frame isn't deopted then pc must not correspond to the caller of last_frame
 531     assert(exception_frame.is_deoptimized_frame(), "must be deopted");
 532     pc = exception_frame.pc();
 533   }
 534   assert(exception.not_null(), "NULL exceptions should be handled by throw_exception");
 535   // Check that exception is a subclass of Throwable
 536   assert(exception->is_a(vmClasses::Throwable_klass()),
 537          "Exception not subclass of Throwable");
 538 
 539   // debugging support
 540   // tracing
 541   if (log_is_enabled(Info, exceptions)) {
 542     ResourceMark rm;
 543     stringStream tempst;
 544     assert(nm->method() != NULL, "Unexpected NULL method()");
 545     tempst.print("C1 compiled method <%s>\n"
 546                  " at PC" INTPTR_FORMAT " for thread " INTPTR_FORMAT,
 547                  nm->method()->print_value_string(), p2i(pc), p2i(current));
 548     Exceptions::log_exception(exception, tempst.as_string());
 549   }
 550   // for AbortVMOnException flag
 551   Exceptions::debug_check_abort(exception);
 552 
 553   // Check the stack guard pages and re-enable them if necessary and there is
 554   // enough space on the stack to do so.  Use fast exceptions only if the guard
 555   // pages are enabled.
 556   bool guard_pages_enabled = current->stack_overflow_state()->reguard_stack_if_needed();
 557 
 558   if (JvmtiExport::can_post_on_exceptions()) {
 559     // To ensure correct notification of exception catches and throws
 560     // we have to deoptimize here.  If we attempted to notify the
 561     // catches and throws during this exception lookup it's possible
 562     // we could deoptimize on the way out of the VM and end back in
 563     // the interpreter at the throw site.  This would result in double
 564     // notifications since the interpreter would also notify about
 565     // these same catches and throws as it unwound the frame.
 566 
 567     RegisterMap reg_map(current);
 568     frame stub_frame = current->last_frame();
 569     frame caller_frame = stub_frame.sender(&reg_map);
 570 
 571     // We don't really want to deoptimize the nmethod itself since we
 572     // can actually continue in the exception handler ourselves but I
 573     // don't see an easy way to have the desired effect.
 574     Deoptimization::deoptimize_frame(current, caller_frame.id());
 575     assert(caller_is_deopted(current), "Must be deoptimized");
 576 
 577     return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
 578   }
 579 
 580   // ExceptionCache is used only for exceptions at call sites and not for implicit exceptions
 581   if (guard_pages_enabled) {
 582     address fast_continuation = nm->handler_for_exception_and_pc(exception, pc);
 583     if (fast_continuation != NULL) {
 584       // Set flag if return address is a method handle call site.
 585       current->set_is_method_handle_return(nm->is_method_handle_return(pc));
 586       return fast_continuation;
 587     }
 588   }
 589 
 590   // If the stack guard pages are enabled, check whether there is a handler in
 591   // the current method.  Otherwise (guard pages disabled), force an unwind and
 592   // skip the exception cache update (i.e., just leave continuation==NULL).
 593   address continuation = NULL;
 594   if (guard_pages_enabled) {
 595 
 596     // New exception handling mechanism can support inlined methods
 597     // with exception handlers since the mappings are from PC to PC
 598 
 599     // Clear out the exception oop and pc since looking up an
 600     // exception handler can cause class loading, which might throw an
 601     // exception and those fields are expected to be clear during
 602     // normal bytecode execution.
 603     current->clear_exception_oop_and_pc();
 604 
 605     bool recursive_exception = false;
 606     continuation = SharedRuntime::compute_compiled_exc_handler(nm, pc, exception, false, false, recursive_exception);
 607     // If an exception was thrown during exception dispatch, the exception oop may have changed
 608     current->set_exception_oop(exception());
 609     current->set_exception_pc(pc);
 610 
 611     // the exception cache is used only by non-implicit exceptions
 612     // Update the exception cache only when there didn't happen
 613     // another exception during the computation of the compiled
 614     // exception handler. Checking for exception oop equality is not
 615     // sufficient because some exceptions are pre-allocated and reused.
 616     if (continuation != NULL && !recursive_exception) {
 617       nm->add_handler_for_exception_and_pc(exception, pc, continuation);
 618     }
 619   }
 620 
 621   current->set_vm_result(exception());
 622   // Set flag if return address is a method handle call site.
 623   current->set_is_method_handle_return(nm->is_method_handle_return(pc));
 624 
 625   if (log_is_enabled(Info, exceptions)) {
 626     ResourceMark rm;
 627     log_info(exceptions)("Thread " PTR_FORMAT " continuing at PC " PTR_FORMAT
 628                          " for exception thrown at PC " PTR_FORMAT,
 629                          p2i(current), p2i(continuation), p2i(pc));
 630   }
 631 
 632   return continuation;
 633 JRT_END
 634 
 635 // Enter this method from compiled code only if there is a Java exception handler
 636 // in the method handling the exception.
 637 // We are entering here from exception stub. We don't do a normal VM transition here.
 638 // We do it in a helper. This is so we can check to see if the nmethod we have just
 639 // searched for an exception handler has been deoptimized in the meantime.
 640 address Runtime1::exception_handler_for_pc(JavaThread* current) {
 641   oop exception = current->exception_oop();
 642   address pc = current->exception_pc();
 643   // Still in Java mode
 644   DEBUG_ONLY(NoHandleMark nhm);
 645   nmethod* nm = NULL;
 646   address continuation = NULL;
 647   {
 648     // Enter VM mode by calling the helper
 649     ResetNoHandleMark rnhm;
 650     continuation = exception_handler_for_pc_helper(current, exception, pc, nm);
 651   }
 652   // Back in JAVA, use no oops DON'T safepoint
 653 
 654   // Now check to see if the nmethod we were called from is now deoptimized.
 655   // If so we must return to the deopt blob and deoptimize the nmethod
 656   if (nm != NULL && caller_is_deopted(current)) {
 657     continuation = SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
 658   }
 659 
 660   assert(continuation != NULL, "no handler found");
 661   return continuation;
 662 }
 663 
 664 
 665 JRT_ENTRY(void, Runtime1::throw_range_check_exception(JavaThread* current, int index, arrayOopDesc* a))
 666 #ifndef PRODUCT
 667   if (PrintC1Statistics) {
 668     _throw_range_check_exception_count++;
 669   }
 670 #endif
 671   const int len = 35;
 672   assert(len < strlen("Index %d out of bounds for length %d"), "Must allocate more space for message.");
 673   char message[2 * jintAsStringSize + len];
 674   sprintf(message, "Index %d out of bounds for length %d", index, a->length());
 675   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), message);
 676 JRT_END
 677 
 678 
 679 JRT_ENTRY(void, Runtime1::throw_index_exception(JavaThread* current, int index))
 680 #ifndef PRODUCT
 681   if (PrintC1Statistics) {
 682     _throw_index_exception_count++;
 683   }
 684 #endif
 685   char message[16];
 686   sprintf(message, "%d", index);
 687   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IndexOutOfBoundsException(), message);
 688 JRT_END
 689 
 690 
 691 JRT_ENTRY(void, Runtime1::throw_div0_exception(JavaThread* current))
 692 #ifndef PRODUCT
 693   if (PrintC1Statistics) {
 694     _throw_div0_exception_count++;
 695   }
 696 #endif
 697   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArithmeticException(), "/ by zero");
 698 JRT_END
 699 
 700 
 701 JRT_ENTRY(void, Runtime1::throw_null_pointer_exception(JavaThread* current))
 702 #ifndef PRODUCT
 703   if (PrintC1Statistics) {
 704     _throw_null_pointer_exception_count++;
 705   }
 706 #endif
 707   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_NullPointerException());
 708 JRT_END
 709 
 710 
 711 JRT_ENTRY(void, Runtime1::throw_class_cast_exception(JavaThread* current, oopDesc* object))
 712 #ifndef PRODUCT
 713   if (PrintC1Statistics) {
 714     _throw_class_cast_exception_count++;
 715   }
 716 #endif
 717   ResourceMark rm(current);
 718   char* message = SharedRuntime::generate_class_cast_message(current, object->klass());
 719   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ClassCastException(), message);
 720 JRT_END
 721 
 722 
 723 JRT_ENTRY(void, Runtime1::throw_incompatible_class_change_error(JavaThread* current))
 724 #ifndef PRODUCT
 725   if (PrintC1Statistics) {
 726     _throw_incompatible_class_change_error_count++;
 727   }
 728 #endif
 729   ResourceMark rm(current);
 730   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IncompatibleClassChangeError());
 731 JRT_END
 732 
 733 
 734 JRT_BLOCK_ENTRY(void, Runtime1::monitorenter(JavaThread* current, oopDesc* obj, BasicObjectLock* lock))
 735 #ifndef PRODUCT
 736   if (PrintC1Statistics) {
 737     _monitorenter_slowcase_cnt++;
 738   }
 739 #endif
 740   if (UseHeavyMonitors) {
 741     lock->set_obj(obj);
 742   }
 743   assert(obj == lock->obj(), "must match");
 744   SharedRuntime::monitor_enter_helper(obj, lock->lock(), current);
 745 JRT_END
 746 
 747 
 748 JRT_LEAF(void, Runtime1::monitorexit(JavaThread* current, BasicObjectLock* lock))
 749 #ifndef PRODUCT
 750   if (PrintC1Statistics) {
 751     _monitorexit_slowcase_cnt++;
 752   }
 753 #endif
 754   assert(current->last_Java_sp(), "last_Java_sp must be set");
 755   oop obj = lock->obj();
 756   assert(oopDesc::is_oop(obj), "must be NULL or an object");
 757   SharedRuntime::monitor_exit_helper(obj, lock->lock(), current);
 758 JRT_END
 759 
 760 // Cf. OptoRuntime::deoptimize_caller_frame
 761 JRT_ENTRY(void, Runtime1::deoptimize(JavaThread* current, jint trap_request))
 762   // Called from within the owner thread, so no need for safepoint
 763   RegisterMap reg_map(current, false);
 764   frame stub_frame = current->last_frame();
 765   assert(stub_frame.is_runtime_frame(), "Sanity check");
 766   frame caller_frame = stub_frame.sender(&reg_map);
 767   nmethod* nm = caller_frame.cb()->as_nmethod_or_null();
 768   assert(nm != NULL, "Sanity check");
 769   methodHandle method(current, nm->method());
 770   assert(nm == CodeCache::find_nmethod(caller_frame.pc()), "Should be the same");
 771   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
 772   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
 773 
 774   if (action == Deoptimization::Action_make_not_entrant) {
 775     if (nm->make_not_entrant()) {
 776       if (reason == Deoptimization::Reason_tenured) {
 777         MethodData* trap_mdo = Deoptimization::get_method_data(current, method, true /*create_if_missing*/);
 778         if (trap_mdo != NULL) {
 779           trap_mdo->inc_tenure_traps();
 780         }
 781       }
 782     }
 783   }
 784 
 785   // Deoptimize the caller frame.
 786   Deoptimization::deoptimize_frame(current, caller_frame.id());
 787   // Return to the now deoptimized frame.
 788 JRT_END
 789 
 790 
 791 #ifndef DEOPTIMIZE_WHEN_PATCHING
 792 
 793 static Klass* resolve_field_return_klass(const methodHandle& caller, int bci, TRAPS) {
 794   Bytecode_field field_access(caller, bci);
 795   // This can be static or non-static field access
 796   Bytecodes::Code code       = field_access.code();
 797 
 798   // We must load class, initialize class and resolve the field
 799   fieldDescriptor result; // initialize class if needed
 800   constantPoolHandle constants(THREAD, caller->constants());
 801   LinkResolver::resolve_field_access(result, constants, field_access.index(), caller, Bytecodes::java_code(code), CHECK_NULL);
 802   return result.field_holder();
 803 }
 804 
 805 
 806 //
 807 // This routine patches sites where a class wasn't loaded or
 808 // initialized at the time the code was generated.  It handles
 809 // references to classes, fields and forcing of initialization.  Most
 810 // of the cases are straightforward and involving simply forcing
 811 // resolution of a class, rewriting the instruction stream with the
 812 // needed constant and replacing the call in this function with the
 813 // patched code.  The case for static field is more complicated since
 814 // the thread which is in the process of initializing a class can
 815 // access it's static fields but other threads can't so the code
 816 // either has to deoptimize when this case is detected or execute a
 817 // check that the current thread is the initializing thread.  The
 818 // current
 819 //
 820 // Patches basically look like this:
 821 //
 822 //
 823 // patch_site: jmp patch stub     ;; will be patched
 824 // continue:   ...
 825 //             ...
 826 //             ...
 827 //             ...
 828 //
 829 // They have a stub which looks like this:
 830 //
 831 //             ;; patch body
 832 //             movl <const>, reg           (for class constants)
 833 //        <or> movl [reg1 + <const>], reg  (for field offsets)
 834 //        <or> movl reg, [reg1 + <const>]  (for field offsets)
 835 //             <being_init offset> <bytes to copy> <bytes to skip>
 836 // patch_stub: call Runtime1::patch_code (through a runtime stub)
 837 //             jmp patch_site
 838 //
 839 //
 840 // A normal patch is done by rewriting the patch body, usually a move,
 841 // and then copying it into place over top of the jmp instruction
 842 // being careful to flush caches and doing it in an MP-safe way.  The
 843 // constants following the patch body are used to find various pieces
 844 // of the patch relative to the call site for Runtime1::patch_code.
 845 // The case for getstatic and putstatic is more complicated because
 846 // getstatic and putstatic have special semantics when executing while
 847 // the class is being initialized.  getstatic/putstatic on a class
 848 // which is being_initialized may be executed by the initializing
 849 // thread but other threads have to block when they execute it.  This
 850 // is accomplished in compiled code by executing a test of the current
 851 // thread against the initializing thread of the class.  It's emitted
 852 // as boilerplate in their stub which allows the patched code to be
 853 // executed before it's copied back into the main body of the nmethod.
 854 //
 855 // being_init: get_thread(<tmp reg>
 856 //             cmpl [reg1 + <init_thread_offset>], <tmp reg>
 857 //             jne patch_stub
 858 //             movl [reg1 + <const>], reg  (for field offsets)  <or>
 859 //             movl reg, [reg1 + <const>]  (for field offsets)
 860 //             jmp continue
 861 //             <being_init offset> <bytes to copy> <bytes to skip>
 862 // patch_stub: jmp Runtim1::patch_code (through a runtime stub)
 863 //             jmp patch_site
 864 //
 865 // If the class is being initialized the patch body is rewritten and
 866 // the patch site is rewritten to jump to being_init, instead of
 867 // patch_stub.  Whenever this code is executed it checks the current
 868 // thread against the initializing thread so other threads will enter
 869 // the runtime and end up blocked waiting the class to finish
 870 // initializing inside the calls to resolve_field below.  The
 871 // initializing class will continue on it's way.  Once the class is
 872 // fully_initialized, the intializing_thread of the class becomes
 873 // NULL, so the next thread to execute this code will fail the test,
 874 // call into patch_code and complete the patching process by copying
 875 // the patch body back into the main part of the nmethod and resume
 876 // executing.
 877 
 878 // NB:
 879 //
 880 // Patchable instruction sequences inherently exhibit race conditions,
 881 // where thread A is patching an instruction at the same time thread B
 882 // is executing it.  The algorithms we use ensure that any observation
 883 // that B can make on any intermediate states during A's patching will
 884 // always end up with a correct outcome.  This is easiest if there are
 885 // few or no intermediate states.  (Some inline caches have two
 886 // related instructions that must be patched in tandem.  For those,
 887 // intermediate states seem to be unavoidable, but we will get the
 888 // right answer from all possible observation orders.)
 889 //
 890 // When patching the entry instruction at the head of a method, or a
 891 // linkable call instruction inside of a method, we try very hard to
 892 // use a patch sequence which executes as a single memory transaction.
 893 // This means, in practice, that when thread A patches an instruction,
 894 // it should patch a 32-bit or 64-bit word that somehow overlaps the
 895 // instruction or is contained in it.  We believe that memory hardware
 896 // will never break up such a word write, if it is naturally aligned
 897 // for the word being written.  We also know that some CPUs work very
 898 // hard to create atomic updates even of naturally unaligned words,
 899 // but we don't want to bet the farm on this always working.
 900 //
 901 // Therefore, if there is any chance of a race condition, we try to
 902 // patch only naturally aligned words, as single, full-word writes.
 903 
 904 JRT_ENTRY(void, Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id ))
 905 #ifndef PRODUCT
 906   if (PrintC1Statistics) {
 907     _patch_code_slowcase_cnt++;
 908   }
 909 #endif
 910 
 911   ResourceMark rm(current);
 912   RegisterMap reg_map(current, false);
 913   frame runtime_frame = current->last_frame();
 914   frame caller_frame = runtime_frame.sender(&reg_map);
 915 
 916   // last java frame on stack
 917   vframeStream vfst(current, true);
 918   assert(!vfst.at_end(), "Java frame must exist");
 919 
 920   methodHandle caller_method(current, vfst.method());
 921   // Note that caller_method->code() may not be same as caller_code because of OSR's
 922   // Note also that in the presence of inlining it is not guaranteed
 923   // that caller_method() == caller_code->method()
 924 
 925   int bci = vfst.bci();
 926   Bytecodes::Code code = caller_method()->java_code_at(bci);
 927 
 928   // this is used by assertions in the access_field_patching_id
 929   BasicType patch_field_type = T_ILLEGAL;
 930   bool deoptimize_for_volatile = false;
 931   bool deoptimize_for_atomic = false;
 932   int patch_field_offset = -1;
 933   Klass* init_klass = NULL; // klass needed by load_klass_patching code
 934   Klass* load_klass = NULL; // klass needed by load_klass_patching code
 935   Handle mirror(current, NULL);                    // oop needed by load_mirror_patching code
 936   Handle appendix(current, NULL);                  // oop needed by appendix_patching code
 937   bool load_klass_or_mirror_patch_id =
 938     (stub_id == Runtime1::load_klass_patching_id || stub_id == Runtime1::load_mirror_patching_id);
 939 
 940   if (stub_id == Runtime1::access_field_patching_id) {
 941 
 942     Bytecode_field field_access(caller_method, bci);
 943     fieldDescriptor result; // initialize class if needed
 944     Bytecodes::Code code = field_access.code();
 945     constantPoolHandle constants(current, caller_method->constants());
 946     LinkResolver::resolve_field_access(result, constants, field_access.index(), caller_method, Bytecodes::java_code(code), CHECK);
 947     patch_field_offset = result.offset();
 948 
 949     // If we're patching a field which is volatile then at compile it
 950     // must not have been know to be volatile, so the generated code
 951     // isn't correct for a volatile reference.  The nmethod has to be
 952     // deoptimized so that the code can be regenerated correctly.
 953     // This check is only needed for access_field_patching since this
 954     // is the path for patching field offsets.  load_klass is only
 955     // used for patching references to oops which don't need special
 956     // handling in the volatile case.
 957 
 958     deoptimize_for_volatile = result.access_flags().is_volatile();
 959 
 960     // If we are patching a field which should be atomic, then
 961     // the generated code is not correct either, force deoptimizing.
 962     // We need to only cover T_LONG and T_DOUBLE fields, as we can
 963     // break access atomicity only for them.
 964 
 965     // Strictly speaking, the deoptimization on 64-bit platforms
 966     // is unnecessary, and T_LONG stores on 32-bit platforms need
 967     // to be handled by special patching code when AlwaysAtomicAccesses
 968     // becomes product feature. At this point, we are still going
 969     // for the deoptimization for consistency against volatile
 970     // accesses.
 971 
 972     patch_field_type = result.field_type();
 973     deoptimize_for_atomic = (AlwaysAtomicAccesses && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG));
 974 
 975   } else if (load_klass_or_mirror_patch_id) {
 976     Klass* k = NULL;
 977     switch (code) {
 978       case Bytecodes::_putstatic:
 979       case Bytecodes::_getstatic:
 980         { Klass* klass = resolve_field_return_klass(caller_method, bci, CHECK);
 981           init_klass = klass;
 982           mirror = Handle(current, klass->java_mirror());
 983         }
 984         break;
 985       case Bytecodes::_new:
 986         { Bytecode_new bnew(caller_method(), caller_method->bcp_from(bci));
 987           k = caller_method->constants()->klass_at(bnew.index(), CHECK);
 988         }
 989         break;
 990       case Bytecodes::_multianewarray:
 991         { Bytecode_multianewarray mna(caller_method(), caller_method->bcp_from(bci));
 992           k = caller_method->constants()->klass_at(mna.index(), CHECK);
 993         }
 994         break;
 995       case Bytecodes::_instanceof:
 996         { Bytecode_instanceof io(caller_method(), caller_method->bcp_from(bci));
 997           k = caller_method->constants()->klass_at(io.index(), CHECK);
 998         }
 999         break;
1000       case Bytecodes::_checkcast:
1001         { Bytecode_checkcast cc(caller_method(), caller_method->bcp_from(bci));
1002           k = caller_method->constants()->klass_at(cc.index(), CHECK);
1003         }
1004         break;
1005       case Bytecodes::_anewarray:
1006         { Bytecode_anewarray anew(caller_method(), caller_method->bcp_from(bci));
1007           Klass* ek = caller_method->constants()->klass_at(anew.index(), CHECK);
1008           k = ek->array_klass(CHECK);
1009         }
1010         break;
1011       case Bytecodes::_ldc:
1012       case Bytecodes::_ldc_w:
1013       case Bytecodes::_ldc2_w:
1014         {
1015           Bytecode_loadconstant cc(caller_method, bci);
1016           oop m = cc.resolve_constant(CHECK);
1017           mirror = Handle(current, m);
1018         }
1019         break;
1020       default: fatal("unexpected bytecode for load_klass_or_mirror_patch_id");
1021     }
1022     load_klass = k;
1023   } else if (stub_id == load_appendix_patching_id) {
1024     Bytecode_invoke bytecode(caller_method, bci);
1025     Bytecodes::Code bc = bytecode.invoke_code();
1026 
1027     CallInfo info;
1028     constantPoolHandle pool(current, caller_method->constants());
1029     int index = bytecode.index();
1030     LinkResolver::resolve_invoke(info, Handle(), pool, index, bc, CHECK);
1031     switch (bc) {
1032       case Bytecodes::_invokehandle: {
1033         int cache_index = ConstantPool::decode_cpcache_index(index, true);
1034         assert(cache_index >= 0 && cache_index < pool->cache()->length(), "unexpected cache index");
1035         ConstantPoolCacheEntry* cpce = pool->cache()->entry_at(cache_index);
1036         cpce->set_method_handle(pool, info);
1037         appendix = Handle(current, cpce->appendix_if_resolved(pool)); // just in case somebody already resolved the entry
1038         break;
1039       }
1040       case Bytecodes::_invokedynamic: {
1041         ConstantPoolCacheEntry* cpce = pool->invokedynamic_cp_cache_entry_at(index);
1042         cpce->set_dynamic_call(pool, info);
1043         appendix = Handle(current, cpce->appendix_if_resolved(pool)); // just in case somebody already resolved the entry
1044         break;
1045       }
1046       default: fatal("unexpected bytecode for load_appendix_patching_id");
1047     }
1048   } else {
1049     ShouldNotReachHere();
1050   }
1051 
1052   if (deoptimize_for_volatile || deoptimize_for_atomic) {
1053     // At compile time we assumed the field wasn't volatile/atomic but after
1054     // loading it turns out it was volatile/atomic so we have to throw the
1055     // compiled code out and let it be regenerated.
1056     if (TracePatching) {
1057       if (deoptimize_for_volatile) {
1058         tty->print_cr("Deoptimizing for patching volatile field reference");
1059       }
1060       if (deoptimize_for_atomic) {
1061         tty->print_cr("Deoptimizing for patching atomic field reference");
1062       }
1063     }
1064 
1065     // It's possible the nmethod was invalidated in the last
1066     // safepoint, but if it's still alive then make it not_entrant.
1067     nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1068     if (nm != NULL) {
1069       nm->make_not_entrant();
1070     }
1071 
1072     Deoptimization::deoptimize_frame(current, caller_frame.id());
1073 
1074     // Return to the now deoptimized frame.
1075   }
1076 
1077   // Now copy code back
1078 
1079   {
1080     MutexLocker ml_patch (current, Patching_lock, Mutex::_no_safepoint_check_flag);
1081     //
1082     // Deoptimization may have happened while we waited for the lock.
1083     // In that case we don't bother to do any patching we just return
1084     // and let the deopt happen
1085     if (!caller_is_deopted(current)) {
1086       NativeGeneralJump* jump = nativeGeneralJump_at(caller_frame.pc());
1087       address instr_pc = jump->jump_destination();
1088       NativeInstruction* ni = nativeInstruction_at(instr_pc);
1089       if (ni->is_jump() ) {
1090         // the jump has not been patched yet
1091         // The jump destination is slow case and therefore not part of the stubs
1092         // (stubs are only for StaticCalls)
1093 
1094         // format of buffer
1095         //    ....
1096         //    instr byte 0     <-- copy_buff
1097         //    instr byte 1
1098         //    ..
1099         //    instr byte n-1
1100         //      n
1101         //    ....             <-- call destination
1102 
1103         address stub_location = caller_frame.pc() + PatchingStub::patch_info_offset();
1104         unsigned char* byte_count = (unsigned char*) (stub_location - 1);
1105         unsigned char* byte_skip = (unsigned char*) (stub_location - 2);
1106         unsigned char* being_initialized_entry_offset = (unsigned char*) (stub_location - 3);
1107         address copy_buff = stub_location - *byte_skip - *byte_count;
1108         address being_initialized_entry = stub_location - *being_initialized_entry_offset;
1109         if (TracePatching) {
1110           ttyLocker ttyl;
1111           tty->print_cr(" Patching %s at bci %d at address " INTPTR_FORMAT "  (%s)", Bytecodes::name(code), bci,
1112                         p2i(instr_pc), (stub_id == Runtime1::access_field_patching_id) ? "field" : "klass");
1113           nmethod* caller_code = CodeCache::find_nmethod(caller_frame.pc());
1114           assert(caller_code != NULL, "nmethod not found");
1115 
1116           // NOTE we use pc() not original_pc() because we already know they are
1117           // identical otherwise we'd have never entered this block of code
1118 
1119           const ImmutableOopMap* map = caller_code->oop_map_for_return_address(caller_frame.pc());
1120           assert(map != NULL, "null check");
1121           map->print();
1122           tty->cr();
1123 
1124           Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1125         }
1126         // depending on the code below, do_patch says whether to copy the patch body back into the nmethod
1127         bool do_patch = true;
1128         if (stub_id == Runtime1::access_field_patching_id) {
1129           // The offset may not be correct if the class was not loaded at code generation time.
1130           // Set it now.
1131           NativeMovRegMem* n_move = nativeMovRegMem_at(copy_buff);
1132           assert(n_move->offset() == 0 || (n_move->offset() == 4 && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG)), "illegal offset for type");
1133           assert(patch_field_offset >= 0, "illegal offset");
1134           n_move->add_offset_in_bytes(patch_field_offset);
1135         } else if (load_klass_or_mirror_patch_id) {
1136           // If a getstatic or putstatic is referencing a klass which
1137           // isn't fully initialized, the patch body isn't copied into
1138           // place until initialization is complete.  In this case the
1139           // patch site is setup so that any threads besides the
1140           // initializing thread are forced to come into the VM and
1141           // block.
1142           do_patch = (code != Bytecodes::_getstatic && code != Bytecodes::_putstatic) ||
1143                      InstanceKlass::cast(init_klass)->is_initialized();
1144           NativeGeneralJump* jump = nativeGeneralJump_at(instr_pc);
1145           if (jump->jump_destination() == being_initialized_entry) {
1146             assert(do_patch == true, "initialization must be complete at this point");
1147           } else {
1148             // patch the instruction <move reg, klass>
1149             NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1150 
1151             assert(n_copy->data() == 0 ||
1152                    n_copy->data() == (intptr_t)Universe::non_oop_word(),
1153                    "illegal init value");
1154             if (stub_id == Runtime1::load_klass_patching_id) {
1155               assert(load_klass != NULL, "klass not set");
1156               n_copy->set_data((intx) (load_klass));
1157             } else {
1158               // Don't need a G1 pre-barrier here since we assert above that data isn't an oop.
1159               n_copy->set_data(cast_from_oop<intx>(mirror()));
1160             }
1161 
1162             if (TracePatching) {
1163               Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1164             }
1165           }
1166         } else if (stub_id == Runtime1::load_appendix_patching_id) {
1167           NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1168           assert(n_copy->data() == 0 ||
1169                  n_copy->data() == (intptr_t)Universe::non_oop_word(),
1170                  "illegal init value");
1171           n_copy->set_data(cast_from_oop<intx>(appendix()));
1172 
1173           if (TracePatching) {
1174             Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1175           }
1176         } else {
1177           ShouldNotReachHere();
1178         }
1179 
1180         if (do_patch) {
1181           // replace instructions
1182           // first replace the tail, then the call
1183 #ifdef ARM
1184           if((load_klass_or_mirror_patch_id ||
1185               stub_id == Runtime1::load_appendix_patching_id) &&
1186               nativeMovConstReg_at(copy_buff)->is_pc_relative()) {
1187             nmethod* nm = CodeCache::find_nmethod(instr_pc);
1188             address addr = NULL;
1189             assert(nm != NULL, "invalid nmethod_pc");
1190             RelocIterator mds(nm, copy_buff, copy_buff + 1);
1191             while (mds.next()) {
1192               if (mds.type() == relocInfo::oop_type) {
1193                 assert(stub_id == Runtime1::load_mirror_patching_id ||
1194                        stub_id == Runtime1::load_appendix_patching_id, "wrong stub id");
1195                 oop_Relocation* r = mds.oop_reloc();
1196                 addr = (address)r->oop_addr();
1197                 break;
1198               } else if (mds.type() == relocInfo::metadata_type) {
1199                 assert(stub_id == Runtime1::load_klass_patching_id, "wrong stub id");
1200                 metadata_Relocation* r = mds.metadata_reloc();
1201                 addr = (address)r->metadata_addr();
1202                 break;
1203               }
1204             }
1205             assert(addr != NULL, "metadata relocation must exist");
1206             copy_buff -= *byte_count;
1207             NativeMovConstReg* n_copy2 = nativeMovConstReg_at(copy_buff);
1208             n_copy2->set_pc_relative_offset(addr, instr_pc);
1209           }
1210 #endif
1211 
1212           for (int i = NativeGeneralJump::instruction_size; i < *byte_count; i++) {
1213             address ptr = copy_buff + i;
1214             int a_byte = (*ptr) & 0xFF;
1215             address dst = instr_pc + i;
1216             *(unsigned char*)dst = (unsigned char) a_byte;
1217           }
1218           ICache::invalidate_range(instr_pc, *byte_count);
1219           NativeGeneralJump::replace_mt_safe(instr_pc, copy_buff);
1220 
1221           if (load_klass_or_mirror_patch_id ||
1222               stub_id == Runtime1::load_appendix_patching_id) {
1223             relocInfo::relocType rtype =
1224               (stub_id == Runtime1::load_klass_patching_id) ?
1225                                    relocInfo::metadata_type :
1226                                    relocInfo::oop_type;
1227             // update relocInfo to metadata
1228             nmethod* nm = CodeCache::find_nmethod(instr_pc);
1229             assert(nm != NULL, "invalid nmethod_pc");
1230 
1231             // The old patch site is now a move instruction so update
1232             // the reloc info so that it will get updated during
1233             // future GCs.
1234             RelocIterator iter(nm, (address)instr_pc, (address)(instr_pc + 1));
1235             relocInfo::change_reloc_info_for_address(&iter, (address) instr_pc,
1236                                                      relocInfo::none, rtype);
1237           }
1238 
1239         } else {
1240           ICache::invalidate_range(copy_buff, *byte_count);
1241           NativeGeneralJump::insert_unconditional(instr_pc, being_initialized_entry);
1242         }
1243       }
1244     }
1245   }
1246 
1247   // If we are patching in a non-perm oop, make sure the nmethod
1248   // is on the right list.
1249   {
1250     MutexLocker ml_code (current, CodeCache_lock, Mutex::_no_safepoint_check_flag);
1251     nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1252     guarantee(nm != NULL, "only nmethods can contain non-perm oops");
1253 
1254     // Since we've patched some oops in the nmethod,
1255     // (re)register it with the heap.
1256     Universe::heap()->register_nmethod(nm);
1257   }
1258 JRT_END
1259 
1260 #else // DEOPTIMIZE_WHEN_PATCHING
1261 
1262 void Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id) {
1263 #ifndef PRODUCT
1264   if (PrintC1Statistics) {
1265     _patch_code_slowcase_cnt++;
1266   }
1267 #endif
1268 
1269   // Enable WXWrite: the function is called by c1 stub as a runtime function
1270   // (see another implementation above).
1271   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
1272 
1273   if (TracePatching) {
1274     tty->print_cr("Deoptimizing because patch is needed");
1275   }
1276 
1277   RegisterMap reg_map(current, false);
1278 
1279   frame runtime_frame = current->last_frame();
1280   frame caller_frame = runtime_frame.sender(&reg_map);
1281   assert(caller_frame.is_compiled_frame(), "Wrong frame type");
1282 
1283   // Make sure the nmethod is invalidated, i.e. made not entrant.
1284   nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1285   if (nm != NULL) {
1286     nm->make_not_entrant();
1287   }
1288 
1289   Deoptimization::deoptimize_frame(current, caller_frame.id());
1290   // Return to the now deoptimized frame.
1291   postcond(caller_is_deopted(current));
1292 }
1293 
1294 #endif // DEOPTIMIZE_WHEN_PATCHING
1295 
1296 // Entry point for compiled code. We want to patch a nmethod.
1297 // We don't do a normal VM transition here because we want to
1298 // know after the patching is complete and any safepoint(s) are taken
1299 // if the calling nmethod was deoptimized. We do this by calling a
1300 // helper method which does the normal VM transition and when it
1301 // completes we can check for deoptimization. This simplifies the
1302 // assembly code in the cpu directories.
1303 //
1304 int Runtime1::move_klass_patching(JavaThread* current) {
1305 //
1306 // NOTE: we are still in Java
1307 //
1308   debug_only(NoHandleMark nhm;)
1309   {
1310     // Enter VM mode
1311     ResetNoHandleMark rnhm;
1312     patch_code(current, load_klass_patching_id);
1313   }
1314   // Back in JAVA, use no oops DON'T safepoint
1315 
1316   // Return true if calling code is deoptimized
1317 
1318   return caller_is_deopted(current);
1319 }
1320 
1321 int Runtime1::move_mirror_patching(JavaThread* current) {
1322 //
1323 // NOTE: we are still in Java
1324 //
1325   debug_only(NoHandleMark nhm;)
1326   {
1327     // Enter VM mode
1328     ResetNoHandleMark rnhm;
1329     patch_code(current, load_mirror_patching_id);
1330   }
1331   // Back in JAVA, use no oops DON'T safepoint
1332 
1333   // Return true if calling code is deoptimized
1334 
1335   return caller_is_deopted(current);
1336 }
1337 
1338 int Runtime1::move_appendix_patching(JavaThread* current) {
1339 //
1340 // NOTE: we are still in Java
1341 //
1342   debug_only(NoHandleMark nhm;)
1343   {
1344     // Enter VM mode
1345     ResetNoHandleMark rnhm;
1346     patch_code(current, load_appendix_patching_id);
1347   }
1348   // Back in JAVA, use no oops DON'T safepoint
1349 
1350   // Return true if calling code is deoptimized
1351 
1352   return caller_is_deopted(current);
1353 }
1354 
1355 // Entry point for compiled code. We want to patch a nmethod.
1356 // We don't do a normal VM transition here because we want to
1357 // know after the patching is complete and any safepoint(s) are taken
1358 // if the calling nmethod was deoptimized. We do this by calling a
1359 // helper method which does the normal VM transition and when it
1360 // completes we can check for deoptimization. This simplifies the
1361 // assembly code in the cpu directories.
1362 //
1363 int Runtime1::access_field_patching(JavaThread* current) {
1364   //
1365   // NOTE: we are still in Java
1366   //
1367   // Handles created in this function will be deleted by the
1368   // HandleMarkCleaner in the transition to the VM.
1369   NoHandleMark nhm;
1370   {
1371     // Enter VM mode
1372     ResetNoHandleMark rnhm;
1373     patch_code(current, access_field_patching_id);
1374   }
1375   // Back in JAVA, use no oops DON'T safepoint
1376 
1377   // Return true if calling code is deoptimized
1378 
1379   return caller_is_deopted(current);
1380 }
1381 
1382 
1383 JRT_LEAF(void, Runtime1::trace_block_entry(jint block_id))
1384   // for now we just print out the block id
1385   tty->print("%d ", block_id);
1386 JRT_END
1387 
1388 
1389 JRT_LEAF(int, Runtime1::is_instance_of(oopDesc* mirror, oopDesc* obj))
1390   // had to return int instead of bool, otherwise there may be a mismatch
1391   // between the C calling convention and the Java one.
1392   // e.g., on x86, GCC may clear only %al when returning a bool false, but
1393   // JVM takes the whole %eax as the return value, which may misinterpret
1394   // the return value as a boolean true.
1395 
1396   assert(mirror != NULL, "should null-check on mirror before calling");
1397   Klass* k = java_lang_Class::as_Klass(mirror);
1398   return (k != NULL && obj != NULL && obj->is_a(k)) ? 1 : 0;
1399 JRT_END
1400 
1401 JRT_ENTRY(void, Runtime1::predicate_failed_trap(JavaThread* current))
1402   ResourceMark rm;
1403 
1404   RegisterMap reg_map(current, false);
1405   frame runtime_frame = current->last_frame();
1406   frame caller_frame = runtime_frame.sender(&reg_map);
1407 
1408   nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1409   assert (nm != NULL, "no more nmethod?");
1410   nm->make_not_entrant();
1411 
1412   methodHandle m(current, nm->method());
1413   MethodData* mdo = m->method_data();
1414 
1415   if (mdo == NULL && !HAS_PENDING_EXCEPTION) {
1416     // Build an MDO.  Ignore errors like OutOfMemory;
1417     // that simply means we won't have an MDO to update.
1418     Method::build_interpreter_method_data(m, THREAD);
1419     if (HAS_PENDING_EXCEPTION) {
1420       // Only metaspace OOM is expected. No Java code executed.
1421       assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1422       CLEAR_PENDING_EXCEPTION;
1423     }
1424     mdo = m->method_data();
1425   }
1426 
1427   if (mdo != NULL) {
1428     mdo->inc_trap_count(Deoptimization::Reason_none);
1429   }
1430 
1431   if (TracePredicateFailedTraps) {
1432     stringStream ss1, ss2;
1433     vframeStream vfst(current);
1434     Method* inlinee = vfst.method();
1435     inlinee->print_short_name(&ss1);
1436     m->print_short_name(&ss2);
1437     tty->print_cr("Predicate failed trap in method %s at bci %d inlined in %s at pc " INTPTR_FORMAT, ss1.as_string(), vfst.bci(), ss2.as_string(), p2i(caller_frame.pc()));
1438   }
1439 
1440 
1441   Deoptimization::deoptimize_frame(current, caller_frame.id());
1442 
1443 JRT_END
1444 
1445 #ifndef PRODUCT
1446 void Runtime1::print_statistics() {
1447   tty->print_cr("C1 Runtime statistics:");
1448   tty->print_cr(" _resolve_invoke_virtual_cnt:     %d", SharedRuntime::_resolve_virtual_ctr);
1449   tty->print_cr(" _resolve_invoke_opt_virtual_cnt: %d", SharedRuntime::_resolve_opt_virtual_ctr);
1450   tty->print_cr(" _resolve_invoke_static_cnt:      %d", SharedRuntime::_resolve_static_ctr);
1451   tty->print_cr(" _handle_wrong_method_cnt:        %d", SharedRuntime::_wrong_method_ctr);
1452   tty->print_cr(" _ic_miss_cnt:                    %d", SharedRuntime::_ic_miss_ctr);
1453   tty->print_cr(" _generic_arraycopystub_cnt:      %d", _generic_arraycopystub_cnt);
1454   tty->print_cr(" _byte_arraycopy_cnt:             %d", _byte_arraycopy_stub_cnt);
1455   tty->print_cr(" _short_arraycopy_cnt:            %d", _short_arraycopy_stub_cnt);
1456   tty->print_cr(" _int_arraycopy_cnt:              %d", _int_arraycopy_stub_cnt);
1457   tty->print_cr(" _long_arraycopy_cnt:             %d", _long_arraycopy_stub_cnt);
1458   tty->print_cr(" _oop_arraycopy_cnt:              %d", _oop_arraycopy_stub_cnt);
1459   tty->print_cr(" _arraycopy_slowcase_cnt:         %d", _arraycopy_slowcase_cnt);
1460   tty->print_cr(" _arraycopy_checkcast_cnt:        %d", _arraycopy_checkcast_cnt);
1461   tty->print_cr(" _arraycopy_checkcast_attempt_cnt:%d", _arraycopy_checkcast_attempt_cnt);
1462 
1463   tty->print_cr(" _new_type_array_slowcase_cnt:    %d", _new_type_array_slowcase_cnt);
1464   tty->print_cr(" _new_object_array_slowcase_cnt:  %d", _new_object_array_slowcase_cnt);
1465   tty->print_cr(" _new_instance_slowcase_cnt:      %d", _new_instance_slowcase_cnt);
1466   tty->print_cr(" _new_multi_array_slowcase_cnt:   %d", _new_multi_array_slowcase_cnt);
1467   tty->print_cr(" _monitorenter_slowcase_cnt:      %d", _monitorenter_slowcase_cnt);
1468   tty->print_cr(" _monitorexit_slowcase_cnt:       %d", _monitorexit_slowcase_cnt);
1469   tty->print_cr(" _patch_code_slowcase_cnt:        %d", _patch_code_slowcase_cnt);
1470 
1471   tty->print_cr(" _throw_range_check_exception_count:            %d:", _throw_range_check_exception_count);
1472   tty->print_cr(" _throw_index_exception_count:                  %d:", _throw_index_exception_count);
1473   tty->print_cr(" _throw_div0_exception_count:                   %d:", _throw_div0_exception_count);
1474   tty->print_cr(" _throw_null_pointer_exception_count:           %d:", _throw_null_pointer_exception_count);
1475   tty->print_cr(" _throw_class_cast_exception_count:             %d:", _throw_class_cast_exception_count);
1476   tty->print_cr(" _throw_incompatible_class_change_error_count:  %d:", _throw_incompatible_class_change_error_count);
1477   tty->print_cr(" _throw_count:                                  %d:", _throw_count);
1478 
1479   SharedRuntime::print_ic_miss_histogram();
1480   tty->cr();
1481 }
1482 #endif // PRODUCT