1 /*
   2  * Copyright (c) 1999, 2021, 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/continuation.hpp"
  63 #include "runtime/fieldDescriptor.inline.hpp"
  64 #include "runtime/frame.inline.hpp"
  65 #include "runtime/handles.inline.hpp"
  66 #include "runtime/interfaceSupport.inline.hpp"
  67 #include "runtime/javaCalls.hpp"
  68 #include "runtime/sharedRuntime.hpp"
  69 #include "runtime/stackWatermarkSet.hpp"
  70 #include "runtime/stubRoutines.hpp"
  71 #include "runtime/threadCritical.hpp"
  72 #include "runtime/vframe.inline.hpp"
  73 #include "runtime/vframeArray.hpp"
  74 #include "runtime/vm_version.hpp"
  75 #include "utilities/copy.hpp"
  76 #include "utilities/events.hpp"
  77 
  78 
  79 // Implementation of StubAssembler
  80 
  81 StubAssembler::StubAssembler(CodeBuffer* code, const char * name, int stub_id) : C1_MacroAssembler(code) {
  82   _name = name;
  83   _must_gc_arguments = false;
  84   _frame_size = no_frame_size;
  85   _num_rt_args = 0;
  86   _stub_id = stub_id;
  87 }
  88 
  89 
  90 void StubAssembler::set_info(const char* name, bool must_gc_arguments) {
  91   _name = name;
  92   _must_gc_arguments = must_gc_arguments;
  93 }
  94 
  95 
  96 void StubAssembler::set_frame_size(int size) {
  97   if (_frame_size == no_frame_size) {
  98     _frame_size = size;
  99   }
 100   assert(_frame_size == size, "can't change the frame size");
 101 }
 102 
 103 
 104 void StubAssembler::set_num_rt_args(int args) {
 105   if (_num_rt_args == 0) {
 106     _num_rt_args = args;
 107   }
 108   assert(_num_rt_args == args, "can't change the number of args");
 109 }
 110 
 111 // Implementation of Runtime1
 112 
 113 CodeBlob* Runtime1::_blobs[Runtime1::number_of_ids];
 114 const char *Runtime1::_blob_names[] = {
 115   RUNTIME1_STUBS(STUB_NAME, LAST_STUB_NAME)
 116 };
 117 
 118 #ifndef PRODUCT
 119 // statistics
 120 int Runtime1::_generic_arraycopystub_cnt = 0;
 121 int Runtime1::_arraycopy_slowcase_cnt = 0;
 122 int Runtime1::_arraycopy_checkcast_cnt = 0;
 123 int Runtime1::_arraycopy_checkcast_attempt_cnt = 0;
 124 int Runtime1::_new_type_array_slowcase_cnt = 0;
 125 int Runtime1::_new_object_array_slowcase_cnt = 0;
 126 int Runtime1::_new_instance_slowcase_cnt = 0;
 127 int Runtime1::_new_multi_array_slowcase_cnt = 0;
 128 int Runtime1::_monitorenter_slowcase_cnt = 0;
 129 int Runtime1::_monitorexit_slowcase_cnt = 0;
 130 int Runtime1::_patch_code_slowcase_cnt = 0;
 131 int Runtime1::_throw_range_check_exception_count = 0;
 132 int Runtime1::_throw_index_exception_count = 0;
 133 int Runtime1::_throw_div0_exception_count = 0;
 134 int Runtime1::_throw_null_pointer_exception_count = 0;
 135 int Runtime1::_throw_class_cast_exception_count = 0;
 136 int Runtime1::_throw_incompatible_class_change_error_count = 0;
 137 int Runtime1::_throw_count = 0;
 138 
 139 static int _byte_arraycopy_stub_cnt = 0;
 140 static int _short_arraycopy_stub_cnt = 0;
 141 static int _int_arraycopy_stub_cnt = 0;
 142 static int _long_arraycopy_stub_cnt = 0;
 143 static int _oop_arraycopy_stub_cnt = 0;
 144 
 145 address Runtime1::arraycopy_count_address(BasicType type) {
 146   switch (type) {
 147   case T_BOOLEAN:
 148   case T_BYTE:   return (address)&_byte_arraycopy_stub_cnt;
 149   case T_CHAR:
 150   case T_SHORT:  return (address)&_short_arraycopy_stub_cnt;
 151   case T_FLOAT:
 152   case T_INT:    return (address)&_int_arraycopy_stub_cnt;
 153   case T_DOUBLE:
 154   case T_LONG:   return (address)&_long_arraycopy_stub_cnt;
 155   case T_ARRAY:
 156   case T_OBJECT: return (address)&_oop_arraycopy_stub_cnt;
 157   default:
 158     ShouldNotReachHere();
 159     return NULL;
 160   }
 161 }
 162 
 163 
 164 #endif
 165 
 166 // Simple helper to see if the caller of a runtime stub which
 167 // entered the VM has been deoptimized
 168 
 169 static bool caller_is_deopted(JavaThread* current) {
 170   RegisterMap reg_map(current, false);
 171   frame runtime_frame = current->last_frame();
 172   frame caller_frame = runtime_frame.sender(&reg_map);
 173   assert(caller_frame.is_compiled_frame(), "must be compiled");
 174   return caller_frame.is_deoptimized_frame();
 175 }
 176 
 177 // Stress deoptimization
 178 static void deopt_caller(JavaThread* current) {
 179   if (!caller_is_deopted(current)) {
 180     RegisterMap reg_map(current, false);
 181     frame runtime_frame = current->last_frame();
 182     frame caller_frame = runtime_frame.sender(&reg_map);
 183     Deoptimization::deoptimize_frame(current, caller_frame.id());
 184     assert(caller_is_deopted(current), "Must be deoptimized");
 185   }
 186 }
 187 
 188 class StubIDStubAssemblerCodeGenClosure: public StubAssemblerCodeGenClosure {
 189  private:
 190   Runtime1::StubID _id;
 191  public:
 192   StubIDStubAssemblerCodeGenClosure(Runtime1::StubID id) : _id(id) {}
 193   virtual OopMapSet* generate_code(StubAssembler* sasm) {
 194     return Runtime1::generate_code_for(_id, sasm);
 195   }
 196 };
 197 
 198 CodeBlob* Runtime1::generate_blob(BufferBlob* buffer_blob, int stub_id, const char* name, bool expect_oop_map, StubAssemblerCodeGenClosure* cl) {
 199   ResourceMark rm;
 200   // create code buffer for code storage
 201   CodeBuffer code(buffer_blob);
 202 
 203   OopMapSet* oop_maps;
 204   int frame_size;
 205   bool must_gc_arguments;
 206 
 207   Compilation::setup_code_buffer(&code, 0);
 208 
 209   // create assembler for code generation
 210   StubAssembler* sasm = new StubAssembler(&code, name, stub_id);
 211   // generate code for runtime stub
 212   oop_maps = cl->generate_code(sasm);
 213   assert(oop_maps == NULL || sasm->frame_size() != no_frame_size,
 214          "if stub has an oop map it must have a valid frame size");
 215   assert(!expect_oop_map || oop_maps != NULL, "must have an oopmap");
 216 
 217   // align so printing shows nop's instead of random code at the end (SimpleStubs are aligned)
 218   sasm->align(BytesPerWord);
 219   // make sure all code is in code buffer
 220   sasm->flush();
 221 
 222   frame_size = sasm->frame_size();
 223   must_gc_arguments = sasm->must_gc_arguments();
 224   // create blob - distinguish a few special cases
 225   CodeBlob* blob = RuntimeStub::new_runtime_stub(name,
 226                                                  &code,
 227                                                  CodeOffsets::frame_never_safe,
 228                                                  frame_size,
 229                                                  oop_maps,
 230                                                  must_gc_arguments);
 231   assert(blob != NULL, "blob must exist");
 232   return blob;
 233 }
 234 
 235 void Runtime1::generate_blob_for(BufferBlob* buffer_blob, StubID id) {
 236   assert(0 <= id && id < number_of_ids, "illegal stub id");
 237   bool expect_oop_map = true;
 238 #ifdef ASSERT
 239   // Make sure that stubs that need oopmaps have them
 240   switch (id) {
 241     // These stubs don't need to have an oopmap
 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 #if defined(PPC32)
 248   case handle_exception_nofpu_id:
 249 #endif
 250     expect_oop_map = false;
 251     break;
 252   default:
 253     break;
 254   }
 255 #endif
 256   StubIDStubAssemblerCodeGenClosure cl(id);
 257   CodeBlob* blob = generate_blob(buffer_blob, id, name_for(id), expect_oop_map, &cl);
 258   // install blob
 259   _blobs[id] = blob;
 260 }
 261 
 262 void Runtime1::initialize(BufferBlob* blob) {
 263   // platform-dependent initialization
 264   initialize_pd();
 265   // generate stubs
 266   for (int id = 0; id < number_of_ids; id++) generate_blob_for(blob, (StubID)id);
 267   // printing
 268 #ifndef PRODUCT
 269   if (PrintSimpleStubs) {
 270     ResourceMark rm;
 271     for (int id = 0; id < number_of_ids; id++) {
 272       _blobs[id]->print();
 273       if (_blobs[id]->oop_maps() != NULL) {
 274         _blobs[id]->oop_maps()->print();
 275       }
 276     }
 277   }
 278 #endif
 279   BarrierSetC1* bs = BarrierSet::barrier_set()->barrier_set_c1();
 280   bs->generate_c1_runtime_stubs(blob);
 281 }
 282 
 283 CodeBlob* Runtime1::blob_for(StubID id) {
 284   assert(0 <= id && id < number_of_ids, "illegal stub id");
 285   return _blobs[id];
 286 }
 287 
 288 
 289 const char* Runtime1::name_for(StubID id) {
 290   assert(0 <= id && id < number_of_ids, "illegal stub id");
 291   return _blob_names[id];
 292 }
 293 
 294 const char* Runtime1::name_for_address(address entry) {
 295   for (int id = 0; id < number_of_ids; id++) {
 296     if (entry == entry_for((StubID)id)) return name_for((StubID)id);
 297   }
 298 
 299 #define FUNCTION_CASE(a, f) \
 300   if ((intptr_t)a == CAST_FROM_FN_PTR(intptr_t, f))  return #f
 301 
 302   FUNCTION_CASE(entry, os::javaTimeMillis);
 303   FUNCTION_CASE(entry, os::javaTimeNanos);
 304   FUNCTION_CASE(entry, SharedRuntime::OSR_migration_end);
 305   FUNCTION_CASE(entry, SharedRuntime::d2f);
 306   FUNCTION_CASE(entry, SharedRuntime::d2i);
 307   FUNCTION_CASE(entry, SharedRuntime::d2l);
 308   FUNCTION_CASE(entry, SharedRuntime::dcos);
 309   FUNCTION_CASE(entry, SharedRuntime::dexp);
 310   FUNCTION_CASE(entry, SharedRuntime::dlog);
 311   FUNCTION_CASE(entry, SharedRuntime::dlog10);
 312   FUNCTION_CASE(entry, SharedRuntime::dpow);
 313   FUNCTION_CASE(entry, SharedRuntime::drem);
 314   FUNCTION_CASE(entry, SharedRuntime::dsin);
 315   FUNCTION_CASE(entry, SharedRuntime::dtan);
 316   FUNCTION_CASE(entry, SharedRuntime::f2i);
 317   FUNCTION_CASE(entry, SharedRuntime::f2l);
 318   FUNCTION_CASE(entry, SharedRuntime::frem);
 319   FUNCTION_CASE(entry, SharedRuntime::l2d);
 320   FUNCTION_CASE(entry, SharedRuntime::l2f);
 321   FUNCTION_CASE(entry, SharedRuntime::ldiv);
 322   FUNCTION_CASE(entry, SharedRuntime::lmul);
 323   FUNCTION_CASE(entry, SharedRuntime::lrem);
 324   FUNCTION_CASE(entry, SharedRuntime::lrem);
 325   FUNCTION_CASE(entry, SharedRuntime::dtrace_method_entry);
 326   FUNCTION_CASE(entry, SharedRuntime::dtrace_method_exit);
 327   FUNCTION_CASE(entry, is_instance_of);
 328   FUNCTION_CASE(entry, trace_block_entry);
 329 #ifdef JFR_HAVE_INTRINSICS
 330   FUNCTION_CASE(entry, JFR_TIME_FUNCTION);
 331   FUNCTION_CASE(entry, StubRoutines::jfr_get_event_writer());
 332 #endif
 333   FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32());
 334   FUNCTION_CASE(entry, StubRoutines::updateBytesCRC32C());
 335   FUNCTION_CASE(entry, StubRoutines::vectorizedMismatch());
 336   FUNCTION_CASE(entry, StubRoutines::dexp());
 337   FUNCTION_CASE(entry, StubRoutines::dlog());
 338   FUNCTION_CASE(entry, StubRoutines::dlog10());
 339   FUNCTION_CASE(entry, StubRoutines::dpow());
 340   FUNCTION_CASE(entry, StubRoutines::dsin());
 341   FUNCTION_CASE(entry, StubRoutines::dcos());
 342   FUNCTION_CASE(entry, StubRoutines::dtan());
 343   FUNCTION_CASE(entry, StubRoutines::cont_doYield());
 344 
 345 #undef FUNCTION_CASE
 346 
 347   // Soft float adds more runtime names.
 348   return pd_name_for_address(entry);
 349 }
 350 
 351 
 352 JRT_ENTRY(void, Runtime1::new_instance(JavaThread* current, Klass* klass))
 353 #ifndef PRODUCT
 354   if (PrintC1Statistics) {
 355     _new_instance_slowcase_cnt++;
 356   }
 357 #endif
 358   assert(klass->is_klass(), "not a class");
 359   Handle holder(current, klass->klass_holder()); // keep the klass alive
 360   InstanceKlass* h = InstanceKlass::cast(klass);
 361   h->check_valid_for_instantiation(true, CHECK);
 362   // make sure klass is initialized
 363   h->initialize(CHECK);
 364   // allocate instance and return via TLS
 365   oop obj = h->allocate_instance(CHECK);
 366   current->set_vm_result(obj);
 367 JRT_END
 368 
 369 
 370 JRT_ENTRY(void, Runtime1::new_type_array(JavaThread* current, Klass* klass, jint length))
 371 #ifndef PRODUCT
 372   if (PrintC1Statistics) {
 373     _new_type_array_slowcase_cnt++;
 374   }
 375 #endif
 376   // Note: no handle for klass needed since they are not used
 377   //       anymore after new_typeArray() and no GC can happen before.
 378   //       (This may have to change if this code changes!)
 379   assert(klass->is_klass(), "not a class");
 380   BasicType elt_type = TypeArrayKlass::cast(klass)->element_type();
 381   oop obj = oopFactory::new_typeArray(elt_type, length, CHECK);
 382   current->set_vm_result(obj);
 383   // This is pretty rare but this runtime patch is stressful to deoptimization
 384   // if we deoptimize here so force a deopt to stress the path.
 385   if (DeoptimizeALot) {
 386     deopt_caller(current);
 387   }
 388 
 389 JRT_END
 390 
 391 
 392 JRT_ENTRY(void, Runtime1::new_object_array(JavaThread* current, Klass* array_klass, jint length))
 393 #ifndef PRODUCT
 394   if (PrintC1Statistics) {
 395     _new_object_array_slowcase_cnt++;
 396   }
 397 #endif
 398   // Note: no handle for klass needed since they are not used
 399   //       anymore after new_objArray() and no GC can happen before.
 400   //       (This may have to change if this code changes!)
 401   assert(array_klass->is_klass(), "not a class");
 402   Handle holder(current, array_klass->klass_holder()); // keep the klass alive
 403   Klass* elem_klass = ObjArrayKlass::cast(array_klass)->element_klass();
 404   objArrayOop obj = oopFactory::new_objArray(elem_klass, length, CHECK);
 405   current->set_vm_result(obj);
 406   // This is pretty rare but this runtime patch is stressful to deoptimization
 407   // if we deoptimize here so force a deopt to stress the path.
 408   if (DeoptimizeALot) {
 409     deopt_caller(current);
 410   }
 411 JRT_END
 412 
 413 
 414 JRT_ENTRY(void, Runtime1::new_multi_array(JavaThread* current, Klass* klass, int rank, jint* dims))
 415 #ifndef PRODUCT
 416   if (PrintC1Statistics) {
 417     _new_multi_array_slowcase_cnt++;
 418   }
 419 #endif
 420   assert(klass->is_klass(), "not a class");
 421   assert(rank >= 1, "rank must be nonzero");
 422   Handle holder(current, klass->klass_holder()); // keep the klass alive
 423   oop obj = ArrayKlass::cast(klass)->multi_allocate(rank, dims, CHECK);
 424   current->set_vm_result(obj);
 425 JRT_END
 426 
 427 
 428 JRT_ENTRY(void, Runtime1::unimplemented_entry(JavaThread* current, StubID id))
 429   tty->print_cr("Runtime1::entry_for(%d) returned unimplemented entry point", id);
 430 JRT_END
 431 
 432 
 433 JRT_ENTRY(void, Runtime1::throw_array_store_exception(JavaThread* current, oopDesc* obj))
 434   ResourceMark rm(current);
 435   const char* klass_name = obj->klass()->external_name();
 436   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayStoreException(), klass_name);
 437 JRT_END
 438 
 439 
 440 // counter_overflow() is called from within C1-compiled methods. The enclosing method is the method
 441 // associated with the top activation record. The inlinee (that is possibly included in the enclosing
 442 // method) method is passed as an argument. In order to do that it is embedded in the code as
 443 // a constant.
 444 static nmethod* counter_overflow_helper(JavaThread* current, int branch_bci, Method* m) {
 445   nmethod* osr_nm = NULL;
 446   methodHandle method(current, m);
 447 
 448   RegisterMap map(current, false);
 449   frame fr =  current->last_frame().sender(&map);
 450   nmethod* nm = (nmethod*) fr.cb();
 451   assert(nm!= NULL && nm->is_nmethod(), "Sanity check");
 452   methodHandle enclosing_method(current, nm->method());
 453 
 454   CompLevel level = (CompLevel)nm->comp_level();
 455   int bci = InvocationEntryBci;
 456   if (branch_bci != InvocationEntryBci) {
 457     // Compute destination bci
 458     address pc = method()->code_base() + branch_bci;
 459     Bytecodes::Code branch = Bytecodes::code_at(method(), pc);
 460     int offset = 0;
 461     switch (branch) {
 462       case Bytecodes::_if_icmplt: case Bytecodes::_iflt:
 463       case Bytecodes::_if_icmpgt: case Bytecodes::_ifgt:
 464       case Bytecodes::_if_icmple: case Bytecodes::_ifle:
 465       case Bytecodes::_if_icmpge: case Bytecodes::_ifge:
 466       case Bytecodes::_if_icmpeq: case Bytecodes::_if_acmpeq: case Bytecodes::_ifeq:
 467       case Bytecodes::_if_icmpne: case Bytecodes::_if_acmpne: case Bytecodes::_ifne:
 468       case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: case Bytecodes::_goto:
 469         offset = (int16_t)Bytes::get_Java_u2(pc + 1);
 470         break;
 471       case Bytecodes::_goto_w:
 472         offset = Bytes::get_Java_u4(pc + 1);
 473         break;
 474       default: ;
 475     }
 476     bci = branch_bci + offset;
 477   }
 478   osr_nm = CompilationPolicy::event(enclosing_method, method, branch_bci, bci, level, nm, current);
 479   return osr_nm;
 480 }
 481 
 482 JRT_BLOCK_ENTRY(address, Runtime1::counter_overflow(JavaThread* current, int bci, Method* method))
 483   nmethod* osr_nm;
 484   JRT_BLOCK
 485     osr_nm = counter_overflow_helper(current, bci, method);
 486     if (osr_nm != NULL) {
 487       RegisterMap map(current, false);
 488       frame fr =  current->last_frame().sender(&map);
 489       Deoptimization::deoptimize_frame(current, fr.id());
 490     }
 491   JRT_BLOCK_END
 492   return NULL;
 493 JRT_END
 494 
 495 extern void vm_exit(int code);
 496 
 497 // Enter this method from compiled code handler below. This is where we transition
 498 // to VM mode. This is done as a helper routine so that the method called directly
 499 // from compiled code does not have to transition to VM. This allows the entry
 500 // method to see if the nmethod that we have just looked up a handler for has
 501 // been deoptimized while we were in the vm. This simplifies the assembly code
 502 // cpu directories.
 503 //
 504 // We are entering here from exception stub (via the entry method below)
 505 // If there is a compiled exception handler in this method, we will continue there;
 506 // otherwise we will unwind the stack and continue at the caller of top frame method
 507 // Note: we enter in Java using a special JRT wrapper. This wrapper allows us to
 508 // control the area where we can allow a safepoint. After we exit the safepoint area we can
 509 // check to see if the handler we are going to return is now in a nmethod that has
 510 // been deoptimized. If that is the case we return the deopt blob
 511 // unpack_with_exception entry instead. This makes life for the exception blob easier
 512 // because making that same check and diverting is painful from assembly language.
 513 JRT_ENTRY_NO_ASYNC(static address, exception_handler_for_pc_helper(JavaThread* current, oopDesc* ex, address pc, nmethod*& nm))
 514   // Reset method handle flag.
 515   current->set_is_method_handle_return(false);
 516 
 517   Handle exception(current, ex);
 518 
 519   // This function is called when we are about to throw an exception. Therefore,
 520   // we have to poll the stack watermark barrier to make sure that not yet safe
 521   // stack frames are made safe before returning into them.
 522   if (current->last_frame().cb() == Runtime1::blob_for(Runtime1::handle_exception_from_callee_id)) {
 523     // The Runtime1::handle_exception_from_callee_id handler is invoked after the
 524     // frame has been unwound. It instead builds its own stub frame, to call the
 525     // runtime. But the throwing frame has already been unwound here.
 526     StackWatermarkSet::after_unwind(current);
 527   }
 528 
 529   nm = CodeCache::find_nmethod(pc);
 530   assert(nm != NULL, "this is not an nmethod");
 531   // Adjust the pc as needed/
 532   if (nm->is_deopt_pc(pc)) {
 533     RegisterMap map(current, false);
 534     frame exception_frame = current->last_frame().sender(&map);
 535     // if the frame isn't deopted then pc must not correspond to the caller of last_frame
 536     assert(exception_frame.is_deoptimized_frame(), "must be deopted");
 537     pc = exception_frame.pc();
 538   }
 539   assert(exception.not_null(), "NULL exceptions should be handled by throw_exception");
 540   // Check that exception is a subclass of Throwable
 541   assert(exception->is_a(vmClasses::Throwable_klass()),
 542          "Exception not subclass of Throwable");
 543 
 544   // debugging support
 545   // tracing
 546   if (log_is_enabled(Info, exceptions)) {
 547     ResourceMark rm;
 548     stringStream tempst;
 549     assert(nm->method() != NULL, "Unexpected NULL method()");
 550     tempst.print("C1 compiled method <%s>\n"
 551                  " at PC" INTPTR_FORMAT " for thread " INTPTR_FORMAT,
 552                  nm->method()->print_value_string(), p2i(pc), p2i(current));
 553     Exceptions::log_exception(exception, tempst.as_string());
 554   }
 555   // for AbortVMOnException flag
 556   Exceptions::debug_check_abort(exception);
 557 
 558   // Check the stack guard pages and reenable them if necessary and there is
 559   // enough space on the stack to do so.  Use fast exceptions only if the guard
 560   // pages are enabled.
 561   bool guard_pages_enabled = current->stack_overflow_state()->reguard_stack_if_needed();
 562 
 563   if (JvmtiExport::can_post_on_exceptions()) {
 564     // To ensure correct notification of exception catches and throws
 565     // we have to deoptimize here.  If we attempted to notify the
 566     // catches and throws during this exception lookup it's possible
 567     // we could deoptimize on the way out of the VM and end back in
 568     // the interpreter at the throw site.  This would result in double
 569     // notifications since the interpreter would also notify about
 570     // these same catches and throws as it unwound the frame.
 571 
 572     RegisterMap reg_map(current);
 573     frame stub_frame = current->last_frame();
 574     frame caller_frame = stub_frame.sender(&reg_map);
 575 
 576     // We don't really want to deoptimize the nmethod itself since we
 577     // can actually continue in the exception handler ourselves but I
 578     // don't see an easy way to have the desired effect.
 579     Deoptimization::deoptimize_frame(current, caller_frame.id());
 580     assert(caller_is_deopted(current), "Must be deoptimized");
 581 
 582     return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
 583   }
 584 
 585   // ExceptionCache is used only for exceptions at call sites and not for implicit exceptions
 586   if (guard_pages_enabled) {
 587     address fast_continuation = nm->handler_for_exception_and_pc(exception, pc);
 588     if (fast_continuation != NULL) {
 589       // Set flag if return address is a method handle call site.
 590       current->set_is_method_handle_return(nm->is_method_handle_return(pc));
 591       return fast_continuation;
 592     }
 593   }
 594 
 595   // If the stack guard pages are enabled, check whether there is a handler in
 596   // the current method.  Otherwise (guard pages disabled), force an unwind and
 597   // skip the exception cache update (i.e., just leave continuation==NULL).
 598   address continuation = NULL;
 599   if (guard_pages_enabled) {
 600 
 601     // New exception handling mechanism can support inlined methods
 602     // with exception handlers since the mappings are from PC to PC
 603 
 604     // Clear out the exception oop and pc since looking up an
 605     // exception handler can cause class loading, which might throw an
 606     // exception and those fields are expected to be clear during
 607     // normal bytecode execution.
 608     current->clear_exception_oop_and_pc();
 609 
 610     bool recursive_exception = false;
 611     continuation = SharedRuntime::compute_compiled_exc_handler(nm, pc, exception, false, false, recursive_exception);
 612     // If an exception was thrown during exception dispatch, the exception oop may have changed
 613     current->set_exception_oop(exception());
 614     current->set_exception_pc(pc);
 615 
 616     // the exception cache is used only by non-implicit exceptions
 617     // Update the exception cache only when there didn't happen
 618     // another exception during the computation of the compiled
 619     // exception handler. Checking for exception oop equality is not
 620     // sufficient because some exceptions are pre-allocated and reused.
 621     if (continuation != NULL && !recursive_exception) {
 622       nm->add_handler_for_exception_and_pc(exception, pc, continuation);
 623     }
 624   }
 625 
 626   current->set_vm_result(exception());
 627   // Set flag if return address is a method handle call site.
 628   current->set_is_method_handle_return(nm->is_method_handle_return(pc));
 629 
 630   if (log_is_enabled(Info, exceptions)) {
 631     ResourceMark rm;
 632     log_info(exceptions)("Thread " PTR_FORMAT " continuing at PC " PTR_FORMAT
 633                          " for exception thrown at PC " PTR_FORMAT,
 634                          p2i(current), p2i(continuation), p2i(pc));
 635   }
 636 
 637   return continuation;
 638 JRT_END
 639 
 640 // Enter this method from compiled code only if there is a Java exception handler
 641 // in the method handling the exception.
 642 // We are entering here from exception stub. We don't do a normal VM transition here.
 643 // We do it in a helper. This is so we can check to see if the nmethod we have just
 644 // searched for an exception handler has been deoptimized in the meantime.
 645 address Runtime1::exception_handler_for_pc(JavaThread* current) {
 646   oop exception = current->exception_oop();
 647   address pc = current->exception_pc();
 648   // Still in Java mode
 649   DEBUG_ONLY(NoHandleMark nhm);
 650   nmethod* nm = NULL;
 651   address continuation = NULL;
 652   {
 653     // Enter VM mode by calling the helper
 654     ResetNoHandleMark rnhm;
 655     continuation = exception_handler_for_pc_helper(current, exception, pc, nm);
 656   }
 657   // Back in JAVA, use no oops DON'T safepoint
 658 
 659   // Now check to see if the nmethod we were called from is now deoptimized.
 660   // If so we must return to the deopt blob and deoptimize the nmethod
 661   if (nm != NULL && caller_is_deopted(current)) {
 662     continuation = SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
 663   }
 664 
 665   assert(continuation != NULL, "no handler found");
 666   return continuation;
 667 }
 668 
 669 
 670 JRT_ENTRY(void, Runtime1::throw_range_check_exception(JavaThread* current, int index, arrayOopDesc* a))
 671 #ifndef PRODUCT
 672   if (PrintC1Statistics) {
 673     _throw_range_check_exception_count++;
 674   }
 675 #endif
 676   const int len = 35;
 677   assert(len < strlen("Index %d out of bounds for length %d"), "Must allocate more space for message.");
 678   char message[2 * jintAsStringSize + len];
 679   sprintf(message, "Index %d out of bounds for length %d", index, a->length());
 680   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), message);
 681 JRT_END
 682 
 683 
 684 JRT_ENTRY(void, Runtime1::throw_index_exception(JavaThread* current, int index))
 685 #ifndef PRODUCT
 686   if (PrintC1Statistics) {
 687     _throw_index_exception_count++;
 688   }
 689 #endif
 690   char message[16];
 691   sprintf(message, "%d", index);
 692   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IndexOutOfBoundsException(), message);
 693 JRT_END
 694 
 695 
 696 JRT_ENTRY(void, Runtime1::throw_div0_exception(JavaThread* current))
 697 #ifndef PRODUCT
 698   if (PrintC1Statistics) {
 699     _throw_div0_exception_count++;
 700   }
 701 #endif
 702   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ArithmeticException(), "/ by zero");
 703 JRT_END
 704 
 705 
 706 JRT_ENTRY(void, Runtime1::throw_null_pointer_exception(JavaThread* current))
 707 #ifndef PRODUCT
 708   if (PrintC1Statistics) {
 709     _throw_null_pointer_exception_count++;
 710   }
 711 #endif
 712   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_NullPointerException());
 713 JRT_END
 714 
 715 
 716 JRT_ENTRY(void, Runtime1::throw_class_cast_exception(JavaThread* current, oopDesc* object))
 717 #ifndef PRODUCT
 718   if (PrintC1Statistics) {
 719     _throw_class_cast_exception_count++;
 720   }
 721 #endif
 722   ResourceMark rm(current);
 723   char* message = SharedRuntime::generate_class_cast_message(current, object->klass());
 724   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_ClassCastException(), message);
 725 JRT_END
 726 
 727 
 728 JRT_ENTRY(void, Runtime1::throw_incompatible_class_change_error(JavaThread* current))
 729 #ifndef PRODUCT
 730   if (PrintC1Statistics) {
 731     _throw_incompatible_class_change_error_count++;
 732   }
 733 #endif
 734   ResourceMark rm(current);
 735   SharedRuntime::throw_and_post_jvmti_exception(current, vmSymbols::java_lang_IncompatibleClassChangeError());
 736 JRT_END
 737 
 738 
 739 JRT_BLOCK_ENTRY(void, Runtime1::monitorenter(JavaThread* current, oopDesc* obj, BasicObjectLock* lock))
 740 #ifndef PRODUCT
 741   if (PrintC1Statistics) {
 742     _monitorenter_slowcase_cnt++;
 743   }
 744 #endif
 745   if (!UseFastLocking) {
 746     lock->set_obj(obj);
 747   }
 748   assert(obj == lock->obj(), "must match");
 749   SharedRuntime::monitor_enter_helper(obj, lock->lock(), current);
 750   current->inc_held_monitor_count();
 751 JRT_END
 752 
 753 
 754 JRT_LEAF(void, Runtime1::monitorexit(JavaThread* current, BasicObjectLock* lock))
 755 #ifndef PRODUCT
 756   if (PrintC1Statistics) {
 757     _monitorexit_slowcase_cnt++;
 758   }
 759 #endif
 760   assert(current->last_Java_sp(), "last_Java_sp must be set");
 761   oop obj = lock->obj();
 762   assert(oopDesc::is_oop(obj), "must be NULL or an object");
 763   SharedRuntime::monitor_exit_helper(obj, lock->lock(), current);
 764 JRT_END
 765 
 766 // Cf. OptoRuntime::deoptimize_caller_frame
 767 JRT_ENTRY(void, Runtime1::deoptimize(JavaThread* current, jint trap_request))
 768   // Called from within the owner thread, so no need for safepoint
 769   RegisterMap reg_map(current, false);
 770   frame stub_frame = current->last_frame();
 771   assert(stub_frame.is_runtime_frame(), "Sanity check");
 772   frame caller_frame = stub_frame.sender(&reg_map);
 773   nmethod* nm = caller_frame.cb()->as_nmethod_or_null();
 774   assert(nm != NULL, "Sanity check");
 775   methodHandle method(current, nm->method());
 776   assert(nm == CodeCache::find_nmethod(caller_frame.pc()), "Should be the same");
 777   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
 778   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
 779 
 780   if (action == Deoptimization::Action_make_not_entrant) {
 781     if (nm->make_not_entrant()) {
 782       if (reason == Deoptimization::Reason_tenured) {
 783         MethodData* trap_mdo = Deoptimization::get_method_data(current, method, true /*create_if_missing*/);
 784         if (trap_mdo != NULL) {
 785           trap_mdo->inc_tenure_traps();
 786         }
 787       }
 788     }
 789   }
 790 
 791   // Deoptimize the caller frame.
 792   Deoptimization::deoptimize_frame(current, caller_frame.id());
 793   // Return to the now deoptimized frame.
 794 JRT_END
 795 
 796 
 797 #ifndef DEOPTIMIZE_WHEN_PATCHING
 798 
 799 static Klass* resolve_field_return_klass(const methodHandle& caller, int bci, TRAPS) {
 800   Bytecode_field field_access(caller, bci);
 801   // This can be static or non-static field access
 802   Bytecodes::Code code       = field_access.code();
 803 
 804   // We must load class, initialize class and resolve the field
 805   fieldDescriptor result; // initialize class if needed
 806   constantPoolHandle constants(THREAD, caller->constants());
 807   LinkResolver::resolve_field_access(result, constants, field_access.index(), caller, Bytecodes::java_code(code), CHECK_NULL);
 808   return result.field_holder();
 809 }
 810 
 811 
 812 //
 813 // This routine patches sites where a class wasn't loaded or
 814 // initialized at the time the code was generated.  It handles
 815 // references to classes, fields and forcing of initialization.  Most
 816 // of the cases are straightforward and involving simply forcing
 817 // resolution of a class, rewriting the instruction stream with the
 818 // needed constant and replacing the call in this function with the
 819 // patched code.  The case for static field is more complicated since
 820 // the thread which is in the process of initializing a class can
 821 // access it's static fields but other threads can't so the code
 822 // either has to deoptimize when this case is detected or execute a
 823 // check that the current thread is the initializing thread.  The
 824 // current
 825 //
 826 // Patches basically look like this:
 827 //
 828 //
 829 // patch_site: jmp patch stub     ;; will be patched
 830 // continue:   ...
 831 //             ...
 832 //             ...
 833 //             ...
 834 //
 835 // They have a stub which looks like this:
 836 //
 837 //             ;; patch body
 838 //             movl <const>, reg           (for class constants)
 839 //        <or> movl [reg1 + <const>], reg  (for field offsets)
 840 //        <or> movl reg, [reg1 + <const>]  (for field offsets)
 841 //             <being_init offset> <bytes to copy> <bytes to skip>
 842 // patch_stub: call Runtime1::patch_code (through a runtime stub)
 843 //             jmp patch_site
 844 //
 845 //
 846 // A normal patch is done by rewriting the patch body, usually a move,
 847 // and then copying it into place over top of the jmp instruction
 848 // being careful to flush caches and doing it in an MP-safe way.  The
 849 // constants following the patch body are used to find various pieces
 850 // of the patch relative to the call site for Runtime1::patch_code.
 851 // The case for getstatic and putstatic is more complicated because
 852 // getstatic and putstatic have special semantics when executing while
 853 // the class is being initialized.  getstatic/putstatic on a class
 854 // which is being_initialized may be executed by the initializing
 855 // thread but other threads have to block when they execute it.  This
 856 // is accomplished in compiled code by executing a test of the current
 857 // thread against the initializing thread of the class.  It's emitted
 858 // as boilerplate in their stub which allows the patched code to be
 859 // executed before it's copied back into the main body of the nmethod.
 860 //
 861 // being_init: get_thread(<tmp reg>
 862 //             cmpl [reg1 + <init_thread_offset>], <tmp reg>
 863 //             jne patch_stub
 864 //             movl [reg1 + <const>], reg  (for field offsets)  <or>
 865 //             movl reg, [reg1 + <const>]  (for field offsets)
 866 //             jmp continue
 867 //             <being_init offset> <bytes to copy> <bytes to skip>
 868 // patch_stub: jmp Runtim1::patch_code (through a runtime stub)
 869 //             jmp patch_site
 870 //
 871 // If the class is being initialized the patch body is rewritten and
 872 // the patch site is rewritten to jump to being_init, instead of
 873 // patch_stub.  Whenever this code is executed it checks the current
 874 // thread against the intializing thread so other threads will enter
 875 // the runtime and end up blocked waiting the class to finish
 876 // initializing inside the calls to resolve_field below.  The
 877 // initializing class will continue on it's way.  Once the class is
 878 // fully_initialized, the intializing_thread of the class becomes
 879 // NULL, so the next thread to execute this code will fail the test,
 880 // call into patch_code and complete the patching process by copying
 881 // the patch body back into the main part of the nmethod and resume
 882 // executing.
 883 
 884 // NB:
 885 //
 886 // Patchable instruction sequences inherently exhibit race conditions,
 887 // where thread A is patching an instruction at the same time thread B
 888 // is executing it.  The algorithms we use ensure that any observation
 889 // that B can make on any intermediate states during A's patching will
 890 // always end up with a correct outcome.  This is easiest if there are
 891 // few or no intermediate states.  (Some inline caches have two
 892 // related instructions that must be patched in tandem.  For those,
 893 // intermediate states seem to be unavoidable, but we will get the
 894 // right answer from all possible observation orders.)
 895 //
 896 // When patching the entry instruction at the head of a method, or a
 897 // linkable call instruction inside of a method, we try very hard to
 898 // use a patch sequence which executes as a single memory transaction.
 899 // This means, in practice, that when thread A patches an instruction,
 900 // it should patch a 32-bit or 64-bit word that somehow overlaps the
 901 // instruction or is contained in it.  We believe that memory hardware
 902 // will never break up such a word write, if it is naturally aligned
 903 // for the word being written.  We also know that some CPUs work very
 904 // hard to create atomic updates even of naturally unaligned words,
 905 // but we don't want to bet the farm on this always working.
 906 //
 907 // Therefore, if there is any chance of a race condition, we try to
 908 // patch only naturally aligned words, as single, full-word writes.
 909 
 910 JRT_ENTRY(void, Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id ))
 911 #ifndef PRODUCT
 912   if (PrintC1Statistics) {
 913     _patch_code_slowcase_cnt++;
 914   }
 915 #endif
 916 
 917   ResourceMark rm(current);
 918   RegisterMap reg_map(current, false);
 919   frame runtime_frame = current->last_frame();
 920   frame caller_frame = runtime_frame.sender(&reg_map);
 921 
 922   // last java frame on stack
 923   vframeStream vfst(current, true);
 924   assert(!vfst.at_end(), "Java frame must exist");
 925 
 926   methodHandle caller_method(current, vfst.method());
 927   // Note that caller_method->code() may not be same as caller_code because of OSR's
 928   // Note also that in the presence of inlining it is not guaranteed
 929   // that caller_method() == caller_code->method()
 930 
 931   int bci = vfst.bci();
 932   Bytecodes::Code code = caller_method()->java_code_at(bci);
 933 
 934   // this is used by assertions in the access_field_patching_id
 935   BasicType patch_field_type = T_ILLEGAL;
 936   bool deoptimize_for_volatile = false;
 937   bool deoptimize_for_atomic = false;
 938   int patch_field_offset = -1;
 939   Klass* init_klass = NULL; // klass needed by load_klass_patching code
 940   Klass* load_klass = NULL; // klass needed by load_klass_patching code
 941   Handle mirror(current, NULL);                    // oop needed by load_mirror_patching code
 942   Handle appendix(current, NULL);                  // oop needed by appendix_patching code
 943   bool load_klass_or_mirror_patch_id =
 944     (stub_id == Runtime1::load_klass_patching_id || stub_id == Runtime1::load_mirror_patching_id);
 945 
 946   if (stub_id == Runtime1::access_field_patching_id) {
 947 
 948     Bytecode_field field_access(caller_method, bci);
 949     fieldDescriptor result; // initialize class if needed
 950     Bytecodes::Code code = field_access.code();
 951     constantPoolHandle constants(current, caller_method->constants());
 952     LinkResolver::resolve_field_access(result, constants, field_access.index(), caller_method, Bytecodes::java_code(code), CHECK);
 953     patch_field_offset = result.offset();
 954 
 955     // If we're patching a field which is volatile then at compile it
 956     // must not have been know to be volatile, so the generated code
 957     // isn't correct for a volatile reference.  The nmethod has to be
 958     // deoptimized so that the code can be regenerated correctly.
 959     // This check is only needed for access_field_patching since this
 960     // is the path for patching field offsets.  load_klass is only
 961     // used for patching references to oops which don't need special
 962     // handling in the volatile case.
 963 
 964     deoptimize_for_volatile = result.access_flags().is_volatile();
 965 
 966     // If we are patching a field which should be atomic, then
 967     // the generated code is not correct either, force deoptimizing.
 968     // We need to only cover T_LONG and T_DOUBLE fields, as we can
 969     // break access atomicity only for them.
 970 
 971     // Strictly speaking, the deoptimization on 64-bit platforms
 972     // is unnecessary, and T_LONG stores on 32-bit platforms need
 973     // to be handled by special patching code when AlwaysAtomicAccesses
 974     // becomes product feature. At this point, we are still going
 975     // for the deoptimization for consistency against volatile
 976     // accesses.
 977 
 978     patch_field_type = result.field_type();
 979     deoptimize_for_atomic = (AlwaysAtomicAccesses && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG));
 980 
 981   } else if (load_klass_or_mirror_patch_id) {
 982     Klass* k = NULL;
 983     switch (code) {
 984       case Bytecodes::_putstatic:
 985       case Bytecodes::_getstatic:
 986         { Klass* klass = resolve_field_return_klass(caller_method, bci, CHECK);
 987           init_klass = klass;
 988           mirror = Handle(current, klass->java_mirror());
 989         }
 990         break;
 991       case Bytecodes::_new:
 992         { Bytecode_new bnew(caller_method(), caller_method->bcp_from(bci));
 993           k = caller_method->constants()->klass_at(bnew.index(), CHECK);
 994         }
 995         break;
 996       case Bytecodes::_multianewarray:
 997         { Bytecode_multianewarray mna(caller_method(), caller_method->bcp_from(bci));
 998           k = caller_method->constants()->klass_at(mna.index(), CHECK);
 999         }
1000         break;
1001       case Bytecodes::_instanceof:
1002         { Bytecode_instanceof io(caller_method(), caller_method->bcp_from(bci));
1003           k = caller_method->constants()->klass_at(io.index(), CHECK);
1004         }
1005         break;
1006       case Bytecodes::_checkcast:
1007         { Bytecode_checkcast cc(caller_method(), caller_method->bcp_from(bci));
1008           k = caller_method->constants()->klass_at(cc.index(), CHECK);
1009         }
1010         break;
1011       case Bytecodes::_anewarray:
1012         { Bytecode_anewarray anew(caller_method(), caller_method->bcp_from(bci));
1013           Klass* ek = caller_method->constants()->klass_at(anew.index(), CHECK);
1014           k = ek->array_klass(CHECK);
1015         }
1016         break;
1017       case Bytecodes::_ldc:
1018       case Bytecodes::_ldc_w:
1019         {
1020           Bytecode_loadconstant cc(caller_method, bci);
1021           oop m = cc.resolve_constant(CHECK);
1022           mirror = Handle(current, m);
1023         }
1024         break;
1025       default: fatal("unexpected bytecode for load_klass_or_mirror_patch_id");
1026     }
1027     load_klass = k;
1028   } else if (stub_id == load_appendix_patching_id) {
1029     Bytecode_invoke bytecode(caller_method, bci);
1030     Bytecodes::Code bc = bytecode.invoke_code();
1031 
1032     CallInfo info;
1033     constantPoolHandle pool(current, caller_method->constants());
1034     int index = bytecode.index();
1035     LinkResolver::resolve_invoke(info, Handle(), pool, index, bc, CHECK);
1036     switch (bc) {
1037       case Bytecodes::_invokehandle: {
1038         int cache_index = ConstantPool::decode_cpcache_index(index, true);
1039         assert(cache_index >= 0 && cache_index < pool->cache()->length(), "unexpected cache index");
1040         ConstantPoolCacheEntry* cpce = pool->cache()->entry_at(cache_index);
1041         cpce->set_method_handle(pool, info);
1042         appendix = Handle(current, cpce->appendix_if_resolved(pool)); // just in case somebody already resolved the entry
1043         break;
1044       }
1045       case Bytecodes::_invokedynamic: {
1046         ConstantPoolCacheEntry* cpce = pool->invokedynamic_cp_cache_entry_at(index);
1047         cpce->set_dynamic_call(pool, info);
1048         appendix = Handle(current, cpce->appendix_if_resolved(pool)); // just in case somebody already resolved the entry
1049         break;
1050       }
1051       default: fatal("unexpected bytecode for load_appendix_patching_id");
1052     }
1053   } else {
1054     ShouldNotReachHere();
1055   }
1056 
1057   if (deoptimize_for_volatile || deoptimize_for_atomic) {
1058     // At compile time we assumed the field wasn't volatile/atomic but after
1059     // loading it turns out it was volatile/atomic so we have to throw the
1060     // compiled code out and let it be regenerated.
1061     if (TracePatching) {
1062       if (deoptimize_for_volatile) {
1063         tty->print_cr("Deoptimizing for patching volatile field reference");
1064       }
1065       if (deoptimize_for_atomic) {
1066         tty->print_cr("Deoptimizing for patching atomic field reference");
1067       }
1068     }
1069 
1070     // It's possible the nmethod was invalidated in the last
1071     // safepoint, but if it's still alive then make it not_entrant.
1072     nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1073     if (nm != NULL) {
1074       nm->make_not_entrant();
1075     }
1076 
1077     Deoptimization::deoptimize_frame(current, caller_frame.id());
1078 
1079     // Return to the now deoptimized frame.
1080   }
1081 
1082   // Now copy code back
1083 
1084   {
1085     MutexLocker ml_patch (current, Patching_lock, Mutex::_no_safepoint_check_flag);
1086     //
1087     // Deoptimization may have happened while we waited for the lock.
1088     // In that case we don't bother to do any patching we just return
1089     // and let the deopt happen
1090     if (!caller_is_deopted(current)) {
1091       NativeGeneralJump* jump = nativeGeneralJump_at(caller_frame.pc());
1092       address instr_pc = jump->jump_destination();
1093       NativeInstruction* ni = nativeInstruction_at(instr_pc);
1094       if (ni->is_jump() ) {
1095         // the jump has not been patched yet
1096         // The jump destination is slow case and therefore not part of the stubs
1097         // (stubs are only for StaticCalls)
1098 
1099         // format of buffer
1100         //    ....
1101         //    instr byte 0     <-- copy_buff
1102         //    instr byte 1
1103         //    ..
1104         //    instr byte n-1
1105         //      n
1106         //    ....             <-- call destination
1107 
1108         address stub_location = caller_frame.pc() + PatchingStub::patch_info_offset();
1109         unsigned char* byte_count = (unsigned char*) (stub_location - 1);
1110         unsigned char* byte_skip = (unsigned char*) (stub_location - 2);
1111         unsigned char* being_initialized_entry_offset = (unsigned char*) (stub_location - 3);
1112         address copy_buff = stub_location - *byte_skip - *byte_count;
1113         address being_initialized_entry = stub_location - *being_initialized_entry_offset;
1114         if (TracePatching) {
1115           ttyLocker ttyl;
1116           tty->print_cr(" Patching %s at bci %d at address " INTPTR_FORMAT "  (%s)", Bytecodes::name(code), bci,
1117                         p2i(instr_pc), (stub_id == Runtime1::access_field_patching_id) ? "field" : "klass");
1118           nmethod* caller_code = CodeCache::find_nmethod(caller_frame.pc());
1119           assert(caller_code != NULL, "nmethod not found");
1120 
1121           // NOTE we use pc() not original_pc() because we already know they are
1122           // identical otherwise we'd have never entered this block of code
1123 
1124           const ImmutableOopMap* map = caller_code->oop_map_for_return_address(caller_frame.pc());
1125           assert(map != NULL, "null check");
1126           map->print();
1127           tty->cr();
1128 
1129           Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1130         }
1131         // depending on the code below, do_patch says whether to copy the patch body back into the nmethod
1132         bool do_patch = true;
1133         if (stub_id == Runtime1::access_field_patching_id) {
1134           // The offset may not be correct if the class was not loaded at code generation time.
1135           // Set it now.
1136           NativeMovRegMem* n_move = nativeMovRegMem_at(copy_buff);
1137           assert(n_move->offset() == 0 || (n_move->offset() == 4 && (patch_field_type == T_DOUBLE || patch_field_type == T_LONG)), "illegal offset for type");
1138           assert(patch_field_offset >= 0, "illegal offset");
1139           n_move->add_offset_in_bytes(patch_field_offset);
1140         } else if (load_klass_or_mirror_patch_id) {
1141           // If a getstatic or putstatic is referencing a klass which
1142           // isn't fully initialized, the patch body isn't copied into
1143           // place until initialization is complete.  In this case the
1144           // patch site is setup so that any threads besides the
1145           // initializing thread are forced to come into the VM and
1146           // block.
1147           do_patch = (code != Bytecodes::_getstatic && code != Bytecodes::_putstatic) ||
1148                      InstanceKlass::cast(init_klass)->is_initialized();
1149           NativeGeneralJump* jump = nativeGeneralJump_at(instr_pc);
1150           if (jump->jump_destination() == being_initialized_entry) {
1151             assert(do_patch == true, "initialization must be complete at this point");
1152           } else {
1153             // patch the instruction <move reg, klass>
1154             NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1155 
1156             assert(n_copy->data() == 0 ||
1157                    n_copy->data() == (intptr_t)Universe::non_oop_word(),
1158                    "illegal init value");
1159             if (stub_id == Runtime1::load_klass_patching_id) {
1160               assert(load_klass != NULL, "klass not set");
1161               n_copy->set_data((intx) (load_klass));
1162             } else {
1163               assert(mirror() != NULL, "klass not set");
1164               // Don't need a G1 pre-barrier here since we assert above that data isn't an oop.
1165               n_copy->set_data(cast_from_oop<intx>(mirror()));
1166             }
1167 
1168             if (TracePatching) {
1169               Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1170             }
1171           }
1172         } else if (stub_id == Runtime1::load_appendix_patching_id) {
1173           NativeMovConstReg* n_copy = nativeMovConstReg_at(copy_buff);
1174           assert(n_copy->data() == 0 ||
1175                  n_copy->data() == (intptr_t)Universe::non_oop_word(),
1176                  "illegal init value");
1177           n_copy->set_data(cast_from_oop<intx>(appendix()));
1178 
1179           if (TracePatching) {
1180             Disassembler::decode(copy_buff, copy_buff + *byte_count, tty);
1181           }
1182         } else {
1183           ShouldNotReachHere();
1184         }
1185 
1186 #if defined(PPC32)
1187         if (load_klass_or_mirror_patch_id ||
1188             stub_id == Runtime1::load_appendix_patching_id) {
1189           // Update the location in the nmethod with the proper
1190           // metadata.  When the code was generated, a NULL was stuffed
1191           // in the metadata table and that table needs to be update to
1192           // have the right value.  On intel the value is kept
1193           // directly in the instruction instead of in the metadata
1194           // table, so set_data above effectively updated the value.
1195           nmethod* nm = CodeCache::find_nmethod(instr_pc);
1196           assert(nm != NULL, "invalid nmethod_pc");
1197           RelocIterator mds(nm, copy_buff, copy_buff + 1);
1198           bool found = false;
1199           while (mds.next() && !found) {
1200             if (mds.type() == relocInfo::oop_type) {
1201               assert(stub_id == Runtime1::load_mirror_patching_id ||
1202                      stub_id == Runtime1::load_appendix_patching_id, "wrong stub id");
1203               oop_Relocation* r = mds.oop_reloc();
1204               oop* oop_adr = r->oop_addr();
1205               *oop_adr = stub_id == Runtime1::load_mirror_patching_id ? mirror() : appendix();
1206               r->fix_oop_relocation();
1207               found = true;
1208             } else if (mds.type() == relocInfo::metadata_type) {
1209               assert(stub_id == Runtime1::load_klass_patching_id, "wrong stub id");
1210               metadata_Relocation* r = mds.metadata_reloc();
1211               Metadata** metadata_adr = r->metadata_addr();
1212               *metadata_adr = load_klass;
1213               r->fix_metadata_relocation();
1214               found = true;
1215             }
1216           }
1217           assert(found, "the metadata must exist!");
1218         }
1219 #endif
1220         if (do_patch) {
1221           // replace instructions
1222           // first replace the tail, then the call
1223 #ifdef ARM
1224           if((load_klass_or_mirror_patch_id ||
1225               stub_id == Runtime1::load_appendix_patching_id) &&
1226               nativeMovConstReg_at(copy_buff)->is_pc_relative()) {
1227             nmethod* nm = CodeCache::find_nmethod(instr_pc);
1228             address addr = NULL;
1229             assert(nm != NULL, "invalid nmethod_pc");
1230             RelocIterator mds(nm, copy_buff, copy_buff + 1);
1231             while (mds.next()) {
1232               if (mds.type() == relocInfo::oop_type) {
1233                 assert(stub_id == Runtime1::load_mirror_patching_id ||
1234                        stub_id == Runtime1::load_appendix_patching_id, "wrong stub id");
1235                 oop_Relocation* r = mds.oop_reloc();
1236                 addr = (address)r->oop_addr();
1237                 break;
1238               } else if (mds.type() == relocInfo::metadata_type) {
1239                 assert(stub_id == Runtime1::load_klass_patching_id, "wrong stub id");
1240                 metadata_Relocation* r = mds.metadata_reloc();
1241                 addr = (address)r->metadata_addr();
1242                 break;
1243               }
1244             }
1245             assert(addr != NULL, "metadata relocation must exist");
1246             copy_buff -= *byte_count;
1247             NativeMovConstReg* n_copy2 = nativeMovConstReg_at(copy_buff);
1248             n_copy2->set_pc_relative_offset(addr, instr_pc);
1249           }
1250 #endif
1251 
1252           for (int i = NativeGeneralJump::instruction_size; i < *byte_count; i++) {
1253             address ptr = copy_buff + i;
1254             int a_byte = (*ptr) & 0xFF;
1255             address dst = instr_pc + i;
1256             *(unsigned char*)dst = (unsigned char) a_byte;
1257           }
1258           ICache::invalidate_range(instr_pc, *byte_count);
1259           NativeGeneralJump::replace_mt_safe(instr_pc, copy_buff);
1260 
1261           if (load_klass_or_mirror_patch_id ||
1262               stub_id == Runtime1::load_appendix_patching_id) {
1263             relocInfo::relocType rtype =
1264               (stub_id == Runtime1::load_klass_patching_id) ?
1265                                    relocInfo::metadata_type :
1266                                    relocInfo::oop_type;
1267             // update relocInfo to metadata
1268             nmethod* nm = CodeCache::find_nmethod(instr_pc);
1269             assert(nm != NULL, "invalid nmethod_pc");
1270 
1271             // The old patch site is now a move instruction so update
1272             // the reloc info so that it will get updated during
1273             // future GCs.
1274             RelocIterator iter(nm, (address)instr_pc, (address)(instr_pc + 1));
1275             relocInfo::change_reloc_info_for_address(&iter, (address) instr_pc,
1276                                                      relocInfo::none, rtype);
1277 #ifdef PPC32
1278           { address instr_pc2 = instr_pc + NativeMovConstReg::lo_offset;
1279             RelocIterator iter2(nm, instr_pc2, instr_pc2 + 1);
1280             relocInfo::change_reloc_info_for_address(&iter2, (address) instr_pc2,
1281                                                      relocInfo::none, rtype);
1282           }
1283 #endif
1284           }
1285 
1286         } else {
1287           ICache::invalidate_range(copy_buff, *byte_count);
1288           NativeGeneralJump::insert_unconditional(instr_pc, being_initialized_entry);
1289         }
1290       }
1291     }
1292   }
1293 
1294   // If we are patching in a non-perm oop, make sure the nmethod
1295   // is on the right list.
1296   {
1297     MutexLocker ml_code (current, CodeCache_lock, Mutex::_no_safepoint_check_flag);
1298     nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1299     guarantee(nm != NULL, "only nmethods can contain non-perm oops");
1300 
1301     // Since we've patched some oops in the nmethod,
1302     // (re)register it with the heap.
1303     Universe::heap()->register_nmethod(nm);
1304   }
1305 JRT_END
1306 
1307 #else // DEOPTIMIZE_WHEN_PATCHING
1308 
1309 void Runtime1::patch_code(JavaThread* current, Runtime1::StubID stub_id) {
1310 #ifndef PRODUCT
1311   if (PrintC1Statistics) {
1312     _patch_code_slowcase_cnt++;
1313   }
1314 #endif
1315 
1316   // Enable WXWrite: the function is called by c1 stub as a runtime function
1317   // (see another implementation above).
1318   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
1319 
1320   if (TracePatching) {
1321     tty->print_cr("Deoptimizing because patch is needed");
1322   }
1323 
1324   RegisterMap reg_map(current, false);
1325 
1326   frame runtime_frame = current->last_frame();
1327   frame caller_frame = runtime_frame.sender(&reg_map);
1328   assert(caller_frame.is_compiled_frame(), "Wrong frame type");
1329 
1330   // Make sure the nmethod is invalidated, i.e. made not entrant.
1331   nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1332   if (nm != NULL) {
1333     nm->make_not_entrant();
1334   }
1335 
1336   Deoptimization::deoptimize_frame(current, caller_frame.id());
1337   // Return to the now deoptimized frame.
1338   postcond(caller_is_deopted(current));
1339 }
1340 
1341 #endif // DEOPTIMIZE_WHEN_PATCHING
1342 
1343 // Entry point for compiled code. We want to patch a nmethod.
1344 // We don't do a normal VM transition here because we want to
1345 // know after the patching is complete and any safepoint(s) are taken
1346 // if the calling nmethod was deoptimized. We do this by calling a
1347 // helper method which does the normal VM transition and when it
1348 // completes we can check for deoptimization. This simplifies the
1349 // assembly code in the cpu directories.
1350 //
1351 int Runtime1::move_klass_patching(JavaThread* current) {
1352 //
1353 // NOTE: we are still in Java
1354 //
1355   debug_only(NoHandleMark nhm;)
1356   {
1357     // Enter VM mode
1358     ResetNoHandleMark rnhm;
1359     patch_code(current, load_klass_patching_id);
1360   }
1361   // Back in JAVA, use no oops DON'T safepoint
1362 
1363   // Return true if calling code is deoptimized
1364 
1365   return caller_is_deopted(current);
1366 }
1367 
1368 int Runtime1::move_mirror_patching(JavaThread* current) {
1369 //
1370 // NOTE: we are still in Java
1371 //
1372   debug_only(NoHandleMark nhm;)
1373   {
1374     // Enter VM mode
1375     ResetNoHandleMark rnhm;
1376     patch_code(current, load_mirror_patching_id);
1377   }
1378   // Back in JAVA, use no oops DON'T safepoint
1379 
1380   // Return true if calling code is deoptimized
1381 
1382   return caller_is_deopted(current);
1383 }
1384 
1385 int Runtime1::move_appendix_patching(JavaThread* current) {
1386 //
1387 // NOTE: we are still in Java
1388 //
1389   debug_only(NoHandleMark nhm;)
1390   {
1391     // Enter VM mode
1392     ResetNoHandleMark rnhm;
1393     patch_code(current, load_appendix_patching_id);
1394   }
1395   // Back in JAVA, use no oops DON'T safepoint
1396 
1397   // Return true if calling code is deoptimized
1398 
1399   return caller_is_deopted(current);
1400 }
1401 
1402 // Entry point for compiled code. We want to patch a nmethod.
1403 // We don't do a normal VM transition here because we want to
1404 // know after the patching is complete and any safepoint(s) are taken
1405 // if the calling nmethod was deoptimized. We do this by calling a
1406 // helper method which does the normal VM transition and when it
1407 // completes we can check for deoptimization. This simplifies the
1408 // assembly code in the cpu directories.
1409 //
1410 int Runtime1::access_field_patching(JavaThread* current) {
1411   //
1412   // NOTE: we are still in Java
1413   //
1414   // Handles created in this function will be deleted by the
1415   // HandleMarkCleaner in the transition to the VM.
1416   NoHandleMark nhm;
1417   {
1418     // Enter VM mode
1419     ResetNoHandleMark rnhm;
1420     patch_code(current, access_field_patching_id);
1421   }
1422   // Back in JAVA, use no oops DON'T safepoint
1423 
1424   // Return true if calling code is deoptimized
1425 
1426   return caller_is_deopted(current);
1427 }
1428 
1429 
1430 JRT_LEAF(void, Runtime1::trace_block_entry(jint block_id))
1431   // for now we just print out the block id
1432   tty->print("%d ", block_id);
1433 JRT_END
1434 
1435 
1436 JRT_LEAF(int, Runtime1::is_instance_of(oopDesc* mirror, oopDesc* obj))
1437   // had to return int instead of bool, otherwise there may be a mismatch
1438   // between the C calling convention and the Java one.
1439   // e.g., on x86, GCC may clear only %al when returning a bool false, but
1440   // JVM takes the whole %eax as the return value, which may misinterpret
1441   // the return value as a boolean true.
1442 
1443   assert(mirror != NULL, "should null-check on mirror before calling");
1444   Klass* k = java_lang_Class::as_Klass(mirror);
1445   return (k != NULL && obj != NULL && obj->is_a(k)) ? 1 : 0;
1446 JRT_END
1447 
1448 JRT_ENTRY(void, Runtime1::predicate_failed_trap(JavaThread* current))
1449   ResourceMark rm;
1450 
1451   RegisterMap reg_map(current, false);
1452   frame runtime_frame = current->last_frame();
1453   frame caller_frame = runtime_frame.sender(&reg_map);
1454 
1455   nmethod* nm = CodeCache::find_nmethod(caller_frame.pc());
1456   assert (nm != NULL, "no more nmethod?");
1457   nm->make_not_entrant();
1458 
1459   methodHandle m(current, nm->method());
1460   MethodData* mdo = m->method_data();
1461 
1462   if (mdo == NULL && !HAS_PENDING_EXCEPTION) {
1463     // Build an MDO.  Ignore errors like OutOfMemory;
1464     // that simply means we won't have an MDO to update.
1465     Method::build_interpreter_method_data(m, THREAD);
1466     if (HAS_PENDING_EXCEPTION) {
1467       // Only metaspace OOM is expected. No Java code executed.
1468       assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1469       CLEAR_PENDING_EXCEPTION;
1470     }
1471     mdo = m->method_data();
1472   }
1473 
1474   if (mdo != NULL) {
1475     mdo->inc_trap_count(Deoptimization::Reason_none);
1476   }
1477 
1478   if (TracePredicateFailedTraps) {
1479     stringStream ss1, ss2;
1480     vframeStream vfst(current);
1481     Method* inlinee = vfst.method();
1482     inlinee->print_short_name(&ss1);
1483     m->print_short_name(&ss2);
1484     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()));
1485   }
1486 
1487 
1488   Deoptimization::deoptimize_frame(current, caller_frame.id());
1489 
1490 JRT_END
1491 
1492 #ifndef PRODUCT
1493 void Runtime1::print_statistics() {
1494   tty->print_cr("C1 Runtime statistics:");
1495   tty->print_cr(" _resolve_invoke_virtual_cnt:     %d", SharedRuntime::_resolve_virtual_ctr);
1496   tty->print_cr(" _resolve_invoke_opt_virtual_cnt: %d", SharedRuntime::_resolve_opt_virtual_ctr);
1497   tty->print_cr(" _resolve_invoke_static_cnt:      %d", SharedRuntime::_resolve_static_ctr);
1498   tty->print_cr(" _handle_wrong_method_cnt:        %d", SharedRuntime::_wrong_method_ctr);
1499   tty->print_cr(" _ic_miss_cnt:                    %d", SharedRuntime::_ic_miss_ctr);
1500   tty->print_cr(" _generic_arraycopystub_cnt:      %d", _generic_arraycopystub_cnt);
1501   tty->print_cr(" _byte_arraycopy_cnt:             %d", _byte_arraycopy_stub_cnt);
1502   tty->print_cr(" _short_arraycopy_cnt:            %d", _short_arraycopy_stub_cnt);
1503   tty->print_cr(" _int_arraycopy_cnt:              %d", _int_arraycopy_stub_cnt);
1504   tty->print_cr(" _long_arraycopy_cnt:             %d", _long_arraycopy_stub_cnt);
1505   tty->print_cr(" _oop_arraycopy_cnt:              %d", _oop_arraycopy_stub_cnt);
1506   tty->print_cr(" _arraycopy_slowcase_cnt:         %d", _arraycopy_slowcase_cnt);
1507   tty->print_cr(" _arraycopy_checkcast_cnt:        %d", _arraycopy_checkcast_cnt);
1508   tty->print_cr(" _arraycopy_checkcast_attempt_cnt:%d", _arraycopy_checkcast_attempt_cnt);
1509 
1510   tty->print_cr(" _new_type_array_slowcase_cnt:    %d", _new_type_array_slowcase_cnt);
1511   tty->print_cr(" _new_object_array_slowcase_cnt:  %d", _new_object_array_slowcase_cnt);
1512   tty->print_cr(" _new_instance_slowcase_cnt:      %d", _new_instance_slowcase_cnt);
1513   tty->print_cr(" _new_multi_array_slowcase_cnt:   %d", _new_multi_array_slowcase_cnt);
1514   tty->print_cr(" _monitorenter_slowcase_cnt:      %d", _monitorenter_slowcase_cnt);
1515   tty->print_cr(" _monitorexit_slowcase_cnt:       %d", _monitorexit_slowcase_cnt);
1516   tty->print_cr(" _patch_code_slowcase_cnt:        %d", _patch_code_slowcase_cnt);
1517 
1518   tty->print_cr(" _throw_range_check_exception_count:            %d:", _throw_range_check_exception_count);
1519   tty->print_cr(" _throw_index_exception_count:                  %d:", _throw_index_exception_count);
1520   tty->print_cr(" _throw_div0_exception_count:                   %d:", _throw_div0_exception_count);
1521   tty->print_cr(" _throw_null_pointer_exception_count:           %d:", _throw_null_pointer_exception_count);
1522   tty->print_cr(" _throw_class_cast_exception_count:             %d:", _throw_class_cast_exception_count);
1523   tty->print_cr(" _throw_incompatible_class_change_error_count:  %d:", _throw_incompatible_class_change_error_count);
1524   tty->print_cr(" _throw_count:                                  %d:", _throw_count);
1525 
1526   SharedRuntime::print_ic_miss_histogram();
1527   tty->cr();
1528 }
1529 #endif // PRODUCT